[RFC PATCH v4 00/26] Return of smart HTTP

[RFC PATCH v4 00/26] Return of smart HTTP

[Shawn O. Pearce]

I think this is the final spin of the smart HTTP series.  I've
collected patches from a few others (thanks folks!)  and added
tests specific to the smart variant of the HTTP transport.

At this point, I think it is "next ready"... but would appreciate
any additional feedback if folks identify something we should
address before hitting next.


Clemens Buchacher (1):
  remote-helpers: return successfully if everything up-to-date

Mark Lodato (5):
  http-backend: add GIT_PROJECT_ROOT environment var
  http-backend: reword some documentation
  http-backend: use mod_alias instead of mod_rewrite
  http-backend: add example for gitweb on same URL
  http-backend: more explict LocationMatch

Shawn O. Pearce (18):
  pkt-line: Add strbuf based functions
  pkt-line: Make packet_read_line easier to debug
  fetch-pack: Use a strbuf to compose the want list
  Move "get_ack()" back to fetch-pack
  Add multi_ack_detailed capability to fetch-pack/upload-pack
  remote-curl: Refactor walker initialization
  fetch: Allow transport -v -v -v to set verbosity to 3
  remote-helpers: Fetch more than one ref in a batch
  remote-helpers: Support custom transport options
  Move WebDAV HTTP push under remote-curl
  Git-aware CGI to provide dumb HTTP transport
  Add stateless RPC options to upload-pack, receive-pack
  Smart fetch and push over HTTP: server side
  Discover refs via smart HTTP server when available
  Smart push over HTTP: client side
  Smart fetch over HTTP: client side
  Smart HTTP fetch: gzip requests
  test smart http fetch and push

Tay Ray Chuan (2):
  http-push: fix check condition on http.c::finish_http_pack_request()
  t5540-http-push: remove redundant fetches

 .gitignore                           |    1 +
 Documentation/config.txt             |    8 +
 Documentation/git-http-backend.txt   |  170 ++++++++
 Documentation/git-remote-helpers.txt |   85 ++++-
 Makefile                             |    1 +
 builtin-fetch-pack.c                 |  210 ++++++++--
 builtin-fetch.c                      |    2 +-
 builtin-receive-pack.c               |   26 +-
 builtin-send-pack.c                  |  116 +++++-
 cache.h                              |    1 -
 commit.c                             |   10 +-
 commit.h                             |    2 +-
 connect.c                            |   21 -
 fetch-pack.h                         |    3 +-
 http-backend.c                       |  627 ++++++++++++++++++++++++++++
 http-push.c                          |   31 ++-
 http.c                               |   13 +-
 http.h                               |    2 +
 pkt-line.c                           |   86 ++++-
 pkt-line.h                           |    4 +
 remote-curl.c                        |  759 ++++++++++++++++++++++++++++++++--
 send-pack.h                          |    3 +-
 sideband.c                           |   11 +-
 t/lib-httpd/apache.conf              |   20 +
 t/t5540-http-push.sh                 |   18 +-
 t/t5541-http-push.sh                 |  103 +++++
 t/t5550-http-fetch.sh                |    8 +-
 t/t5551-http-fetch.sh                |   87 ++++
 transport-helper.c                   |  264 +++++++++++-
 transport.c                          |   32 +--
 transport.h                          |    2 +-
 upload-pack.c                        |   71 +++-
 32 files changed, 2574 insertions(+), 223 deletions(-)
 create mode 100644 Documentation/git-http-backend.txt
 create mode 100644 http-backend.c
 create mode 100755 t/t5541-http-push.sh
 create mode 100755 t/t5551-http-fetch.sh

[RFC PATCH v4 01/26] http-push: fix check condition on http.c::finish_http_pack_request()

[Shawn O. Pearce]

From: Tay Ray Chuan <rctay89@gmail.com>

Check that http.c::finish_http_pack_request() returns 0 (for success).

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 http-push.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/http-push.c b/http-push.c
index 00e83dc..cc5d4b8 100644
--- a/http-push.c
+++ b/http-push.c
@@ -604,7 +604,7 @@ static void finish_request(struct transfer_request *request)
 			preq = (struct http_pack_request *)request->userData;
 
 			if (preq) {
-				if (finish_http_pack_request(preq) > 0)
+				if (finish_http_pack_request(preq) == 0)
 					fail = 0;
 				release_http_pack_request(preq);
 			}
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 02/26] pkt-line: Add strbuf based functions

[Shawn O. Pearce]

These routines help to work with pkt-line values inside of a strbuf,
permitting simple formatting of buffered network messages.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 pkt-line.c |   84 +++++++++++++++++++++++++++++++++++++++++++++++++++--------
 pkt-line.h |    4 +++
 2 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/pkt-line.c b/pkt-line.c
index b691abe..bd603f8 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -42,17 +42,19 @@ void packet_flush(int fd)
 	safe_write(fd, "0000", 4);
 }
 
+void packet_buf_flush(struct strbuf *buf)
+{
+	strbuf_add(buf, "0000", 4);
+}
+
 #define hex(a) (hexchar[(a) & 15])
-void packet_write(int fd, const char *fmt, ...)
+static char buffer[1000];
+static unsigned format_packet(const char *fmt, va_list args)
 {
-	static char buffer[1000];
 	static char hexchar[] = "0123456789abcdef";
-	va_list args;
 	unsigned n;
 
-	va_start(args, fmt);
 	n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
-	va_end(args);
 	if (n >= sizeof(buffer)-4)
 		die("protocol error: impossibly long line");
 	n += 4;
@@ -60,9 +62,31 @@ void packet_write(int fd, const char *fmt, ...)
 	buffer[1] = hex(n >> 8);
 	buffer[2] = hex(n >> 4);
 	buffer[3] = hex(n);
+	return n;
+}
+
+void packet_write(int fd, const char *fmt, ...)
+{
+	va_list args;
+	unsigned n;
+
+	va_start(args, fmt);
+	n = format_packet(fmt, args);
+	va_end(args);
 	safe_write(fd, buffer, n);
 }
 
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
+{
+	va_list args;
+	unsigned n;
+
+	va_start(args, fmt);
+	n = format_packet(fmt, args);
+	va_end(args);
+	strbuf_add(buf, buffer, n);
+}
+
 static void safe_read(int fd, void *buffer, unsigned size)
 {
 	ssize_t ret = read_in_full(fd, buffer, size);
@@ -72,15 +96,11 @@ static void safe_read(int fd, void *buffer, unsigned size)
 		die("The remote end hung up unexpectedly");
 }
 
-int packet_read_line(int fd, char *buffer, unsigned size)
+static int packet_length(const char *linelen)
 {
 	int n;
-	unsigned len;
-	char linelen[4];
-
-	safe_read(fd, linelen, 4);
+	int len = 0;
 
-	len = 0;
 	for (n = 0; n < 4; n++) {
 		unsigned char c = linelen[n];
 		len <<= 4;
@@ -96,8 +116,20 @@ int packet_read_line(int fd, char *buffer, unsigned size)
 			len += c - 'A' + 10;
 			continue;
 		}
-		die("protocol error: bad line length character");
+		return -1;
 	}
+	return len;
+}
+
+int packet_read_line(int fd, char *buffer, unsigned size)
+{
+	int len;
+	char linelen[4];
+
+	safe_read(fd, linelen, 4);
+	len = packet_length(linelen);
+	if (len < 0)
+		die("protocol error: bad line length character");
 	if (!len)
 		return 0;
 	len -= 4;
@@ -107,3 +139,31 @@ int packet_read_line(int fd, char *buffer, unsigned size)
 	buffer[len] = 0;
 	return len;
 }
+
+int packet_get_line(struct strbuf *out,
+	char **src_buf, size_t *src_len)
+{
+	int len;
+
+	if (*src_len < 4)
+		return -1;
+	len = packet_length(*src_buf);
+	if (len < 0)
+		return -1;
+	if (!len) {
+		*src_buf += 4;
+		*src_len -= 4;
+		return 0;
+	}
+	if (*src_len < len)
+		return -2;
+
+	*src_buf += 4;
+	*src_len -= 4;
+	len -= 4;
+
+	strbuf_add(out, *src_buf, len);
+	*src_buf += len;
+	*src_len -= len;
+	return len;
+}
diff --git a/pkt-line.h b/pkt-line.h
index 9df653f..1e5dcfe 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -2,14 +2,18 @@
 #define PKTLINE_H
 
 #include "git-compat-util.h"
+#include "strbuf.h"
 
 /*
  * Silly packetized line writing interface
  */
 void packet_flush(int fd);
 void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_buf_flush(struct strbuf *buf);
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 
 int packet_read_line(int fd, char *buffer, unsigned size);
+int packet_get_line(struct strbuf *out, char **src_buf, size_t *src_len);
 ssize_t safe_write(int, const void *, ssize_t);
 
 #endif
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Shawn O. Pearce]

When there is an error parsing the 4 byte length component we now
NUL terminate the string and display it as part of the die message,
this may hint as to what data was misunderstood by the application.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 pkt-line.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/pkt-line.c b/pkt-line.c
index bd603f8..893dd3c 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -124,12 +124,14 @@ static int packet_length(const char *linelen)
 int packet_read_line(int fd, char *buffer, unsigned size)
 {
 	int len;
-	char linelen[4];
+	char linelen[5];
 
 	safe_read(fd, linelen, 4);
 	len = packet_length(linelen);
-	if (len < 0)
-		die("protocol error: bad line length character");
+	if (len < 0) {
+		linelen[4] = '\0';
+		die("protocol error: bad line length character: %s", linelen);
+	}
 	if (!len)
 		return 0;
 	len -= 4;
-- 
1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> diff --git a/pkt-line.c b/pkt-line.c
> index bd603f8..893dd3c 100644
> --- a/pkt-line.c
> +++ b/pkt-line.c
> @@ -124,12 +124,14 @@ static int packet_length(const char *linelen)
>  int packet_read_line(int fd, char *buffer, unsigned size)
>  {
>  	int len;
> -	char linelen[4];
> +	char linelen[5];
>  
>  	safe_read(fd, linelen, 4);
>  	len = packet_length(linelen);
> -	if (len < 0)
> -		die("protocol error: bad line length character");
> +	if (len < 0) {
> +		linelen[4] = '\0';
> +		die("protocol error: bad line length character: %s", linelen);
> +	}

Since this is not called recursively, you can make linelen[] static and do
without the NUL assignment; safe_read() won't read beyond 4 bytes anyway.

>  	if (!len)
>  		return 0;
>  	len -= 4;
> -- 
> 1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> > diff --git a/pkt-line.c b/pkt-line.c
> > index bd603f8..893dd3c 100644
> > --- a/pkt-line.c
> > +++ b/pkt-line.c
> > @@ -124,12 +124,14 @@ static int packet_length(const char *linelen)
> >  int packet_read_line(int fd, char *buffer, unsigned size)
> >  {
> >  	int len;
> > -	char linelen[4];
> > +	char linelen[5];
> >  
> >  	safe_read(fd, linelen, 4);
> >  	len = packet_length(linelen);
> > -	if (len < 0)
> > -		die("protocol error: bad line length character");
> > +	if (len < 0) {
> > +		linelen[4] = '\0';
> > +		die("protocol error: bad line length character: %s", linelen);
> > +	}
> 
> Since this is not called recursively, you can make linelen[] static

Sure.  But it wasn't static before.  It was stack allocated.  Its a
5 byte stack allocation.  Its not a lot of data to push onto the
stack, why does it suddenly matter that we make it static and charge
everyone for its memory instead of just those who really need it?

> and do
> without the NUL assignment; safe_read() won't read beyond 4 bytes anyway.

The NUL assignment isn't about safe_read(), its about making the
block of 4 bytes read a proper C-style string so we can safely pass
it down into the snprintf that is within die().

-- 
Shawn.

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> Junio C Hamano <gitster@pobox.com> wrote:
>> "Shawn O. Pearce" <spearce@spearce.org> writes:
>> > diff --git a/pkt-line.c b/pkt-line.c
>> > index bd603f8..893dd3c 100644
>> > --- a/pkt-line.c
>> > +++ b/pkt-line.c
>> > @@ -124,12 +124,14 @@ static int packet_length(const char *linelen)
>> >  int packet_read_line(int fd, char *buffer, unsigned size)
>> >  {
>> >  	int len;
>> > -	char linelen[4];
>> > +	char linelen[5];
>> >  
>> >  	safe_read(fd, linelen, 4);
>> >  	len = packet_length(linelen);
>> > -	if (len < 0)
>> > -		die("protocol error: bad line length character");
>> > +	if (len < 0) {
>> > +		linelen[4] = '\0';
>> > +		die("protocol error: bad line length character: %s", linelen);
>> > +	}
>> 
>> Since this is not called recursively, you can make linelen[] static
>
> Sure.  But it wasn't static before.  It was stack allocated.  Its a
> 5 byte stack allocation.  Its not a lot of data to push onto the
> stack, why does it suddenly matter that we make it static and charge
> everyone for its memory instead of just those who really need it?
>
>> and do
>> without the NUL assignment; safe_read() won't read beyond 4 bytes anyway.
>
> The NUL assignment isn't about safe_read(), its about making the
> block of 4 bytes read a proper C-style string so we can safely pass
> it down into the snprintf that is within die().

I knew and understood all of what you just said.  static linelen[] is not
about stack allocation.  It's about letting the compiler initialize it to
five NULs so that you do not have to assign NUL to its fifth place before
you die.  This removes one added line from your patch.

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> > The NUL assignment isn't about safe_read(), its about making the
> > block of 4 bytes read a proper C-style string so we can safely pass
> > it down into the snprintf that is within die().
> 
> I knew and understood all of what you just said.  static linelen[] is not
> about stack allocation.  It's about letting the compiler initialize it to
> five NULs so that you do not have to assign NUL to its fifth place before
> you die.  This removes one added line from your patch.

Thanks, I get it now.  Patch amended.

-- 
Shawn.

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Jeff King]

On Thu, Oct 29, 2009 at 02:58:29PM -0700, Shawn O. Pearce wrote:

> Junio C Hamano <gitster@pobox.com> wrote:
> > > The NUL assignment isn't about safe_read(), its about making the
> > > block of 4 bytes read a proper C-style string so we can safely pass
> > > it down into the snprintf that is within die().
> > 
> > I knew and understood all of what you just said.  static linelen[] is not
> > about stack allocation.  It's about letting the compiler initialize it to
> > five NULs so that you do not have to assign NUL to its fifth place before
> > you die.  This removes one added line from your patch.
> 
> Thanks, I get it now.  Patch amended.

I am just a bystander, so maybe my opinion is not worth anything, but
personally I think you are obfuscating the code to save a single line.
When I see a static variable, I assume it is because the value should be
saved from invocation to invocation, and now I will spend time wondering
why that would be the case here.

If you really just want to initialize to zero, using

  char linelen[5] = { 0 };

should be sufficient (I think all of the compilers we care about support
such incomplete array assignments, right?).

I think it would be even more clear to leave it as

  char linelen[4];

which declares how the data is _actually_ expected to be used, and then
do:

  die("protocol error: bad line length character: %.4s", linelen);

-Peff

PS All of the proposals also suffer from the fact that die will truncate
broken output at a NUL sent by the remote. Probably OK, since we are
expecting ascii hex or some variant, and if we don't correctly print
what the remote said in a totally broken NUL-filled case, it is not that
big a deal.

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Shawn O. Pearce]

Jeff King <peff@peff.net> wrote:
> On Thu, Oct 29, 2009 at 02:58:29PM -0700, Shawn O. Pearce wrote:
> > Junio C Hamano <gitster@pobox.com> wrote:
> > > I knew and understood all of what you just said.  static linelen[] is not
> > > about stack allocation.  It's about letting the compiler initialize it to
> > > five NULs so that you do not have to assign NUL to its fifth place before
> > > you die.  This removes one added line from your patch.
> 
> I am just a bystander, so maybe my opinion is not worth anything, but
> personally I think you are obfuscating the code to save a single line.

Yup, me too.  But I'm also willing to do what I need to get my
patches included in git.git.  Smart HTTP is something a lot of people
have been waiting for.  If the maintainer wants the bikeshed to be
a particular shade of red, I'll paint it that way.

> When I see a static variable, I assume it is because the value should be
> saved from invocation to invocation, and now I will spend time wondering
> why that would be the case here.

Me too.  I also can't grok the code I just wrote, for the same
reason, it just reads wrong.  But who am I to argue with the guy
who is most likely going to be the one who needs to deal with it
in the future?
 
> If you really just want to initialize to zero, using
> 
>   char linelen[5] = { 0 };

Bleh, I find that has hard to grok as what we have now.  Perhaps my
understanding of the relevant standards is incomplete, but I'd read
that as linelen[0] = 0, but the other 4 positions are undefined
and may be not be initialized.
 
> I think it would be even more clear to leave it as
> 
>   die("protocol error: bad line length character: %.4s", linelen);

I actually considered this one, but again I wasn't clear what would
happen in the standard C library when we fed a string that wasn't
actually NUL terminated.  Is the library permitted to call strlen()
before formatting?  If so strlen() could SIGSEGV if we are unlucky
and no NUL is present between our string and the end of the assigned
memory region.

To me, my original version was the most clear, to me and anyone
else who could ever possibly come by to read it.  The "one extra
line of code" is also only in an error condition which never occurs
(but did once due to a bug in the HTTP code, which is why I added
this patch to my series, to help debug it).  Its not like this is
a performance sensitive section of git that Linus is going to come
back and overhaul.

-- 
Shawn.

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Jeff King]

On Fri, Oct 30, 2009 at 12:12:40PM -0700, Shawn O. Pearce wrote:

> > I am just a bystander, so maybe my opinion is not worth anything, but
> > personally I think you are obfuscating the code to save a single line.
> 
> Yup, me too.  But I'm also willing to do what I need to get my
> patches included in git.git.  Smart HTTP is something a lot of people
> have been waiting for.  If the maintainer wants the bikeshed to be
> a particular shade of red, I'll paint it that way.

Yes, I too want it merged ASAP, so please Junio if you disagree with my
comments, ignore them. But I did want to point out that the proposed
"improvement" was making things worse, IMHO. So I feel like I was at
least bikeshedding his bikeshed, instead of starting my own. ;)

> > If you really just want to initialize to zero, using
> > 
> >   char linelen[5] = { 0 };
> 
> Bleh, I find that has hard to grok as what we have now.  Perhaps my
> understanding of the relevant standards is incomplete, but I'd read
> that as linelen[0] = 0, but the other 4 positions are undefined
> and may be not be initialized.

Your understanding is incomplete. :) C99, 6.7.8, paragraph 19:

  ... all subobjects that are not initialized explicitly shall be
  initialized implicitly the same as objects that have static storage
  duration.

I don't recall offhand whether that was the case in C89 or not.

But that being said, it was an attempt to make the meaning clear. If
it's not to you (who I consider at least reasonably competent ;) ), then
it failed.

> >   die("protocol error: bad line length character: %.4s", linelen);
> 
> I actually considered this one, but again I wasn't clear what would
> happen in the standard C library when we fed a string that wasn't
> actually NUL terminated.  Is the library permitted to call strlen()
> before formatting?  If so strlen() could SIGSEGV if we are unlucky
> and no NUL is present between our string and the end of the assigned
> memory region.

No, using a precision specifier for a string with no NUL is explicitly
allowed by the standard (and we use it elsewhere in git, IIRC).

> To me, my original version was the most clear, to me and anyone
> else who could ever possibly come by to read it.  The "one extra
> line of code" is also only in an error condition which never occurs
> (but did once due to a bug in the HTTP code, which is why I added
> this patch to my series, to help debug it).  Its not like this is
> a performance sensitive section of git that Linus is going to come
> back and overhaul.

Heh. You never know what performance item Linus will complain about. ;)
But yes, I am fine with your initial one, too. The drawback to it (and
my "%.4s") is not that one line of code is so unbearable, but that it is
one extra thing anyone using it as a string must do, and if they forget,
we get a horrible segfault.

Anyway, my complaint has been lodged. Junio is aware of the alternatives
and can pick whichever he wants.

-Peff

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[David Brown]

On Fri, Oct 30, 2009 at 12:12:40PM -0700, Shawn O. Pearce wrote:

> > If you really just want to initialize to zero, using
> > 
> >   char linelen[5] = { 0 };
> 
> Bleh, I find that has hard to grok as what we have now.  Perhaps my
> understanding of the relevant standards is incomplete, but I'd read
> that as linelen[0] = 0, but the other 4 positions are undefined
> and may be not be initialized.

C isn't that into undefined things.  In this particular case, all
remaining values will be initialized to zero.

> I actually considered this one, but again I wasn't clear what would
> happen in the standard C library when we fed a string that wasn't
> actually NUL terminated.  Is the library permitted to call strlen()
> before formatting?  If so strlen() could SIGSEGV if we are unlucky
> and no NUL is present between our string and the end of the assigned
> memory region.

The linux manpage says "If a precision is given, no null byte
need be present".  This text is copied verbatim out of the Posix
specification, so a C library that failed to handle this would be
non-compliant.

I think the %.4s is clearest, and is, in fact, somewhat
idiomatic.

David

Re: [RFC PATCH v4 03/26] pkt-line: Make packet_read_line easier to debug

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

> On Thu, Oct 29, 2009 at 02:58:29PM -0700, Shawn O. Pearce wrote:
>
>> Junio C Hamano <gitster@pobox.com> wrote:
>> > > The NUL assignment isn't about safe_read(), its about making the
>> > > block of 4 bytes read a proper C-style string so we can safely pass
>> > > it down into the snprintf that is within die().
>> > 
>> > I knew and understood all of what you just said.  static linelen[] is not
>> > about stack allocation.  It's about letting the compiler initialize it to
>> > five NULs so that you do not have to assign NUL to its fifth place before
>> > you die.  This removes one added line from your patch.
>> 
>> Thanks, I get it now.  Patch amended.
>
> I am just a bystander, so maybe my opinion is not worth anything, but
> personally I think you are obfuscating the code to save a single line.

Well, the comment was not a serious "you should do it this way" to begin
with.  An extra assignment in the error path is not a big deal.

[RFC PATCH v4 04/26] fetch-pack: Use a strbuf to compose the want list

[Shawn O. Pearce]

This change is being offered as a refactoring to make later
commits in the smart HTTP series easier.

By changing the enabled capabilities to be formatted in a strbuf
it is easier to add a new capability to the set of supported
capabilities.

By formatting the want portion of the request into a strbuf and
writing it as a whole block we can later decide to hold onto
the req_buf (instead of releasing it) to recycle in stateless
communications.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 builtin-fetch-pack.c |   52 ++++++++++++++++++++++++++++++++-----------------
 commit.c             |   10 +++-----
 commit.h             |    2 +-
 3 files changed, 39 insertions(+), 25 deletions(-)

diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 629735f..783c2b0 100644
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -165,6 +165,7 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 	const unsigned char *sha1;
 	unsigned in_vain = 0;
 	int got_continue = 0;
+	struct strbuf req_buf = STRBUF_INIT;
 
 	if (marked)
 		for_each_ref(clear_marks, NULL);
@@ -175,6 +176,7 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
 		unsigned char *remote = refs->old_sha1;
+		const char *remote_hex;
 		struct object *o;
 
 		/*
@@ -192,27 +194,36 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 			continue;
 		}
 
-		if (!fetching)
-			packet_write(fd[1], "want %s%s%s%s%s%s%s%s\n",
-				     sha1_to_hex(remote),
-				     (multi_ack ? " multi_ack" : ""),
-				     (use_sideband == 2 ? " side-band-64k" : ""),
-				     (use_sideband == 1 ? " side-band" : ""),
-				     (args.use_thin_pack ? " thin-pack" : ""),
-				     (args.no_progress ? " no-progress" : ""),
-				     (args.include_tag ? " include-tag" : ""),
-				     (prefer_ofs_delta ? " ofs-delta" : ""));
-		else
-			packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
+		remote_hex = sha1_to_hex(remote);
+		if (!fetching) {
+			struct strbuf c = STRBUF_INIT;
+			if (multi_ack)          strbuf_addstr(&c, " multi_ack");
+			if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
+			if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
+			if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
+			if (args.no_progress)   strbuf_addstr(&c, " no-progress");
+			if (args.include_tag)   strbuf_addstr(&c, " include-tag");
+			if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
+			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
+			strbuf_release(&c);
+		} else
+			packet_buf_write(&req_buf, "want %s\n", remote_hex);
 		fetching++;
 	}
+
+	if (!fetching) {
+		strbuf_release(&req_buf);
+		packet_flush(fd[1]);
+		return 1;
+	}
+
 	if (is_repository_shallow())
-		write_shallow_commits(fd[1], 1);
+		write_shallow_commits(&req_buf, 1);
 	if (args.depth > 0)
-		packet_write(fd[1], "deepen %d", args.depth);
-	packet_flush(fd[1]);
-	if (!fetching)
-		return 1;
+		packet_buf_write(&req_buf, "deepen %d", args.depth);
+	packet_buf_flush(&req_buf);
+
+	safe_write(fd[1], req_buf.buf, req_buf.len);
 
 	if (args.depth > 0) {
 		char line[1024];
@@ -296,6 +307,8 @@ done:
 		multi_ack = 0;
 		flushes++;
 	}
+	strbuf_release(&req_buf);
+
 	while (flushes || multi_ack) {
 		int ack = get_ack(fd[0], result_sha1);
 		if (ack) {
@@ -809,6 +822,7 @@ struct ref *fetch_pack(struct fetch_pack_args *my_args,
 
 	if (args.depth > 0) {
 		struct cache_time mtime;
+		struct strbuf sb = STRBUF_INIT;
 		char *shallow = git_path("shallow");
 		int fd;
 
@@ -826,12 +840,14 @@ struct ref *fetch_pack(struct fetch_pack_args *my_args,
 
 		fd = hold_lock_file_for_update(&lock, shallow,
 					       LOCK_DIE_ON_ERROR);
-		if (!write_shallow_commits(fd, 0)) {
+		if (!write_shallow_commits(&sb, 0)
+		 || write_in_full(fd, sb.buf, sb.len) != sb.len) {
 			unlink_or_warn(shallow);
 			rollback_lock_file(&lock);
 		} else {
 			commit_lock_file(&lock);
 		}
+		strbuf_release(&sb);
 	}
 
 	reprepare_packed_git();
diff --git a/commit.c b/commit.c
index fedbd5e..471efb0 100644
--- a/commit.c
+++ b/commit.c
@@ -199,7 +199,7 @@ struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 	return commit_graft[pos];
 }
 
-int write_shallow_commits(int fd, int use_pack_protocol)
+int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 {
 	int i, count = 0;
 	for (i = 0; i < commit_graft_nr; i++)
@@ -208,12 +208,10 @@ int write_shallow_commits(int fd, int use_pack_protocol)
 				sha1_to_hex(commit_graft[i]->sha1);
 			count++;
 			if (use_pack_protocol)
-				packet_write(fd, "shallow %s", hex);
+				packet_buf_write(out, "shallow %s", hex);
 			else {
-				if (write_in_full(fd, hex,  40) != 40)
-					break;
-				if (write_str_in_full(fd, "\n") != 1)
-					break;
+				strbuf_addstr(out, hex);
+				strbuf_addch(out, '\n');
 			}
 		}
 	return count;
diff --git a/commit.h b/commit.h
index f4fc5c5..817c75c 100644
--- a/commit.h
+++ b/commit.h
@@ -131,7 +131,7 @@ extern struct commit_list *get_octopus_merge_bases(struct commit_list *in);
 
 extern int register_shallow(const unsigned char *sha1);
 extern int unregister_shallow(const unsigned char *sha1);
-extern int write_shallow_commits(int fd, int use_pack_protocol);
+extern int write_shallow_commits(struct strbuf *out, int use_pack_protocol);
 extern int is_repository_shallow(void);
 extern struct commit_list *get_shallow_commits(struct object_array *heads,
 		int depth, int shallow_flag, int not_shallow_flag);
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 05/26] Move "get_ack()" back to fetch-pack

[Shawn O. Pearce]

In 41cb7488 Linus moved this function to connect.c for reuse inside
of the git-clone-pack command.  That was 2005, but in 2006 Junio
retired git-clone-pack in commit efc7fa53.  Since then the only
caller has been fetch-pack.  Since this ACK/NAK exchange is only
used by the fetch-pack/upload-pack protocol we should keep move
it back to a private detail of fetch-pack.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 builtin-fetch-pack.c |   21 +++++++++++++++++++++
 cache.h              |    1 -
 connect.c            |   21 ---------------------
 3 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 783c2b0..7c09d46 100644
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -157,6 +157,27 @@ static const unsigned char *get_rev(void)
 	return commit->object.sha1;
 }
 
+static int get_ack(int fd, unsigned char *result_sha1)
+{
+	static char line[1000];
+	int len = packet_read_line(fd, line, sizeof(line));
+
+	if (!len)
+		die("git fetch-pack: expected ACK/NAK, got EOF");
+	if (line[len-1] == '\n')
+		line[--len] = 0;
+	if (!strcmp(line, "NAK"))
+		return 0;
+	if (!prefixcmp(line, "ACK ")) {
+		if (!get_sha1_hex(line+4, result_sha1)) {
+			if (strstr(line+45, "continue"))
+				return 2;
+			return 1;
+		}
+	}
+	die("git fetch_pack: expected ACK/NAK, got '%s'", line);
+}
+
 static int find_common(int fd[2], unsigned char *result_sha1,
 		       struct ref *refs)
 {
diff --git a/cache.h b/cache.h
index a5eeead..4e283be 100644
--- a/cache.h
+++ b/cache.h
@@ -856,7 +856,6 @@ extern struct ref *find_ref_by_name(const struct ref *list, const char *name);
 extern struct child_process *git_connect(int fd[2], const char *url, const char *prog, int flags);
 extern int finish_connect(struct child_process *conn);
 extern int path_match(const char *path, int nr, char **match);
-extern int get_ack(int fd, unsigned char *result_sha1);
 struct extra_have_objects {
 	int nr, alloc;
 	unsigned char (*array)[20];
diff --git a/connect.c b/connect.c
index 7945e38..839a103 100644
--- a/connect.c
+++ b/connect.c
@@ -107,27 +107,6 @@ int server_supports(const char *feature)
 		strstr(server_capabilities, feature) != NULL;
 }
 
-int get_ack(int fd, unsigned char *result_sha1)
-{
-	static char line[1000];
-	int len = packet_read_line(fd, line, sizeof(line));
-
-	if (!len)
-		die("git fetch-pack: expected ACK/NAK, got EOF");
-	if (line[len-1] == '\n')
-		line[--len] = 0;
-	if (!strcmp(line, "NAK"))
-		return 0;
-	if (!prefixcmp(line, "ACK ")) {
-		if (!get_sha1_hex(line+4, result_sha1)) {
-			if (strstr(line+45, "continue"))
-				return 2;
-			return 1;
-		}
-	}
-	die("git fetch_pack: expected ACK/NAK, got '%s'", line);
-}
-
 int path_match(const char *path, int nr, char **match)
 {
 	int i;
-- 
1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 05/26] Move "get_ack()" back to fetch-pack

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> In 41cb7488 Linus moved this function to connect.c for reuse inside
> of the git-clone-pack command.  That was 2005, but in 2006 Junio
> retired git-clone-pack in commit efc7fa53.  Since then the only
> caller has been fetch-pack.  Since this ACK/NAK exchange is only
> used by the fetch-pack/upload-pack protocol we should keep move
> it back to a private detail of fetch-pack.

Should we keep it there or should we move it?  which? ;-)

Re: [RFC PATCH v4 05/26] Move "get_ack()" back to fetch-pack

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> 
> > In 41cb7488 Linus moved this function to connect.c for reuse inside
> > of the git-clone-pack command.  That was 2005, but in 2006 Junio
> > retired git-clone-pack in commit efc7fa53.  Since then the only
> > caller has been fetch-pack.  Since this ACK/NAK exchange is only
> > used by the fetch-pack/upload-pack protocol we should keep move
> > it back to a private detail of fetch-pack.
> 
> Should we keep it there or should we move it?  which? ;-)

Right.  Fixed.

-- 
Shawn.

[RFC PATCH v4 06/26] Add multi_ack_detailed capability to fetch-pack/upload-pack

[Shawn O. Pearce]

When multi_ack_detailed is enabled the ACK continue messages returned
by the remote upload-pack are broken out to describe the different
states within the peer.  This permits the client to better understand
the server's in-memory state.

The fetch-pack/upload-pack protocol now looks like:

NAK
---------------------------------
  Always sent in response to "done" if there was no common base
  selected from the "have" lines (or no have lines were sent).

  * no multi_ack or multi_ack_detailed:

    Sent when the client has sent a pkt-line flush ("0000") and
    the server has not yet found a common base object.

  * either multi_ack or multi_ack_detailed:

    Always sent in response to a pkt-line flush.

ACK %s
-----------------------------------
  * no multi_ack or multi_ack_detailed:

    Sent in response to "have" when the object exists on the remote
    side and is therefore an object in common between the peers.
    The argument is the SHA-1 of the common object.

  * either multi_ack or multi_ack_detailed:

    Sent in response to "done" if there are common objects.
    The argument is the last SHA-1 determined to be common.

ACK %s continue
-----------------------------------
  * multi_ack only:

    Sent in response to "have".

    The remote side wants the client to consider this object as
    common, and immediately stop transmitting additional "have"
    lines for objects that are reachable from it.  The reason
    the client should stop is not given, but is one of the two
    cases below available under multi_ack_detailed.

ACK %s common
-----------------------------------
  * multi_ack_detailed only:

    Sent in response to "have".  Both sides have this object.
    Like with "ACK %s continue" above the client should stop
    sending have lines reachable for objects from the argument.

ACK %s ready
-----------------------------------
  * multi_ack_detailed only:

    Sent in response to "have".

    The client should stop transmitting objects which are reachable
    from the argument, and send "done" soon to get the objects.

    If the remote side has the specified object, it should
    first send an "ACK %s common" message prior to sending
    "ACK %s ready".

    Clients may still submit additional "have" lines if there are
    more side branches for the client to explore that might be added
    to the common set and reduce the number of objects to transfer.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 builtin-fetch-pack.c |   41 ++++++++++++++++++++++++++++++++---------
 upload-pack.c        |   31 ++++++++++++++++++-------------
 2 files changed, 50 insertions(+), 22 deletions(-)

diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 7c09d46..615f549 100644
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -157,7 +157,15 @@ static const unsigned char *get_rev(void)
 	return commit->object.sha1;
 }
 
-static int get_ack(int fd, unsigned char *result_sha1)
+enum ack_type {
+	NAK = 0,
+	ACK,
+	ACK_continue,
+	ACK_common,
+	ACK_ready
+};
+
+static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 {
 	static char line[1000];
 	int len = packet_read_line(fd, line, sizeof(line));
@@ -167,12 +175,16 @@ static int get_ack(int fd, unsigned char *result_sha1)
 	if (line[len-1] == '\n')
 		line[--len] = 0;
 	if (!strcmp(line, "NAK"))
-		return 0;
+		return NAK;
 	if (!prefixcmp(line, "ACK ")) {
 		if (!get_sha1_hex(line+4, result_sha1)) {
 			if (strstr(line+45, "continue"))
-				return 2;
-			return 1;
+				return ACK_continue;
+			if (strstr(line+45, "common"))
+				return ACK_common;
+			if (strstr(line+45, "ready"))
+				return ACK_ready;
+			return ACK;
 		}
 	}
 	die("git fetch_pack: expected ACK/NAK, got '%s'", line);
@@ -218,7 +230,8 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 		remote_hex = sha1_to_hex(remote);
 		if (!fetching) {
 			struct strbuf c = STRBUF_INIT;
-			if (multi_ack)          strbuf_addstr(&c, " multi_ack");
+			if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
+			if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 			if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 			if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 			if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
@@ -298,18 +311,23 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 				if (args.verbose && ack)
 					fprintf(stderr, "got ack %d %s\n", ack,
 							sha1_to_hex(result_sha1));
-				if (ack == 1) {
+				switch (ack) {
+				case ACK:
 					flushes = 0;
 					multi_ack = 0;
 					retval = 0;
 					goto done;
-				} else if (ack == 2) {
+				case ACK_common:
+				case ACK_ready:
+				case ACK_continue: {
 					struct commit *commit =
 						lookup_commit(result_sha1);
 					mark_common(commit, 0, 1);
 					retval = 0;
 					in_vain = 0;
 					got_continue = 1;
+					break;
+					}
 				}
 			} while (ack);
 			flushes--;
@@ -336,7 +354,7 @@ done:
 			if (args.verbose)
 				fprintf(stderr, "got ack (%d) %s\n", ack,
 					sha1_to_hex(result_sha1));
-			if (ack == 1)
+			if (ack == ACK)
 				return 0;
 			multi_ack = 1;
 			continue;
@@ -618,7 +636,12 @@ static struct ref *do_fetch_pack(int fd[2],
 
 	if (is_repository_shallow() && !server_supports("shallow"))
 		die("Server does not support shallow clients");
-	if (server_supports("multi_ack")) {
+	if (server_supports("multi_ack_detailed")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports multi_ack_detailed\n");
+		multi_ack = 2;
+	}
+	else if (server_supports("multi_ack")) {
 		if (args.verbose)
 			fprintf(stderr, "Server supports multi_ack\n");
 		multi_ack = 1;
diff --git a/upload-pack.c b/upload-pack.c
index 38ddac2..f1dc3a3 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -498,7 +498,7 @@ static int get_common_commits(void)
 {
 	static char line[1000];
 	unsigned char sha1[20];
-	char hex[41], last_hex[41];
+	char last_hex[41];
 
 	save_commit_buffer = 0;
 
@@ -515,19 +515,22 @@ static int get_common_commits(void)
 		if (!prefixcmp(line, "have ")) {
 			switch (got_sha1(line+5, sha1)) {
 			case -1: /* they have what we do not */
-				if (multi_ack && ok_to_give_up())
-					packet_write(1, "ACK %s continue\n",
-						     sha1_to_hex(sha1));
+				if (multi_ack && ok_to_give_up()) {
+					const char *hex = sha1_to_hex(sha1);
+					if (multi_ack == 2)
+						packet_write(1, "ACK %s ready\n", hex);
+					else
+						packet_write(1, "ACK %s continue\n", hex);
+				}
 				break;
 			default:
-				memcpy(hex, sha1_to_hex(sha1), 41);
-				if (multi_ack) {
-					const char *msg = "ACK %s continue\n";
-					packet_write(1, msg, hex);
-					memcpy(last_hex, hex, 41);
-				}
+				memcpy(last_hex, sha1_to_hex(sha1), 41);
+				if (multi_ack == 2)
+					packet_write(1, "ACK %s common\n", last_hex);
+				else if (multi_ack)
+					packet_write(1, "ACK %s continue\n", last_hex);
 				else if (have_obj.nr == 1)
-					packet_write(1, "ACK %s\n", hex);
+					packet_write(1, "ACK %s\n", last_hex);
 				break;
 			}
 			continue;
@@ -587,7 +590,9 @@ static void receive_needs(void)
 		    get_sha1_hex(line+5, sha1_buf))
 			die("git upload-pack: protocol error, "
 			    "expected to get sha, not '%s'", line);
-		if (strstr(line+45, "multi_ack"))
+		if (strstr(line+45, "multi_ack_detailed"))
+			multi_ack = 2;
+		else if (strstr(line+45, "multi_ack"))
 			multi_ack = 1;
 		if (strstr(line+45, "thin-pack"))
 			use_thin_pack = 1;
@@ -681,7 +686,7 @@ static int send_ref(const char *refname, const unsigned char *sha1, int flag, vo
 {
 	static const char *capabilities = "multi_ack thin-pack side-band"
 		" side-band-64k ofs-delta shallow no-progress"
-		" include-tag";
+		" include-tag multi_ack_detailed";
 	struct object *o = parse_object(sha1);
 
 	if (!o)
-- 
1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 06/26] Add multi_ack_detailed capability to fetch-pack/upload-pack

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> ACK %s
> -----------------------------------
>   * no multi_ack or multi_ack_detailed:
>
>     Sent in response to "have" when the object exists on the remote
>     side and is therefore an object in common between the peers.
>     The argument is the SHA-1 of the common object.

Do you mean by "exists" something a bit stronger than that, namely, it
exists and everything reachable from it also exists, right?

> ACK %s common
> -----------------------------------
>   * multi_ack_detailed only:
>
>     Sent in response to "have".  Both sides have this object.
>     Like with "ACK %s continue" above the client should stop
>     sending have lines reachable for objects from the argument.
>
> ACK %s ready
> -----------------------------------
>   * multi_ack_detailed only:
>
>     Sent in response to "have".
>
>     The client should stop transmitting objects which are reachable
>     from the argument, and send "done" soon to get the objects.
>
>     If the remote side has the specified object, it should
>     first send an "ACK %s common" message prior to sending
>     "ACK %s ready".
>
>     Clients may still submit additional "have" lines if there are
>     more side branches for the client to explore that might be added
>     to the common set and reduce the number of objects to transfer.

I do not understand this after reading it three times.  The remote side
says "ACK $it common", allow the requestor to feed more "have", then
eventually send an "ACK $it ready" for the same object it earlier sent
"common" for?  The first one tells the requestor not to go down the path
from $it further, so presumably all the "have"s that come after it will be
about different ancestry paths.

What is the advantage of using this?  In other words, how, in what
situation and why would the remote side choose to use "ready" --- it looks
to me that it could always say "common" whenever it hits a "have" that it
can determine to be common.

Re: [RFC PATCH v4 06/26] Add multi_ack_detailed capability to fetch-pack/upload-pack

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> 
> > ACK %s
> > -----------------------------------
> >   * no multi_ack or multi_ack_detailed:
> >
> >     Sent in response to "have" when the object exists on the remote
> >     side and is therefore an object in common between the peers.
> >     The argument is the SHA-1 of the common object.
> 
> Do you mean by "exists" something a bit stronger than that, namely, it
> exists and everything reachable from it also exists, right?

No, I mean "object exists".  The upload-pack code makes no check that
the object is in fact complete, just that it has the object in the
object database.  The object could be a dangling commit whose parents
aren't present, and we'd still (currently) return an "ACK %s" for it.

I specifically didn't get into completeness here because we don't
actually check for it.
 
> > ACK %s common
> > -----------------------------------
> >   * multi_ack_detailed only:
> >
> >     Sent in response to "have".  Both sides have this object.
> >     Like with "ACK %s continue" above the client should stop
> >     sending have lines reachable for objects from the argument.
> >
> > ACK %s ready
> > -----------------------------------
> >   * multi_ack_detailed only:
> >
> >     Sent in response to "have".
> >
> >     The client should stop transmitting objects which are reachable
> >     from the argument, and send "done" soon to get the objects.
> >
> >     If the remote side has the specified object, it should
> >     first send an "ACK %s common" message prior to sending
> >     "ACK %s ready".
> >
> >     Clients may still submit additional "have" lines if there are
> >     more side branches for the client to explore that might be added
> >     to the common set and reduce the number of objects to transfer.
> 
> I do not understand this after reading it three times.  The remote side
> says "ACK $it common", allow the requestor to feed more "have", then
> eventually send an "ACK $it ready" for the same object it earlier sent
> "common" for?  The first one tells the requestor not to go down the path
> from $it further, so presumably all the "have"s that come after it will be
> about different ancestry paths.
> 
> What is the advantage of using this?  In other words, how, in what
> situation and why would the remote side choose to use "ready" --- it looks
> to me that it could always say "common" whenever it hits a "have" that it
> can determine to be common.

"ACK $it ready" should be used when ok_to_give_up() returns true.

The "ACK $it ready" message is trying to say "don't talk any more
about things reachable from $it, and by the way, if you say 'done'
now I will give you a pack".

The "ACK $it common" message is trying to say "$it is a common base,
don't talk any more about things reachable from $it, but there
may be other branches you should explore before I send you a pack,
so talk about those if you can".


A client only wants to store $it into its request state vector for
replay on the next RPC if $it is truely common.

The "ACK $it common" before "ACK $it ready" is because clients can't
assume that "ACK $it ready" means $it is really common.  Servers send
"ACK $it ready" if they don't have $it but are ok_to_give_up().
But if it is common, *and* ok_to_give_up() is true, a server can
send both messages, but it must send "ACK $it common" first.

-- 
Shawn.

[RFC PATCH v4 07/26] remote-curl: Refactor walker initialization

[Shawn O. Pearce]

We will need the walker, url and remote in other functions as the
code grows larger to support smart HTTP.  Extract this out into a
set of globals we can easily reference once configured.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 remote-curl.c |   24 ++++++++++++++----------
 1 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/remote-curl.c b/remote-curl.c
index 2faf1c6..478f3ea 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -5,7 +5,17 @@
 #include "http.h"
 #include "exec_cmd.h"
 
-static struct ref *get_refs(struct walker *walker, const char *url)
+static struct remote *remote;
+static const char *url;
+static struct walker *walker;
+
+static void init_walker(void)
+{
+	if (!walker)
+		walker = get_http_walker(url, remote);
+}
+
+static struct ref *get_refs(void)
 {
 	struct strbuf buffer = STRBUF_INIT;
 	char *data, *start, *mid;
@@ -21,6 +31,7 @@ static struct ref *get_refs(struct walker *walker, const char *url)
 	refs_url = xmalloc(strlen(url) + 11);
 	sprintf(refs_url, "%s/info/refs", url);
 
+	init_walker();
 	http_ret = http_get_strbuf(refs_url, &buffer, HTTP_NO_CACHE);
 	switch (http_ret) {
 	case HTTP_OK:
@@ -78,10 +89,7 @@ static struct ref *get_refs(struct walker *walker, const char *url)
 
 int main(int argc, const char **argv)
 {
-	struct remote *remote;
 	struct strbuf buf = STRBUF_INIT;
-	const char *url;
-	struct walker *walker = NULL;
 
 	git_extract_argv0_path(argv[0]);
 	setup_git_directory();
@@ -103,8 +111,7 @@ int main(int argc, const char **argv)
 			break;
 		if (!prefixcmp(buf.buf, "fetch ")) {
 			char *obj = buf.buf + strlen("fetch ");
-			if (!walker)
-				walker = get_http_walker(url, remote);
+			init_walker();
 			walker->get_all = 1;
 			walker->get_tree = 1;
 			walker->get_history = 1;
@@ -115,11 +122,8 @@ int main(int argc, const char **argv)
 			printf("\n");
 			fflush(stdout);
 		} else if (!strcmp(buf.buf, "list")) {
-			struct ref *refs;
+			struct ref *refs = get_refs();
 			struct ref *posn;
-			if (!walker)
-				walker = get_http_walker(url, remote);
-			refs = get_refs(walker, url);
 			for (posn = refs; posn; posn = posn->next) {
 				if (posn->symref)
 					printf("@%s %s\n", posn->symref, posn->name);
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 08/26] fetch: Allow transport -v -v -v to set verbosity to 3

[Shawn O. Pearce]

Helpers might want a higher level of verbosity than just +1 (the
porcelain default setting) and +2 (-v -v).  Expand the field to
allow verbosity in the range -1..3.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 builtin-fetch.c |    2 +-
 transport.h     |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/builtin-fetch.c b/builtin-fetch.c
index cb48c57..52a9a42 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c
@@ -665,7 +665,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 
 	transport = transport_get(remote, remote->url[0]);
 	if (verbosity >= 2)
-		transport->verbose = 1;
+		transport->verbose = verbosity <= 3 ? verbosity : 3;
 	if (verbosity < 0)
 		transport->verbose = -1;
 	if (upload_pack)
diff --git a/transport.h b/transport.h
index c14da6f..e4e6177 100644
--- a/transport.h
+++ b/transport.h
@@ -25,7 +25,7 @@ struct transport {
 
 	int (*disconnect)(struct transport *connection);
 	char *pack_lockfile;
-	signed verbose : 2;
+	signed verbose : 3;
 	/* Force progress even if the output is not a tty */
 	unsigned progress : 1;
 };
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 09/26] remote-helpers: Fetch more than one ref in a batch

[Shawn O. Pearce]

Some network protocols (e.g. native git://) are able to fetch more
than one ref at a time and reduce the overall transfer cost by
combining the requests into a single exchange.  Instead of feeding
each fetch request one at a time to the helper, feed all of them
at once so the helper can decide whether or not it should batch them.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 Documentation/git-remote-helpers.txt |   14 ++++--
 remote-curl.c                        |   88 +++++++++++++++++++++++++++++----
 transport-helper.c                   |   39 +++++++++++----
 3 files changed, 115 insertions(+), 26 deletions(-)

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index 173ee23..e44d821 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -36,10 +36,16 @@ Commands are given by the caller on the helper's standard input, one per line.
 	complete list, outputs a blank line.
 
 'fetch' <sha1> <name>::
-	Fetches the given object, writing the necessary objects to the
-	database. Outputs a blank line when the fetch is
-	complete. Only objects which were reported in the ref list
-	with a sha1 may be fetched this way.
+	Fetches the given object, writing the necessary objects
+	to the database.  Fetch commands are sent in a batch, one
+	per line, and the batch is terminated with a blank line.
+	Outputs a single blank line when all fetch commands in the
+	same batch are complete. Only objects which were reported
+	in the ref list with a sha1 may be fetched this way.
++
+Optionally may output a 'lock <file>' line indicating a file under
+GIT_DIR/objects/pack which is keeping a pack until refs can be
+suitably updated.
 +
 Supported if the helper has the "fetch" capability.
 
diff --git a/remote-curl.c b/remote-curl.c
index 478f3ea..22cd5c5 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -87,6 +87,81 @@ static struct ref *get_refs(void)
 	return refs;
 }
 
+static int fetch_dumb(int nr_heads, struct ref **to_fetch)
+{
+	char **targets = xmalloc(nr_heads * sizeof(char*));
+	int ret, i;
+
+	for (i = 0; i < nr_heads; i++)
+		targets[i] = xstrdup(sha1_to_hex(to_fetch[i]->old_sha1));
+
+	init_walker();
+	walker->get_all = 1;
+	walker->get_tree = 1;
+	walker->get_history = 1;
+	walker->get_verbosely = 0;
+	walker->get_recover = 0;
+	ret = walker_fetch(walker, nr_heads, targets, NULL, NULL);
+
+	for (i = 0; i < nr_heads; i++)
+		free(targets[i]);
+	free(targets);
+
+	return ret ? error("Fetch failed.") : 0;
+}
+
+static void parse_fetch(struct strbuf *buf)
+{
+	struct ref **to_fetch = NULL;
+	struct ref *list_head = NULL;
+	struct ref **list = &list_head;
+	int alloc_heads = 0, nr_heads = 0;
+
+	do {
+		if (!prefixcmp(buf->buf, "fetch ")) {
+			char *p = buf->buf + strlen("fetch ");
+			char *name;
+			struct ref *ref;
+			unsigned char old_sha1[20];
+
+			if (strlen(p) < 40 || get_sha1_hex(p, old_sha1))
+				die("protocol error: expected sha/ref, got %s'", p);
+			if (p[40] == ' ')
+				name = p + 41;
+			else if (!p[40])
+				name = "";
+			else
+				die("protocol error: expected sha/ref, got %s'", p);
+
+			ref = alloc_ref(name);
+			hashcpy(ref->old_sha1, old_sha1);
+
+			*list = ref;
+			list = &ref->next;
+
+			ALLOC_GROW(to_fetch, nr_heads + 1, alloc_heads);
+			to_fetch[nr_heads++] = ref;
+		}
+		else
+			die("http transport does not support %s", buf->buf);
+
+		strbuf_reset(buf);
+		if (strbuf_getline(buf, stdin, '\n') == EOF)
+			return;
+		if (!*buf->buf)
+			break;
+	} while (1);
+
+	if (fetch_dumb(nr_heads, to_fetch))
+		exit(128); /* error already reported */
+	free_refs(list_head);
+	free(to_fetch);
+
+	printf("\n");
+	fflush(stdout);
+	strbuf_reset(buf);
+}
+
 int main(int argc, const char **argv)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -110,17 +185,8 @@ int main(int argc, const char **argv)
 		if (strbuf_getline(&buf, stdin, '\n') == EOF)
 			break;
 		if (!prefixcmp(buf.buf, "fetch ")) {
-			char *obj = buf.buf + strlen("fetch ");
-			init_walker();
-			walker->get_all = 1;
-			walker->get_tree = 1;
-			walker->get_history = 1;
-			walker->get_verbosely = 0;
-			walker->get_recover = 0;
-			if (walker_fetch(walker, 1, &obj, NULL, NULL))
-				die("Fetch failed.");
-			printf("\n");
-			fflush(stdout);
+			parse_fetch(&buf);
+
 		} else if (!strcmp(buf.buf, "list")) {
 			struct ref *refs = get_refs();
 			struct ref *posn;
diff --git a/transport-helper.c b/transport-helper.c
index f57e84c..9de3408 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -10,6 +10,7 @@ struct helper_data
 {
 	const char *name;
 	struct child_process *helper;
+	FILE *out;
 	unsigned fetch : 1;
 };
 
@@ -18,7 +19,6 @@ static struct child_process *get_helper(struct transport *transport)
 	struct helper_data *data = transport->data;
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process *helper;
-	FILE *file;
 
 	if (data->helper)
 		return data->helper;
@@ -39,9 +39,9 @@ static struct child_process *get_helper(struct transport *transport)
 
 	write_str_in_full(helper->in, "capabilities\n");
 
-	file = xfdopen(helper->out, "r");
+	data->out = xfdopen(helper->out, "r");
 	while (1) {
-		if (strbuf_getline(&buf, file, '\n') == EOF)
+		if (strbuf_getline(&buf, data->out, '\n') == EOF)
 			exit(128); /* child died, message supplied already */
 
 		if (!*buf.buf)
@@ -58,6 +58,7 @@ static int disconnect_helper(struct transport *transport)
 	if (data->helper) {
 		write_str_in_full(data->helper->in, "\n");
 		close(data->helper->in);
+		fclose(data->out);
 		finish_command(data->helper);
 		free((char *)data->helper->argv[0]);
 		free(data->helper->argv);
@@ -70,8 +71,7 @@ static int disconnect_helper(struct transport *transport)
 static int fetch_with_fetch(struct transport *transport,
 			    int nr_heads, const struct ref **to_fetch)
 {
-	struct child_process *helper = get_helper(transport);
-	FILE *file = xfdopen(helper->out, "r");
+	struct helper_data *data = transport->data;
 	int i;
 	struct strbuf buf = STRBUF_INIT;
 
@@ -82,12 +82,30 @@ static int fetch_with_fetch(struct transport *transport,
 
 		strbuf_addf(&buf, "fetch %s %s\n",
 			    sha1_to_hex(posn->old_sha1), posn->name);
-		write_in_full(helper->in, buf.buf, buf.len);
-		strbuf_reset(&buf);
+	}
 
-		if (strbuf_getline(&buf, file, '\n') == EOF)
+	strbuf_addch(&buf, '\n');
+	if (write_in_full(data->helper->in, buf.buf, buf.len) != buf.len)
+		die_errno("cannot send fetch to %s", data->name);
+
+	while (1) {
+		strbuf_reset(&buf);
+		if (strbuf_getline(&buf, data->out, '\n') == EOF)
 			exit(128); /* child died, message supplied already */
+
+		if (!prefixcmp(buf.buf, "lock ")) {
+			const char *name = buf.buf + 5;
+			if (transport->pack_lockfile)
+				warning("%s also locked %s", data->name, name);
+			else
+				transport->pack_lockfile = xstrdup(name);
+		}
+		else if (!buf.len)
+			break;
+		else
+			warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 	}
+	strbuf_release(&buf);
 	return 0;
 }
 
@@ -113,21 +131,20 @@ static int fetch(struct transport *transport,
 
 static struct ref *get_refs_list(struct transport *transport, int for_push)
 {
+	struct helper_data *data = transport->data;
 	struct child_process *helper;
 	struct ref *ret = NULL;
 	struct ref **tail = &ret;
 	struct ref *posn;
 	struct strbuf buf = STRBUF_INIT;
-	FILE *file;
 
 	helper = get_helper(transport);
 
 	write_str_in_full(helper->in, "list\n");
 
-	file = xfdopen(helper->out, "r");
 	while (1) {
 		char *eov, *eon;
-		if (strbuf_getline(&buf, file, '\n') == EOF)
+		if (strbuf_getline(&buf, data->out, '\n') == EOF)
 			exit(128); /* child died, message supplied already */
 
 		if (!*buf.buf)
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 10/26] remote-helpers: Support custom transport options

[Shawn O. Pearce]

Some transports, like the native pack transport implemented by
fetch-pack, support useful features like depth or include tags.
These should be exposed if the underlying helper knows how to
use them.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 Documentation/git-remote-helpers.txt |   38 +++++++++++++++
 remote-curl.c                        |   74 ++++++++++++++++++++++++++++-
 transport-helper.c                   |   88 +++++++++++++++++++++++++++++++++-
 3 files changed, 198 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index e44d821..1133f04 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -35,6 +35,16 @@ Commands are given by the caller on the helper's standard input, one per line.
 	the name; unrecognized attributes are ignored. After the
 	complete list, outputs a blank line.
 
+'option' <name> <value>::
+	Set the transport helper option <name> to <value>.  Outputs a
+	single line containing one of 'ok' (option successfully set),
+	'unsupported' (option not recognized) or 'error <msg>'
+	(option <name> is supported but <value> is not correct
+	for it).  Options should be set before other commands,
+	and may how those commands behave.
++
+Supported if the helper has the "option" capability.
+
 'fetch' <sha1> <name>::
 	Fetches the given object, writing the necessary objects
 	to the database.  Fetch commands are sent in a batch, one
@@ -63,11 +73,39 @@ CAPABILITIES
 'fetch'::
 	This helper supports the 'fetch' command.
 
+'option'::
+	This helper supports the option command.
+
 REF LIST ATTRIBUTES
 -------------------
 
 None are defined yet, but the caller must accept any which are supplied.
 
+OPTIONS
+-------
+'option verbosity' <N>::
+	Change the level of messages displayed by the helper.
+	When N is 0 the end-user has asked the process to be
+	quiet, and the helper should produce only error output.
+	N of 1 is the default level of verbosity, higher values
+	of N correspond to the number of -v flags passed on the
+	command line.
+
+'option progress' \{'true'|'false'\}::
+	Enable (or disable) progress messages displayed by the
+	transport helper during a command.
+
+'option depth' <depth>::
+	Deepen the history of a shallow repository.
+
+'option followtags' \{'true'|'false'\}::
+	If enabled the helper should automatically fetch annotated
+	tag objects if the object the tag points at was transferred
+	during the fetch command.  If the tag is not fetched by
+	the helper a second fetch command will usually be sent to
+	ask for the tag specifically.  Some helpers may be able to
+	use this option to avoid a second network connection.
+
 Documentation
 -------------
 Documentation by Daniel Barkalow.
diff --git a/remote-curl.c b/remote-curl.c
index 22cd5c5..0951f11 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -9,12 +9,61 @@ static struct remote *remote;
 static const char *url;
 static struct walker *walker;
 
+struct options {
+	int verbosity;
+	unsigned long depth;
+	unsigned progress : 1,
+		followtags : 1;
+};
+static struct options options;
+
 static void init_walker(void)
 {
 	if (!walker)
 		walker = get_http_walker(url, remote);
 }
 
+static int set_option(const char *name, const char *value)
+{
+	if (!strcmp(name, "verbosity")) {
+		char *end;
+		int v = strtol(value, &end, 10);
+		if (value == end || *end)
+			return -1;
+		options.verbosity = v;
+		return 0;
+	}
+	else if (!strcmp(name, "progress")) {
+		if (!strcmp(value, "true"))
+			options.progress = 1;
+		else if (!strcmp(value, "false"))
+			options.progress = 0;
+		else
+			return -1;
+		return 1 /* TODO implement later */;
+	}
+	else if (!strcmp(name, "depth")) {
+		char *end;
+		unsigned long v = strtoul(value, &end, 10);
+		if (value == end || *end)
+			return -1;
+		options.depth = v;
+		return 1 /* TODO implement later */;
+	}
+	else if (!strcmp(name, "followtags")) {
+		if (!strcmp(value, "true"))
+			options.followtags = 1;
+		else if (!strcmp(value, "false"))
+			options.followtags = 0;
+		else
+			return -1;
+		return 1 /* TODO implement later */;
+	}
+	else {
+		return 1 /* unsupported */;
+	}
+}
+
 static struct ref *get_refs(void)
 {
 	struct strbuf buffer = STRBUF_INIT;
@@ -99,7 +148,7 @@ static int fetch_dumb(int nr_heads, struct ref **to_fetch)
 	walker->get_all = 1;
 	walker->get_tree = 1;
 	walker->get_history = 1;
-	walker->get_verbosely = 0;
+	walker->get_verbosely = options.verbosity >= 3;
 	walker->get_recover = 0;
 	ret = walker_fetch(walker, nr_heads, targets, NULL, NULL);
 
@@ -173,6 +222,9 @@ int main(int argc, const char **argv)
 		return 1;
 	}
 
+	options.verbosity = 1;
+	options.progress = !!isatty(2);
+
 	remote = remote_get(argv[1]);
 
 	if (argc > 2) {
@@ -198,8 +250,28 @@ int main(int argc, const char **argv)
 			}
 			printf("\n");
 			fflush(stdout);
+		} else if (!prefixcmp(buf.buf, "option ")) {
+			char *name = buf.buf + strlen("option ");
+			char *value = strchr(name, ' ');
+			int result;
+
+			if (value)
+				*value++ = '\0';
+			else
+				value = "true";
+
+			result = set_option(name, value);
+			if (!result)
+				printf("ok\n");
+			else if (result < 0)
+				printf("error invalid value\n");
+			else
+				printf("unsupported\n");
+			fflush(stdout);
+
 		} else if (!strcmp(buf.buf, "capabilities")) {
 			printf("fetch\n");
+			printf("option\n");
 			printf("\n");
 			fflush(stdout);
 		} else {
diff --git a/transport-helper.c b/transport-helper.c
index 9de3408..577abc6 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -5,13 +5,15 @@
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
+#include "quote.h"
 
 struct helper_data
 {
 	const char *name;
 	struct child_process *helper;
 	FILE *out;
-	unsigned fetch : 1;
+	unsigned fetch : 1,
+		option : 1;
 };
 
 static struct child_process *get_helper(struct transport *transport)
@@ -48,6 +50,8 @@ static struct child_process *get_helper(struct transport *transport)
 			break;
 		if (!strcmp(buf.buf, "fetch"))
 			data->fetch = 1;
+		if (!strcmp(buf.buf, "option"))
+			data->option = 1;
 	}
 	return data->helper;
 }
@@ -65,9 +69,88 @@ static int disconnect_helper(struct transport *transport)
 		free(data->helper);
 		data->helper = NULL;
 	}
+	free(data);
 	return 0;
 }
 
+static const char *unsupported_options[] = {
+	TRANS_OPT_UPLOADPACK,
+	TRANS_OPT_RECEIVEPACK,
+	TRANS_OPT_THIN,
+	TRANS_OPT_KEEP
+	};
+static const char *boolean_options[] = {
+	TRANS_OPT_THIN,
+	TRANS_OPT_KEEP,
+	TRANS_OPT_FOLLOWTAGS
+	};
+
+static int set_helper_option(struct transport *transport,
+			  const char *name, const char *value)
+{
+	struct helper_data *data = transport->data;
+	struct child_process *helper = get_helper(transport);
+	struct strbuf buf = STRBUF_INIT;
+	int i, ret, is_bool = 0;
+
+	if (!data->option)
+		return 1;
+
+	for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
+		if (!strcmp(name, unsupported_options[i]))
+			return 1;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
+		if (!strcmp(name, boolean_options[i])) {
+			is_bool = 1;
+			break;
+		}
+	}
+
+	strbuf_addf(&buf, "option %s ", name);
+	if (is_bool)
+		strbuf_addstr(&buf, value ? "true" : "false");
+	else
+		quote_c_style(value, &buf, NULL, 0);
+	strbuf_addch(&buf, '\n');
+
+	if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
+		die_errno("cannot send option to %s", data->name);
+
+	strbuf_reset(&buf);
+	if (strbuf_getline(&buf, data->out, '\n') == EOF)
+		exit(128); /* child died, message supplied already */
+
+	if (!strcmp(buf.buf, "ok"))
+		ret = 0;
+	else if (!prefixcmp(buf.buf, "error")) {
+		ret = -1;
+	} else if (!strcmp(buf.buf, "unsupported"))
+		ret = 1;
+	else {
+		warning("%s unexpectedly said: '%s'", data->name, buf.buf);
+		ret = 1;
+	}
+	strbuf_release(&buf);
+	return ret;
+}
+
+static void standard_options(struct transport *t)
+{
+	char buf[16];
+	int n;
+	int v = t->verbose;
+	int no_progress = v < 0 || (!t->progress && !isatty(1));
+
+	set_helper_option(t, "progress", !no_progress ? "true" : "false");
+
+	n = snprintf(buf, sizeof(buf), "%d", v + 1);
+	if (n >= sizeof(buf))
+		die("impossibly large verbosity value");
+	set_helper_option(t, "verbosity", buf);
+}
+
 static int fetch_with_fetch(struct transport *transport,
 			    int nr_heads, const struct ref **to_fetch)
 {
@@ -75,6 +158,8 @@ static int fetch_with_fetch(struct transport *transport,
 	int i;
 	struct strbuf buf = STRBUF_INIT;
 
+	standard_options(transport);
+
 	for (i = 0; i < nr_heads; i++) {
 		const struct ref *posn = to_fetch[i];
 		if (posn->status & REF_STATUS_UPTODATE)
@@ -178,6 +263,7 @@ int transport_helper_init(struct transport *transport, const char *name)
 	data->name = name;
 
 	transport->data = data;
+	transport->set_option = set_helper_option;
 	transport->get_refs_list = get_refs_list;
 	transport->fetch = fetch;
 	transport->disconnect = disconnect_helper;
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 11/26] Move WebDAV HTTP push under remote-curl

[Shawn O. Pearce]

The remote helper interface now supports the push capability,
which can be used to ask the implementation to push one or more
specs to the remote repository.  For remote-curl we implement this
by calling the existing WebDAV based git-http-push executable.

Internally the helper interface uses the push_refs transport hook
so that the complexity of the refspec parsing and matching can be
reused between remote implementations.  When possible however the
helper protocol uses source ref name rather than the source SHA-1,
thereby allowing the helper to access this name if it is useful.

>From Clemens Buchacher <drizzd@aon.at>:
 update http tests according to remote-curl capabilities

 o Pushing packed refs is now fixed.

 o The transport helper fails if refs are already up-to-date. Add
   a test for that.

 o The transport helper will notice if refs are already
   up-to-date. We therefore need to update server info in the
   unpacked-refs test.

 o The transport helper will purge deleted branches automatically.

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
CC: Mike Hommey <mh@glandium.org>
---
 Documentation/git-remote-helpers.txt |   33 ++++++++-
 http-push.c                          |   29 +++++++-
 remote-curl.c                        |   97 +++++++++++++++++++++---
 t/t5540-http-push.sh                 |   14 ++-
 transport-helper.c                   |  137 +++++++++++++++++++++++++++++++++-
 transport.c                          |   31 --------
 6 files changed, 287 insertions(+), 54 deletions(-)

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index 1133f04..8beb42d 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -34,6 +34,10 @@ Commands are given by the caller on the helper's standard input, one per line.
 	value of the ref. A space-separated list of attributes follows
 	the name; unrecognized attributes are ignored. After the
 	complete list, outputs a blank line.
++
+If 'push' is supported this may be called as 'list for-push'
+to obtain the current refs prior to sending one or more 'push'
+commands to the helper.
 
 'option' <name> <value>::
 	Set the transport helper option <name> to <value>.  Outputs a
@@ -59,6 +63,22 @@ suitably updated.
 +
 Supported if the helper has the "fetch" capability.
 
+'push' +<src>:<dst>::
+	Pushes the given <src> commit or branch locally to the
+	remote branch described by <dst>.  A batch sequence of
+	one or more push commands is terminated with a blank line.
++
+Zero or more protocol options may be entered after the last 'push'
+command, before the batch's terminating blank line.
++
+When the push is complete, outputs one or more 'ok <dst>' or
+'error <dst> <why>?' lines to indicate success or failure of
+each pushed ref.  The status report output is terminated by
+a blank line.  The option field <why> may be quoted in a C
+style string if it contains an LF.
++
+Supported if the helper has the "push" capability.
+
 If a fatal error occurs, the program writes the error message to
 stderr and exits. The caller should expect that a suitable error
 message has been printed if the child closes the connection without
@@ -76,10 +96,16 @@ CAPABILITIES
 'option'::
 	This helper supports the option command.
 
+'push'::
+	This helper supports the 'push' command.
+
 REF LIST ATTRIBUTES
 -------------------
 
-None are defined yet, but the caller must accept any which are supplied.
+'for-push'::
+	The caller wants to use the ref list to prepare push
+	commands.  A helper might chose to acquire the ref list by
+	opening a different type of connection to the destination.
 
 OPTIONS
 -------
@@ -106,6 +132,11 @@ OPTIONS
 	ask for the tag specifically.  Some helpers may be able to
 	use this option to avoid a second network connection.
 
+'option dry-run' \{'true'|'false'\}:
+	If true, pretend the operation completed successfully,
+	but don't actually change any repository data.	For most
+	helpers this only applies to the 'push', if supported.
+
 Documentation
 -------------
 Documentation by Daniel Barkalow.
diff --git a/http-push.c b/http-push.c
index cc5d4b8..f10803a 100644
--- a/http-push.c
+++ b/http-push.c
@@ -78,6 +78,7 @@ static int push_verbosely;
 static int push_all = MATCH_REFS_NONE;
 static int force_all;
 static int dry_run;
+static int helper_status;
 
 static struct object_list *objects;
 
@@ -1813,6 +1814,10 @@ int main(int argc, char **argv)
 				dry_run = 1;
 				continue;
 			}
+			if (!strcmp(arg, "--helper-status")) {
+				helper_status = 1;
+				continue;
+			}
 			if (!strcmp(arg, "--verbose")) {
 				push_verbosely = 1;
 				http_is_verbose = 1;
@@ -1911,9 +1916,12 @@ int main(int argc, char **argv)
 
 	/* Remove a remote branch if -d or -D was specified */
 	if (delete_branch) {
-		if (delete_remote_branch(refspec[0], force_delete) == -1)
+		if (delete_remote_branch(refspec[0], force_delete) == -1) {
 			fprintf(stderr, "Unable to delete remote branch %s\n",
 				refspec[0]);
+			if (helper_status)
+				printf("error %s cannot remove\n", refspec[0]);
+		}
 		goto cleanup;
 	}
 
@@ -1925,6 +1933,8 @@ int main(int argc, char **argv)
 	}
 	if (!remote_refs) {
 		fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
+		if (helper_status)
+			printf("error null no match\n");
 		rc = 0;
 		goto cleanup;
 	}
@@ -1942,8 +1952,12 @@ int main(int argc, char **argv)
 		if (is_null_sha1(ref->peer_ref->new_sha1)) {
 			if (delete_remote_branch(ref->name, 1) == -1) {
 				error("Could not remove %s", ref->name);
+				if (helper_status)
+					printf("error %s cannot remove\n", ref->name);
 				rc = -4;
 			}
+			else if (helper_status)
+				printf("ok %s\n", ref->name);
 			new_refs++;
 			continue;
 		}
@@ -1951,6 +1965,8 @@ int main(int argc, char **argv)
 		if (!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 			if (push_verbosely || 1)
 				fprintf(stderr, "'%s': up-to-date\n", ref->name);
+			if (helper_status)
+				printf("ok %s up to date\n", ref->name);
 			continue;
 		}
 
@@ -1974,6 +1990,8 @@ int main(int argc, char **argv)
 				      "need to pull first?",
 				      ref->name,
 				      ref->peer_ref->name);
+				if (helper_status)
+					printf("error %s non-fast forward\n", ref->name);
 				rc = -2;
 				continue;
 			}
@@ -1987,14 +2005,19 @@ int main(int argc, char **argv)
 		if (strcmp(ref->name, ref->peer_ref->name))
 			fprintf(stderr, " using '%s'", ref->peer_ref->name);
 		fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
-		if (dry_run)
+		if (dry_run) {
+			if (helper_status)
+				printf("ok %s\n", ref->name);
 			continue;
+		}
 
 		/* Lock remote branch ref */
 		ref_lock = lock_remote(ref->name, LOCK_TIME);
 		if (ref_lock == NULL) {
 			fprintf(stderr, "Unable to lock remote branch %s\n",
 				ref->name);
+			if (helper_status)
+				printf("error %s lock error\n", ref->name);
 			rc = 1;
 			continue;
 		}
@@ -2045,6 +2068,8 @@ int main(int argc, char **argv)
 
 		if (!rc)
 			fprintf(stderr, "    done\n");
+		if (helper_status)
+			printf("%s %s\n", !rc ? "ok" : "error", ref->name);
 		unlock_remote(ref_lock);
 		check_locks();
 	}
diff --git a/remote-curl.c b/remote-curl.c
index 0951f11..5c9dd97 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -4,6 +4,7 @@
 #include "walker.h"
 #include "http.h"
 #include "exec_cmd.h"
+#include "run-command.h"
 
 static struct remote *remote;
 static const char *url;
@@ -13,7 +14,8 @@ struct options {
 	int verbosity;
 	unsigned long depth;
 	unsigned progress : 1,
-		followtags : 1;
+		followtags : 1,
+		dry_run : 1;
 };
 static struct options options;
 
@@ -59,6 +61,15 @@ static int set_option(const char *name, const char *value)
 			return -1;
 		return 1 /* TODO implement later */;
 	}
+	else if (!strcmp(name, "dry-run")) {
+		if (!strcmp(value, "true"))
+			options.dry_run = 1;
+		else if (!strcmp(value, "false"))
+			options.dry_run = 0;
+		else
+			return -1;
+		return 0;
+	}
 	else {
 		return 1 /* unsupported */;
 	}
@@ -136,6 +147,20 @@ static struct ref *get_refs(void)
 	return refs;
 }
 
+static void output_refs(struct ref *refs)
+{
+	struct ref *posn;
+	for (posn = refs; posn; posn = posn->next) {
+		if (posn->symref)
+			printf("@%s %s\n", posn->symref, posn->name);
+		else
+			printf("%s %s\n", sha1_to_hex(posn->old_sha1), posn->name);
+	}
+	printf("\n");
+	fflush(stdout);
+	free_refs(refs);
+}
+
 static int fetch_dumb(int nr_heads, struct ref **to_fetch)
 {
 	char **targets = xmalloc(nr_heads * sizeof(char*));
@@ -211,6 +236,58 @@ static void parse_fetch(struct strbuf *buf)
 	strbuf_reset(buf);
 }
 
+static int push_dav(int nr_spec, char **specs)
+{
+	const char **argv = xmalloc((10 + nr_spec) * sizeof(char*));
+	int argc = 0, i;
+
+	argv[argc++] = "http-push";
+	argv[argc++] = "--helper-status";
+	if (options.dry_run)
+		argv[argc++] = "--dry-run";
+	if (options.verbosity > 1)
+		argv[argc++] = "--verbose";
+	argv[argc++] = url;
+	for (i = 0; i < nr_spec; i++)
+		argv[argc++] = specs[i];
+	argv[argc++] = NULL;
+
+	if (run_command_v_opt(argv, RUN_GIT_CMD))
+		die("git-%s failed", argv[0]);
+	free(argv);
+	return 0;
+}
+
+static void parse_push(struct strbuf *buf)
+{
+	char **specs = NULL;
+	int alloc_spec = 0, nr_spec = 0, i;
+
+	do {
+		if (!prefixcmp(buf->buf, "push ")) {
+			ALLOC_GROW(specs, nr_spec + 1, alloc_spec);
+			specs[nr_spec++] = xstrdup(buf->buf + 5);
+		}
+		else
+			die("http transport does not support %s", buf->buf);
+
+		strbuf_reset(buf);
+		if (strbuf_getline(buf, stdin, '\n') == EOF)
+			return;
+		if (!*buf->buf)
+			break;
+	} while (1);
+
+	if (push_dav(nr_spec, specs))
+		exit(128); /* error already reported */
+	for (i = 0; i < nr_spec; i++)
+		free(specs[i]);
+	free(specs);
+
+	printf("\n");
+	fflush(stdout);
+}
+
 int main(int argc, const char **argv)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -239,17 +316,12 @@ int main(int argc, const char **argv)
 		if (!prefixcmp(buf.buf, "fetch ")) {
 			parse_fetch(&buf);
 
-		} else if (!strcmp(buf.buf, "list")) {
-			struct ref *refs = get_refs();
-			struct ref *posn;
-			for (posn = refs; posn; posn = posn->next) {
-				if (posn->symref)
-					printf("@%s %s\n", posn->symref, posn->name);
-				else
-					printf("%s %s\n", sha1_to_hex(posn->old_sha1), posn->name);
-			}
-			printf("\n");
-			fflush(stdout);
+		} else if (!strcmp(buf.buf, "list") || !prefixcmp(buf.buf, "list ")) {
+			output_refs(get_refs());
+
+		} else if (!prefixcmp(buf.buf, "push ")) {
+			parse_push(&buf);
+
 		} else if (!prefixcmp(buf.buf, "option ")) {
 			char *name = buf.buf + strlen("option ");
 			char *value = strchr(name, ' ');
@@ -272,6 +344,7 @@ int main(int argc, const char **argv)
 		} else if (!strcmp(buf.buf, "capabilities")) {
 			printf("fetch\n");
 			printf("option\n");
+			printf("push\n");
 			printf("\n");
 			fflush(stdout);
 		} else {
diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
index f4a2cf6..09edd23 100755
--- a/t/t5540-http-push.sh
+++ b/t/t5540-http-push.sh
@@ -36,6 +36,7 @@ test_expect_success 'setup remote repository' '
 	cd test_repo.git &&
 	git --bare update-server-info &&
 	mv hooks/post-update.sample hooks/post-update &&
+	ORIG_HEAD=$(git rev-parse --verify HEAD) &&
 	cd - &&
 	mv test_repo.git "$HTTPD_DOCUMENT_ROOT_PATH"
 '
@@ -45,7 +46,7 @@ test_expect_success 'clone remote repository' '
 	git clone $HTTPD_URL/test_repo.git test_repo_clone
 '
 
-test_expect_failure 'push to remote repository with packed refs' '
+test_expect_success 'push to remote repository with packed refs' '
 	cd "$ROOT_PATH"/test_repo_clone &&
 	: >path2 &&
 	git add path2 &&
@@ -57,11 +58,15 @@ test_expect_failure 'push to remote repository with packed refs' '
 	 test $HEAD = $(git rev-parse --verify HEAD))
 '
 
-test_expect_success ' push to remote repository with unpacked refs' '
+test_expect_failure 'push already up-to-date' '
+	git push
+'
+
+test_expect_success 'push to remote repository with unpacked refs' '
 	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
 	 rm packed-refs &&
-	 git update-ref refs/heads/master \
-		0c973ae9bd51902a28466f3850b543fa66a6aaf4) &&
+	 git update-ref refs/heads/master $ORIG_HEAD &&
+	 git --bare update-server-info) &&
 	git push &&
 	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
 	 test $HEAD = $(git rev-parse --verify HEAD))
@@ -113,7 +118,6 @@ test_expect_success 'create and delete remote branch' '
 	git push origin dev &&
 	git fetch &&
 	git push origin :dev &&
-	git branch -d -r origin/dev &&
 	git fetch &&
 	test_must_fail git show-ref --verify refs/remotes/origin/dev
 '
diff --git a/transport-helper.c b/transport-helper.c
index 577abc6..16c6641 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -1,6 +1,6 @@
 #include "cache.h"
 #include "transport.h"
-
+#include "quote.h"
 #include "run-command.h"
 #include "commit.h"
 #include "diff.h"
@@ -13,7 +13,8 @@ struct helper_data
 	struct child_process *helper;
 	FILE *out;
 	unsigned fetch : 1,
-		option : 1;
+		option : 1,
+		push : 1;
 };
 
 static struct child_process *get_helper(struct transport *transport)
@@ -52,6 +53,8 @@ static struct child_process *get_helper(struct transport *transport)
 			data->fetch = 1;
 		if (!strcmp(buf.buf, "option"))
 			data->option = 1;
+		if (!strcmp(buf.buf, "push"))
+			data->push = 1;
 	}
 	return data->helper;
 }
@@ -214,6 +217,130 @@ static int fetch(struct transport *transport,
 	return -1;
 }
 
+static int push_refs(struct transport *transport,
+		struct ref *remote_refs, int flags)
+{
+	int force_all = flags & TRANSPORT_PUSH_FORCE;
+	int mirror = flags & TRANSPORT_PUSH_MIRROR;
+	struct helper_data *data = transport->data;
+	struct strbuf buf = STRBUF_INIT;
+	struct child_process *helper;
+	struct ref *ref;
+
+	if (!remote_refs)
+		return 0;
+
+	helper = get_helper(transport);
+	if (!data->push)
+		return 1;
+
+	for (ref = remote_refs; ref; ref = ref->next) {
+		if (ref->peer_ref)
+			hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
+		else if (!mirror)
+			continue;
+
+		ref->deletion = is_null_sha1(ref->new_sha1);
+		if (!ref->deletion &&
+			!hashcmp(ref->old_sha1, ref->new_sha1)) {
+			ref->status = REF_STATUS_UPTODATE;
+			continue;
+		}
+
+		if (force_all)
+			ref->force = 1;
+
+		strbuf_addstr(&buf, "push ");
+		if (!ref->deletion) {
+			if (ref->force)
+				strbuf_addch(&buf, '+');
+			if (ref->peer_ref)
+				strbuf_addstr(&buf, ref->peer_ref->name);
+			else
+				strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
+		}
+		strbuf_addch(&buf, ':');
+		strbuf_addstr(&buf, ref->name);
+		strbuf_addch(&buf, '\n');
+	}
+
+	transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
+	standard_options(transport);
+
+	if (flags & TRANSPORT_PUSH_DRY_RUN) {
+		if (set_helper_option(transport, "dry-run", "true") != 0)
+			die("helper %s does not support dry-run", data->name);
+	}
+
+	strbuf_addch(&buf, '\n');
+	if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
+		exit(128);
+
+	ref = remote_refs;
+	while (1) {
+		char *refname, *msg;
+		int status;
+
+		strbuf_reset(&buf);
+		if (strbuf_getline(&buf, data->out, '\n') == EOF)
+			exit(128); /* child died, message supplied already */
+		if (!buf.len)
+			break;
+
+		if (!prefixcmp(buf.buf, "ok ")) {
+			status = REF_STATUS_OK;
+			refname = buf.buf + 3;
+		} else if (!prefixcmp(buf.buf, "error ")) {
+			status = REF_STATUS_REMOTE_REJECT;
+			refname = buf.buf + 6;
+		} else
+			die("expected ok/error, helper said '%s'\n", buf.buf);
+
+		msg = strchr(refname, ' ');
+		if (msg) {
+			struct strbuf msg_buf = STRBUF_INIT;
+			const char *end;
+
+			*msg++ = '\0';
+			if (!unquote_c_style(&msg_buf, msg, &end))
+				msg = strbuf_detach(&msg_buf, NULL);
+			else
+				msg = xstrdup(msg);
+			strbuf_release(&msg_buf);
+
+			if (!strcmp(msg, "no match")) {
+				status = REF_STATUS_NONE;
+				free(msg);
+				msg = NULL;
+			}
+			else if (!strcmp(msg, "up to date")) {
+				status = REF_STATUS_UPTODATE;
+				free(msg);
+				msg = NULL;
+			}
+			else if (!strcmp(msg, "non-fast forward")) {
+				status = REF_STATUS_REJECT_NONFASTFORWARD;
+				free(msg);
+				msg = NULL;
+			}
+		}
+
+		if (ref)
+			ref = find_ref_by_name(ref, refname);
+		if (!ref)
+			ref = find_ref_by_name(remote_refs, refname);
+		if (!ref) {
+			warning("helper reported unexpected status of %s", refname);
+			continue;
+		}
+
+		ref->status = status;
+		ref->remote_status = msg;
+	}
+	strbuf_release(&buf);
+	return 0;
+}
+
 static struct ref *get_refs_list(struct transport *transport, int for_push)
 {
 	struct helper_data *data = transport->data;
@@ -225,7 +352,10 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 
 	helper = get_helper(transport);
 
-	write_str_in_full(helper->in, "list\n");
+	if (data->push && for_push)
+		write_str_in_full(helper->in, "list for-push\n");
+	else
+		write_str_in_full(helper->in, "list\n");
 
 	while (1) {
 		char *eov, *eon;
@@ -266,6 +396,7 @@ int transport_helper_init(struct transport *transport, const char *name)
 	transport->set_option = set_helper_option;
 	transport->get_refs_list = get_refs_list;
 	transport->fetch = fetch;
+	transport->push_refs = push_refs;
 	transport->disconnect = disconnect_helper;
 	return 0;
 }
diff --git a/transport.c b/transport.c
index 644a30a..6d9652d 100644
--- a/transport.c
+++ b/transport.c
@@ -349,35 +349,6 @@ static int rsync_transport_push(struct transport *transport,
 	return result;
 }
 
-#ifndef NO_CURL
-static int curl_transport_push(struct transport *transport, int refspec_nr, const char **refspec, int flags)
-{
-	const char **argv;
-	int argc;
-
-	if (flags & TRANSPORT_PUSH_MIRROR)
-		return error("http transport does not support mirror mode");
-
-	argv = xmalloc((refspec_nr + 12) * sizeof(char *));
-	argv[0] = "http-push";
-	argc = 1;
-	if (flags & TRANSPORT_PUSH_ALL)
-		argv[argc++] = "--all";
-	if (flags & TRANSPORT_PUSH_FORCE)
-		argv[argc++] = "--force";
-	if (flags & TRANSPORT_PUSH_DRY_RUN)
-		argv[argc++] = "--dry-run";
-	if (flags & TRANSPORT_PUSH_VERBOSE)
-		argv[argc++] = "--verbose";
-	argv[argc++] = transport->url;
-	while (refspec_nr--)
-		argv[argc++] = *refspec++;
-	argv[argc] = NULL;
-	return !!run_command_v_opt(argv, RUN_GIT_CMD);
-}
-
-#endif
-
 struct bundle_transport_data {
 	int fd;
 	struct bundle_header header;
@@ -826,8 +797,6 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		transport_helper_init(ret, "curl");
 #ifdef NO_CURL
 		error("git was compiled without libcurl support.");
-#else
-		ret->push = curl_transport_push;
 #endif
 
 	} else if (is_local(url) && is_file(url)) {
-- 
1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 11/26] Move WebDAV HTTP push under remote-curl

[Tay Ray Chuan]

Hi,

On Thu, Oct 29, 2009 at 8:00 AM, Shawn O. Pearce <spearce@spearce.org> wrote:
>  update http tests according to remote-curl capabilities

it would be great if you could mention the $ORIG_HEAD bit:

 o Use a variable ($ORIG_HEAD) instead of full SHA-1 name.

-- 
Cheers,
Ray Chuan

Re: [RFC PATCH v4 11/26] Move WebDAV HTTP push under remote-curl

[Shawn O. Pearce]

Tay Ray Chuan <rctay89@gmail.com> wrote:
> On Thu, Oct 29, 2009 at 8:00 AM, Shawn O. Pearce <spearce@spearce.org> wrote:
> > ?update http tests according to remote-curl capabilities
> 
> it would be great if you could mention the $ORIG_HEAD bit:
> 
>  o Use a variable ($ORIG_HEAD) instead of full SHA-1 name.

Thanks, added.

-- 
Shawn.

Re: [RFC PATCH v4 11/26] Move WebDAV HTTP push under remote-curl

[Tay Ray Chuan]

Hi,

On Thu, Oct 29, 2009 at 8:00 AM, Shawn O. Pearce <spearce@spearce.org> wrote:
> diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
>[snip]
> @@ -57,11 +58,15 @@ test_expect_failure 'push to remote repository with packed refs' '
>         test $HEAD = $(git rev-parse --verify HEAD))
>  '
>
> -test_expect_success ' push to remote repository with unpacked refs' '
> +test_expect_failure 'push already up-to-date' '
> +       git push
> +'
> +
> +test_expect_success 'push to remote repository with unpacked refs' '
>        (cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
>         rm packed-refs &&
> -        git update-ref refs/heads/master \
> -               0c973ae9bd51902a28466f3850b543fa66a6aaf4) &&
> +        git update-ref refs/heads/master $ORIG_HEAD &&
> +        git --bare update-server-info) &&
>        git push &&
>        (cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
>         test $HEAD = $(git rev-parse --verify HEAD))

Clemens, the following addresses your non-desire to remove the
"unpacked refs" test in your earlier email
<20091025161630.GB8532@localhost>.

Now that the first push in "push to remote repository with packed
refs" succeeds, the "unpacked refs" test is redundant. Since http-push
in that first test already updated /refs/heads/master and /info/refs,
'git update-ref' incorrectly reverts the earlier push, and 'git
update-server-info' is redundant.

-- 
Cheers,
Ray Chuan

Re: [RFC PATCH v4 11/26] Move WebDAV HTTP push under remote-curl

[Clemens Buchacher]

On Sat, Oct 31, 2009 at 12:10:29AM +0800, Tay Ray Chuan wrote:

> Clemens, the following addresses your non-desire to remove the
> "unpacked refs" test in your earlier email
> <20091025161630.GB8532@localhost>.

> Now that the first push in "push to remote repository with packed
> refs" succeeds, the "unpacked refs" test is redundant.

How can the changed result of one test suddenly make another test redundant?
The two are testing different things.

> Since http-push
> in that first test already updated /refs/heads/master and /info/refs,
> 'git update-ref' incorrectly reverts the earlier push, and 'git
> update-server-info' is redundant.

No, 'git update-ref' correctly reverts the earlier push, so we can push again
and 'git update-server-info' is therefore necessary for the test to work
independently of its predecessors result.

Clemens

Re: [RFC PATCH v4 11/26] Move WebDAV HTTP push under remote-curl

[Tay Ray Chuan]

Hi,

On Sat, Oct 31, 2009 at 3:06 AM, Clemens Buchacher <drizzd@aon.at> wrote:
> How can the changed result of one test suddenly make another test redundant?
> The two are testing different things.
>[snip]
> No, 'git update-ref' correctly reverts the earlier push, so we can push again
> and 'git update-server-info' is therefore necessary for the test to work
> independently of its predecessors result.

I said "redundant" because in the first push, we've already 1) updated
/refs/heads/master (which is what the 'git update-ref' here does) and
2) updated /info/refs (which is what the 'git update-server-info' does
and 3) pushed changes. To me, the "unpacked refs" test reads as a
trivial test of http-push's ability to update /refs/heads/master and
/info/refs (something we've already done in the first "packed refs"
test), rather than its pushing per se. Is it your intention to keep
the "unpacked refs" test due to the former?

-- 
Cheers,
Ray Chuan

[RFC PATCH v4 12/26] remote-helpers: return successfully if everything up-to-date

[Shawn O. Pearce]

From: Clemens Buchacher <drizzd@aon.at>

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 t/t5540-http-push.sh |    2 +-
 transport-helper.c   |    2 ++
 2 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
index 09edd23..2ece661 100755
--- a/t/t5540-http-push.sh
+++ b/t/t5540-http-push.sh
@@ -58,7 +58,7 @@ test_expect_success 'push to remote repository with packed refs' '
 	 test $HEAD = $(git rev-parse --verify HEAD))
 '
 
-test_expect_failure 'push already up-to-date' '
+test_expect_success 'push already up-to-date' '
 	git push
 '
 
diff --git a/transport-helper.c b/transport-helper.c
index 16c6641..5078c71 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -263,6 +263,8 @@ static int push_refs(struct transport *transport,
 		strbuf_addstr(&buf, ref->name);
 		strbuf_addch(&buf, '\n');
 	}
+	if (buf.len == 0)
+		return 0;
 
 	transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
 	standard_options(transport);
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 13/26] Git-aware CGI to provide dumb HTTP transport

[Shawn O. Pearce]

The git-http-backend CGI can be configured into any Apache server
using ScriptAlias, such as with the following configuration:

  LoadModule cgi_module /usr/libexec/apache2/mod_cgi.so
  LoadModule alias_module /usr/libexec/apache2/mod_alias.so
  ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/

Repositories are accessed via the translated PATH_INFO.

The CGI is backwards compatible with the dumb client, allowing all
older HTTP clients to continue to download repositories which are
managed by the CGI.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 .gitignore                         |    1 +
 Documentation/git-http-backend.txt |  105 +++++++++++++
 Makefile                           |    1 +
 http-backend.c                     |  290 ++++++++++++++++++++++++++++++++++++
 4 files changed, 397 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/git-http-backend.txt
 create mode 100644 http-backend.c

diff --git a/.gitignore b/.gitignore
index 51a37b1..353d22f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -55,6 +55,7 @@ git-get-tar-commit-id
 git-grep
 git-hash-object
 git-help
+git-http-backend
 git-http-fetch
 git-http-push
 git-imap-send
diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
new file mode 100644
index 0000000..867675f
--- /dev/null
+++ b/Documentation/git-http-backend.txt
@@ -0,0 +1,105 @@
+git-http-backend(1)
+===================
+
+NAME
+----
+git-http-backend - Server side implementation of Git over HTTP
+
+SYNOPSIS
+--------
+[verse]
+'git-http-backend'
+
+DESCRIPTION
+-----------
+A simple CGI program to serve the contents of a Git repository to Git
+clients accessing the repository over http:// and https:// protocols.
+
+By default, only the `upload-pack` service is enabled, which serves
+'git-fetch-pack' and 'git-ls-remote' clients, which are invoked from
+'git-fetch', 'git-pull', and 'git-clone'.
+
+This is ideally suited for read-only updates, i.e., pulling from
+git repositories.
+
+URL TRANSLATION
+---------------
+'git-http-backend' relies on the invoking web server to perform
+URL to path translation, and store the repository path into the
+PATH_TRANSLATED environment variable.  Most web servers will do
+this translation automatically, resolving the suffix after the
+CGI name relative to the server's document root.
+
+EXAMPLES
+--------
+
+Apache 2.x::
+	To serve all Git repositories contained within the '/git/'
+	subdirectory of the DocumentRoot, ensure mod_cgi and
+	mod_alias are enabled, and create a ScriptAlias to the CGI:
++
+----------------------------------------------------------------
+ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/git/
+
+<Directory /usr/libexec/git-core>
+	Options None
+</Directory>
+<Files /usr/libexec/git-core/git-http-backend>
+	Options ExecCGI
+</Files>
+----------------------------------------------------------------
++
+To require authentication for reads, use a Directory
+directive around the repository, or one of its parent directories:
++
+----------------------------------------------------------------
+<Directory /var/www/git/private>
+	AuthType Basic
+	AuthName "Private Git Access"
+	Require group committers
+	...
+</Directory>
+----------------------------------------------------------------
+
+Accelerated static Apache 2.x::
+	Similar to the above, but Apache can be used to return static
+	files that are stored on disk.	On many systems this may
+	be more efficient as Apache can ask the kernel to copy the
+	file contents from the file system directly to the network:
++
+----------------------------------------------------------------
+DocumentRoot /var/www
+
+ScriptAlias /git/        /usr/libexec/git-core/git-http-backend/git/
+Alias       /git_static/ /var/www/git/
+
+RewriteEngine on
+RewriteRule ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$    /git_static/$1 [PT]
+RewriteRule ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.pack)$ /git_static/$1 [PT]
+RewriteRule ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.idx)$  /git_static/$1 [PT]
+----------------------------------------------------------------
+
+
+ENVIRONMENT
+-----------
+'git-http-backend' relies upon the CGI environment variables set
+by the invoking web server, including:
+
+* PATH_TRANSLATED
+* REMOTE_USER
+* REMOTE_ADDR
+* CONTENT_TYPE
+* QUERY_STRING
+* REQUEST_METHOD
+
+Author
+------
+Written by Shawn O. Pearce <spearce@spearce.org>.
+
+Documentation
+--------------
+Documentation by Shawn O. Pearce <spearce@spearce.org>.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Makefile b/Makefile
index fea237b..271c290 100644
--- a/Makefile
+++ b/Makefile
@@ -365,6 +365,7 @@ PROGRAMS += git-show-index$X
 PROGRAMS += git-unpack-file$X
 PROGRAMS += git-upload-pack$X
 PROGRAMS += git-var$X
+PROGRAMS += git-http-backend$X
 
 # List built-in command $C whose implementation cmd_$C() is not in
 # builtin-$C.o but is linked in as part of some other command.
diff --git a/http-backend.c b/http-backend.c
new file mode 100644
index 0000000..374f60d
--- /dev/null
+++ b/http-backend.c
@@ -0,0 +1,290 @@
+#include "cache.h"
+#include "refs.h"
+#include "pkt-line.h"
+#include "object.h"
+#include "tag.h"
+#include "exec_cmd.h"
+
+static const char content_type[] = "Content-Type";
+static const char content_length[] = "Content-Length";
+static const char last_modified[] = "Last-Modified";
+
+static void format_write(int fd, const char *fmt, ...)
+{
+	static char buffer[1024];
+
+	va_list args;
+	unsigned n;
+
+	va_start(args, fmt);
+	n = vsnprintf(buffer, sizeof(buffer), fmt, args);
+	va_end(args);
+	if (n >= sizeof(buffer))
+		die("protocol error: impossibly long line");
+
+	safe_write(fd, buffer, n);
+}
+
+static void http_status(unsigned code, const char *msg)
+{
+	format_write(1, "Status: %u %s\r\n", code, msg);
+}
+
+static void hdr_str(const char *name, const char *value)
+{
+	format_write(1, "%s: %s\r\n", name, value);
+}
+
+static void hdr_int(const char *name, size_t value)
+{
+	format_write(1, "%s: %" PRIuMAX "\r\n", name, value);
+}
+
+static void hdr_date(const char *name, unsigned long when)
+{
+	const char *value = show_date(when, 0, DATE_RFC2822);
+	hdr_str(name, value);
+}
+
+static void hdr_nocache(void)
+{
+	hdr_str("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
+	hdr_str("Pragma", "no-cache");
+	hdr_str("Cache-Control", "no-cache, max-age=0, must-revalidate");
+}
+
+static void hdr_cache_forever(void)
+{
+	unsigned long now = time(NULL);
+	hdr_date("Date", now);
+	hdr_date("Expires", now + 31536000);
+	hdr_str("Cache-Control", "public, max-age=31536000");
+}
+
+static void end_headers(void)
+{
+	safe_write(1, "\r\n", 2);
+}
+
+static NORETURN void not_found(const char *err, ...)
+{
+	va_list params;
+
+	http_status(404, "Not Found");
+	hdr_nocache();
+	end_headers();
+
+	va_start(params, err);
+	if (err && *err)
+		vfprintf(stderr, err, params);
+	va_end(params);
+	exit(0);
+}
+
+static void send_strbuf(const char *type, struct strbuf *buf)
+{
+	hdr_int(content_length, buf->len);
+	hdr_str(content_type, type);
+	end_headers();
+	safe_write(1, buf->buf, buf->len);
+}
+
+static void send_file(const char *the_type, const char *name)
+{
+	const char *p = git_path("%s", name);
+	size_t buf_alloc = 8192;
+	char *buf = xmalloc(buf_alloc);
+	int fd;
+	struct stat sb;
+	size_t size;
+
+	fd = open(p, O_RDONLY);
+	if (fd < 0)
+		not_found("Cannot open '%s': %s", p, strerror(errno));
+	if (fstat(fd, &sb) < 0)
+		die_errno("Cannot stat '%s'", p);
+
+	size = xsize_t(sb.st_size);
+
+	hdr_int(content_length, size);
+	hdr_str(content_type, the_type);
+	hdr_date(last_modified, sb.st_mtime);
+	end_headers();
+
+	while (size) {
+		ssize_t n = xread(fd, buf, buf_alloc);
+		if (n < 0)
+			die_errno("Cannot read '%s'", p);
+		if (!n)
+			break;
+		safe_write(1, buf, n);
+	}
+	close(fd);
+	free(buf);
+}
+
+static void get_text_file(char *name)
+{
+	hdr_nocache();
+	send_file("text/plain", name);
+}
+
+static void get_loose_object(char *name)
+{
+	hdr_cache_forever();
+	send_file("application/x-git-loose-object", name);
+}
+
+static void get_pack_file(char *name)
+{
+	hdr_cache_forever();
+	send_file("application/x-git-packed-objects", name);
+}
+
+static void get_idx_file(char *name)
+{
+	hdr_cache_forever();
+	send_file("application/x-git-packed-objects-toc", name);
+}
+
+static int show_text_ref(const char *name, const unsigned char *sha1,
+	int flag, void *cb_data)
+{
+	struct strbuf *buf = cb_data;
+	struct object *o = parse_object(sha1);
+	if (!o)
+		return 0;
+
+	strbuf_addf(buf, "%s\t%s\n", sha1_to_hex(sha1), name);
+	if (o->type == OBJ_TAG) {
+		o = deref_tag(o, name, 0);
+		if (!o)
+			return 0;
+		strbuf_addf(buf, "%s\t%s^{}\n", sha1_to_hex(o->sha1), name);
+	}
+	return 0;
+}
+
+static void get_info_refs(char *arg)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	for_each_ref(show_text_ref, &buf);
+	hdr_nocache();
+	send_strbuf("text/plain", &buf);
+	strbuf_release(&buf);
+}
+
+static void get_info_packs(char *arg)
+{
+	size_t objdirlen = strlen(get_object_directory());
+	struct strbuf buf = STRBUF_INIT;
+	struct packed_git *p;
+	size_t cnt = 0;
+
+	prepare_packed_git();
+	for (p = packed_git; p; p = p->next) {
+		if (p->pack_local)
+			cnt++;
+	}
+
+	strbuf_grow(&buf, cnt * 53 + 2);
+	for (p = packed_git; p; p = p->next) {
+		if (p->pack_local)
+			strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
+	}
+	strbuf_addch(&buf, '\n');
+
+	hdr_nocache();
+	send_strbuf("text/plain; charset=utf-8", &buf);
+	strbuf_release(&buf);
+}
+
+static NORETURN void die_webcgi(const char *err, va_list params)
+{
+	char buffer[1000];
+
+	http_status(500, "Internal Server Error");
+	hdr_nocache();
+	end_headers();
+
+	vsnprintf(buffer, sizeof(buffer), err, params);
+	fprintf(stderr, "fatal: %s\n", buffer);
+	exit(0);
+}
+
+static struct service_cmd {
+	const char *method;
+	const char *pattern;
+	void (*imp)(char *);
+} services[] = {
+	{"GET", "/HEAD$", get_text_file},
+	{"GET", "/info/refs$", get_info_refs},
+	{"GET", "/objects/info/alternates$", get_text_file},
+	{"GET", "/objects/info/http-alternates$", get_text_file},
+	{"GET", "/objects/info/packs$", get_info_packs},
+	{"GET", "/objects/info/[^/]*$", get_text_file},
+	{"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
+	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
+	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file}
+};
+
+int main(int argc, char **argv)
+{
+	char *method = getenv("REQUEST_METHOD");
+	char *dir = getenv("PATH_TRANSLATED");
+	struct service_cmd *cmd = NULL;
+	char *cmd_arg = NULL;
+	int i;
+
+	git_extract_argv0_path(argv[0]);
+	set_die_routine(die_webcgi);
+
+	if (!method)
+		die("No REQUEST_METHOD from server");
+	if (!strcmp(method, "HEAD"))
+		method = "GET";
+	if (!dir)
+		die("No PATH_TRANSLATED from server");
+
+	for (i = 0; i < ARRAY_SIZE(services); i++) {
+		struct service_cmd *c = &services[i];
+		regex_t re;
+		regmatch_t out[1];
+
+		if (regcomp(&re, c->pattern, REG_EXTENDED))
+			die("Bogus regex in service table: %s", c->pattern);
+		if (!regexec(&re, dir, 1, out, 0)) {
+			size_t n = out[0].rm_eo - out[0].rm_so;
+
+			if (strcmp(method, c->method)) {
+				const char *proto = getenv("SERVER_PROTOCOL");
+				if (proto && !strcmp(proto, "HTTP/1.1"))
+					http_status(405, "Method Not Allowed");
+				else
+					http_status(400, "Bad Request");
+				hdr_nocache();
+				end_headers();
+				return 0;
+			}
+
+			cmd = c;
+			cmd_arg = xmalloc(n);
+			strncpy(cmd_arg, dir + out[0].rm_so + 1, n);
+			cmd_arg[n] = '\0';
+			dir[out[0].rm_so] = 0;
+			break;
+		}
+		regfree(&re);
+	}
+
+	if (!cmd)
+		not_found("Request not supported: '%s'", dir);
+
+	setup_path();
+	if (!enter_repo(dir, 0))
+		not_found("Not a git repository: '%s'", dir);
+
+	cmd->imp(cmd_arg);
+	return 0;
+}
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 14/26] Add stateless RPC options to upload-pack, receive-pack

[Shawn O. Pearce]

When --stateless-rpc is passed as a command line parameter to
upload-pack or receive-pack the programs now assume they may
perform only a single read-write cycle with stdin and stdout.
This fits with the HTTP POST request processing model where a
program may read the request, write a response, and must exit.

When --advertise-refs is passed as a command line parameter only
the initial ref advertisement is output, and the program exits
immediately.  This fits with the HTTP GET request model, where
no request content is received but a response must be produced.

HTTP headers and/or environment are not processed here, but
instead are assumed to be handled by the program invoking
either service backend.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 builtin-receive-pack.c |   26 ++++++++++++++++++++------
 upload-pack.c          |   40 ++++++++++++++++++++++++++++++++++++----
 2 files changed, 56 insertions(+), 10 deletions(-)

diff --git a/builtin-receive-pack.c b/builtin-receive-pack.c
index b771fe9..70ff8c5 100644
--- a/builtin-receive-pack.c
+++ b/builtin-receive-pack.c
@@ -615,6 +615,8 @@ static void add_alternate_refs(void)
 
 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 {
+	int advertise_refs = 0;
+	int stateless_rpc = 0;
 	int i;
 	char *dir = NULL;
 
@@ -623,7 +625,15 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		const char *arg = *argv++;
 
 		if (*arg == '-') {
-			/* Do flag handling here */
+			if (!strcmp(arg, "--advertise-refs")) {
+				advertise_refs = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--stateless-rpc")) {
+				stateless_rpc = 1;
+				continue;
+			}
+
 			usage(receive_pack_usage);
 		}
 		if (dir)
@@ -652,12 +662,16 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		" report-status delete-refs ofs-delta " :
 		" report-status delete-refs ";
 
-	add_alternate_refs();
-	write_head_info();
-	clear_extra_refs();
+	if (advertise_refs || !stateless_rpc) {
+		add_alternate_refs();
+		write_head_info();
+		clear_extra_refs();
 
-	/* EOF */
-	packet_flush(1);
+		/* EOF */
+		packet_flush(1);
+	}
+	if (advertise_refs)
+		return 0;
 
 	read_head_info();
 	if (commands) {
diff --git a/upload-pack.c b/upload-pack.c
index f1dc3a3..70badcf 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -39,6 +39,8 @@ static unsigned int timeout;
  */
 static int use_sideband;
 static int debug_fd;
+static int advertise_refs;
+static int stateless_rpc;
 
 static void reset_timeout(void)
 {
@@ -509,6 +511,8 @@ static int get_common_commits(void)
 		if (!len) {
 			if (have_obj.nr == 0 || multi_ack)
 				packet_write(1, "NAK\n");
+			if (stateless_rpc)
+				exit(0);
 			continue;
 		}
 		strip(line, len);
@@ -710,12 +714,32 @@ static int send_ref(const char *refname, const unsigned char *sha1, int flag, vo
 	return 0;
 }
 
+static int mark_our_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *o = parse_object(sha1);
+	if (!o)
+		die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
+	if (!(o->flags & OUR_REF)) {
+		o->flags |= OUR_REF;
+		nr_our_refs++;
+	}
+	return 0;
+}
+
 static void upload_pack(void)
 {
-	reset_timeout();
-	head_ref(send_ref, NULL);
-	for_each_ref(send_ref, NULL);
-	packet_flush(1);
+	if (advertise_refs || !stateless_rpc) {
+		reset_timeout();
+		head_ref(send_ref, NULL);
+		for_each_ref(send_ref, NULL);
+		packet_flush(1);
+	} else {
+		head_ref(mark_our_ref, NULL);
+		for_each_ref(mark_our_ref, NULL);
+	}
+	if (advertise_refs)
+		return;
+
 	receive_needs();
 	if (want_obj.nr) {
 		get_common_commits();
@@ -737,6 +761,14 @@ int main(int argc, char **argv)
 
 		if (arg[0] != '-')
 			break;
+		if (!strcmp(arg, "--advertise-refs")) {
+			advertise_refs = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--stateless-rpc")) {
+			stateless_rpc = 1;
+			continue;
+		}
 		if (!strcmp(arg, "--strict")) {
 			strict = 1;
 			continue;
-- 
1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 14/26] Add stateless RPC options to upload-pack, receive-pack

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> When --stateless-rpc is passed as a command line parameter to
> upload-pack or receive-pack the programs now assume they may
> perform only a single read-write cycle with stdin and stdout.
> This fits with the HTTP POST request processing model where a
> program may read the request, write a response, and must exit.
>
> When --advertise-refs is passed as a command line parameter only
> the initial ref advertisement is output, and the program exits
> immediately.  This fits with the HTTP GET request model, where
> no request content is received but a response must be produced.

Is the idea to first run with --advertise-refs to get the set of refs, and
then doing another, separate run with --stateless-rpc, assuming that the
refs the other end advertised does not change in the meantime, to conclude
the business?

I suspect that two separate invocations on a (supposedly) single
repository made back-to-back can produce an inconsistent response in
verious situations (e.g. somebody pushing in the middle, or the same
hostname served by more than one mirrors) and the other end can get
confused.

I do not think there is any way to avoid it, short of adding to the second
request some "cookie" that allows the second requestee to verify that the
request is based on what he would give to the requester if this request
were the first step of the request made to him, iow, his state did not
change in the middle since the first request was made (either to him or to
the equivalent mirror sitting next to himm).

I wouldn't worry too much about this if the only negative effect could be
that the requestor's second request may result in an error, but I am
wondering if this can be used to attack the requestee.

Re: [RFC PATCH v4 14/26] Add stateless RPC options to upload-pack, receive-pack

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> 
> > When --stateless-rpc is passed [...]
> > When --advertise-refs is passed [...]
> 
> Is the idea to first run with --advertise-refs to get the set of refs, and
> then doing another, separate run with --stateless-rpc, assuming that the
> refs the other end advertised does not change in the meantime, to conclude
> the business?

Yes.
 
> I suspect that two separate invocations on a (supposedly) single
> repository made back-to-back can produce an inconsistent response in
> verious situations (e.g. somebody pushing in the middle, or the same
> hostname served by more than one mirrors) and the other end can get
> confused.

Yes, that can happen.

> I do not think there is any way to avoid it, short of adding to the second
> request some "cookie" that allows the second requestee to verify that the
> request is based on what he would give to the requester if this request
> were the first step of the request made to him, iow, his state did not
> change in the middle since the first request was made (either to him or to
> the equivalent mirror sitting next to himm).

There isn't a lot we can do, you are right.

One approach is to use an HMAC and sign each advertised SHA-1
during the initial --advertise-refs phase.  Requesters then present
the SHA-1 and the HAMC signature in each "want" line, and the
--stateless-rpc phase validates the signatures to ensure they came
from a trusted party.

The major problem with this approach is the private key management.
All mirrors of that repository need to have a common private key
so they can generate and later verify that HMAC signature.  This is
additional complexity, for perhaps not much gain.

A different approach is to have the --stateless-rpc phase validate
the want lines against its refs (like we do now), but if the validate
fails (no ref exactly matches) support walking backwards through the
last few records in the reflog, or through that ref's own history
for a few hundred commits, to see if the want SHA-1 appears in the
recent prior past.

Obviously when walking the reflog we would need to use a time bound,
e.g. "only examine last record if more recent than 5 minutes ago".
This way a force push to erase something will still erase it, but
a client who had just recently observed the prior SHA-1 can still
complete their fetch request, just as with native git:// they could
do that due to the prior SHA-1 being held in the git-upload-pack's
private memory.

Also, obviously when walking the commit history of a ref (to see
if the want'd SHA-1 is merged into one or more reachable refs)
we don't want to walk backwards too far, as it costs CPU time on
the server side, but we also don't want to walk too few commits.
E.g. pushes for me tend to be in the 20 commit range, while Linus
probably pushes a thousand commits or more in a single merge.
Finding the right balance may be tricky.

> I wouldn't worry too much about this if the only negative effect could be
> that the requestor's second request may result in an error, but I am
> wondering if this can be used to attack the requestee.

I don't think it can be used to attack the server.  The only impact
I can see is the client gets confused and gets an error response
from the server when the server aborts due to the invalid "want"
line sent during that 2nd (or any subsequent) request.

-- 
Shawn.

Re: [RFC PATCH v4 14/26] Add stateless RPC options to upload-pack, receive-pack

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> One approach is to use an HMAC and sign each advertised SHA-1
> during the initial --advertise-refs phase.  Requesters then present
> the SHA-1 and the HAMC signature in each "want" line, and the
> --stateless-rpc phase validates the signatures to ensure they came
> from a trusted party.
>
> The major problem with this approach is the private key management.
> All mirrors of that repository need to have a common private key
> so they can generate and later verify that HMAC signature.  This is
> additional complexity, for perhaps not much gain.

I am not worried so much about malicious clients getting themselves
confused.  One simple alternative would be to internally recreate the
response the requestee would send if it were the first phase request upon
receiving the request for the second phase---then you take an SHA-1 hash
of it.  In the second phase request have the requestor include the SHA-1
hash of what it received in the response to its first phase request, and
the requestee can make sure they match.  No per-ref signing nor secret key
management is necessary, and it would let the requestor retry if you allow
the response to the second phase request to be "your request is stale, try
again".

> A different approach is to have the --stateless-rpc phase validate
> the want lines against its refs (like we do now), but if the validate
> fails (no ref exactly matches) support walking backwards through the
> last few records in the reflog, or through that ref's own history
> for a few hundred commits, to see if the want SHA-1 appears in the
> recent prior past.
>
> Obviously when walking the reflog we would need to use a time bound,
> e.g. "only examine last record if more recent than 5 minutes ago".

I think that is probably too much complexity for too little gain.  I think
detecting stale request and having requestor retry would be sufficient,
and validating the want lines as we already do would give the same level
of assurance as "check against the hash of first phase response" I
outlined above, and would be much simpler thus more robust.

Re: [RFC PATCH v4 14/26] Add stateless RPC options to upload-pack, receive-pack

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> I think that is probably too much complexity for too little gain.  I think
> detecting stale request and having requestor retry would be sufficient,
> and validating the want lines as we already do would give the same level
> of assurance as "check against the hash of first phase response" I
> outlined above, and would be much simpler thus more robust.

Ack.

I think what we want here is to just add an "ERR invalid want"
message just before disconnecting when the client gives us a SHA-1
which we don't point to directly.  Client implementations can choose
how to handle this error.  They could retry from the beginning,
or they could abort.

-- 
Shawn.

[RFC PATCH v4 15/26] Smart fetch and push over HTTP: server side

[Shawn O. Pearce]

Requests for $GIT_URL/git-receive-pack and $GIT_URL/git-upload-pack
are forwarded to the corresponding backend process by directly
executing it and leaving stdin and stdout connected to the invoking
web server.  Prior to starting the backend process the HTTP response
headers are sent, thereby freeing the backend from needing to know
about the HTTP protocol.

Requests that are encoded with Content-Encoding: gzip are
automatically inflated before being streamed into the backend.
This is primarily useful for the git-upload-pack backend, which
receives highly repetitive text data from clients that easily
compresses to 50% of its original size.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-http-backend.txt |   39 +++++-
 http-backend.c                     |  324 +++++++++++++++++++++++++++++++++++-
 2 files changed, 359 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index 867675f..022a243 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -22,6 +22,23 @@ By default, only the `upload-pack` service is enabled, which serves
 This is ideally suited for read-only updates, i.e., pulling from
 git repositories.
 
+SERVICES
+--------
+These services can be enabled/disabled using the per-repository
+configuration file:
+
+http.uploadpack::
+	This serves 'git-fetch-pack' and 'git-ls-remote' clients.
+	It is enabled by default, but a repository can disable it
+	by setting this configuration item to `false`.
+
+http.receivepack::
+	This serves 'git-send-pack' clients, allowing push.  It is
+	disabled by default for anonymous users, and enabled by
+	default for users authenticated by the web server.  It can be
+	disabled by setting this item to `false`, or enabled for all
+	users, including anonymous users, by setting it to `true`.
+
 URL TRANSLATION
 ---------------
 'git-http-backend' relies on the invoking web server to perform
@@ -49,7 +66,19 @@ ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/git/
 </Files>
 ----------------------------------------------------------------
 +
-To require authentication for reads, use a Directory
+To enable anonymous read access but authenticated write access,
+require authorization with a LocationMatch directive:
++
+----------------------------------------------------------------
+<LocationMatch ".*/git-receive-pack$">
+	AuthType Basic
+	AuthName "Git Access"
+	Require group committers
+	...
+</LocationMatch>
+----------------------------------------------------------------
++
+To require authentication for both reads and writes, use a Directory
 directive around the repository, or one of its parent directories:
 +
 ----------------------------------------------------------------
@@ -92,6 +121,14 @@ by the invoking web server, including:
 * QUERY_STRING
 * REQUEST_METHOD
 
+The backend process sets GIT_COMMITTER_NAME to '$REMOTE_USER' and
+GIT_COMMITTER_EMAIL to '$\{REMOTE_USER}@http.$\{REMOTE_ADDR\}',
+ensuring that any reflogs created by 'git-receive-pack' contain some
+identifying information of the remote user who performed the push.
+
+All CGI environment variables are available to each of the hooks
+invoked by the 'git-receive-pack'.
+
 Author
 ------
 Written by Shawn O. Pearce <spearce@spearce.org>.
diff --git a/http-backend.c b/http-backend.c
index 374f60d..67030b5 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -4,11 +4,109 @@
 #include "object.h"
 #include "tag.h"
 #include "exec_cmd.h"
+#include "run-command.h"
+#include "string-list.h"
 
 static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
 static const char last_modified[] = "Last-Modified";
 
+static struct string_list *query_params;
+
+struct rpc_service {
+	const char *name;
+	const char *config_name;
+	signed enabled : 2;
+};
+
+static struct rpc_service rpc_service[] = {
+	{ "upload-pack", "uploadpack", 1 },
+	{ "receive-pack", "receivepack", -1 },
+};
+
+static int decode_char(const char *q)
+{
+	int i;
+	unsigned char val = 0;
+	for (i = 0; i < 2; i++) {
+		unsigned char c = *q++;
+		val <<= 4;
+		if (c >= '0' && c <= '9')
+			val += c - '0';
+		else if (c >= 'a' && c <= 'f')
+			val += c - 'a' + 10;
+		else if (c >= 'A' && c <= 'F')
+			val += c - 'A' + 10;
+		else
+			return -1;
+	}
+	return val;
+}
+
+static char *decode_parameter(const char **query, int is_name)
+{
+	const char *q = *query;
+	struct strbuf out;
+
+	strbuf_init(&out, 16);
+	do {
+		unsigned char c = *q;
+
+		if (!c)
+			break;
+		if (c == '&' || (is_name && c == '=')) {
+			q++;
+			break;
+		}
+
+		if (c == '%') {
+			int val = decode_char(q + 1);
+			if (0 <= val) {
+				strbuf_addch(&out, val);
+				q += 3;
+				continue;
+			}
+		}
+
+		if (c == '+')
+			strbuf_addch(&out, ' ');
+		else
+			strbuf_addch(&out, c);
+		q++;
+	} while (1);
+	*query = q;
+	return strbuf_detach(&out, NULL);
+}
+
+static struct string_list *get_parameters(void)
+{
+	if (!query_params) {
+		const char *query = getenv("QUERY_STRING");
+
+		query_params = xcalloc(1, sizeof(*query_params));
+		while (query && *query) {
+			char *name = decode_parameter(&query, 1);
+			char *value = decode_parameter(&query, 0);
+			struct string_list_item *i;
+
+			i = string_list_lookup(name, query_params);
+			if (!i)
+				i = string_list_insert(name, query_params);
+			else
+				free(i->util);
+			i->util = value;
+		}
+	}
+	return query_params;
+}
+
+static const char *get_parameter(const char *name)
+{
+	struct string_list_item *i;
+	i = string_list_lookup(name, get_parameters());
+	return i ? i->util : NULL;
+}
+
 static void format_write(int fd, const char *fmt, ...)
 {
 	static char buffer[1024];
@@ -81,6 +179,21 @@ static NORETURN void not_found(const char *err, ...)
 	exit(0);
 }
 
+static NORETURN void forbidden(const char *err, ...)
+{
+	va_list params;
+
+	http_status(403, "Forbidden");
+	hdr_nocache();
+	end_headers();
+
+	va_start(params, err);
+	if (err && *err)
+		vfprintf(stderr, err, params);
+	va_end(params);
+	exit(0);
+}
+
 static void send_strbuf(const char *type, struct strbuf *buf)
 {
 	hdr_int(content_length, buf->len);
@@ -147,6 +260,145 @@ static void get_idx_file(char *name)
 	send_file("application/x-git-packed-objects-toc", name);
 }
 
+static int http_config(const char *var, const char *value, void *cb)
+{
+	struct rpc_service *svc = cb;
+
+	if (!prefixcmp(var, "http.") &&
+	    !strcmp(var + 5, svc->config_name)) {
+		svc->enabled = git_config_bool(var, value);
+		return 0;
+	}
+
+	/* we are not interested in parsing any other configuration here */
+	return 0;
+}
+
+static struct rpc_service *select_service(const char *name)
+{
+	struct rpc_service *svc = NULL;
+	int i;
+
+	if (prefixcmp(name, "git-"))
+		forbidden("Unsupported service: '%s'", name);
+
+	for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
+		struct rpc_service *s = &rpc_service[i];
+		if (!strcmp(s->name, name + 4)) {
+			svc = s;
+			break;
+		}
+	}
+
+	if (!svc)
+		forbidden("Unsupported service: '%s'", name);
+
+	git_config(http_config, svc);
+	if (svc->enabled < 0) {
+		const char *user = getenv("REMOTE_USER");
+		svc->enabled = (user && *user) ? 1 : 0;
+	}
+	if (!svc->enabled)
+		forbidden("Service not enabled: '%s'", svc->name);
+	return svc;
+}
+
+static void inflate_request(const char *prog_name, int out)
+{
+	z_stream stream;
+	unsigned char in_buf[8192];
+	unsigned char out_buf[8192];
+	unsigned long cnt = 0;
+	int ret;
+
+	memset(&stream, 0, sizeof(stream));
+	ret = inflateInit2(&stream, (15 + 16));
+	if (ret != Z_OK)
+		die("cannot start zlib inflater, zlib err %d", ret);
+
+	while (1) {
+		ssize_t n = xread(0, in_buf, sizeof(in_buf));
+		if (n <= 0)
+			die("request ended in the middle of the gzip stream");
+
+		stream.next_in = in_buf;
+		stream.avail_in = n;
+
+		while (0 < stream.avail_in) {
+			int ret;
+
+			stream.next_out = out_buf;
+			stream.avail_out = sizeof(out_buf);
+
+			ret = inflate(&stream, Z_NO_FLUSH);
+			if (ret != Z_OK && ret != Z_STREAM_END)
+				die("zlib error inflating request, result %d", ret);
+
+			n = stream.total_out - cnt;
+			if (write_in_full(out, out_buf, n) != n)
+				die("%s aborted reading request", prog_name);
+			cnt += n;
+
+			if (ret == Z_STREAM_END)
+				goto done;
+		}
+	}
+
+done:
+	inflateEnd(&stream);
+	close(out);
+}
+
+static void run_service(const char **argv)
+{
+	const char *encoding = getenv("HTTP_CONTENT_ENCODING");
+	const char *user = getenv("REMOTE_USER");
+	const char *host = getenv("REMOTE_ADDR");
+	char *env[3];
+	struct strbuf buf = STRBUF_INIT;
+	int gzipped_request = 0;
+	struct child_process cld;
+
+	if (encoding && !strcmp(encoding, "gzip"))
+		gzipped_request = 1;
+	else if (encoding && !strcmp(encoding, "x-gzip"))
+		gzipped_request = 1;
+
+	if (!user || !*user)
+		user = "anonymous";
+	if (!host || !*host)
+		host = "(none)";
+
+	memset(&env, 0, sizeof(env));
+	strbuf_addf(&buf, "GIT_COMMITTER_NAME=%s", user);
+	env[0] = strbuf_detach(&buf, NULL);
+
+	strbuf_addf(&buf, "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
+	env[1] = strbuf_detach(&buf, NULL);
+	env[2] = NULL;
+
+	memset(&cld, 0, sizeof(cld));
+	cld.argv = argv;
+	cld.env = (const char *const *)env;
+	if (gzipped_request)
+		cld.in = -1;
+	cld.git_cmd = 1;
+	if (start_command(&cld))
+		exit(1);
+
+	close(1);
+	if (gzipped_request)
+		inflate_request(argv[0], cld.in);
+	else
+		close(0);
+
+	if (finish_command(&cld))
+		exit(1);
+	free(env[0]);
+	free(env[1]);
+	strbuf_release(&buf);
+}
+
 static int show_text_ref(const char *name, const unsigned char *sha1,
 	int flag, void *cb_data)
 {
@@ -167,11 +419,32 @@ static int show_text_ref(const char *name, const unsigned char *sha1,
 
 static void get_info_refs(char *arg)
 {
+	const char *service_name = get_parameter("service");
 	struct strbuf buf = STRBUF_INIT;
 
-	for_each_ref(show_text_ref, &buf);
 	hdr_nocache();
-	send_strbuf("text/plain", &buf);
+
+	if (service_name) {
+		const char *argv[] = {NULL /* service name */,
+			"--stateless-rpc", "--advertise-refs",
+			".", NULL};
+		struct rpc_service *svc = select_service(service_name);
+
+		strbuf_addf(&buf, "application/x-git-%s-advertisement",
+			svc->name);
+		hdr_str(content_type, buf.buf);
+		end_headers();
+
+		packet_write(1, "# service=git-%s\n", svc->name);
+		packet_flush(1);
+
+		argv[0] = svc->name;
+		run_service(argv);
+
+	} else {
+		for_each_ref(show_text_ref, &buf);
+		send_strbuf("text/plain", &buf);
+	}
 	strbuf_release(&buf);
 }
 
@@ -200,6 +473,48 @@ static void get_info_packs(char *arg)
 	strbuf_release(&buf);
 }
 
+static void check_content_type(const char *accepted_type)
+{
+	const char *actual_type = getenv("CONTENT_TYPE");
+
+	if (!actual_type)
+		actual_type = "";
+
+	if (strcmp(actual_type, accepted_type)) {
+		http_status(415, "Unsupported Media Type");
+		hdr_nocache();
+		end_headers();
+		format_write(1,
+			"Expected POST with Content-Type '%s',"
+			" but received '%s' instead.\n",
+			accepted_type, actual_type);
+		exit(0);
+	}
+}
+
+static void service_rpc(char *service_name)
+{
+	const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
+	struct rpc_service *svc = select_service(service_name);
+	struct strbuf buf = STRBUF_INIT;
+
+	strbuf_reset(&buf);
+	strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
+	check_content_type(buf.buf);
+
+	hdr_nocache();
+
+	strbuf_reset(&buf);
+	strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
+	hdr_str(content_type, buf.buf);
+
+	end_headers();
+
+	argv[0] = svc->name;
+	run_service(argv);
+	strbuf_release(&buf);
+}
+
 static NORETURN void die_webcgi(const char *err, va_list params)
 {
 	char buffer[1000];
@@ -226,7 +541,10 @@ static struct service_cmd {
 	{"GET", "/objects/info/[^/]*$", get_text_file},
 	{"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
-	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file}
+	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
+
+	{"POST", "/git-upload-pack$", service_rpc},
+	{"POST", "/git-receive-pack$", service_rpc}
 };
 
 int main(int argc, char **argv)
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 16/26] http-backend: add GIT_PROJECT_ROOT environment var

[Shawn O. Pearce]

From: Mark Lodato <lodatom@gmail.com>

Add a new environment variable, GIT_PROJECT_ROOT, to override the
method of using PATH_TRANSLATED to find the git repository on disk.
This makes it much easier to configure the web server, especially when
the web server's DocumentRoot does not contain the git repositories,
which is the usual case.

Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-http-backend.txt |   39 +++++++++++++++--------------------
 http-backend.c                     |   25 ++++++++++++++++++++--
 2 files changed, 39 insertions(+), 25 deletions(-)

diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index 022a243..99dbbfb 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -41,29 +41,24 @@ http.receivepack::
 
 URL TRANSLATION
 ---------------
-'git-http-backend' relies on the invoking web server to perform
-URL to path translation, and store the repository path into the
-PATH_TRANSLATED environment variable.  Most web servers will do
-this translation automatically, resolving the suffix after the
-CGI name relative to the server's document root.
+To determine the location of the repository on disk, 'git-http-backend'
+concatenates the environment variables PATH_INFO, which is set
+automatically by the web server, and GIT_PROJECT_ROOT, which must be set
+manually in the web server configuration.  If GIT_PROJECT_ROOT is not
+set, 'git-http-backend' reads PATH_TRANSLATED, which is also set
+automatically by the web server.
 
 EXAMPLES
 --------
 
 Apache 2.x::
-	To serve all Git repositories contained within the '/git/'
-	subdirectory of the DocumentRoot, ensure mod_cgi and
-	mod_alias are enabled, and create a ScriptAlias to the CGI:
+	Ensure mod_cgi, mod_alias, and mod_env are enabled, set
+	GIT_PROJECT_ROOT (or DocumentRoot) appropriately, and
+	create a ScriptAlias to the CGI:
 +
 ----------------------------------------------------------------
-ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/git/
-
-<Directory /usr/libexec/git-core>
-	Options None
-</Directory>
-<Files /usr/libexec/git-core/git-http-backend>
-	Options ExecCGI
-</Files>
+SetEnv GIT_PROJECT_ROOT /var/www/git
+ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
 ----------------------------------------------------------------
 +
 To enable anonymous read access but authenticated write access,
@@ -78,16 +73,16 @@ require authorization with a LocationMatch directive:
 </LocationMatch>
 ----------------------------------------------------------------
 +
-To require authentication for both reads and writes, use a Directory
+To require authentication for both reads and writes, use a Location
 directive around the repository, or one of its parent directories:
 +
 ----------------------------------------------------------------
-<Directory /var/www/git/private>
+<Location /git/private>
 	AuthType Basic
 	AuthName "Private Git Access"
 	Require group committers
 	...
-</Directory>
+</Location>
 ----------------------------------------------------------------
 
 Accelerated static Apache 2.x::
@@ -97,9 +92,9 @@ Accelerated static Apache 2.x::
 	file contents from the file system directly to the network:
 +
 ----------------------------------------------------------------
-DocumentRoot /var/www
+SetEnv GIT_PROJECT_ROOT /var/www/git
 
-ScriptAlias /git/        /usr/libexec/git-core/git-http-backend/git/
+ScriptAlias /git/        /usr/libexec/git-core/git-http-backend/
 Alias       /git_static/ /var/www/git/
 
 RewriteEngine on
@@ -114,7 +109,7 @@ ENVIRONMENT
 'git-http-backend' relies upon the CGI environment variables set
 by the invoking web server, including:
 
-* PATH_TRANSLATED
+* PATH_INFO (if GIT_PROJECT_ROOT is set, otherwise PATH_TRANSLATED)
 * REMOTE_USER
 * REMOTE_ADDR
 * CONTENT_TYPE
diff --git a/http-backend.c b/http-backend.c
index 67030b5..8e5c0a2 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -528,6 +528,26 @@ static NORETURN void die_webcgi(const char *err, va_list params)
 	exit(0);
 }
 
+static char* getdir(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	char *pathinfo = getenv("PATH_INFO");
+	char *root = getenv("GIT_PROJECT_ROOT");
+	char *path = getenv("PATH_TRANSLATED");
+
+	if (root && *root) {
+		if (!pathinfo || !*pathinfo)
+			die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
+		strbuf_addstr(&buf, root);
+		strbuf_addstr(&buf, pathinfo);
+		return strbuf_detach(&buf, NULL);
+	} else if (path && *path) {
+		return xstrdup(path);
+	} else
+		die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
+	return NULL;
+}
+
 static struct service_cmd {
 	const char *method;
 	const char *pattern;
@@ -550,7 +570,7 @@ static struct service_cmd {
 int main(int argc, char **argv)
 {
 	char *method = getenv("REQUEST_METHOD");
-	char *dir = getenv("PATH_TRANSLATED");
+	char *dir;
 	struct service_cmd *cmd = NULL;
 	char *cmd_arg = NULL;
 	int i;
@@ -562,8 +582,7 @@ int main(int argc, char **argv)
 		die("No REQUEST_METHOD from server");
 	if (!strcmp(method, "HEAD"))
 		method = "GET";
-	if (!dir)
-		die("No PATH_TRANSLATED from server");
+	dir = getdir();
 
 	for (i = 0; i < ARRAY_SIZE(services); i++) {
 		struct service_cmd *c = &services[i];
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 17/26] http-backend: reword some documentation

[Shawn O. Pearce]

From: Mark Lodato <lodatom@gmail.com>

Clarify some of the git-http-backend documentation, particularly:

* In the Description, state that smart/dumb HTTP fetch and smart HTTP
  push are supported, state that authenticated clients allow push, and
  remove the note that this is only suited for read-only updates.

* At the start of Examples, state explicitly what URL is mapping to what
  location on disk.

Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-http-backend.txt |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index 99dbbfb..0b5e951 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -14,13 +14,15 @@ DESCRIPTION
 -----------
 A simple CGI program to serve the contents of a Git repository to Git
 clients accessing the repository over http:// and https:// protocols.
+The program supports clients fetching using both the smart HTTP protcol
+and the backwards-compatible dumb HTTP protocol, as well as clients
+pushing using the smart HTTP protocol.
 
 By default, only the `upload-pack` service is enabled, which serves
 'git-fetch-pack' and 'git-ls-remote' clients, which are invoked from
-'git-fetch', 'git-pull', and 'git-clone'.
-
-This is ideally suited for read-only updates, i.e., pulling from
-git repositories.
+'git-fetch', 'git-pull', and 'git-clone'.  If the client is authenticated,
+the `receive-pack` service is enabled, which serves 'git-send-pack'
+clients, which is invoked from 'git-push'.
 
 SERVICES
 --------
@@ -50,6 +52,8 @@ automatically by the web server.
 
 EXAMPLES
 --------
+All of the following examples map 'http://$hostname/git/foo/bar.git'
+to '/var/www/git/foo/bar.git'.
 
 Apache 2.x::
 	Ensure mod_cgi, mod_alias, and mod_env are enabled, set
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 18/26] http-backend: use mod_alias instead of mod_rewrite

[Shawn O. Pearce]

From: Mark Lodato <lodatom@gmail.com>

In the git-http-backend documentation, use mod_alias exlusively, instead
of using a combination of mod_alias and mod_rewrite.  This makes the
example slightly shorted and a bit more clear.

Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-http-backend.txt |   10 +++-------
 1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index 0b5e951..e67519d 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -98,13 +98,9 @@ Accelerated static Apache 2.x::
 ----------------------------------------------------------------
 SetEnv GIT_PROJECT_ROOT /var/www/git
 
-ScriptAlias /git/        /usr/libexec/git-core/git-http-backend/
-Alias       /git_static/ /var/www/git/
-
-RewriteEngine on
-RewriteRule ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$    /git_static/$1 [PT]
-RewriteRule ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.pack)$ /git_static/$1 [PT]
-RewriteRule ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.idx)$  /git_static/$1 [PT]
+AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
+AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
+ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
 ----------------------------------------------------------------
 
 
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 19/26] http-backend: add example for gitweb on same URL

[Shawn O. Pearce]

From: Mark Lodato <lodatom@gmail.com>

In the git-http-backend documentation, add an example of how to set up
gitweb and git-http-backend on the same URL by using a series of
mod_alias commands.

Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-http-backend.txt |   33 +++++++++++++++++++++++++++++++++
 1 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index e67519d..2989c9f 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -88,6 +88,23 @@ directive around the repository, or one of its parent directories:
 	...
 </Location>
 ----------------------------------------------------------------
++
+To serve gitweb at the same url, use a ScriptAliasMatch to only
+those URLs that 'git-http-backend' can handle, and forward the
+rest to gitweb:
++
+----------------------------------------------------------------
+ScriptAliasMatch \
+	"(?x)^/git/(.*/(HEAD | \
+			info/refs | \
+			objects/(info/[^/]+ | \
+				 [0-9a-f]{2}/[0-9a-f]{38} | \
+				 pack/pack-[0-9a-f]{40}\.(pack|idx)) | \
+			git-(upload|receive)-pack))$" \
+	/usr/libexec/git-core/git-http-backend/$1
+
+ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
+----------------------------------------------------------------
 
 Accelerated static Apache 2.x::
 	Similar to the above, but Apache can be used to return static
@@ -102,6 +119,22 @@ AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
 AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
 ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
 ----------------------------------------------------------------
++
+This can be combined with the gitweb configuration:
++
+----------------------------------------------------------------
+SetEnv GIT_PROJECT_ROOT /var/www/git
+
+AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
+AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
+ScriptAliasMatch \
+	"(?x)^/git/(.*/(HEAD | \
+			info/refs | \
+			objects/info/[^/]+ | \
+			git-(upload|receive)-pack))$" \
+	/usr/libexec/git-core/git-http-backend/$1
+ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
+----------------------------------------------------------------
 
 
 ENVIRONMENT
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 20/26] http-backend: more explict LocationMatch

[Shawn O. Pearce]

From: Mark Lodato <lodatom@gmail.com>

In the git-http-backend examples, only match git-receive-pack within
/git/.

Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-http-backend.txt |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index 2989c9f..f17251a 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -69,7 +69,7 @@ To enable anonymous read access but authenticated write access,
 require authorization with a LocationMatch directive:
 +
 ----------------------------------------------------------------
-<LocationMatch ".*/git-receive-pack$">
+<LocationMatch "^/git/.*/git-receive-pack$">
 	AuthType Basic
 	AuthName "Git Access"
 	Require group committers
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 21/26] Discover refs via smart HTTP server when available

[Shawn O. Pearce]

Instead of loading the cached info/refs, try to use the smart HTTP
version when the server supports it.  Since the smart variant is
actually the pkt-line stream from the start of either upload-pack
or receive-pack we need to parse these through get_remote_heads,
which requires a background thread to feed its pipe.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 remote-curl.c |  148 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 131 insertions(+), 17 deletions(-)

diff --git a/remote-curl.c b/remote-curl.c
index 5c9dd97..3917d45 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -5,6 +5,7 @@
 #include "http.h"
 #include "exec_cmd.h"
 #include "run-command.h"
+#include "pkt-line.h"
 
 static struct remote *remote;
 static const char *url;
@@ -75,21 +76,46 @@ static int set_option(const char *name, const char *value)
 	}
 }
 
-static struct ref *get_refs(void)
+struct discovery {
+	const char *service;
+	char *buf_alloc;
+	char *buf;
+	size_t len;
+	unsigned proto_git : 1;
+};
+static struct discovery *last_discovery;
+
+static void free_discovery(struct discovery *d)
+{
+	if (d) {
+		if (d == last_discovery)
+			last_discovery = NULL;
+		free(d->buf_alloc);
+		free(d);
+	}
+}
+
+static struct discovery* discover_refs(const char *service)
 {
 	struct strbuf buffer = STRBUF_INIT;
-	char *data, *start, *mid;
-	char *ref_name;
+	struct discovery *last = last_discovery;
 	char *refs_url;
-	int i = 0;
-	int http_ret;
+	int http_ret, is_http = 0;
 
-	struct ref *refs = NULL;
-	struct ref *ref = NULL;
-	struct ref *last_ref = NULL;
+	if (last && !strcmp(service, last->service))
+		return last;
+	free_discovery(last);
 
-	refs_url = xmalloc(strlen(url) + 11);
-	sprintf(refs_url, "%s/info/refs", url);
+	strbuf_addf(&buffer, "%s/info/refs", url);
+	if (!prefixcmp(url, "http://") || !prefixcmp(url, "https://")) {
+		is_http = 1;
+		if (!strchr(url, '?'))
+			strbuf_addch(&buffer, '?');
+		else
+			strbuf_addch(&buffer, '&');
+		strbuf_addf(&buffer, "service=%s", service);
+	}
+	refs_url = strbuf_detach(&buffer, NULL);
 
 	init_walker();
 	http_ret = http_get_strbuf(refs_url, &buffer, HTTP_NO_CACHE);
@@ -104,10 +130,86 @@ static struct ref *get_refs(void)
 		die("HTTP request failed");
 	}
 
-	data = buffer.buf;
+	last= xcalloc(1, sizeof(*last_discovery));
+	last->service = service;
+	last->buf_alloc = strbuf_detach(&buffer, &last->len);
+	last->buf = last->buf_alloc;
+
+	if (is_http && 5 <= last->len && last->buf[4] == '#') {
+		/* smart HTTP response; validate that the service
+		 * pkt-line matches our request.
+		 */
+		struct strbuf exp = STRBUF_INIT;
+
+		if (packet_get_line(&buffer, &last->buf, &last->len) <= 0)
+			die("%s has invalid packet header", refs_url);
+		if (buffer.len && buffer.buf[buffer.len - 1] == '\n')
+			strbuf_setlen(&buffer, buffer.len - 1);
+
+		strbuf_addf(&exp, "# service=%s", service);
+		if (strbuf_cmp(&exp, &buffer))
+			die("invalid server response; got '%s'", buffer.buf);
+		strbuf_release(&exp);
+
+		/* The header can include additional metadata lines, up
+		 * until a packet flush marker.  Ignore these now, but
+		 * in the future we might start to scan them.
+		 */
+		strbuf_reset(&buffer);
+		while (packet_get_line(&buffer, &last->buf, &last->len) > 0)
+			strbuf_reset(&buffer);
+
+		last->proto_git = 1;
+	}
+
+	free(refs_url);
+	strbuf_release(&buffer);
+	last_discovery = last;
+	return last;
+}
+
+static int write_discovery(int fd, void *data)
+{
+	struct discovery *heads = data;
+	int err = 0;
+	if (write_in_full(fd, heads->buf, heads->len) != heads->len)
+		err = 1;
+	close(fd);
+	return err;
+}
+
+static struct ref *parse_git_refs(struct discovery *heads)
+{
+	struct ref *list = NULL;
+	struct async async;
+
+	memset(&async, 0, sizeof(async));
+	async.proc = write_discovery;
+	async.data = heads;
+
+	if (start_async(&async))
+		die("cannot start thread to parse advertised refs");
+	get_remote_heads(async.out, &list, 0, NULL, 0, NULL);
+	close(async.out);
+	if (finish_async(&async))
+		die("ref parsing thread failed");
+	return list;
+}
+
+static struct ref *parse_info_refs(struct discovery *heads)
+{
+	char *data, *start, *mid;
+	char *ref_name;
+	int i = 0;
+
+	struct ref *refs = NULL;
+	struct ref *ref = NULL;
+	struct ref *last_ref = NULL;
+
+	data = heads->buf;
 	start = NULL;
 	mid = data;
-	while (i < buffer.len) {
+	while (i < heads->len) {
 		if (!start) {
 			start = &data[i];
 		}
@@ -131,8 +233,7 @@ static struct ref *get_refs(void)
 		i++;
 	}
 
-	strbuf_release(&buffer);
-
+	init_walker();
 	ref = alloc_ref("HEAD");
 	if (!walker->fetch_ref(walker, ref) &&
 	    !resolve_remote_symref(ref, refs)) {
@@ -142,11 +243,23 @@ static struct ref *get_refs(void)
 		free(ref);
 	}
 
-	strbuf_release(&buffer);
-	free(refs_url);
 	return refs;
 }
 
+static struct ref *get_refs(int for_push)
+{
+	struct discovery *heads;
+
+	if (for_push)
+		heads = discover_refs("git-receive-pack");
+	else
+		heads = discover_refs("git-upload-pack");
+
+	if (heads->proto_git)
+		return parse_git_refs(heads);
+	return parse_info_refs(heads);
+}
+
 static void output_refs(struct ref *refs)
 {
 	struct ref *posn;
@@ -317,7 +430,8 @@ int main(int argc, const char **argv)
 			parse_fetch(&buf);
 
 		} else if (!strcmp(buf.buf, "list") || !prefixcmp(buf.buf, "list ")) {
-			output_refs(get_refs());
+			int for_push = !!strstr(buf.buf + 4, "for-push");
+			output_refs(get_refs(for_push));
 
 		} else if (!prefixcmp(buf.buf, "push ")) {
 			parse_push(&buf);
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 22/26] Smart push over HTTP: client side

[Shawn O. Pearce]

The git-remote-curl backend detects if the remote server supports
the git-receive-pack service, and if so, runs git-send-pack in a
pipe to dump the command and pack data as a single POST request.

The advertisements from the server that were obtained during the
discovery are passed into git-send-pack before the POST request
starts.  This permits git-send-pack to operate largely unmodified.

For smaller packs (those under 1 MiB) a HTTP/1.0 POST with a
Content-Length is used, permitting interaction with any server.
The 1 MiB limit is arbitrary, but is sufficent to fit most deltas
created by human authors against text sources with the occasional
small binary file (e.g. few KiB icon image).  The configuration
option http.postBuffer can be used to increase (or shink) this
buffer if the default is not sufficient.

For larger packs which cannot be spooled entirely into the helper's
memory space (due to http.postBuffer being too small), the POST
request requires HTTP/1.1 and sets "Transfer-Encoding: chunked".
This permits the client to upload an unknown amount of data in one
HTTP transaction without needing to pregenerate the entire pack
file locally.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 Documentation/config.txt |    8 ++
 builtin-send-pack.c      |  116 +++++++++++++++++++++-
 http.c                   |   13 ++-
 http.h                   |    2 +
 remote-curl.c            |  235 +++++++++++++++++++++++++++++++++++++++++++++-
 send-pack.h              |    3 +-
 sideband.c               |   11 ++-
 transport.c              |    1 +
 8 files changed, 374 insertions(+), 15 deletions(-)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index cd17814..7130d07 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1089,6 +1089,14 @@ http.maxRequests::
 	How many HTTP requests to launch in parallel. Can be overridden
 	by the 'GIT_HTTP_MAX_REQUESTS' environment variable. Default is 5.
 
+http.postBuffer::
+	Maximum size in bytes of the buffer used by smart HTTP
+	transports when POSTing data to the remote system.
+	For requests larger than this buffer size, HTTP/1.1 and
+	Transfer-Encoding: chunked is used to avoid creating a
+	massive pack file locally.  Default is 1 MiB, which is
+	sufficient for most requests.
+
 http.lowSpeedLimit, http.lowSpeedTime::
 	If the HTTP transfer speed is less than 'http.lowSpeedLimit'
 	for longer than 'http.lowSpeedTime' seconds, the transfer is aborted.
diff --git a/builtin-send-pack.c b/builtin-send-pack.c
index 37e528e..a0fbad0 100644
--- a/builtin-send-pack.c
+++ b/builtin-send-pack.c
@@ -2,9 +2,11 @@
 #include "commit.h"
 #include "refs.h"
 #include "pkt-line.h"
+#include "sideband.h"
 #include "run-command.h"
 #include "remote.h"
 #include "send-pack.h"
+#include "quote.h"
 
 static const char send_pack_usage[] =
 "git send-pack [--all | --mirror] [--dry-run] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
@@ -59,7 +61,7 @@ static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *ext
 	memset(&po, 0, sizeof(po));
 	po.argv = argv;
 	po.in = -1;
-	po.out = fd;
+	po.out = args->stateless_rpc ? -1 : fd;
 	po.git_cmd = 1;
 	if (start_command(&po))
 		die_errno("git pack-objects failed");
@@ -83,6 +85,20 @@ static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *ext
 	}
 
 	close(po.in);
+
+	if (args->stateless_rpc) {
+		char *buf = xmalloc(LARGE_PACKET_MAX);
+		while (1) {
+			ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
+			if (n <= 0)
+				break;
+			send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
+		}
+		free(buf);
+		close(po.out);
+		po.out = -1;
+	}
+
 	if (finish_command(&po))
 		return error("pack-objects died with strange error");
 	return 0;
@@ -303,6 +319,59 @@ static int refs_pushed(struct ref *ref)
 	return 0;
 }
 
+static void print_helper_status(struct ref *ref)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	for (; ref; ref = ref->next) {
+		const char *msg = NULL;
+		const char *res;
+
+		switch(ref->status) {
+		case REF_STATUS_NONE:
+			res = "error";
+			msg = "no match";
+			break;
+
+		case REF_STATUS_OK:
+			res = "ok";
+			break;
+
+		case REF_STATUS_UPTODATE:
+			res = "ok";
+			msg = "up to date";
+			break;
+
+		case REF_STATUS_REJECT_NONFASTFORWARD:
+			res = "error";
+			msg = "non-fast forward";
+			break;
+
+		case REF_STATUS_REJECT_NODELETE:
+		case REF_STATUS_REMOTE_REJECT:
+			res = "error";
+			break;
+
+		case REF_STATUS_EXPECTING_REPORT:
+		default:
+			continue;
+		}
+
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "%s %s", res, ref->name);
+		if (ref->remote_status)
+			msg = ref->remote_status;
+		if (msg) {
+			strbuf_addch(&buf, ' ');
+			quote_two_c_style(&buf, "", msg, 0);
+		}
+		strbuf_addch(&buf, '\n');
+
+		safe_write(1, buf.buf, buf.len);
+	}
+	strbuf_release(&buf);
+}
+
 int send_pack(struct send_pack_args *args,
 	      int fd[], struct child_process *conn,
 	      struct ref *remote_refs,
@@ -310,6 +379,7 @@ int send_pack(struct send_pack_args *args,
 {
 	int in = fd[0];
 	int out = fd[1];
+	struct strbuf req_buf = STRBUF_INIT;
 	struct ref *ref;
 	int new_refs;
 	int ask_for_status_report = 0;
@@ -391,14 +461,14 @@ int send_pack(struct send_pack_args *args,
 			char *new_hex = sha1_to_hex(ref->new_sha1);
 
 			if (ask_for_status_report) {
-				packet_write(out, "%s %s %s%c%s",
+				packet_buf_write(&req_buf, "%s %s %s%c%s",
 					old_hex, new_hex, ref->name, 0,
 					"report-status");
 				ask_for_status_report = 0;
 				expect_status_report = 1;
 			}
 			else
-				packet_write(out, "%s %s %s",
+				packet_buf_write(&req_buf, "%s %s %s",
 					old_hex, new_hex, ref->name);
 		}
 		ref->status = expect_status_report ?
@@ -406,7 +476,17 @@ int send_pack(struct send_pack_args *args,
 			REF_STATUS_OK;
 	}
 
-	packet_flush(out);
+	if (args->stateless_rpc) {
+		if (!args->dry_run) {
+			packet_buf_flush(&req_buf);
+			send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
+		}
+	} else {
+		safe_write(out, req_buf.buf, req_buf.len);
+		packet_flush(out);
+	}
+	strbuf_release(&req_buf);
+
 	if (new_refs && !args->dry_run) {
 		if (pack_objects(out, remote_refs, extra_have, args) < 0) {
 			for (ref = remote_refs; ref; ref = ref->next)
@@ -414,11 +494,15 @@ int send_pack(struct send_pack_args *args,
 			return -1;
 		}
 	}
+	if (args->stateless_rpc && !args->dry_run)
+		packet_flush(out);
 
 	if (expect_status_report)
 		ret = receive_status(in, remote_refs);
 	else
 		ret = 0;
+	if (args->stateless_rpc)
+		packet_flush(out);
 
 	if (ret < 0)
 		return ret;
@@ -478,6 +562,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	struct extra_have_objects extra_have;
 	struct ref *remote_refs, *local_refs;
 	int ret;
+	int helper_status = 0;
 	int send_all = 0;
 	const char *receivepack = "git-receive-pack";
 	int flags;
@@ -523,6 +608,14 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 				args.use_thin_pack = 1;
 				continue;
 			}
+			if (!strcmp(arg, "--stateless-rpc")) {
+				args.stateless_rpc = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--helper-status")) {
+				helper_status = 1;
+				continue;
+			}
 			usage(send_pack_usage);
 		}
 		if (!dest) {
@@ -551,7 +644,14 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	conn = git_connect(fd, dest, receivepack, args.verbose ? CONNECT_VERBOSE : 0);
+	if (args.stateless_rpc) {
+		conn = NULL;
+		fd[0] = 0;
+		fd[1] = 1;
+	} else {
+		conn = git_connect(fd, dest, receivepack,
+			args.verbose ? CONNECT_VERBOSE : 0);
+	}
 
 	memset(&extra_have, 0, sizeof(extra_have));
 
@@ -575,12 +675,16 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 
 	ret = send_pack(&args, fd, conn, remote_refs, &extra_have);
 
+	if (helper_status)
+		print_helper_status(remote_refs);
+
 	close(fd[1]);
 	close(fd[0]);
 
 	ret |= finish_connect(conn);
 
-	print_push_status(dest, remote_refs);
+	if (!helper_status)
+		print_push_status(dest, remote_refs);
 
 	if (!args.dry_run && remote) {
 		struct ref *ref;
diff --git a/http.c b/http.c
index 23b2a19..ed6414a 100644
--- a/http.c
+++ b/http.c
@@ -1,9 +1,11 @@
 #include "http.h"
 #include "pack.h"
+#include "sideband.h"
 
 int data_received;
 int active_requests;
 int http_is_verbose;
+size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
 
 #ifdef USE_CURL_MULTI
 static int max_requests = -1;
@@ -97,8 +99,6 @@ size_t fwrite_null(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 	return eltsize * nmemb;
 }
 
-static void finish_active_slot(struct active_request_slot *slot);
-
 #ifdef USE_CURL_MULTI
 static void process_curl_messages(void)
 {
@@ -174,6 +174,13 @@ static int http_options(const char *var, const char *value, void *cb)
 	if (!strcmp("http.proxy", var))
 		return git_config_string(&curl_http_proxy, var, value);
 
+	if (!strcmp("http.postbuffer", var)) {
+		http_post_buffer = git_config_int(var, value);
+		if (http_post_buffer < LARGE_PACKET_MAX)
+			http_post_buffer = LARGE_PACKET_MAX;
+		return 0;
+	}
+
 	/* Fall back on the default ones */
 	return git_default_config(var, value, cb);
 }
@@ -638,7 +645,7 @@ void release_active_slot(struct active_request_slot *slot)
 #endif
 }
 
-static void finish_active_slot(struct active_request_slot *slot)
+void finish_active_slot(struct active_request_slot *slot)
 {
 	closedown_active_slot(slot);
 	curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
diff --git a/http.h b/http.h
index 4c4e99c..f828e1d 100644
--- a/http.h
+++ b/http.h
@@ -79,6 +79,7 @@ extern curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
 extern struct active_request_slot *get_active_slot(void);
 extern int start_active_slot(struct active_request_slot *slot);
 extern void run_active_slot(struct active_request_slot *slot);
+extern void finish_active_slot(struct active_request_slot *slot);
 extern void finish_all_active_slots(void);
 extern void release_active_slot(struct active_request_slot *slot);
 
@@ -94,6 +95,7 @@ extern void http_cleanup(void);
 extern int data_received;
 extern int active_requests;
 extern int http_is_verbose;
+extern size_t http_post_buffer;
 
 extern char curl_errorstr[CURL_ERROR_SIZE];
 
diff --git a/remote-curl.c b/remote-curl.c
index 3917d45..f1206cb 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -6,6 +6,7 @@
 #include "exec_cmd.h"
 #include "run-command.h"
 #include "pkt-line.h"
+#include "sideband.h"
 
 static struct remote *remote;
 static const char *url;
@@ -16,7 +17,8 @@ struct options {
 	unsigned long depth;
 	unsigned progress : 1,
 		followtags : 1,
-		dry_run : 1;
+		dry_run : 1,
+		thin : 1;
 };
 static struct options options;
 
@@ -274,6 +276,188 @@ static void output_refs(struct ref *refs)
 	free_refs(refs);
 }
 
+struct rpc_state {
+	const char *service_name;
+	const char **argv;
+	char *service_url;
+	char *hdr_content_type;
+	char *hdr_accept;
+	char *buf;
+	size_t alloc;
+	size_t len;
+	size_t pos;
+	int in;
+	int out;
+	struct strbuf result;
+};
+
+static size_t rpc_out(void *ptr, size_t eltsize,
+		size_t nmemb, void *buffer_)
+{
+	size_t max = eltsize * nmemb;
+	struct rpc_state *rpc = buffer_;
+	size_t avail = rpc->len - rpc->pos;
+
+	if (!avail) {
+		avail = packet_read_line(rpc->out, rpc->buf, rpc->alloc);
+		if (!avail)
+			return 0;
+		rpc->pos = 0;
+		rpc->len = avail;
+	}
+
+	if (max < avail);
+		avail = max;
+	memcpy(ptr, rpc->buf + rpc->pos, avail);
+	rpc->pos += avail;
+	return avail;
+}
+
+static size_t rpc_in(const void *ptr, size_t eltsize,
+		size_t nmemb, void *buffer_)
+{
+	size_t size = eltsize * nmemb;
+	struct rpc_state *rpc = buffer_;
+	write_or_die(rpc->in, ptr, size);
+	return size;
+}
+
+static int post_rpc(struct rpc_state *rpc)
+{
+	struct active_request_slot *slot;
+	struct slot_results results;
+	struct curl_slist *headers = NULL;
+	int err = 0, large_request = 0;
+
+	/* Try to load the entire request, if we can fit it into the
+	 * allocated buffer space we can use HTTP/1.0 and avoid the
+	 * chunked encoding mess.
+	 */
+	while (1) {
+		size_t left = rpc->alloc - rpc->len;
+		char *buf = rpc->buf + rpc->len;
+		int n;
+
+		if (left < LARGE_PACKET_MAX) {
+			large_request = 1;
+			break;
+		}
+
+		n = packet_read_line(rpc->out, buf, left);
+		if (!n)
+			break;
+		rpc->len += n;
+	}
+
+	slot = get_active_slot();
+	slot->results = &results;
+
+	curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, rpc->service_url);
+
+	headers = curl_slist_append(headers, rpc->hdr_content_type);
+	headers = curl_slist_append(headers, rpc->hdr_accept);
+
+	if (large_request) {
+		/* The request body is large and the size cannot be predicted.
+		 * We must use chunked encoding to send it.
+		 */
+		headers = curl_slist_append(headers, "Expect: 100-continue");
+		headers = curl_slist_append(headers, "Transfer-Encoding: chunked");
+		curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, rpc_out);
+		curl_easy_setopt(slot->curl, CURLOPT_INFILE, rpc);
+		if (options.verbosity > 1) {
+			fprintf(stderr, "POST %s (chunked)\n", rpc->service_name);
+			fflush(stderr);
+		}
+
+	} else {
+		/* We know the complete request size in advance, use the
+		 * more normal Content-Length approach.
+		 */
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, rpc->buf);
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, rpc->len);
+		if (options.verbosity > 1) {
+			fprintf(stderr, "POST %s (%lu bytes)\n",
+				rpc->service_name, (unsigned long)rpc->len);
+			fflush(stderr);
+		}
+	}
+
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
+
+	slot->curl_result = curl_easy_perform(slot->curl);
+	finish_active_slot(slot);
+
+	if (results.curl_result != CURLE_OK) {
+		err |= error("RPC failed; result=%d, HTTP code = %ld",
+			results.curl_result, results.http_code);
+	}
+
+	curl_slist_free_all(headers);
+	return err;
+}
+
+static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
+{
+	const char *svc = rpc->service_name;
+	struct strbuf buf = STRBUF_INIT;
+	struct child_process client;
+	int err = 0;
+
+	init_walker();
+	memset(&client, 0, sizeof(client));
+	client.in = -1;
+	client.out = -1;
+	client.git_cmd = 1;
+	client.argv = rpc->argv;
+	if (start_command(&client))
+		exit(1);
+	if (heads)
+		write_or_die(client.in, heads->buf, heads->len);
+
+	rpc->alloc = http_post_buffer;
+	rpc->buf = xmalloc(rpc->alloc);
+	rpc->in = client.in;
+	rpc->out = client.out;
+	strbuf_init(&rpc->result, 0);
+
+	strbuf_addf(&buf, "%s/%s", url, svc);
+	rpc->service_url = strbuf_detach(&buf, NULL);
+
+	strbuf_addf(&buf, "Content-Type: application/x-%s-request", svc);
+	rpc->hdr_content_type = strbuf_detach(&buf, NULL);
+
+	strbuf_addf(&buf, "Accept: application/x-%s-response", svc);
+	rpc->hdr_accept = strbuf_detach(&buf, NULL);
+
+	while (!err) {
+		int n = packet_read_line(rpc->out, rpc->buf, rpc->alloc);
+		if (!n)
+			break;
+		rpc->pos = 0;
+		rpc->len = n;
+		err |= post_rpc(rpc);
+	}
+	strbuf_read(&rpc->result, client.out, 0);
+
+	close(client.in);
+	close(client.out);
+	client.in = -1;
+	client.out = -1;
+
+	err |= finish_command(&client);
+	free(rpc->service_url);
+	free(rpc->hdr_content_type);
+	free(rpc->hdr_accept);
+	free(rpc->buf);
+	strbuf_release(&buf);
+	return err;
+}
+
 static int fetch_dumb(int nr_heads, struct ref **to_fetch)
 {
 	char **targets = xmalloc(nr_heads * sizeof(char*));
@@ -371,6 +555,52 @@ static int push_dav(int nr_spec, char **specs)
 	return 0;
 }
 
+static int push_git(struct discovery *heads, int nr_spec, char **specs)
+{
+	struct rpc_state rpc;
+	const char **argv;
+	int argc = 0, i, err;
+
+	argv = xmalloc((10 + nr_spec) * sizeof(char*));
+	argv[argc++] = "send-pack";
+	argv[argc++] = "--stateless-rpc";
+	argv[argc++] = "--helper-status";
+	if (options.thin)
+		argv[argc++] = "--thin";
+	if (options.dry_run)
+		argv[argc++] = "--dry-run";
+	if (options.verbosity > 1)
+		argv[argc++] = "--verbose";
+	argv[argc++] = url;
+	for (i = 0; i < nr_spec; i++)
+		argv[argc++] = specs[i];
+	argv[argc++] = NULL;
+
+	memset(&rpc, 0, sizeof(rpc));
+	rpc.service_name = "git-receive-pack",
+	rpc.argv = argv;
+
+	err = rpc_service(&rpc, heads);
+	if (rpc.result.len)
+		safe_write(1, rpc.result.buf, rpc.result.len);
+	strbuf_release(&rpc.result);
+	free(argv);
+	return err;
+}
+
+static int push(int nr_spec, char **specs)
+{
+	struct discovery *heads = discover_refs("git-receive-pack");
+	int ret;
+
+	if (heads->proto_git)
+		ret = push_git(heads, nr_spec, specs);
+	else
+		ret = push_dav(nr_spec, specs);
+	free_discovery(heads);
+	return ret;
+}
+
 static void parse_push(struct strbuf *buf)
 {
 	char **specs = NULL;
@@ -391,7 +621,7 @@ static void parse_push(struct strbuf *buf)
 			break;
 	} while (1);
 
-	if (push_dav(nr_spec, specs))
+	if (push(nr_spec, specs))
 		exit(128); /* error already reported */
 	for (i = 0; i < nr_spec; i++)
 		free(specs[i]);
@@ -414,6 +644,7 @@ int main(int argc, const char **argv)
 
 	options.verbosity = 1;
 	options.progress = !!isatty(2);
+	options.thin = 1;
 
 	remote = remote_get(argv[1]);
 
diff --git a/send-pack.h b/send-pack.h
index 8b3cf02..28141ac 100644
--- a/send-pack.h
+++ b/send-pack.h
@@ -8,7 +8,8 @@ struct send_pack_args {
 		force_update:1,
 		use_thin_pack:1,
 		use_ofs_delta:1,
-		dry_run:1;
+		dry_run:1,
+		stateless_rpc:1;
 };
 
 int send_pack(struct send_pack_args *args,
diff --git a/sideband.c b/sideband.c
index 899b1ff..d5ffa1c 100644
--- a/sideband.c
+++ b/sideband.c
@@ -135,9 +135,14 @@ ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet
 		n = sz;
 		if (packet_max - 5 < n)
 			n = packet_max - 5;
-		sprintf(hdr, "%04x", n + 5);
-		hdr[4] = band;
-		safe_write(fd, hdr, 5);
+		if (0 <= band) {
+			sprintf(hdr, "%04x", n + 5);
+			hdr[4] = band;
+			safe_write(fd, hdr, 5);
+		} else {
+			sprintf(hdr, "%04x", n + 4);
+			safe_write(fd, hdr, 4);
+		}
 		safe_write(fd, p, n);
 		p += n;
 		sz -= n;
diff --git a/transport.c b/transport.c
index 6d9652d..2ff1650 100644
--- a/transport.c
+++ b/transport.c
@@ -731,6 +731,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 				 NULL);
 	}
 
+	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
 	args.force_update = !!(flags & TRANSPORT_PUSH_FORCE);
 	args.use_thin_pack = data->thin;
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 23/26] Smart fetch over HTTP: client side

[Shawn O. Pearce]

The git-remote-curl backend detects if the remote server supports
the git-upload-pack service, and if so, runs git-fetch-pack locally
in a pipe to generate the want/have commands.

The advertisements from the server that were obtained during the
discovery are passed into git-fetch-pack before the POST request
starts, permitting server capability discovery and enablement.

Common objects that are discovered are appended onto the request as
have lines and are sent again on the next request.  This allows the
remote side to reinitialize its in-memory list of common objects
during the next request.

Because all requests are relatively short, below git-remote-curl's
1 MiB buffer limit, requests will use the standard Content-Length
header and be valid HTTP/1.0 POST requests.  This makes the fetch
client more tolerant of proxy servers which don't support HTTP/1.1
or the chunked transfer encoding.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 builtin-fetch-pack.c |  110 ++++++++++++++++++++++++++++++++++++++++++--------
 fetch-pack.h         |    3 +-
 remote-curl.c        |   69 +++++++++++++++++++++++++++++--
 3 files changed, 160 insertions(+), 22 deletions(-)

diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 615f549..8ed4a6f 100644
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -165,6 +165,24 @@ enum ack_type {
 	ACK_ready
 };
 
+static void consume_shallow_list(int fd)
+{
+	if (args.stateless_rpc && args.depth > 0) {
+		/* If we sent a depth we will get back "duplicate"
+		 * shallow and unshallow commands every time there
+		 * is a block of have lines exchanged.
+		 */
+		char line[1000];
+		while (packet_read_line(fd, line, sizeof(line))) {
+			if (!prefixcmp(line, "shallow "))
+				continue;
+			if (!prefixcmp(line, "unshallow "))
+				continue;
+			die("git fetch-pack: expected shallow list");
+		}
+	}
+}
+
 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 {
 	static char line[1000];
@@ -190,6 +208,15 @@ static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 	die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 }
 
+static void send_request(int fd, struct strbuf *buf)
+{
+	if (args.stateless_rpc) {
+		send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
+		packet_flush(fd);
+	} else
+		safe_write(fd, buf->buf, buf->len);
+}
+
 static int find_common(int fd[2], unsigned char *result_sha1,
 		       struct ref *refs)
 {
@@ -199,7 +226,10 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 	unsigned in_vain = 0;
 	int got_continue = 0;
 	struct strbuf req_buf = STRBUF_INIT;
+	size_t state_len = 0;
 
+	if (args.stateless_rpc && multi_ack == 1)
+		die("--stateless-rpc requires multi_ack_detailed");
 	if (marked)
 		for_each_ref(clear_marks, NULL);
 	marked = 1;
@@ -256,13 +286,13 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 	if (args.depth > 0)
 		packet_buf_write(&req_buf, "deepen %d", args.depth);
 	packet_buf_flush(&req_buf);
-
-	safe_write(fd[1], req_buf.buf, req_buf.len);
+	state_len = req_buf.len;
 
 	if (args.depth > 0) {
 		char line[1024];
 		unsigned char sha1[20];
 
+		send_request(fd[1], &req_buf);
 		while (packet_read_line(fd[0], line, sizeof(line))) {
 			if (!prefixcmp(line, "shallow ")) {
 				if (get_sha1_hex(line + 8, sha1))
@@ -284,28 +314,40 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 			}
 			die("expected shallow/unshallow, got %s", line);
 		}
+	} else if (!args.stateless_rpc)
+		send_request(fd[1], &req_buf);
+
+	if (!args.stateless_rpc) {
+		/* If we aren't using the stateless-rpc interface
+		 * we don't need to retain the headers.
+		 */
+		strbuf_setlen(&req_buf, 0);
+		state_len = 0;
 	}
 
 	flushes = 0;
 	retval = -1;
 	while ((sha1 = get_rev())) {
-		packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
+		packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 		if (args.verbose)
 			fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 		in_vain++;
 		if (!(31 & ++count)) {
 			int ack;
 
-			packet_flush(fd[1]);
+			packet_buf_flush(&req_buf);
+			send_request(fd[1], &req_buf);
+			strbuf_setlen(&req_buf, state_len);
 			flushes++;
 
 			/*
 			 * We keep one window "ahead" of the other side, and
 			 * will wait for an ACK only on the next one
 			 */
-			if (count == 32)
+			if (!args.stateless_rpc && count == 32)
 				continue;
 
+			consume_shallow_list(fd[0]);
 			do {
 				ack = get_ack(fd[0], result_sha1);
 				if (args.verbose && ack)
@@ -322,6 +364,17 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 				case ACK_continue: {
 					struct commit *commit =
 						lookup_commit(result_sha1);
+					if (args.stateless_rpc
+					 && ack == ACK_common
+					 && !(commit->object.flags & COMMON)) {
+						/* We need to replay the have for this object
+						 * on the next RPC request so the peer knows
+						 * it is in common with us.
+						 */
+						const char *hex = sha1_to_hex(result_sha1);
+						packet_buf_write(&req_buf, "have %s\n", hex);
+						state_len = req_buf.len;
+					}
 					mark_common(commit, 0, 1);
 					retval = 0;
 					in_vain = 0;
@@ -339,7 +392,8 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 		}
 	}
 done:
-	packet_write(fd[1], "done\n");
+	packet_buf_write(&req_buf, "done\n");
+	send_request(fd[1], &req_buf);
 	if (args.verbose)
 		fprintf(stderr, "done\n");
 	if (retval != 0) {
@@ -348,6 +402,7 @@ done:
 	}
 	strbuf_release(&req_buf);
 
+	consume_shallow_list(fd[0]);
 	while (flushes || multi_ack) {
 		int ack = get_ack(fd[0], result_sha1);
 		if (ack) {
@@ -672,6 +727,8 @@ static struct ref *do_fetch_pack(int fd[2],
 			 */
 			warning("no common commits");
 
+	if (args.stateless_rpc)
+		packet_flush(fd[1]);
 	if (get_pack(fd, pack_lockfile))
 		die("git fetch-pack: fetch failed.");
 
@@ -742,6 +799,8 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	struct ref *ref = NULL;
 	char *dest = NULL, **heads;
 	int fd[2];
+	char *pack_lockfile = NULL;
+	char **pack_lockfile_ptr = NULL;
 	struct child_process *conn;
 
 	nr_heads = 0;
@@ -791,6 +850,15 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 				args.no_progress = 1;
 				continue;
 			}
+			if (!strcmp("--stateless-rpc", arg)) {
+				args.stateless_rpc = 1;
+				continue;
+			}
+			if (!strcmp("--lock-pack", arg)) {
+				args.lock_pack = 1;
+				pack_lockfile_ptr = &pack_lockfile;
+				continue;
+			}
 			usage(fetch_pack_usage);
 		}
 		dest = (char *)arg;
@@ -801,19 +869,27 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	if (!dest)
 		usage(fetch_pack_usage);
 
-	conn = git_connect(fd, (char *)dest, args.uploadpack,
-			   args.verbose ? CONNECT_VERBOSE : 0);
-	if (conn) {
-		get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
-
-		ref = fetch_pack(&args, fd, conn, ref, dest, nr_heads, heads, NULL);
-		close(fd[0]);
-		close(fd[1]);
-		if (finish_connect(conn))
-			ref = NULL;
+	if (args.stateless_rpc) {
+		conn = NULL;
+		fd[0] = 0;
+		fd[1] = 1;
 	} else {
-		ref = NULL;
+		conn = git_connect(fd, (char *)dest, args.uploadpack,
+				   args.verbose ? CONNECT_VERBOSE : 0);
+	}
+
+	get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
+
+	ref = fetch_pack(&args, fd, conn, ref, dest,
+		nr_heads, heads, pack_lockfile_ptr);
+	if (pack_lockfile) {
+		printf("lock %s\n", pack_lockfile);
+		fflush(stdout);
 	}
+	close(fd[0]);
+	close(fd[1]);
+	if (finish_connect(conn))
+		ref = NULL;
 	ret = !ref;
 
 	if (!ret && nr_heads) {
diff --git a/fetch-pack.h b/fetch-pack.h
index 8bd9c32..fbe85ac 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -13,7 +13,8 @@ struct fetch_pack_args
 		fetch_all:1,
 		verbose:1,
 		no_progress:1,
-		include_tag:1;
+		include_tag:1,
+		stateless_rpc:1;
 };
 
 struct ref *fetch_pack(struct fetch_pack_args *args,
diff --git a/remote-curl.c b/remote-curl.c
index f1206cb..0eb6fc4 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -45,7 +45,7 @@ static int set_option(const char *name, const char *value)
 			options.progress = 0;
 		else
 			return -1;
-		return 1 /* TODO implement later */;
+		return 0;
 	}
 	else if (!strcmp(name, "depth")) {
 		char *end;
@@ -53,7 +53,7 @@ static int set_option(const char *name, const char *value)
 		if (value == end || *end)
 			return -1;
 		options.depth = v;
-		return 1 /* TODO implement later */;
+		return 0;
 	}
 	else if (!strcmp(name, "followtags")) {
 		if (!strcmp(value, "true"))
@@ -62,7 +62,7 @@ static int set_option(const char *name, const char *value)
 			options.followtags = 0;
 		else
 			return -1;
-		return 1 /* TODO implement later */;
+		return 0;
 	}
 	else if (!strcmp(name, "dry-run")) {
 		if (!strcmp(value, "true"))
@@ -463,6 +463,8 @@ static int fetch_dumb(int nr_heads, struct ref **to_fetch)
 	char **targets = xmalloc(nr_heads * sizeof(char*));
 	int ret, i;
 
+	if (options.depth)
+		die("dumb http transport does not support --depth");
 	for (i = 0; i < nr_heads; i++)
 		targets[i] = xstrdup(sha1_to_hex(to_fetch[i]->old_sha1));
 
@@ -481,6 +483,65 @@ static int fetch_dumb(int nr_heads, struct ref **to_fetch)
 	return ret ? error("Fetch failed.") : 0;
 }
 
+static int fetch_git(struct discovery *heads,
+	int nr_heads, struct ref **to_fetch)
+{
+	struct rpc_state rpc;
+	char *depth_arg = NULL;
+	const char **argv;
+	int argc = 0, i, err;
+
+	argv = xmalloc((15 + nr_heads) * sizeof(char*));
+	argv[argc++] = "fetch-pack";
+	argv[argc++] = "--stateless-rpc";
+	argv[argc++] = "--lock-pack";
+	if (options.followtags)
+		argv[argc++] = "--include-tag";
+	if (options.thin)
+		argv[argc++] = "--thin";
+	if (options.verbosity >= 3) {
+		argv[argc++] = "-v";
+		argv[argc++] = "-v";
+	}
+	if (!options.progress)
+		argv[argc++] = "--no-progress";
+	if (options.depth) {
+		struct strbuf buf = STRBUF_INIT;
+		strbuf_addf(&buf, "--depth=%lu", options.depth);
+		depth_arg = strbuf_detach(&buf, NULL);
+		argv[argc++] = depth_arg;
+	}
+	argv[argc++] = url;
+	for (i = 0; i < nr_heads; i++) {
+		struct ref *ref = to_fetch[i];
+		if (!ref->name || !*ref->name)
+			die("cannot fetch by sha1 over smart http");
+		argv[argc++] = ref->name;
+	}
+	argv[argc++] = NULL;
+
+	memset(&rpc, 0, sizeof(rpc));
+	rpc.service_name = "git-upload-pack",
+	rpc.argv = argv;
+
+	err = rpc_service(&rpc, heads);
+	if (rpc.result.len)
+		safe_write(1, rpc.result.buf, rpc.result.len);
+	strbuf_release(&rpc.result);
+	free(argv);
+	free(depth_arg);
+	return err;
+}
+
+static int fetch(int nr_heads, struct ref **to_fetch)
+{
+	struct discovery *d = discover_refs("git-upload-pack");
+	if (d->proto_git)
+		return fetch_git(d, nr_heads, to_fetch);
+	else
+		return fetch_dumb(nr_heads, to_fetch);
+}
+
 static void parse_fetch(struct strbuf *buf)
 {
 	struct ref **to_fetch = NULL;
@@ -523,7 +584,7 @@ static void parse_fetch(struct strbuf *buf)
 			break;
 	} while (1);
 
-	if (fetch_dumb(nr_heads, to_fetch))
+	if (fetch(nr_heads, to_fetch))
 		exit(128); /* error already reported */
 	free_refs(list_head);
 	free(to_fetch);
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 24/26] Smart HTTP fetch: gzip requests

[Shawn O. Pearce]

The upload-pack requests are mostly plain text and they compress
rather well.  Deflating them with Content-Encoding: gzip can easily
drop the size of the request by 50%, reducing the amount of data
to transfer as we negotiate the common commits.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
---
 remote-curl.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 50 insertions(+), 0 deletions(-)

diff --git a/remote-curl.c b/remote-curl.c
index 0eb6fc4..0d7cf16 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -289,6 +289,7 @@ struct rpc_state {
 	int in;
 	int out;
 	struct strbuf result;
+	unsigned gzip_request : 1;
 };
 
 static size_t rpc_out(void *ptr, size_t eltsize,
@@ -327,6 +328,8 @@ static int post_rpc(struct rpc_state *rpc)
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct curl_slist *headers = NULL;
+	int use_gzip = rpc->gzip_request;
+	char *gzip_body = NULL;
 	int err = 0, large_request = 0;
 
 	/* Try to load the entire request, if we can fit it into the
@@ -340,6 +343,7 @@ static int post_rpc(struct rpc_state *rpc)
 
 		if (left < LARGE_PACKET_MAX) {
 			large_request = 1;
+			use_gzip = 0;
 			break;
 		}
 
@@ -355,6 +359,7 @@ static int post_rpc(struct rpc_state *rpc)
 	curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
 	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
 	curl_easy_setopt(slot->curl, CURLOPT_URL, rpc->service_url);
+	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
 
 	headers = curl_slist_append(headers, rpc->hdr_content_type);
 	headers = curl_slist_append(headers, rpc->hdr_accept);
@@ -372,6 +377,49 @@ static int post_rpc(struct rpc_state *rpc)
 			fflush(stderr);
 		}
 
+	} else if (use_gzip && 1024 < rpc->len) {
+		/* The client backend isn't giving us compressed data so
+		 * we can try to deflate it ourselves, this may save on.
+		 * the transfer time.
+		 */
+		size_t size;
+		z_stream stream;
+		int ret;
+
+		memset(&stream, 0, sizeof(stream));
+		ret = deflateInit2(&stream, Z_BEST_COMPRESSION,
+				Z_DEFLATED, (15 + 16),
+				8, Z_DEFAULT_STRATEGY);
+		if (ret != Z_OK)
+			die("cannot deflate request; zlib init error %d", ret);
+		size = deflateBound(&stream, rpc->len);
+		gzip_body = xmalloc(size);
+
+		stream.next_in = (unsigned char *)rpc->buf;
+		stream.avail_in = rpc->len;
+		stream.next_out = (unsigned char *)gzip_body;
+		stream.avail_out = size;
+
+		ret = deflate(&stream, Z_FINISH);
+		if (ret != Z_STREAM_END)
+			die("cannot deflate request; zlib deflate error %d", ret);
+
+		ret = deflateEnd(&stream);
+		if (ret != Z_OK)
+			die("cannot deflate request; zlib end error %d", ret);
+
+		size = stream.total_out;
+
+		headers = curl_slist_append(headers, "Content-Encoding: gzip");
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, gzip_body);
+		curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, size);
+
+		if (options.verbosity > 1) {
+			fprintf(stderr, "POST %s (gzip %lu to %lu bytes)\n",
+				rpc->service_name,
+				(unsigned long)rpc->len, (unsigned long)size);
+			fflush(stderr);
+		}
 	} else {
 		/* We know the complete request size in advance, use the
 		 * more normal Content-Length approach.
@@ -398,6 +446,7 @@ static int post_rpc(struct rpc_state *rpc)
 	}
 
 	curl_slist_free_all(headers);
+	free(gzip_body);
 	return err;
 }
 
@@ -523,6 +572,7 @@ static int fetch_git(struct discovery *heads,
 	memset(&rpc, 0, sizeof(rpc));
 	rpc.service_name = "git-upload-pack",
 	rpc.argv = argv;
+	rpc.gzip_request = 1;
 
 	err = rpc_service(&rpc, heads);
 	if (rpc.result.len)
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 25/26] t5540-http-push: remove redundant fetches

[Shawn O. Pearce]

From: Tay Ray Chuan <rctay89@gmail.com>

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 t/t5540-http-push.sh |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
index 2ece661..28a746e 100755
--- a/t/t5540-http-push.sh
+++ b/t/t5540-http-push.sh
@@ -116,9 +116,7 @@ test_expect_success 'create and delete remote branch' '
 	test_tick &&
 	git commit -m dev &&
 	git push origin dev &&
-	git fetch &&
 	git push origin :dev &&
-	git fetch &&
 	test_must_fail git show-ref --verify refs/remotes/origin/dev
 '
 
-- 
1.6.5.2.181.gd6f41

[RFC PATCH v4 26/26] test smart http fetch and push

[Shawn O. Pearce]

The top level directory "/git/" of the test Apache server is mapped
through our git-http-backend CGI, but uses the same underlying
repository space as the server's document root.  This is the most
simple installation possible.

Server logs are checked to verify the client has accessed only the
smart URLs during the test.  During fetch testing the headers are
also logged from libcurl to ensure we are making a reasonably sane
HTTP request, and getting back reasonably sane response headers
from the CGI.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 t/lib-httpd/apache.conf |   20 +++++++++
 t/t5540-http-push.sh    |    2 +-
 t/t5541-http-push.sh    |  103 +++++++++++++++++++++++++++++++++++++++++++++++
 t/t5550-http-fetch.sh   |    8 +++-
 t/t5551-http-fetch.sh   |   87 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 218 insertions(+), 2 deletions(-)
 create mode 100755 t/t5541-http-push.sh
 create mode 100755 t/t5551-http-fetch.sh

diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 21aa42f..2098ce0 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -8,6 +8,26 @@ ErrorLog error.log
 <IfModule !mod_log_config.c>
 	LoadModule log_config_module modules/mod_log_config.so
 </IfModule>
+<IfModule !mod_cgi.c>
+	LoadModule cgi_module modules/mod_cgi.so
+</IfModule>
+<IfModule !mod_alias.c>
+	LoadModule alias_module modules/mod_alias.so
+</IfModule>
+<IfModule !mod_env.c>
+	LoadModule env_module modules/mod_env.so
+</IfModule>
+
+<Location /git/>
+	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
+</Location>
+ScriptAlias /git/ ${GIT_EXEC_PATH}/git-http-backend/
+<Directory ${GIT_EXEC_PATH}>
+	Options None
+</Directory>
+<Files ${GIT_EXEC_PATH}/git-http-backend>
+	Options ExecCGI
+</Files>
 
 <IfDefine SSL>
 LoadModule ssl_module modules/mod_ssl.so
diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
index 28a746e..5c0f4d7 100755
--- a/t/t5540-http-push.sh
+++ b/t/t5540-http-push.sh
@@ -3,7 +3,7 @@
 # Copyright (c) 2008 Clemens Buchacher <drizzd@aon.at>
 #
 
-test_description='test http-push
+test_description='test WebDAV http-push
 
 This test runs various sanity checks on http-push.'
 
diff --git a/t/t5541-http-push.sh b/t/t5541-http-push.sh
new file mode 100755
index 0000000..690c466
--- /dev/null
+++ b/t/t5541-http-push.sh
@@ -0,0 +1,103 @@
+#!/bin/sh
+#
+# Copyright (c) 2008 Clemens Buchacher <drizzd@aon.at>
+#
+
+test_description='test smart pushing over http via http-backend'
+. ./test-lib.sh
+
+if test -n "$NO_CURL"; then
+	say 'skipping test, git built without http support'
+	test_done
+fi
+
+ROOT_PATH="$PWD"
+LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5550'}
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup remote repository' '
+	cd "$ROOT_PATH" &&
+	mkdir test_repo &&
+	cd test_repo &&
+	git init &&
+	: >path1 &&
+	git add path1 &&
+	test_tick &&
+	git commit -m initial &&
+	cd - &&
+	git clone --bare test_repo test_repo.git &&
+	cd test_repo.git &&
+	git config http.receivepack true &&
+	ORIG_HEAD=$(git rev-parse --verify HEAD) &&
+	cd - &&
+	mv test_repo.git "$HTTPD_DOCUMENT_ROOT_PATH"
+'
+
+test_expect_success 'clone remote repository' '
+	cd "$ROOT_PATH" &&
+	git clone $HTTPD_URL/git/test_repo.git test_repo_clone
+'
+
+test_expect_success 'push to remote repository with packed refs' '
+	cd "$ROOT_PATH"/test_repo_clone &&
+	: >path2 &&
+	git add path2 &&
+	test_tick &&
+	git commit -m path2 &&
+	HEAD=$(git rev-parse --verify HEAD) &&
+	git push &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
+	 test $HEAD = $(git rev-parse --verify HEAD))
+'
+
+test_expect_success 'push already up-to-date' '
+	git push
+'
+
+test_expect_success 'push to remote repository with unpacked refs' '
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
+	 rm packed-refs &&
+	 git update-ref refs/heads/master $ORIG_HEAD) &&
+	git push &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
+	 test $HEAD = $(git rev-parse --verify HEAD))
+'
+
+test_expect_success 'create and delete remote branch' '
+	cd "$ROOT_PATH"/test_repo_clone &&
+	git checkout -b dev &&
+	: >path3 &&
+	git add path3 &&
+	test_tick &&
+	git commit -m dev &&
+	git push origin dev &&
+	git push origin :dev &&
+	test_must_fail git show-ref --verify refs/remotes/origin/dev
+'
+
+cat >exp <<EOF
+GET  /git/test_repo.git/info/refs?service=git-upload-pack HTTP/1.1 200
+POST /git/test_repo.git/git-upload-pack HTTP/1.1 200
+GET  /git/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
+POST /git/test_repo.git/git-receive-pack HTTP/1.1 200
+GET  /git/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
+GET  /git/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
+POST /git/test_repo.git/git-receive-pack HTTP/1.1 200
+GET  /git/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
+POST /git/test_repo.git/git-receive-pack HTTP/1.1 200
+GET  /git/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
+POST /git/test_repo.git/git-receive-pack HTTP/1.1 200
+EOF
+test_expect_success 'used receive-pack service' '
+	sed -e "
+		s/^.* \"//
+		s/\"//
+		s/ [1-9][0-9]*\$//
+		s/^GET /GET  /
+	" >act <"$HTTPD_ROOT_PATH"/access.log &&
+	test_cmp exp act
+'
+
+stop_httpd
+test_done
diff --git a/t/t5550-http-fetch.sh b/t/t5550-http-fetch.sh
index 0e69324..8d6443f 100755
--- a/t/t5550-http-fetch.sh
+++ b/t/t5550-http-fetch.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='test fetching over http'
+test_description='test dumb fetching over http via static file'
 . ./test-lib.sh
 
 if test -n "$NO_CURL"; then
@@ -61,5 +61,11 @@ test_expect_success 'fetch packed objects' '
 	git clone $HTTPD_URL/repo_pack.git
 '
 
+test_expect_success 'did not use upload-pack service' '
+	grep '/git-upload-pack' <"$HTTPD_ROOT_PATH"/access.log >act
+	: >exp
+	test_cmp exp act
+'
+
 stop_httpd
 test_done
diff --git a/t/t5551-http-fetch.sh b/t/t5551-http-fetch.sh
new file mode 100755
index 0000000..afddc2c
--- /dev/null
+++ b/t/t5551-http-fetch.sh
@@ -0,0 +1,87 @@
+#!/bin/sh
+
+test_description='test smart fetching over http via http-backend'
+. ./test-lib.sh
+
+if test -n "$NO_CURL"; then
+	say 'skipping test, git built without http support'
+	test_done
+fi
+
+LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5550'}
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup repository' '
+	echo content >file &&
+	git add file &&
+	git commit -m one
+'
+
+test_expect_success 'create http-accessible bare repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	 git --bare init
+	) &&
+	git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git push public master:master
+'
+
+cat >exp <<EOF
+> GET /git/repo.git/info/refs?service=git-upload-pack HTTP/1.1
+Accept: */*
+Pragma: no-cache
+< HTTP/1.1 200 OK
+< Pragma: no-cache
+< Cache-Control: no-cache, max-age=0, must-revalidate
+< Content-Type: application/x-git-upload-pack-advertisement
+< 
+> POST /git/repo.git/git-upload-pack HTTP/1.1
+Accept-Encoding: deflate, gzip
+Content-Type: application/x-git-upload-pack-request
+Accept: application/x-git-upload-pack-response
+Content-Length: xxxx
+< HTTP/1.1 200 OK
+< Pragma: no-cache
+< Cache-Control: no-cache, max-age=0, must-revalidate
+< Content-Type: application/x-git-upload-pack-result
+< 
+EOF
+test_expect_success 'clone http repository' '
+	GIT_CURL_VERBOSE=1 git clone $HTTPD_URL/git/repo.git clone 2>err &&
+	test_cmp file clone/file &&
+	egrep "^([<>]|Pragma|Accept|Content-|Transfer-)" err |
+	egrep -v "^< (Server|Expires|Date|Content-Length:|Transfer-Encoding: chunked)" |
+	sed -e "
+		s/
//
+		s/^Content-Length: .*$/Content-Length: xxxx/
+	" >act &&
+	test_cmp exp act
+'
+
+test_expect_success 'fetch changes via http' '
+	echo content >>file &&
+	git commit -a -m two &&
+	git push public
+	(cd clone && git pull) &&
+	test_cmp file clone/file
+'
+
+cat >exp <<EOF
+GET  /git/repo.git/info/refs?service=git-upload-pack HTTP/1.1 200
+POST /git/repo.git/git-upload-pack HTTP/1.1 200
+GET  /git/repo.git/info/refs?service=git-upload-pack HTTP/1.1 200
+POST /git/repo.git/git-upload-pack HTTP/1.1 200
+EOF
+test_expect_success 'used upload-pack service' '
+	sed -e "
+		s/^.* \"//
+		s/\"//
+		s/ [1-9][0-9]*\$//
+		s/^GET /GET  /
+	" >act <"$HTTPD_ROOT_PATH"/access.log &&
+	test_cmp exp act
+'
+
+stop_httpd
+test_done
-- 
1.6.5.2.181.gd6f41

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Clemens Buchacher]

On Wed, Oct 28, 2009 at 05:00:48PM -0700, Shawn O. Pearce wrote:

> --- /dev/null
> +++ b/t/t5541-http-push.sh
[...]
> +LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5550'}

This should be 5541. We need different ports to be able to run the tests
simultenously.

> --- a/t/t5550-http-fetch.sh
> +++ b/t/t5550-http-fetch.sh

There is also a http port related bug in t5550. I'm attaching the patch
below. Maybe you want to squash this in here.

> --- /dev/null
> +++ b/t/t5551-http-fetch.sh
[...]
> +LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5550'}

Ditto, 5551.

Clemens

-->o--
Subject: [PATCH] set httpd port before sourcing lib-httpd

If LIB_HTTPD_PORT is not set already, lib-httpd will set it to the
default 8111.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
---
 t/t5540-http-push.sh  |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
index 5c0f4d7..ea46d1e 100755
--- a/t/t5540-http-push.sh
+++ b/t/t5540-http-push.sh
@@ -9,17 +9,16 @@ This test runs various sanity checks on http-push.'
 
 . ./test-lib.sh
 
-ROOT_PATH="$PWD"
-LIB_HTTPD_DAV=t
-LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5540'}
-
 if git http-push > /dev/null 2>&1 || [ $? -eq 128 ]
 then
 	say "skipping test, USE_CURL_MULTI is not defined"
 	test_done
 fi
 
+LIB_HTTPD_DAV=t
+LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5540'}
 . "$TEST_DIRECTORY"/lib-httpd.sh
+ROOT_PATH="$PWD"
 start_httpd
 
 test_expect_success 'setup remote repository' '
-- 
1.6.5.1.208.gd7b37

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Shawn O. Pearce]

Clemens Buchacher <drizzd@aon.at> wrote:
> On Wed, Oct 28, 2009 at 05:00:48PM -0700, Shawn O. Pearce wrote:
> 
> > --- /dev/null
> > +++ b/t/t5541-http-push.sh
> [...]
> > +LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5550'}
> 
> This should be 5541. We need different ports to be able to run the tests
> simultenously.

Thanks, I also realized this myself this morning on my way into work.
I've adjusted my two new test scripts, and inserted your patch to
fix the older test script into the series.
 
-- 
Shawn.

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> +test_expect_success 'clone http repository' '
> +	GIT_CURL_VERBOSE=1 git clone $HTTPD_URL/git/repo.git clone 2>err &&
> +	test_cmp file clone/file &&
> +	egrep "^([<>]|Pragma|Accept|Content-|Transfer-)" err |
> +	egrep -v "^< (Server|Expires|Date|Content-Length:|Transfer-Encoding: chunked)" |
> +	sed -e "
> +		s/
> //
> +		s/^Content-Length: .*$/Content-Length: xxxx/
> +	" >act &&

This chomped line is so unlike you---what happened?

Also, when the last downstream is sed, why would you even need two egrep
process?

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> 
> > +test_expect_success 'clone http repository' '
> > +	GIT_CURL_VERBOSE=1 git clone $HTTPD_URL/git/repo.git clone 2>err &&
> > +	test_cmp file clone/file &&
> > +	egrep "^([<>]|Pragma|Accept|Content-|Transfer-)" err |
> > +	egrep -v "^< (Server|Expires|Date|Content-Length:|Transfer-Encoding: chunked)" |
> > +	sed -e "
> > +		s/
> > //
> > +		s/^Content-Length: .*$/Content-Length: xxxx/
> > +	" >act &&
> 
> This chomped line is so unlike you---what happened?

I was getting different Content-Lengths on different runs of the
test.  I don't know why.  Here the Content-Length is of the gzip'd
request, it shouldn't be varying with each run, but it seemed to be.
 
> Also, when the last downstream is sed, why would you even need two egrep
> process?

That's a really good point.  This is just stupid, I started with
the two egreps to filter the lines, then found I needed to strip
CRs, and then had to munge the Content-Length, and I just forgot
to merge the egrep cases into the sed script.

I'll fix this.  Thanks.

-- 
Shawn.

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Shawn O. Pearce]

"Shawn O. Pearce" <spearce@spearce.org> wrote:
> Junio C Hamano <gitster@pobox.com> wrote:
> > > +		s/^Content-Length: .*$/Content-Length: xxxx/
> > 
> > This chomped line is so unlike you---what happened?
> 
> I was getting different Content-Lengths on different runs of the
> test.  I don't know why.  Here the Content-Length is of the gzip'd
> request, it shouldn't be varying with each run, but it seemed to be.

FWIW, I found the variablity here.  It was triggered by running the
test with -v or without -v, which caused clone to change its first
"want" line to include or exclude progress messages, based on the
tty-ness of stderr.

Adding a --quiet to the clone command means I can avoid this munging
and hard code the length in the test vector.  But I'm still against
doing that here in case the protocol capabilities ever change in
the future.
  
-- 
Shawn.

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Junio C Hamano]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> Junio C Hamano <gitster@pobox.com> wrote:
>> "Shawn O. Pearce" <spearce@spearce.org> writes:
>> 
>> > +test_expect_success 'clone http repository' '
>> > +	GIT_CURL_VERBOSE=1 git clone $HTTPD_URL/git/repo.git clone 2>err &&
>> > +	test_cmp file clone/file &&
>> > +	egrep "^([<>]|Pragma|Accept|Content-|Transfer-)" err |
>> > +	egrep -v "^< (Server|Expires|Date|Content-Length:|Transfer-Encoding: chunked)" |
>> > +	sed -e "
>> > +		s/
>> > //
>> > +		s/^Content-Length: .*$/Content-Length: xxxx/
>> > +	" >act &&
>> 
>> This chomped line is so unlike you---what happened?
>
> I was getting different Content-Lengths on different runs of the
> test.  I don't know why.  Here the Content-Length is of the gzip'd
> request, it shouldn't be varying with each run, but it seemed to be.

What I meant was the patch corruption.  I couldn't tell what you were
trying to filter with the first substitution you are giving to sed.

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Shawn O. Pearce]

Junio C Hamano <gitster@pobox.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> > Junio C Hamano <gitster@pobox.com> wrote:
> >> "Shawn O. Pearce" <spearce@spearce.org> writes:
> >> 
> >> > +	sed -e "
> >> > +		s/
> >> > //
> >> 
> >> This chomped line is so unlike you---what happened?
> 
> What I meant was the patch corruption.  I couldn't tell what you were
> trying to filter with the first substitution you are giving to sed.

Oh, that.  Its a literal CR on the search side, nothing on the
replace side.

-- 
Shawn.

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Tay Ray Chuan]

Hi,

On Thu, Oct 29, 2009 at 8:00 AM, Shawn O. Pearce <spearce@spearce.org> wrote:
> The top level directory "/git/" of the test Apache server is mapped
> through our git-http-backend CGI, but uses the same underlying
> repository space as the server's document root.  This is the most
> simple installation possible.

Having "/git/" reside as a subdirectory in "/" where WebDAV is enabled
may be confusing to readers. I think we should use "/smart/" for the
CGI map, and consequently, use "/dumb/" for WebDAV repositories,
rather than the root "/" that it is occupying.

> diff --git a/t/t5541-http-push.sh b/t/t5541-http-push.sh
>[snip]
> +test_expect_success 'push to remote repository with packed refs' '
> +       cd "$ROOT_PATH"/test_repo_clone &&
> +       : >path2 &&
> +       git add path2 &&
> +       test_tick &&
> +       git commit -m path2 &&
> +       HEAD=$(git rev-parse --verify HEAD) &&
> +       git push &&
> +       (cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
> +        test $HEAD = $(git rev-parse --verify HEAD))
> +'
> +
> +test_expect_success 'push already up-to-date' '
> +       git push
> +'
> +
> +test_expect_success 'push to remote repository with unpacked refs' '
> +       (cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
> +        rm packed-refs &&
> +        git update-ref refs/heads/master $ORIG_HEAD) &&
> +       git push &&
> +       (cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
> +        test $HEAD = $(git rev-parse --verify HEAD))
> +'

Mention of "packed refs" should be removed from the description, and
the 'unpacked refs' test, irrelevant in this context, should be
removed too. The assumptions these tests are based on is relevant to
t5540, but not in t5541. My explanation follows.

(Clemens, the following also addresses your non-desire to remove the
"unpacked refs" test in your earlier email
<20091025161630.GB8532@localhost>.)

In the "old" (v1.6.5) http push mechanism, no refspec is passed to the
http-push helper. This shouldn't be the case, because match_refs is
done in transport.c::transport_push, but then transport->push_refs
isn't defined so this doesn't happen.

http-push is then depended on to learn of the remote refs and match
them itself, but it does badly at this, since it only recurses through
/refs/heads in the remote repository. None could be found, since
they've all been packed. Thus the push in the first test failed.
Nothing has been pushed to the remote repository. The following push
in the "unpacked refs" corrects this after "unpacking" the refs.

Clearly, these test are about the ability of http push mechanism to
learn of refs in /refs/heads and (lack thereof) from /packed-refs.

But in this patch series, this is no longer the case.
transport->push_refs is now defined, so what happens is that the
http-push helper is passed a refspec, unlike in the "old" mechanism.
http-push, using this refspec, now matches refs properly (though it
still does its recursion thing). Thus the push in the first test
(should) succeed. The push in the "unpacked refs" test is now
irrelevant, since the first push has already successfully pushed
changes to the remote repository.

So, what we should have is just one no-frills push test, keeping as
well the "push already up-to-date" test.

-- 
Cheers,
Ray Chuan

Re: [RFC PATCH v4 26/26] test smart http fetch and push

[Shawn O. Pearce]

Tay Ray Chuan <rctay89@gmail.com> wrote:
> 
> Having "/git/" reside as a subdirectory in "/" where WebDAV is enabled
> may be confusing to readers. I think we should use "/smart/" for the
> CGI map, and consequently, use "/dumb/" for WebDAV repositories,
> rather than the root "/" that it is occupying.

Yup, great idea.  Patch added to switch to /dumb/ for WebDAV,
and changed to use /smart/ for this patch.
 
> Mention of "packed refs" should be removed from the description, and
> the 'unpacked refs' test, irrelevant in this context, should be
> removed too. The assumptions these tests are based on is relevant to
> t5540, but not in t5541. My explanation follows.

Yup, you are right, thanks.  Fixed.
 
-- 
Shawn.

Re: [RFC PATCH v4 00/26] Return of smart HTTP

[Jakub Narebski]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> I think this is the final spin of the smart HTTP series.  I've
> collected patches from a few others (thanks folks!)  and added
> tests specific to the smart variant of the HTTP transport.
> 
> At this point, I think it is "next ready"... but would appreciate
> any additional feedback if folks identify something we should
> address before hitting next.
[...]

>  .gitignore                           |    1 +
>  Documentation/config.txt             |    8 +
>  Documentation/git-http-backend.txt   |  170 ++++++++
>  Documentation/git-remote-helpers.txt |   85 ++++-
>  Makefile                             |    1 +
[...]

>  32 files changed, 2574 insertions(+), 223 deletions(-)
>  create mode 100644 Documentation/git-http-backend.txt
>  create mode 100644 http-backend.c
>  create mode 100755 t/t5541-http-push.sh
>  create mode 100755 t/t5551-http-fetch.sh
 
If it is a final spin, then what of missing RFC-like documentation of
Git HTTP protocol in Documentation/technical/http-protocol.txt
(it was present only in first version of new series)?

-- 
Jakub Narebski
Poland
ShadeHawk on #git

Re: [RFC PATCH v4 00/26] Return of smart HTTP

[Shawn O. Pearce]

Jakub Narebski <jnareb@gmail.com> wrote:
> "Shawn O. Pearce" <spearce@spearce.org> writes:
> 
> > I think this is the final spin of the smart HTTP series.
>  
> If it is a final spin, then what of missing RFC-like documentation of
> Git HTTP protocol in Documentation/technical/http-protocol.txt
> (it was present only in first version of new series)?

Its still incomplete.  I want to get the code cooking while I work
on the documentation.  Its a separate patch anyway, whether or not
its in the middle of the code series or after it is doesn't matter.

-- 
Shawn.