* Re: log: option "--follow" not the default for a single file?
From: Jeff King @ 2011-12-01 20:36 UTC (permalink / raw)
To: Ralf Thielow; +Cc: git
In-Reply-To: <CAN0XMOKrCovkmmdqu2GjsDof0wehfbf5a0EQuPo0q7GQaJ=GRQ@mail.gmail.com>
On Thu, Dec 01, 2011 at 09:28:31PM +0100, Ralf Thielow wrote:
> > It's possible, but it is changing the meaning of "git log foo". With
> > the current code, even if "foo" is currently a file, it will match
> > "foo/bar" in a prior revision. Switching this to "--follow" will not.
>
> Why does it actually match both things? I think that's
> maybe wrong.
Because that's what the path argument to "git log" is designed to do --
limit revision traversal based on pathspecs.
You can argue that the "--follow" semantics are more meaningful, but it
doesn't change the fact that it is a behavior change. We have to
consider not only backwards compatibility, but also the confusing-ness
of an inconsistent interface where:
git log foo bar
will treat "foo" as a pathspec, but:
git log foo
will treat it as a file.
> Also I can't use "git log" with another
> file/folder doesn't exists but in another revision. What actually
> exists is the file and that's imho the only thing that should match.
You can:
git log -- existed-long-ago
As a syntax shortcut, you can drop the "--". However, there is some
ambiguity with revision arguments, so git allows path arguments without
a "--" only when they exist in the filesystem (_not_ in a particular
revision).
-Peff
^ permalink raw reply
* [PATCH] Add MYMETA.yml to perl/.gitignore
From: Sebastian Morr @ 2011-12-01 20:31 UTC (permalink / raw)
To: git
This file is auto-generated in the process of building the Perl
extension.
Signed-off-by: Sebastian Morr <sebastian@morr.cc>
---
Good day, fine Sirs and Madams,
I just built Git for the first time, issued "git status", and there
was this untracked file. I guess you could call that an itch. This patch
fixes that, however, I'm not sure whether this is a relevant issue.
Didn't know whom to Cc, as the perl directory doesn't seem to get much
attention lately.
Kind regards,
Sebastian
perl/.gitignore | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/perl/.gitignore b/perl/.gitignore
index 98b2477..9235e73 100644
--- a/perl/.gitignore
+++ b/perl/.gitignore
@@ -1,5 +1,6 @@
perl.mak
perl.mak.old
+MYMETA.yml
blib
blibdirs
pm_to_blib
--
1.7.8.rc4.dirty
^ permalink raw reply related
* Re: Workflow Recommendation - Probably your 1000th
From: bradford @ 2011-12-01 20:46 UTC (permalink / raw)
To: Stephen Bash; +Cc: git
In-Reply-To: <363b3901-eee6-4265-adae-267f4662a1f7@mail>
Thanks, Stephen. I guess I'm looking for more input on the
advantages and disadvantages of using a QA and production branch vs
just doing everything out of master.
Trying to go through the following:
http://news.ycombinator.com/item?id=1617425
scottchacon.com/2011/08/31/github-flow.html
We have some weeks where we release very frequently and some weeks
where we release only once a week and have to do production fixes in
the meantime. Sure other people have similar experiences.
On Thu, Dec 1, 2011 at 1:55 PM, Stephen Bash <bash@genarts.com> wrote:
> ----- Original Message -----
>> From: "bradford" <fingermark@gmail.com>
>> To: git@vger.kernel.org
>> Sent: Thursday, December 1, 2011 1:26:10 PM
>> Subject: Workflow Recommendation - Probably your 1000th
>>
>> You guys probably receive a ton of workflow related questions. I'm
>> trying to convert from svn to git. In order to complete, I would
>> like to be able to provide a workflow to our team. We typically go
>> from dev -> qa -> production (Java and Rails projects). The problem
>> is that sometimes QA can get backed up and we'll need to release
>> something to production while QA is doing their thing. What is a
>> good workflow? I would like to not use git-flow, because it's another
>> tool.
>
> Hey wow... I read that Driessen's workflow post [1] a long time ago, but hadn't run into the git-flow tools until a few days ago. Guess I was just oblivious... Anyway, if it's any consolation, my company runs a model very much inspired by Driessen's post without using git-flow itself.
>
> [1] http://nvie.com/posts/a-successful-git-branching-model/
>
>> I've read suggestions to use environment branches (master,
>> staging, production). I've also read not to do this and just use
>> master, tagging your production releases. How well would our setup,
>> where things can get backed up, work with the latter? Are there any
>> alternative suggestions?
>
> In our workflow we flip Driessen's model on its head. master is the newest code, while we branch off maintenance branches just before each release. We tag each release so it's easy to identify which versions in the field contain a given bug or fix (multiple minor versions come off a single maintenance branch). Our QA guys follow the maintenance branches (they're relatively stable). We recently had to do a hot-fix release which I think would be similar to your "release to production". Basically we found the last commit on the maintenance branch that was well tested, created a new branch from there, did the hot fix, QA did some real fast testing (sounds like you'd skip this step), and we shipped that. As always that hot-fix release gets tagged, so in the future we can still reference that particular build (and in this case the branch merged back into the maintenance branch -- we've had other situations where the branch was simply deleted after tagging).
>
> In the grand scheme of things our model isn't that different than Driessen's; we just name the branches differently. Commits go on the oldest branch that's safe for them, and then everything merges to the newer branches. Tags provide easy reference for where on a given branch a release came from.
>
> Hope that helps.
>
> Stephen
^ permalink raw reply
* Re: Proposal: create meaningful aliases for git reset's hard/soft/mixed
From: Phil Hord @ 2011-12-01 21:02 UTC (permalink / raw)
To: Junio C Hamano; +Cc: Philippe Vaucher, git, Christian Couder
In-Reply-To: <7vlir6brjw.fsf@alter.siamese.dyndns.org>
On Wed, Nov 23, 2011 at 1:51 PM, Junio C Hamano <gitster@pobox.com> wrote:
> "git reset --hard HEAD" is an unambiguously descriptive good name for the
> option. It is a "hard reset" like power cycling a machinery to discard
> anything in progress and get back to a clean slate. I do not see anything
> confusing with this mode nor its name.
As a git expert-user, I agree.
But, honestly, as a git new-user, I had a lot of trouble with this
command. It is mysterious and powerful and new users do not
understand it. Everyone learns "git reset --hard HEAD" as a single
command. Only much later (if ever) do they learn about the other
git-reset options. --hard is the only useful option for the new user,
so it seems superfluous. HEAD is a foreign concept for the new-user
and makes little sense when this command is first memorized. And at
the early stages of the git learning curve, that's what it is:
memorized. _The spelling is what counts; the meaning is mysterious._
(For all its flaws, though, at least "git reset --hard HEAD" serves to
introduce the new-user to the concept of HEAD.)
So, as a git new-user, what I wanted was this:
git clean-checkout [or "git checkout --clean"]
What I found instead was this:
git reset --hard HEAD
What does this have to do with "checking out my files from the last
commit" or "discarding my local, uncommitted edits"? To the new-user,
nothing at all. reset? Meaningless. --hard? Whatever. HEAD?
Shrug.
In the end it doesn't even do what I wanted. What I really wanted was this:
git reset --hard HEAD && git clean -fd
I think the git-reset modes should be relegated to plumbing. I can
see how 'git reset --mixed' is useful for resetting changes out of the
index, but reset is so mired in all sorts of extra mumbo-jumbo that
this usage becomes a forgotten detail for me. I didn't even learn
that usage until later, where it makes loads of sense on its own:
FTH: This means that git reset <paths> is the opposite of git add <paths>.
That is beautiful, clean and useful. If that's all it did, it would be perfect.
Problems with git-reset--hard:
* It has no safety nets (except the reflog, another concept foreign
to new-users)
* It requires extra switches/arguments to be useful
* Surprisingly (at first), it can move your branch, but it's not
spelled 'branch' or 'commit' or 'move'
That last one is particularly troubling in light of the description of
'git reset --hard':
Resets the index and working tree. Any changes to tracked
files in the working tree since <commit> are discarded.
Maybe we should add "and by the way, your currently checked-out branch
is moved to point to <commit>".
</rant>
Phil
^ permalink raw reply
* Re: Proposal: create meaningful aliases for git reset's hard/soft/mixed
From: Phil Hord @ 2011-12-01 21:23 UTC (permalink / raw)
To: Philippe Vaucher; +Cc: Junio C Hamano, git, Christian Couder
In-Reply-To: <CAGK7Mr5nQoubAw11KDj4WKwQnXrfgteKbMj2=AR-HhsGKi52wQ@mail.gmail.com>
On Wed, Nov 23, 2011 at 6:00 PM, Philippe Vaucher
<philippe.vaucher@gmail.com> wrote:
>> In any case, I think your proposal makes it even worse than the current
>> state, and you should aim higher.
>
> Why worse? I'd understand if you said it's doesn't improve it enough
> for it to be worth the change tho.
I think that's what "you should aim higher" means.
> Anyway, my proposal was to get a discussion going, and I'm all for
> aiming higher if there's a way. What do you propose instead? You
> seemed to imply we'd remove --soft and --merge, and make --keep as an
> option for --hard but named differently, something like
> --keep-changes. Maybe I didn't fully understand.
I think there are too many scripts dependent on these switches to
remove them. But I love the direction you're going in.
Aim higher.
> Mathieu even suggested that it'd have the behavior of --keep by
> default, and that you have to add --force to get today's --hard
> behavior, which sounds like a good idea to me (avoid destructive
> behavior by default).
Think outside the "reset" command. Like this:
>From the "most popular" comment on http://progit.org/2011/07/11/reset.html:
> I remember them as:
> --soft -> git uncommit
> --mixed -> git unadd
> --hard -> git undo
I don't particular like these names, but conceptually they are helpful.
What other commands can we embellish or create to replace the overload
git-reset functionality?
How about:
--soft: git checkout -B <commit>
--mixed: git reset -- <paths>
--hard: git checkout --clean
Phil
^ permalink raw reply
* Re: [PATCHv2 0/4] git-p4: small fixes to branches and labels; tests
From: Vitor Antunes @ 2011-12-01 21:59 UTC (permalink / raw)
To: Pete Wyckoff; +Cc: git, Luke Diamand
In-Reply-To: <CAOpHH-UMdLpCPx1+D2dtQJs+=t1+0U2srKfTwBi-TEF4F7EDyw@mail.gmail.com>
On Dec 1, 2011 4:03 AM, "Pete Wyckoff" <pw@padd.com> wrote:
> I see your point. P4 labels are the only way that they support
> tagging, apparently. I'm okay with leaving label support in
> git-p4. And it will be nice if Luke makes it behave a bit
> better. But doing heroics to emulate cross-commit tags feels
> like a lot of work, and the wrong direction.
Agreed. Lets keep it simple.
--
Vitor Antunes
^ permalink raw reply
* Re: [PATCH] Add MYMETA.yml to perl/.gitignore
From: Jeff King @ 2011-12-01 22:35 UTC (permalink / raw)
To: Sebastian Morr; +Cc: git
In-Reply-To: <20111201203114.GA12796@thinkpad>
On Thu, Dec 01, 2011 at 09:31:15PM +0100, Sebastian Morr wrote:
> This file is auto-generated in the process of building the Perl
> extension.
>
> [...]
>
> I just built Git for the first time, issued "git status", and there
> was this untracked file. I guess you could call that an itch. This patch
> fixes that, however, I'm not sure whether this is a relevant issue.
Thanks, I wrote the same patch myself last week. I could swear I sent it
to the list, but it appears that I forgot.
The only thing I would add is the reason this is suddenly coming up now:
generating MYMETA.yml is done only by new-ish versions of
ExtUtils::MakeMaker (it started for me with perl 5.14, which just hit
debian unstable recently). The file just contains extra information
about the environment and arguments to the Makefile-building process,
and can be safely deleted.
-Peff
^ permalink raw reply
* Re: [HELP] Adding git awareness to the darning patch management system.
From: Peter Williams @ 2011-12-01 23:32 UTC (permalink / raw)
To: Jeff King; +Cc: git
In-Reply-To: <20111201062733.GB22141@sigill.intra.peff.net>
On 01/12/11 16:27, Jeff King wrote:
> On Thu, Dec 01, 2011 at 10:56:59AM +1000, Peter Williams wrote:
>
>>> I'm not exactly sure what this means.
>>
>> If you look at the screenshots at sourceforge (which were produced on
>> top of a Mercurial repo) you'll notice that file names in the left
>> most tree have letters in front of them and appear in different
>> foreground colours. These letters are the same as those returned by
>> Mercurial's status command and, hence, give a Mercurial user an easy
>> to understand snapshot of the status of the files in the playground.
>> The colour coding is (relatively) arbitrary (and chosen by me) and is
>> intended to make it easier to detect the different file statuses.
>>
>> My main problem is that I can't find a git file status command (and
>> there are a lot of them to choose from) that gives a snapshot of the
>> statuses of all files in a directory (including those not tracked or
>> ignored).
>
> Thanks, that helps. You probably just want to use "git status
> --porcelain", which will show you the state of file modification with
> respect to the index and the prior commit, as well as any untracked
> files. See the "porcelain format" section in "git help status".
>
> Note that "git status" will not print files which are not modified. You
> may want to also run "git ls-files" to get the full listing of files,
> including unmodified ones.
>
>> A secondary problem is that, if I could cobble together statuses from
>> various commands, mapping git statuses to the Mercurial ones for
>> display would not be a good solution as they would not necessarily
>> make sense to a git user. (It's fairly clear to me from my inability
>> to make sense of git's CLI that git users think differently to me, a
>> Mercurial user, and it's unlikely that I can, without help, make a
>> file tree display that makes sense to a git user.)
>
> I'm hoping that "git status --porcelain" will give you a fairly close
> mapping of the basic "what happened to this file" concept, based on what
> I see in the second screenshot you mentioned.
>
> The trickiest thing is the index, which represents an in-between state
> that is not usually exposed by other version control systems. If your
> tool does not make use of the index, then it probably makes sense to
> just consider a path as modified if it has modifications staged in the
> index or in the working tree, which maps to other VCS's idea of
> "modified" (because for them, marking something as to-be-committed and
> commiting it are part of the same step).
Yes, I think your right. For most of my purposes, I think that it's
irrelevant whether a change is staged or not and the choices that I
offer allow the user to do what he thinks is right for a file with
changes that are staged but uncommitted. For me to automatically do
something based on whether the file was staged for a commit would be a
mistake as I would be reducing the user's options.
However, the distinction might be worth making in the file tree display
to remind the user what's staged and what's not?
>
>>> For this, you probably want "git diff-files --name-only", which will
>>> show files with differences in the working tree. Keep in mind that git
>>> has an "index" or "staging area", which means that you have three states
>>> of content for a given path:
>>>
>>> 1. the state of the prior commit (i.e., HEAD)
>>>
>>> 2. the state that is marked to be committed when "git commit" is run
>>> (i.e., the index)
>>>
>>> 3. the state in the working tree
>>
>> This is a prime example of the different mindset of the git user to
>> the hg user.
>
> You don't have to use those features, of course. It's just that
> something like "git status" is going to report on the differences
> between those states, so as a tool writer you need to know they are
> there (and as I said above, you are free to simplify if it fits into the
> mental model of your tool).
>
>>> You can compare the first two with "git diff-index", and the latter two
>>> with "git diff-files". You can also use "git status --porcelain" to get
>>> a machine-readable output that shows how the three states match up, with
>>> one line per file.
>>
>> This is an example of why I'm confused. There are too many ways to
>> do (similar) things and it's hard to know which to use.
>
> Git is made of little building blocks. The original way to see the
> differences between the index and the working tree was via diff-files.
> But then people build bigger building blocks out of the smaller ones.
> "git status" is really just a shorthand for:
>
> git diff-index HEAD&&
> git diff-files&&
> git ls-files -o
>
> and is in fact implemented using those building blocks (originally as a
> shell script, though these days it is written in C). So you can choose
> either and get the same information. Choosing a higher-level building
> block may save you some work, if the abstraction matches what you want.
> Otherwise, you can compose what you want from the lower levels.
>
> I know it sometimes leads to an overwhelming number of commands, and I'm
> not trying to excuse git's tendency to confuse people. I'm just hoping
> to unconfuse you in this particular situation.
As an aside, I found it easier to delve into git's innards to find out
how to implement git binary patches than I did finding out how to do
things from the CLI :-).
>
> In your case, I think "status" is the most convenient level of
> abstraction for you, because you are interesting in looking at
> differences to both the index and HEAD (i.e., the prior commit). But if
> you find as you implement that want more flexibility, you can switch to
> using the lower-level commands yourself.
I'll investigate this approach. How easy is it to distinguish low level
commands from high level commands?
>
>> Maybe an example of why I think the feature is useful might help.
>> Say that you start editing a file and then decide that you want to
>> put this change into a patch rather than committing it. If you were
>> using quilt you would have to do this manually by any of a number or
>> ways such as:
>>
>> $<git diff command> file> temp.patch
>> $<git revert command> file
>> $ quilt new one.patch
>> $ quilt add file
>> $ patch -p1 file< temp.patch
>> $ rm temp.patch
>>
>> In darning, you just do:
>>
>> $ darn new one.patch
>> $ darn add --absorb file
>
> Sure. We have stgit and topgit, which do similar patch management things
> on top of git. I don't personally user either, though, so I don't have
> much to say on how they compare to darning, or whether it is worth
> looking at their implementations.
And there's MQ on top of hg. I find the idea of doing "temporary"
commits (which is what these tools are essentially doing) a little risky
(e.g. what happens if you do a push with temporary commits in place).
With MQ, I use its hook system to prevent this happening and I imagine
git provides something similar.
Of course, these tools have the advantage that it's easier to promote a
patch to a full blown commit than it is for quilt or darning in its
current form (I'm thinking about how to do this). At this stage,
darning is targeted at the user who has to maintain a set of patches on
top of a third party source tree without the need to eventually commit
the changes themselves (i.e. distribution managers).
I've never used stgit or topgit but I have used both quilt and MQ a lot.
I find them both quite usable but each with their own set of
advantages and disadvantages hence my attempt to make a tool as much
like them as possible but with a smaller set of disadvantages.
>
>> The interface to the SCM to support this is two functions:
>>
>> 1: get_files_with_uncommitted_changes() which called with no
>> arguments returns a list of the paths of all files with uncommitted
>> changes or when given a list of file paths (the more common case)
>> returns the subset of that list which have uncommitted changes; and
>
> "status" will do this for you, modulo the simplification of the concept
> of the index, as we discussed above.
>
>> 2. copy_clean_version_to(filepath, target_path) which makes a copy of
>> the file as recorded in the prior commit and places it at the
>> target_path (usually where darning stores the "original" for
>> reference when creating diffs).
>
> You probably want:
>
> git cat-file blob HEAD:filepath>target_path
>
I think I might do this in two stages. First, just do the bit about
adding files and pushing (as that is the most useful) and leave the file
tree as a vanilla tree for the time being (as it looks like it may be
more complicated).
Thanks for your help,
Peter
^ permalink raw reply
* Re: [HELP] Adding git awareness to the darning patch management system.
From: Jeff King @ 2011-12-01 23:40 UTC (permalink / raw)
To: Peter Williams; +Cc: git
In-Reply-To: <4ED80EA2.80805@users.sourceforge.net>
On Fri, Dec 02, 2011 at 09:32:50AM +1000, Peter Williams wrote:
> Yes, I think your right. For most of my purposes, I think that it's
> irrelevant whether a change is staged or not and the choices that I
> offer allow the user to do what he thinks is right for a file with
> changes that are staged but uncommitted. For me to automatically do
> something based on whether the file was staged for a commit would be
> a mistake as I would be reducing the user's options.
>
> However, the distinction might be worth making in the file tree
> display to remind the user what's staged and what's not?
I'd personally start with ignoring the distinction, and then wait for
some enterprising user to suggest how it would be marked. That takes the
burden off of you for guessing what representation would be best.
> As an aside, I found it easier to delve into git's innards to find
> out how to implement git binary patches than I did finding out how to
> do things from the CLI :-).
Heh. I think that is because the CLI is written by people (myself
included) who want it to give them access to git's innards. ;)
> >In your case, I think "status" is the most convenient level of
> >abstraction for you, because you are interesting in looking at
> >differences to both the index and HEAD (i.e., the prior commit). But if
> >you find as you implement that want more flexibility, you can switch to
> >using the lower-level commands yourself.
>
> I'll investigate this approach. How easy is it to distinguish low
> level commands from high level commands?
git(1) has a list of "porcelain" and "plumbing" commands. If you are
scripting, you generally want to stick with plumbing commands,
lower-level whose output and behavior remains stable across releases.
However, some porcelain commands offer a "plumbing" mode (despite the
name, the "--porcelain" flag to some commands is what you want; it is
about offering parseable output that a custom porcelain could use. In
git lingo, your interface is one such porcelain).
-Peff
^ permalink raw reply
* Re: clean bug on ignored subdirectories with no tracked files?
From: Phil Hord @ 2011-12-01 23:35 UTC (permalink / raw)
To: Phil Hord, Jay Soffian; +Cc: Junio C Hamano, git
In-Reply-To: <CABURp0qv7MB-ZQvvSZQi43nAy1ZaR75-19T2Sd1JBT14Y_dG7w@mail.gmail.com>
On Mon, Nov 21, 2011 at 3:03 PM, Jay Soffian <jaysoffian@gmail.com> wrote:
> On Mon, Nov 21, 2011 at 2:28 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> "clean" without "-x" is meant to preserve untracked but expendable paths
>> (e.g. build products), so if something is removed that is untracked but
>> matches the ignore pattern, then that is a bug to be fixed. Care to roll
>> a patch to fix it?
> Okay, just confirming it is a bug. I'll add this e-mail to my todo
> list, but I don't have time for a patch anytime soon.
I think the fix is in dir.c (treat_directory), but I'm not sure how yet.
How's this for starters?
-- >8 --
Subject: [PATCH] clean: Test known breakage of .gitignore and -d
git-clean -d is used to remove untracked directories. If the
directory still contains .gitignored files it should not be removed.
But git is broken here if neither the ignored files nor the directory
are explicitly ignored.
Document this known breakage with a test for both cases.
Noticed-by: Jay Soffian <jaysoffian@gmail.com>
Signed-off-by: Phil Hord <hordp@cisco.com>
---
t/t7300-clean.sh | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/t/t7300-clean.sh b/t/t7300-clean.sh
index 800b536..e29e383 100755
--- a/t/t7300-clean.sh
+++ b/t/t7300-clean.sh
@@ -14,6 +14,7 @@ test_expect_success 'setup' '
mkdir -p src &&
touch src/part1.c Makefile &&
echo build >.gitignore &&
+ echo /foo/bar >>.gitignore &&
echo \*.o >>.gitignore &&
git add . &&
git commit -m setup &&
@@ -264,6 +265,20 @@ test_expect_success 'git clean -d src/ examples/' '
'
+test_expect_failure 'git clean -d leaves .gitignored files alone' '
+
+ mkdir -p objs foo/bar &&
+ touch objs/foo.o &&
+ touch foo/gone &&
+ touch foo/bar/baz &&
+ git clean -nd &&
+ git clean -d &&
+ test ! -f foo/gone &&
+ test -f foo/bar/baz &&
+ test -f objs/foo.o
+
+'
+
test_expect_success 'git clean -x' '
mkdir -p build docs &&
--
1.7.8.rc4
^ permalink raw reply related
* Git Install link is broken
From: Graham Wideman @ 2011-12-01 23:56 UTC (permalink / raw)
To: git
Hi folks:
On this page:
http://code.google.com/p/msysgit/
the links to "install msysGit" point to:
https://git.wiki.kernel.org/index.php/MSysGit:InstallMSysGit
.. which returns page not found error.
-- Graham
^ permalink raw reply
* [PATCH v3 0/6] Bulk check-in
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322699263-14475-6-git-send-email-gitster@pobox.com>
I would declare that the earlier parts of the v2 that are about factoring
out various API pieces from existing code are basically completed, so they
are not part of this iteration.
The bulk-checkin patch from v2 has been tweaked a bit (deflate_to_pack()
initializes "already_hashed_to" pointer to 0, instead of the current file
position "seekback"), and then the rest of the series builds on top of it
to add a new in-pack encoding that I am tentatively calling "chunked".
The basic idea is to represent a large/huge blob as a concatenation of
smaller blobs. An entry in a pack in "chunked" representation records a
list of object names of the component blob objects. The object name given
to such a blob is computed exactly the same way as before. In other words,
the name of a object does not depend on its representation; we hash "blob
<size> NUL" and the whole large blob contents to come up with its name. It
is *not* the hash of the component blob object names.
As can be seen in the log message of the "support chunked-object encoding"
patch, many pieces are still missing from this series and filling them
will be a long and tortuous journey. But we need to start somewhere.
I specifically excluded any heuristics to split large objects into chunks
in a self-synchronising way so that a small edit near the beginning of a
large blob results in a handful of new component blobs followed by the
same component blobs as used to represent the same blob before such an
edit, and I do not plan to work on that part myself. My impression from
listening Avery's plug for "bup" is that it is a solved problem; it should
be reasonably straightforward to lift the logic and plug it into the
framework presented here (once the codebase gets solid enough, that is).
After this series, the next step for me is likely to teach the streaming
interface about "chunked" objects, and then pack-objects to take notice
and reuse "chunked" representation when sending things out (which means
that sending a "chunked" encoded blob would involve sending the component
blobs it uses, among other things), but I expect that it will extend well
into next year.
Junio C Hamano (6):
bulk-checkin: replace fast-import based implementation
varint-in-pack: refactor varint encoding/decoding
new representation types in the packstream
bulk-checkin: allow the same data to be multiply hashed
bulk-checkin: support chunked-object encoding
chunked-object: fallback checkout codepaths
Makefile | 3 +
builtin/add.c | 5 +
builtin/pack-objects.c | 34 ++---
bulk-checkin.c | 415 ++++++++++++++++++++++++++++++++++++++++++++++++
bulk-checkin.h | 17 ++
cache.h | 13 ++-
config.c | 9 +
environment.c | 2 +
pack-write.c | 50 +++++-
pack.h | 2 +
sha1_file.c | 150 +++++++++---------
split-chunk.c | 28 ++++
t/t1050-large.sh | 135 +++++++++++++++-
zlib.c | 9 +-
14 files changed, 760 insertions(+), 112 deletions(-)
create mode 100644 bulk-checkin.c
create mode 100644 bulk-checkin.h
create mode 100644 split-chunk.c
--
1.7.8.rc4.177.g4d64
^ permalink raw reply
* [PATCH v3 1/6] bulk-checkin: replace fast-import based implementation
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322786449-25753-1-git-send-email-gitster@pobox.com>
This extends the earlier approach to stream a large file directly from the
filesystem to its own packfile, and allows "git add" to send large files
directly into a single pack. Older code used to spawn fast-import, but the
new bulk-checkin API replaces it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Makefile | 2 +
builtin/add.c | 5 +
builtin/pack-objects.c | 6 +-
bulk-checkin.c | 275 ++++++++++++++++++++++++++++++++++++++++++++++++
bulk-checkin.h | 16 +++
cache.h | 2 +
config.c | 4 +
environment.c | 1 +
sha1_file.c | 67 +-----------
t/t1050-large.sh | 94 +++++++++++++++--
zlib.c | 9 ++-
11 files changed, 403 insertions(+), 78 deletions(-)
create mode 100644 bulk-checkin.c
create mode 100644 bulk-checkin.h
diff --git a/Makefile b/Makefile
index 3139c19..418dd2e 100644
--- a/Makefile
+++ b/Makefile
@@ -505,6 +505,7 @@ LIB_H += argv-array.h
LIB_H += attr.h
LIB_H += blob.h
LIB_H += builtin.h
+LIB_H += bulk-checkin.h
LIB_H += cache.h
LIB_H += cache-tree.h
LIB_H += color.h
@@ -591,6 +592,7 @@ LIB_OBJS += base85.o
LIB_OBJS += bisect.o
LIB_OBJS += blob.o
LIB_OBJS += branch.o
+LIB_OBJS += bulk-checkin.o
LIB_OBJS += bundle.o
LIB_OBJS += cache-tree.o
LIB_OBJS += color.o
diff --git a/builtin/add.c b/builtin/add.c
index c59b0c9..1c42900 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -13,6 +13,7 @@
#include "diff.h"
#include "diffcore.h"
#include "revision.h"
+#include "bulk-checkin.h"
static const char * const builtin_add_usage[] = {
"git add [options] [--] <filepattern>...",
@@ -458,11 +459,15 @@ int cmd_add(int argc, const char **argv, const char *prefix)
free(seen);
}
+ plug_bulk_checkin();
+
exit_status |= add_files_to_cache(prefix, pathspec, flags);
if (add_new_files)
exit_status |= add_files(&dir, flags);
+ unplug_bulk_checkin();
+
finish:
if (active_cache_changed) {
if (write_cache(newfd, active_cache, active_nr) ||
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index b458b6d..dde913e 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -76,7 +76,7 @@ static struct pack_idx_option pack_idx_opts;
static const char *base_name;
static int progress = 1;
static int window = 10;
-static unsigned long pack_size_limit, pack_size_limit_cfg;
+static unsigned long pack_size_limit;
static int depth = 50;
static int delta_search_threads;
static int pack_to_stdout;
@@ -2009,10 +2009,6 @@ static int git_pack_config(const char *k, const char *v, void *cb)
pack_idx_opts.version);
return 0;
}
- if (!strcmp(k, "pack.packsizelimit")) {
- pack_size_limit_cfg = git_config_ulong(k, v);
- return 0;
- }
return git_default_config(k, v, cb);
}
diff --git a/bulk-checkin.c b/bulk-checkin.c
new file mode 100644
index 0000000..6b0b6d4
--- /dev/null
+++ b/bulk-checkin.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright (c) 2011, Google Inc.
+ */
+#include "bulk-checkin.h"
+#include "csum-file.h"
+#include "pack.h"
+
+static int pack_compression_level = Z_DEFAULT_COMPRESSION;
+
+static struct bulk_checkin_state {
+ unsigned plugged:1;
+
+ char *pack_tmp_name;
+ struct sha1file *f;
+ off_t offset;
+ struct pack_idx_option pack_idx_opts;
+
+ struct pack_idx_entry **written;
+ uint32_t alloc_written;
+ uint32_t nr_written;
+} state;
+
+static void finish_bulk_checkin(struct bulk_checkin_state *state)
+{
+ unsigned char sha1[20];
+ char packname[PATH_MAX];
+ int i;
+
+ if (!state->f)
+ return;
+
+ if (state->nr_written == 0) {
+ close(state->f->fd);
+ unlink(state->pack_tmp_name);
+ goto clear_exit;
+ } else if (state->nr_written == 1) {
+ sha1close(state->f, sha1, CSUM_FSYNC);
+ } else {
+ int fd = sha1close(state->f, sha1, 0);
+ fixup_pack_header_footer(fd, sha1, state->pack_tmp_name,
+ state->nr_written, sha1,
+ state->offset);
+ close(fd);
+ }
+
+ sprintf(packname, "%s/pack/pack-", get_object_directory());
+ finish_tmp_packfile(packname, state->pack_tmp_name,
+ state->written, state->nr_written,
+ &state->pack_idx_opts, sha1);
+ for (i = 0; i < state->nr_written; i++)
+ free(state->written[i]);
+
+clear_exit:
+ free(state->written);
+ memset(state, 0, sizeof(*state));
+
+ /* Make objects we just wrote available to ourselves */
+ reprepare_packed_git();
+}
+
+static int already_written(struct bulk_checkin_state *state, unsigned char sha1[])
+{
+ int i;
+
+ /* The object may already exist in the repository */
+ if (has_sha1_file(sha1))
+ return 1;
+
+ /* Might want to keep the list sorted */
+ for (i = 0; i < state->nr_written; i++)
+ if (!hashcmp(state->written[i]->sha1, sha1))
+ return 1;
+
+ /* This is a new object we need to keep */
+ return 0;
+}
+
+/*
+ * Read the contents from fd for size bytes, streaming it to the
+ * packfile in state while updating the hash in ctx. Signal a failure
+ * by returning a negative value when the resulting pack would exceed
+ * the pack size limit and this is not the first object in the pack,
+ * so that the caller can discard what we wrote from the current pack
+ * by truncating it and opening a new one. The caller will then call
+ * us again after rewinding the input fd.
+ *
+ * The already_hashed_to pointer is kept untouched by the caller to
+ * make sure we do not hash the same byte when we are called
+ * again. This way, the caller does not have to checkpoint its hash
+ * status before calling us just in case we ask it to call us again
+ * with a new pack.
+ */
+static int stream_to_pack(struct bulk_checkin_state *state,
+ git_SHA_CTX *ctx, off_t *already_hashed_to,
+ int fd, size_t size, enum object_type type,
+ const char *path, unsigned flags)
+{
+ git_zstream s;
+ unsigned char obuf[16384];
+ unsigned hdrlen;
+ int status = Z_OK;
+ int write_object = (flags & HASH_WRITE_OBJECT);
+ off_t offset = 0;
+
+ memset(&s, 0, sizeof(s));
+ git_deflate_init(&s, pack_compression_level);
+
+ hdrlen = encode_in_pack_object_header(type, size, obuf);
+ s.next_out = obuf + hdrlen;
+ s.avail_out = sizeof(obuf) - hdrlen;
+
+ while (status != Z_STREAM_END) {
+ unsigned char ibuf[16384];
+
+ if (size && !s.avail_in) {
+ ssize_t rsize = size < sizeof(ibuf) ? size : sizeof(ibuf);
+ if (xread(fd, ibuf, rsize) != rsize)
+ die("failed to read %d bytes from '%s'",
+ (int)rsize, path);
+ offset += rsize;
+ if (*already_hashed_to < offset) {
+ size_t hsize = offset - *already_hashed_to;
+ if (rsize < hsize)
+ hsize = rsize;
+ if (hsize)
+ git_SHA1_Update(ctx, ibuf, hsize);
+ *already_hashed_to = offset;
+ }
+ s.next_in = ibuf;
+ s.avail_in = rsize;
+ size -= rsize;
+ }
+
+ status = git_deflate(&s, size ? 0 : Z_FINISH);
+
+ if (!s.avail_out || status == Z_STREAM_END) {
+ if (write_object) {
+ size_t written = s.next_out - obuf;
+
+ /* would we bust the size limit? */
+ if (state->nr_written &&
+ pack_size_limit_cfg &&
+ pack_size_limit_cfg < state->offset + written) {
+ git_deflate_abort(&s);
+ return -1;
+ }
+
+ sha1write(state->f, obuf, written);
+ state->offset += written;
+ }
+ s.next_out = obuf;
+ s.avail_out = sizeof(obuf);
+ }
+
+ switch (status) {
+ case Z_OK:
+ case Z_BUF_ERROR:
+ case Z_STREAM_END:
+ continue;
+ default:
+ die("unexpected deflate failure: %d", status);
+ }
+ }
+ git_deflate_end(&s);
+ return 0;
+}
+
+/* Lazily create backing packfile for the state */
+static void prepare_to_stream(struct bulk_checkin_state *state,
+ unsigned flags)
+{
+ if (!(flags & HASH_WRITE_OBJECT) || state->f)
+ return;
+
+ state->f = create_tmp_packfile(&state->pack_tmp_name);
+ reset_pack_idx_option(&state->pack_idx_opts);
+
+ /* Pretend we are going to write only one object */
+ state->offset = write_pack_header(state->f, 1);
+ if (!state->offset)
+ die_errno("unable to write pack header");
+}
+
+static int deflate_to_pack(struct bulk_checkin_state *state,
+ unsigned char result_sha1[],
+ int fd, size_t size,
+ enum object_type type, const char *path,
+ unsigned flags)
+{
+ off_t seekback, already_hashed_to;
+ git_SHA_CTX ctx;
+ unsigned char obuf[16384];
+ unsigned header_len;
+ struct sha1file_checkpoint checkpoint;
+ struct pack_idx_entry *idx = NULL;
+
+ seekback = lseek(fd, 0, SEEK_CUR);
+ if (seekback == (off_t) -1)
+ return error("cannot find the current offset");
+
+ header_len = sprintf((char *)obuf, "%s %" PRIuMAX,
+ typename(type), (uintmax_t)size) + 1;
+ git_SHA1_Init(&ctx);
+ git_SHA1_Update(&ctx, obuf, header_len);
+
+ /* Note: idx is non-NULL when we are writing */
+ if ((flags & HASH_WRITE_OBJECT) != 0)
+ idx = xcalloc(1, sizeof(*idx));
+
+ already_hashed_to = 0;
+
+ while (1) {
+ prepare_to_stream(state, flags);
+ if (idx) {
+ sha1file_checkpoint(state->f, &checkpoint);
+ idx->offset = state->offset;
+ crc32_begin(state->f);
+ }
+ if (!stream_to_pack(state, &ctx, &already_hashed_to,
+ fd, size, type, path, flags))
+ break;
+ /*
+ * Writing this object to the current pack will make
+ * it too big; we need to truncate it, start a new
+ * pack, and write into it.
+ */
+ if (!idx)
+ die("BUG: should not happen");
+ sha1file_truncate(state->f, &checkpoint);
+ state->offset = checkpoint.offset;
+ finish_bulk_checkin(state);
+ if (lseek(fd, seekback, SEEK_SET) == (off_t) -1)
+ return error("cannot seek back");
+ }
+ git_SHA1_Final(result_sha1, &ctx);
+ if (!idx)
+ return 0;
+
+ idx->crc32 = crc32_end(state->f);
+ if (already_written(state, result_sha1)) {
+ sha1file_truncate(state->f, &checkpoint);
+ state->offset = checkpoint.offset;
+ free(idx);
+ } else {
+ hashcpy(idx->sha1, result_sha1);
+ ALLOC_GROW(state->written,
+ state->nr_written + 1,
+ state->alloc_written);
+ state->written[state->nr_written++] = idx;
+ }
+ return 0;
+}
+
+int index_bulk_checkin(unsigned char *sha1,
+ int fd, size_t size, enum object_type type,
+ const char *path, unsigned flags)
+{
+ int status = deflate_to_pack(&state, sha1, fd, size, type,
+ path, flags);
+ if (!state.plugged)
+ finish_bulk_checkin(&state);
+ return status;
+}
+
+void plug_bulk_checkin(void)
+{
+ state.plugged = 1;
+}
+
+void unplug_bulk_checkin(void)
+{
+ state.plugged = 0;
+ if (state.f)
+ finish_bulk_checkin(&state);
+}
diff --git a/bulk-checkin.h b/bulk-checkin.h
new file mode 100644
index 0000000..4f599f8
--- /dev/null
+++ b/bulk-checkin.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2011, Google Inc.
+ */
+#ifndef BULK_CHECKIN_H
+#define BULK_CHECKIN_H
+
+#include "cache.h"
+
+extern int index_bulk_checkin(unsigned char sha1[],
+ int fd, size_t size, enum object_type type,
+ const char *path, unsigned flags);
+
+extern void plug_bulk_checkin(void);
+extern void unplug_bulk_checkin(void);
+
+#endif
diff --git a/cache.h b/cache.h
index 2e6ad36..4f20861 100644
--- a/cache.h
+++ b/cache.h
@@ -35,6 +35,7 @@ int git_inflate(git_zstream *, int flush);
void git_deflate_init(git_zstream *, int level);
void git_deflate_init_gzip(git_zstream *, int level);
void git_deflate_end(git_zstream *);
+int git_deflate_abort(git_zstream *);
int git_deflate_end_gently(git_zstream *);
int git_deflate(git_zstream *, int flush);
unsigned long git_deflate_bound(git_zstream *, unsigned long);
@@ -598,6 +599,7 @@ extern size_t packed_git_window_size;
extern size_t packed_git_limit;
extern size_t delta_base_cache_limit;
extern unsigned long big_file_threshold;
+extern unsigned long pack_size_limit_cfg;
extern int read_replace_refs;
extern int fsync_object_files;
extern int core_preload_index;
diff --git a/config.c b/config.c
index edf9914..c736802 100644
--- a/config.c
+++ b/config.c
@@ -797,6 +797,10 @@ int git_default_config(const char *var, const char *value, void *dummy)
return 0;
}
+ if (!strcmp(var, "pack.packsizelimit")) {
+ pack_size_limit_cfg = git_config_ulong(var, value);
+ return 0;
+ }
/* Add other config variables here and to Documentation/config.txt. */
return 0;
}
diff --git a/environment.c b/environment.c
index 0bee6a7..31e4284 100644
--- a/environment.c
+++ b/environment.c
@@ -60,6 +60,7 @@ char *notes_ref_name;
int grafts_replace_parents = 1;
int core_apply_sparse_checkout;
struct startup_info *startup_info;
+unsigned long pack_size_limit_cfg;
/* Parallel index stat data preload? */
int core_preload_index = 0;
diff --git a/sha1_file.c b/sha1_file.c
index 27f3b9b..c96e366 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -18,6 +18,7 @@
#include "refs.h"
#include "pack-revindex.h"
#include "sha1-lookup.h"
+#include "bulk-checkin.h"
#ifndef O_NOATIME
#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -2679,10 +2680,8 @@ static int index_core(unsigned char *sha1, int fd, size_t size,
}
/*
- * This creates one packfile per large blob, because the caller
- * immediately wants the result sha1, and fast-import can report the
- * object name via marks mechanism only by closing the created
- * packfile.
+ * This creates one packfile per large blob unless bulk-checkin
+ * machinery is "plugged".
*
* This also bypasses the usual "convert-to-git" dance, and that is on
* purpose. We could write a streaming version of the converting
@@ -2696,65 +2695,7 @@ static int index_stream(unsigned char *sha1, int fd, size_t size,
enum object_type type, const char *path,
unsigned flags)
{
- struct child_process fast_import;
- char export_marks[512];
- const char *argv[] = { "fast-import", "--quiet", export_marks, NULL };
- char tmpfile[512];
- char fast_import_cmd[512];
- char buf[512];
- int len, tmpfd;
-
- strcpy(tmpfile, git_path("hashstream_XXXXXX"));
- tmpfd = git_mkstemp_mode(tmpfile, 0600);
- if (tmpfd < 0)
- die_errno("cannot create tempfile: %s", tmpfile);
- if (close(tmpfd))
- die_errno("cannot close tempfile: %s", tmpfile);
- sprintf(export_marks, "--export-marks=%s", tmpfile);
-
- memset(&fast_import, 0, sizeof(fast_import));
- fast_import.in = -1;
- fast_import.argv = argv;
- fast_import.git_cmd = 1;
- if (start_command(&fast_import))
- die_errno("index-stream: git fast-import failed");
-
- len = sprintf(fast_import_cmd, "blob\nmark :1\ndata %lu\n",
- (unsigned long) size);
- write_or_whine(fast_import.in, fast_import_cmd, len,
- "index-stream: feeding fast-import");
- while (size) {
- char buf[10240];
- size_t sz = size < sizeof(buf) ? size : sizeof(buf);
- ssize_t actual;
-
- actual = read_in_full(fd, buf, sz);
- if (actual < 0)
- die_errno("index-stream: reading input");
- if (write_in_full(fast_import.in, buf, actual) != actual)
- die_errno("index-stream: feeding fast-import");
- size -= actual;
- }
- if (close(fast_import.in))
- die_errno("index-stream: closing fast-import");
- if (finish_command(&fast_import))
- die_errno("index-stream: finishing fast-import");
-
- tmpfd = open(tmpfile, O_RDONLY);
- if (tmpfd < 0)
- die_errno("index-stream: cannot open fast-import mark");
- len = read(tmpfd, buf, sizeof(buf));
- if (len < 0)
- die_errno("index-stream: reading fast-import mark");
- if (close(tmpfd) < 0)
- die_errno("index-stream: closing fast-import mark");
- if (unlink(tmpfile))
- die_errno("index-stream: unlinking fast-import mark");
- if (len != 44 ||
- memcmp(":1 ", buf, 3) ||
- get_sha1_hex(buf + 3, sha1))
- die_errno("index-stream: unexpected fast-import mark: <%s>", buf);
- return 0;
+ return index_bulk_checkin(sha1, fd, size, type, path, flags);
}
int index_fd(unsigned char *sha1, int fd, struct stat *st,
diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index deba111..29d6024 100755
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -7,21 +7,97 @@ test_description='adding and checking out large blobs'
test_expect_success setup '
git config core.bigfilethreshold 200k &&
- echo X | dd of=large bs=1k seek=2000
+ echo X | dd of=large1 bs=1k seek=2000 &&
+ echo X | dd of=large2 bs=1k seek=2000 &&
+ echo X | dd of=large3 bs=1k seek=2000 &&
+ echo Y | dd of=huge bs=1k seek=2500
'
-test_expect_success 'add a large file' '
- git add large &&
- # make sure we got a packfile and no loose objects
- test -f .git/objects/pack/pack-*.pack &&
- test ! -f .git/objects/??/??????????????????????????????????????
+test_expect_success 'add a large file or two' '
+ git add large1 huge large2 &&
+ # make sure we got a single packfile and no loose objects
+ bad= count=0 idx= &&
+ for p in .git/objects/pack/pack-*.pack
+ do
+ count=$(( $count + 1 ))
+ if test -f "$p" && idx=${p%.pack}.idx && test -f "$idx"
+ then
+ continue
+ fi
+ bad=t
+ done &&
+ test -z "$bad" &&
+ test $count = 1 &&
+ cnt=$(git show-index <"$idx" | wc -l) &&
+ test $cnt = 2 &&
+ for l in .git/objects/??/??????????????????????????????????????
+ do
+ test -f "$l" || continue
+ bad=t
+ done &&
+ test -z "$bad" &&
+
+ # attempt to add another copy of the same
+ git add large3 &&
+ bad= count=0 &&
+ for p in .git/objects/pack/pack-*.pack
+ do
+ count=$(( $count + 1 ))
+ if test -f "$p" && idx=${p%.pack}.idx && test -f "$idx"
+ then
+ continue
+ fi
+ bad=t
+ done &&
+ test -z "$bad" &&
+ test $count = 1
'
test_expect_success 'checkout a large file' '
- large=$(git rev-parse :large) &&
- git update-index --add --cacheinfo 100644 $large another &&
+ large1=$(git rev-parse :large1) &&
+ git update-index --add --cacheinfo 100644 $large1 another &&
git checkout another &&
- cmp large another ;# this must not be test_cmp
+ cmp large1 another ;# this must not be test_cmp
+'
+
+test_expect_success 'packsize limit' '
+ test_create_repo mid &&
+ (
+ cd mid &&
+ git config core.bigfilethreshold 64k &&
+ git config pack.packsizelimit 256k &&
+
+ # mid1 and mid2 will fit within 256k limit but
+ # appending mid3 will bust the limit and will
+ # result in a separate packfile.
+ test-genrandom "a" $(( 66 * 1024 )) >mid1 &&
+ test-genrandom "b" $(( 80 * 1024 )) >mid2 &&
+ test-genrandom "c" $(( 128 * 1024 )) >mid3 &&
+ git add mid1 mid2 mid3 &&
+
+ count=0
+ for pi in .git/objects/pack/pack-*.idx
+ do
+ test -f "$pi" && count=$(( $count + 1 ))
+ done &&
+ test $count = 2 &&
+
+ (
+ git hash-object --stdin <mid1
+ git hash-object --stdin <mid2
+ git hash-object --stdin <mid3
+ ) |
+ sort >expect &&
+
+ for pi in .git/objects/pack/pack-*.idx
+ do
+ git show-index <"$pi"
+ done |
+ sed -e "s/^[0-9]* \([0-9a-f]*\) .*/\1/" |
+ sort >actual &&
+
+ test_cmp expect actual
+ )
'
test_done
diff --git a/zlib.c b/zlib.c
index 3c63d48..2b2c0c7 100644
--- a/zlib.c
+++ b/zlib.c
@@ -188,13 +188,20 @@ void git_deflate_init_gzip(git_zstream *strm, int level)
strm->z.msg ? strm->z.msg : "no message");
}
-void git_deflate_end(git_zstream *strm)
+int git_deflate_abort(git_zstream *strm)
{
int status;
zlib_pre_call(strm);
status = deflateEnd(&strm->z);
zlib_post_call(strm);
+ return status;
+}
+
+void git_deflate_end(git_zstream *strm)
+{
+ int status = git_deflate_abort(strm);
+
if (status == Z_OK)
return;
error("deflateEnd: %s (%s)", zerr_to_string(status),
--
1.7.8.rc4.177.g4d64
^ permalink raw reply related
* [PATCH v3 3/6] new representation types in the packstream
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322786449-25753-1-git-send-email-gitster@pobox.com>
In addition to four basic types (commit, tree, blob and tag), the pack
stream can encode a few other "representation" types, such as REF_DELTA
and OFS_DELTA. As we allocate 3 bits in the first byte for this purpose,
we do not have much room to add new representation types in place, but we
do have one value reserved for future expansion.
When encoding a new representation type, the early part of the in-pack
object header is encoded as if its type is OBJ_EXT (= 5) using exactly the
same way as before. That is, the lower 4-bit of the first byte is used for
the lowest 4-bit of the size information, the next 3-bit has the type
information, and the MSB says if the subsequent bytes encodes higher bits
for the size information.
An in-pack object header that records OBJ_EXT as the type is followed by
an integer in the same variable-length encoding as OFS_DELTA offset is
encoded. This value is the real type of the representation minus 8 (as we
do not need to use OBJ_EXT to encode types smaller than 8). Because we do
not foresee very many representation types, in practice we would have a
single byte with its MSB clear, to represent types 8-135.
The code does not type=8 and upwards for anything yet.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
cache.h | 4 +++-
pack-write.c | 23 +++++++++++++++++------
sha1_file.c | 11 +++++++++++
3 files changed, 31 insertions(+), 7 deletions(-)
diff --git a/cache.h b/cache.h
index 4f20861..4a3b421 100644
--- a/cache.h
+++ b/cache.h
@@ -381,12 +381,14 @@ enum object_type {
OBJ_TREE = 2,
OBJ_BLOB = 3,
OBJ_TAG = 4,
- /* 5 for future expansion */
+ OBJ_EXT = 5,
OBJ_OFS_DELTA = 6,
OBJ_REF_DELTA = 7,
OBJ_ANY,
OBJ_MAX
};
+#define OBJ_LAST_BASE_TYPE OBJ_REF_DELTA
+#define OBJ_LAST_VALID_TYPE OBJ_REF_DELTA
static inline enum object_type object_type(unsigned int mode)
{
diff --git a/pack-write.c b/pack-write.c
index 5702cec..9309dd1 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -338,22 +338,33 @@ int encode_in_pack_varint(uintmax_t value, unsigned char *buf)
*/
int encode_in_pack_object_header(enum object_type type, uintmax_t size, unsigned char *hdr)
{
- int n = 1;
+ unsigned char *hdr_base;
unsigned char c;
+ enum object_type header_type;
- if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
+ if (type < OBJ_COMMIT || OBJ_LAST_VALID_TYPE < type)
die("bad type %d", type);
+ else if (OBJ_LAST_BASE_TYPE < type)
+ header_type = OBJ_EXT;
+ else
+ header_type = type;
- c = (type << 4) | (size & 15);
+ c = (header_type << 4) | (size & 15);
size >>= 4;
+ hdr_base = hdr;
while (size) {
*hdr++ = c | 0x80;
c = size & 0x7f;
size >>= 7;
- n++;
}
- *hdr = c;
- return n;
+ *hdr++ = c;
+ if (header_type != type) {
+ int sz;
+ type = type - (OBJ_LAST_BASE_TYPE + 1);
+ sz = encode_in_pack_varint(type, hdr);
+ hdr += sz;
+ }
+ return hdr - hdr_base;
}
struct sha1file *create_tmp_packfile(char **pack_tmp_name)
diff --git a/sha1_file.c b/sha1_file.c
index f066c2b..14902cc 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1275,6 +1275,17 @@ unsigned long unpack_object_header_buffer(const unsigned char *buf,
shift += 7;
}
*sizep = size;
+ if (*type == OBJ_EXT) {
+ const unsigned char *p = buf + used;
+ uintmax_t val = decode_in_pack_varint(&p);
+
+ if (p == buf + used && !val) {
+ error("bad extended object type");
+ return 0;
+ }
+ *type = val + (OBJ_LAST_BASE_TYPE + 1);
+ used = p - buf;
+ }
return used;
}
--
1.7.8.rc4.177.g4d64
^ permalink raw reply related
* [PATCH v3 6/6] chunked-object: fallback checkout codepaths
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322786449-25753-1-git-send-email-gitster@pobox.com>
This prepares the default codepaths based on the traditional "slurping
everything in-core" model around read_sha1_file() API for objects that use
chunked encoding. Needless to say, these codepaths are unsuitable for the
kind of objects that use chunked encoding and are intended to only serve
as the fallback where specialized "large object API" support is still
lacking.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
sha1_file.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
t/t1050-large.sh | 14 +++++++++++++-
2 files changed, 67 insertions(+), 1 deletions(-)
diff --git a/sha1_file.c b/sha1_file.c
index 14902cc..7355716 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1607,6 +1607,11 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset,
if (sizep)
*sizep = size;
break;
+ case OBJ_CHUNKED_BLOB:
+ if (sizep)
+ *sizep = size;
+ type = OBJ_DEKNUHC(type);
+ break;
default:
error("unknown object type %i at offset %"PRIuMAX" in %s",
type, (uintmax_t)obj_offset, p->pack_name);
@@ -1648,6 +1653,51 @@ static void *unpack_compressed_entry(struct packed_git *p,
return buffer;
}
+static void *unpack_chunked_entry(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t curpos,
+ unsigned long size)
+{
+ /*
+ * *NOTE* *NOTE* *NOTE*
+ *
+ * In the longer term, we should aim to exercise this codepath
+ * less and less often, as it defeats the whole purpose of
+ * chuncked object encoding!
+ */
+ unsigned char *buffer;
+ const unsigned char *in, *ptr;
+ unsigned long avail, ofs;
+ int chunk_cnt;
+
+ buffer = xmallocz(size);
+ in = use_pack(p, w_curs, curpos, &avail);
+ ptr = in;
+ chunk_cnt = decode_in_pack_varint(&ptr);
+ curpos += ptr - in;
+ ofs = 0;
+ while (chunk_cnt--) {
+ unsigned long csize;
+ unsigned char *data;
+ enum object_type type;
+
+ in = use_pack(p, w_curs, curpos, &avail);
+ data = read_sha1_file(in, &type, &csize);
+ if (!data)
+ die("malformed chunked object contents ('%s' does not exist)",
+ sha1_to_hex(in));
+ if (type != OBJ_BLOB)
+ die("malformed chunked object contents (not a blob)");
+ if (size < ofs + csize)
+ die("malformed chunked object contents (sizes do not add up)");
+ memcpy(buffer + ofs, data, csize);
+ ofs += csize;
+ curpos += 20;
+ free(data);
+ }
+ return buffer;
+}
+
#define MAX_DELTA_CACHE (256)
static size_t delta_base_cached;
@@ -1883,6 +1933,10 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
case OBJ_TAG:
data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
break;
+ case OBJ_CHUNKED_BLOB:
+ data = unpack_chunked_entry(p, &w_curs, curpos, *sizep);
+ *type = OBJ_DEKNUHC(*type);
+ break;
default:
data = NULL;
error("unknown object type %i at offset %"PRIuMAX" in %s",
diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index d6cb66d..eea45d1 100755
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -124,8 +124,20 @@ test_expect_success 'split limit' '
# switch to a better chunking heuristics.
echo cruft >head &&
cat split >>head &&
- git add head
+ git add head &&
+ echo blob >expect &&
+ git cat-file -t :split >actual &&
+ test_cmp expect actual &&
+
+ git cat-file -p :split >actual &&
+ # You probably do not want to use test_cmp here...
+ cmp split actual &&
+
+ mv split expect &&
+ git checkout split &&
+ # You probably do not want to use test_cmp here...
+ cmp expect split
)
'
--
1.7.8.rc4.177.g4d64
^ permalink raw reply related
* [PATCH v3 2/6] varint-in-pack: refactor varint encoding/decoding
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322786449-25753-1-git-send-email-gitster@pobox.com>
Refactor encode/decode_in_pack_varint() functions from OFS_DELTA codepaths
to read and write variable-length integers in the pack stream.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
builtin/pack-objects.c | 28 +++++++++++++---------------
pack-write.c | 27 +++++++++++++++++++++++++++
pack.h | 2 ++
sha1_file.c | 18 ++++++------------
4 files changed, 48 insertions(+), 27 deletions(-)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index dde913e..72206a9 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -210,7 +210,7 @@ static unsigned long write_object(struct sha1file *f,
{
unsigned long size, limit, datalen;
void *buf;
- unsigned char header[10], dheader[10];
+ unsigned char header[10];
unsigned hdrlen;
enum object_type type;
int usable_delta, to_reuse;
@@ -304,17 +304,16 @@ static unsigned long write_object(struct sha1file *f,
* base from this object's position in the pack.
*/
off_t ofs = entry->idx.offset - entry->delta->idx.offset;
- unsigned pos = sizeof(dheader) - 1;
- dheader[pos] = ofs & 127;
- while (ofs >>= 7)
- dheader[--pos] = 128 | (--ofs & 127);
- if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
+ unsigned char dheader[10];
+ unsigned pos = encode_in_pack_varint(ofs, dheader);
+
+ if (limit && hdrlen + pos + datalen + 20 >= limit) {
free(buf);
return 0;
}
sha1write(f, header, hdrlen);
- sha1write(f, dheader + pos, sizeof(dheader) - pos);
- hdrlen += sizeof(dheader) - pos;
+ sha1write(f, dheader, pos);
+ hdrlen += pos;
} else if (type == OBJ_REF_DELTA) {
/*
* Deltas with a base reference contain
@@ -369,17 +368,16 @@ static unsigned long write_object(struct sha1file *f,
if (type == OBJ_OFS_DELTA) {
off_t ofs = entry->idx.offset - entry->delta->idx.offset;
- unsigned pos = sizeof(dheader) - 1;
- dheader[pos] = ofs & 127;
- while (ofs >>= 7)
- dheader[--pos] = 128 | (--ofs & 127);
- if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
+ unsigned char dheader[10];
+ unsigned pos = encode_in_pack_varint(ofs, dheader);
+
+ if (limit && hdrlen + pos + datalen + 20 >= limit) {
unuse_pack(&w_curs);
return 0;
}
sha1write(f, header, hdrlen);
- sha1write(f, dheader + pos, sizeof(dheader) - pos);
- hdrlen += sizeof(dheader) - pos;
+ sha1write(f, dheader, pos);
+ hdrlen += pos;
reused_delta++;
} else if (type == OBJ_REF_DELTA) {
if (limit && hdrlen + 20 + datalen + 20 >= limit) {
diff --git a/pack-write.c b/pack-write.c
index cadc3e1..5702cec 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -302,6 +302,33 @@ char *index_pack_lockfile(int ip_out)
return NULL;
}
+uintmax_t decode_in_pack_varint(const unsigned char **bufp)
+{
+ const unsigned char *buf = *bufp;
+ unsigned char c = *buf++;
+ uintmax_t val = c & 127;
+ while (c & 128) {
+ val += 1;
+ if (!val || MSB(val, 7))
+ return 0; /* overflow */
+ c = *buf++;
+ val = (val << 7) + (c & 127);
+ }
+ *bufp = buf;
+ return val;
+}
+
+int encode_in_pack_varint(uintmax_t value, unsigned char *buf)
+{
+ unsigned char varint[16];
+ unsigned pos = sizeof(varint) - 1;
+ varint[pos] = value & 127;
+ while (value >>= 7)
+ varint[--pos] = 128 | (--value & 127);
+ memcpy(buf, varint + pos, sizeof(varint) - pos);
+ return sizeof(varint) - pos;
+}
+
/*
* The per-object header is a pretty dense thing, which is
* - first byte: low four bits are "size", then three bits of "type",
diff --git a/pack.h b/pack.h
index cfb0f69..d7dc6ca 100644
--- a/pack.h
+++ b/pack.h
@@ -79,6 +79,8 @@ extern off_t write_pack_header(struct sha1file *f, uint32_t);
extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
extern char *index_pack_lockfile(int fd);
extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned char *);
+extern int encode_in_pack_varint(uintmax_t, unsigned char *);
+extern uintmax_t decode_in_pack_varint(const unsigned char **);
#define PH_ERROR_EOF (-1)
#define PH_ERROR_PACK_SIGNATURE (-2)
diff --git a/sha1_file.c b/sha1_file.c
index c96e366..f066c2b 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1484,20 +1484,14 @@ static off_t get_delta_base(struct packed_git *p,
* is stupid, as then a REF_DELTA would be smaller to store.
*/
if (type == OBJ_OFS_DELTA) {
- unsigned used = 0;
- unsigned char c = base_info[used++];
- base_offset = c & 127;
- while (c & 128) {
- base_offset += 1;
- if (!base_offset || MSB(base_offset, 7))
- return 0; /* overflow */
- c = base_info[used++];
- base_offset = (base_offset << 7) + (c & 127);
- }
- base_offset = delta_obj_offset - base_offset;
+ const unsigned char *buf = base_info;
+ uintmax_t ofs = decode_in_pack_varint(&buf);
+ if (!ofs && buf == base_info)
+ return 0; /* overflow */
+ base_offset = delta_obj_offset - ofs;
if (base_offset <= 0 || base_offset >= delta_obj_offset)
return 0; /* out of bound */
- *curpos += used;
+ *curpos += buf - base_info;
} else if (type == OBJ_REF_DELTA) {
/* The base entry _must_ be in the same pack */
base_offset = find_pack_entry_one(base_info, p);
--
1.7.8.rc4.177.g4d64
^ permalink raw reply related
* [PATCH v3 5/6] bulk-checkin: support chunked-object encoding
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322786449-25753-1-git-send-email-gitster@pobox.com>
Instead of recording a huge object as a single entry in the packfile,
record it as a concatenation of smaller blob objects. This is primarily to
make it possible to repack repositories with huge objects and transfer
huge objects out of such repositories.
This is the first step of a long and painful journey. We would still need
to teach many codepaths about the new encoding:
* The streaming checkout codepath must learn how to read these from the
object store and write a concatenation of component blob contents to
the working tree. Note that after a repack, a component blob object
could be represented as a delta to another blob object.
* The in-core object reading codepath must learn to notice and at least
reject reading such objects entirely in-core. It is expected that
nobody is interested in producing a patch out of these huge objects, at
least initially.
* The object connectivity machinery must learn that component blob
objects are reachable from an object that uses them, so that "gc"
will not lose them, and "fsck" will not complain about them.
* The pack-object machinery must learn to copy an object that is encoded
in chunked-object encoding literally to the destination (while perhaps
validating the object name).
* The index-pack and verify-pack machineries need to be told about it.
The split-chunk logic used here is kept deliberately useless in order to
avoid distracting the reviewers, and also make sure that the chunked
encoding machinery does not depend any particular chunk splitting
heuristics. We may want to replace it with a better heuristics, perhaps
the one used in "bup" that is based on a self-synchronizing rolling
checksum logic, or something.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Makefile | 1 +
bulk-checkin.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
bulk-checkin.h | 1 +
cache.h | 9 +++-
config.c | 5 ++
environment.c | 1 +
split-chunk.c | 28 ++++++++++++
t/t1050-large.sh | 29 ++++++++++++
8 files changed, 198 insertions(+), 3 deletions(-)
create mode 100644 split-chunk.c
diff --git a/Makefile b/Makefile
index 418dd2e..7d2fc3a 100644
--- a/Makefile
+++ b/Makefile
@@ -679,6 +679,7 @@ LIB_OBJS += sha1_name.o
LIB_OBJS += shallow.o
LIB_OBJS += sideband.o
LIB_OBJS += sigchain.o
+LIB_OBJS += split-chunk.o
LIB_OBJS += strbuf.o
LIB_OBJS += streaming.o
LIB_OBJS += string-list.o
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 6f1ce58..ebdacb8 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -5,6 +5,10 @@
#include "csum-file.h"
#include "pack.h"
+#ifndef CHUNK_MAX
+#define CHUNK_MAX 2000
+#endif
+
static int pack_compression_level = Z_DEFAULT_COMPRESSION;
static struct bulk_checkin_state {
@@ -268,12 +272,131 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
return 0;
}
+/* This is only called when actually writing the object out */
+static int store_in_chunks(struct bulk_checkin_state *state,
+ unsigned char result_sha1[],
+ int fd, size_t size,
+ enum object_type type, const char *path,
+ unsigned flags,
+ struct chunk_ctx *up)
+{
+ struct pack_idx_entry *idx;
+ struct chunk_ctx ctx;
+ unsigned char chunk[CHUNK_MAX][20];
+ unsigned char header[100];
+ unsigned header_len;
+ unsigned chunk_cnt, i;
+ size_t remainder = size;
+ size_t write_size;
+ int status;
+
+ header_len = sprintf((char *)header, "%s %" PRIuMAX,
+ typename(type), (uintmax_t)size) + 1;
+
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.up = up;
+ git_SHA1_Init(&ctx.ctx);
+ git_SHA1_Update(&ctx.ctx, header, header_len);
+
+ for (chunk_cnt = 0, remainder = size;
+ remainder && chunk_cnt < CHUNK_MAX - 1;
+ chunk_cnt++) {
+ size_t chunk_size = carve_chunk(fd, remainder);
+ status = deflate_to_pack(state, chunk[chunk_cnt], fd,
+ chunk_size, OBJ_BLOB, path, flags,
+ &ctx);
+ if (status)
+ return status;
+ remainder -= chunk_size;
+ }
+
+ if (remainder) {
+ if (split_size_limit_cfg && split_size_limit_cfg < remainder)
+ status = store_in_chunks(state, chunk[chunk_cnt], fd,
+ remainder, OBJ_BLOB, path, flags,
+ &ctx);
+ else
+ status = deflate_to_pack(state, chunk[chunk_cnt], fd,
+ remainder, OBJ_BLOB, path, flags,
+ &ctx);
+ if (status)
+ return status;
+ chunk_cnt++;
+ }
+
+ /*
+ * Now we have chunk_cnt chunks (the last one may be a large
+ * blob that itself is represented as concatenation of
+ * multiple blobs).
+ */
+ git_SHA1_Final(result_sha1, &ctx.ctx);
+ if (already_written(state, result_sha1))
+ return 0;
+
+ /*
+ * The standard type & size header is followed by
+ * - the number of chunks (varint)
+ * - the object names of the chunks (20 * chunk_cnt bytes)
+ * - the resulting object name (20 bytes)
+ */
+ type = OBJ_CHUNKED(type);
+ header_len = encode_in_pack_object_header(type, size, header);
+ header_len += encode_in_pack_varint(chunk_cnt, header + header_len);
+
+ write_size = header_len + 20 * (chunk_cnt + 1);
+
+ prepare_to_stream(state, flags);
+ if (state->nr_written &&
+ pack_size_limit_cfg &&
+ pack_size_limit_cfg < (state->offset + write_size)) {
+ finish_bulk_checkin(state);
+ prepare_to_stream(state, flags);
+ }
+
+ idx = xcalloc(1, sizeof(*idx));
+ idx->offset = state->offset;
+
+ crc32_begin(state->f);
+ sha1write(state->f, header, header_len);
+ for (i = 0; i < chunk_cnt; i++)
+ sha1write(state->f, chunk[i], 20);
+ sha1write(state->f, result_sha1, 20);
+ idx->crc32 = crc32_end(state->f);
+ hashcpy(idx->sha1, result_sha1);
+ ALLOC_GROW(state->written,
+ state->nr_written + 1,
+ state->alloc_written);
+ state->written[state->nr_written++] = idx;
+ state->offset += write_size;
+
+ return 0;
+}
+
int index_bulk_checkin(unsigned char *sha1,
int fd, size_t size, enum object_type type,
const char *path, unsigned flags)
{
- int status = deflate_to_pack(&state, sha1, fd, size, type,
- path, flags, NULL);
+ int status;
+
+ /*
+ * For now, we only deal with blob objects, as validation
+ * of a huge tree object that is split into chunks will be
+ * too cumbersome to be worth it.
+ *
+ * Note that we only have to use store_in_chunks() codepath
+ * when we are actually writing things out. deflate_to_pack()
+ * codepath can hash arbitrarily huge object without keeping
+ * everything in core just fine.
+ */
+ if ((flags & HASH_WRITE_OBJECT) &&
+ type == OBJ_BLOB &&
+ split_size_limit_cfg &&
+ split_size_limit_cfg < size)
+ status = store_in_chunks(&state, sha1, fd, size, type,
+ path, flags, NULL);
+ else
+ status = deflate_to_pack(&state, sha1, fd, size, type,
+ path, flags, NULL);
if (!state.plugged)
finish_bulk_checkin(&state);
return status;
diff --git a/bulk-checkin.h b/bulk-checkin.h
index 4f599f8..89f1741 100644
--- a/bulk-checkin.h
+++ b/bulk-checkin.h
@@ -12,5 +12,6 @@ extern int index_bulk_checkin(unsigned char sha1[],
extern void plug_bulk_checkin(void);
extern void unplug_bulk_checkin(void);
+extern size_t carve_chunk(int fd, size_t size);
#endif
diff --git a/cache.h b/cache.h
index 4a3b421..374f712 100644
--- a/cache.h
+++ b/cache.h
@@ -384,11 +384,17 @@ enum object_type {
OBJ_EXT = 5,
OBJ_OFS_DELTA = 6,
OBJ_REF_DELTA = 7,
+ /* OBJ_CHUNKED_COMMIT = 8 */
+ /* OBJ_CHUNKED_TREE = 9 */
+ OBJ_CHUNKED_BLOB = 10,
+ /* OBJ_CHUNKED_TAG = 11 */
OBJ_ANY,
OBJ_MAX
};
#define OBJ_LAST_BASE_TYPE OBJ_REF_DELTA
-#define OBJ_LAST_VALID_TYPE OBJ_REF_DELTA
+#define OBJ_LAST_VALID_TYPE OBJ_CHUNKED_BLOB
+#define OBJ_CHUNKED(type) ((type) + 7)
+#define OBJ_DEKNUHC(type) ((type) - 7)
static inline enum object_type object_type(unsigned int mode)
{
@@ -602,6 +608,7 @@ extern size_t packed_git_limit;
extern size_t delta_base_cache_limit;
extern unsigned long big_file_threshold;
extern unsigned long pack_size_limit_cfg;
+extern unsigned long split_size_limit_cfg;
extern int read_replace_refs;
extern int fsync_object_files;
extern int core_preload_index;
diff --git a/config.c b/config.c
index c736802..bdc3be1 100644
--- a/config.c
+++ b/config.c
@@ -801,6 +801,11 @@ int git_default_config(const char *var, const char *value, void *dummy)
pack_size_limit_cfg = git_config_ulong(var, value);
return 0;
}
+
+ if (!strcmp(var, "pack.splitsizelimit")) {
+ split_size_limit_cfg = git_config_ulong(var, value);
+ return 0;
+ }
/* Add other config variables here and to Documentation/config.txt. */
return 0;
}
diff --git a/environment.c b/environment.c
index 31e4284..b66df28 100644
--- a/environment.c
+++ b/environment.c
@@ -61,6 +61,7 @@ int grafts_replace_parents = 1;
int core_apply_sparse_checkout;
struct startup_info *startup_info;
unsigned long pack_size_limit_cfg;
+unsigned long split_size_limit_cfg;
/* Parallel index stat data preload? */
int core_preload_index = 0;
diff --git a/split-chunk.c b/split-chunk.c
new file mode 100644
index 0000000..1b60e63
--- /dev/null
+++ b/split-chunk.c
@@ -0,0 +1,28 @@
+#include "git-compat-util.h"
+#include "bulk-checkin.h"
+
+/* Cut at around 512kB */
+#define TARGET_CHUNK_SIZE_LOG2 19
+#define TARGET_CHUNK_SIZE (1U << TARGET_CHUNK_SIZE_LOG2)
+
+/*
+ * Carve out around 500kB to be stored as a separate blob
+ */
+size_t carve_chunk(int fd, size_t size)
+{
+ size_t chunk_size;
+ off_t seekback = lseek(fd, 0, SEEK_CUR);
+
+ if (seekback == (off_t) -1)
+ die("cannot find the current offset");
+
+ /* Next patch will do something complex to find out where to cut */
+ chunk_size = size;
+ if (TARGET_CHUNK_SIZE < chunk_size)
+ chunk_size = TARGET_CHUNK_SIZE;
+
+ if (lseek(fd, seekback, SEEK_SET) == (off_t) -1)
+ return error("cannot seek back");
+
+ return chunk_size;
+}
diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index 29d6024..d6cb66d 100755
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -100,4 +100,33 @@ test_expect_success 'packsize limit' '
)
'
+test_expect_success 'split limit' '
+ test_create_repo split &&
+ (
+ cd split &&
+ git config core.bigfilethreshold 2m &&
+ git config pack.splitsizelimit 1m &&
+
+ test-genrandom "a" $(( 4800 * 1024 )) >split &&
+ git add split &&
+
+ # This should result in a new chunked object "tail"
+ # that shares most of the component blobs in its
+ # early part with "split".
+ cat split >tail &&
+ echo cruft >>tail &&
+ git add tail &&
+
+ # This should result in a new chunked object "head"
+ # that begins with its own unique component blobs
+ # but quickly synchronize and start using the same
+ # component blobs with "split" and "tail", once we
+ # switch to a better chunking heuristics.
+ echo cruft >head &&
+ cat split >>head &&
+ git add head
+
+ )
+'
+
test_done
--
1.7.8.rc4.177.g4d64
^ permalink raw reply related
* [PATCH v3 4/6] bulk-checkin: allow the same data to be multiply hashed
From: Junio C Hamano @ 2011-12-02 0:40 UTC (permalink / raw)
To: git
In-Reply-To: <1322786449-25753-1-git-send-email-gitster@pobox.com>
This updates stream_to_pack() machinery to feed the data it is writing out
to multiple hash contexts at the same time. Right now we only use a single
git_SHA_CTX, so there is no change in functionality.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
bulk-checkin.c | 33 +++++++++++++++++++++++++--------
1 files changed, 25 insertions(+), 8 deletions(-)
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 6b0b6d4..6f1ce58 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -75,6 +75,20 @@ static int already_written(struct bulk_checkin_state *state, unsigned char sha1[
return 0;
}
+struct chunk_ctx {
+ struct chunk_ctx *up;
+ git_SHA_CTX ctx;
+};
+
+static void chunk_SHA1_Update(struct chunk_ctx *ctx,
+ const unsigned char *buf, size_t size)
+{
+ while (ctx) {
+ git_SHA1_Update(&ctx->ctx, buf, size);
+ ctx = ctx->up;
+ }
+}
+
/*
* Read the contents from fd for size bytes, streaming it to the
* packfile in state while updating the hash in ctx. Signal a failure
@@ -91,7 +105,7 @@ static int already_written(struct bulk_checkin_state *state, unsigned char sha1[
* with a new pack.
*/
static int stream_to_pack(struct bulk_checkin_state *state,
- git_SHA_CTX *ctx, off_t *already_hashed_to,
+ struct chunk_ctx *ctx, off_t *already_hashed_to,
int fd, size_t size, enum object_type type,
const char *path, unsigned flags)
{
@@ -123,7 +137,7 @@ static int stream_to_pack(struct bulk_checkin_state *state,
if (rsize < hsize)
hsize = rsize;
if (hsize)
- git_SHA1_Update(ctx, ibuf, hsize);
+ chunk_SHA1_Update(ctx, ibuf, hsize);
*already_hashed_to = offset;
}
s.next_in = ibuf;
@@ -185,10 +199,11 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
unsigned char result_sha1[],
int fd, size_t size,
enum object_type type, const char *path,
- unsigned flags)
+ unsigned flags,
+ struct chunk_ctx *up)
{
off_t seekback, already_hashed_to;
- git_SHA_CTX ctx;
+ struct chunk_ctx ctx;
unsigned char obuf[16384];
unsigned header_len;
struct sha1file_checkpoint checkpoint;
@@ -200,8 +215,10 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
header_len = sprintf((char *)obuf, "%s %" PRIuMAX,
typename(type), (uintmax_t)size) + 1;
- git_SHA1_Init(&ctx);
- git_SHA1_Update(&ctx, obuf, header_len);
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.up = up;
+ git_SHA1_Init(&ctx.ctx);
+ git_SHA1_Update(&ctx.ctx, obuf, header_len);
/* Note: idx is non-NULL when we are writing */
if ((flags & HASH_WRITE_OBJECT) != 0)
@@ -232,7 +249,7 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
if (lseek(fd, seekback, SEEK_SET) == (off_t) -1)
return error("cannot seek back");
}
- git_SHA1_Final(result_sha1, &ctx);
+ git_SHA1_Final(result_sha1, &ctx.ctx);
if (!idx)
return 0;
@@ -256,7 +273,7 @@ int index_bulk_checkin(unsigned char *sha1,
const char *path, unsigned flags)
{
int status = deflate_to_pack(&state, sha1, fd, size, type,
- path, flags);
+ path, flags, NULL);
if (!state.plugged)
finish_bulk_checkin(&state);
return status;
--
1.7.8.rc4.177.g4d64
^ permalink raw reply related
* Re: Anyone have a commit hook for forbidding old branches from being merged in?
From: Neal Kreitzinger @ 2011-12-02 1:37 UTC (permalink / raw)
To: Ævar Arnfjörð Bjarmason; +Cc: Git Mailing List
In-Reply-To: <CACBZZX4LyTaz=fU1vvgpeL904QFjJULCMVSP0uutcuxZT+-vWQ@mail.gmail.com>
On 12/1/2011 9:34 AM, Ævar Arnfjörð Bjarmason wrote:
> I work on a web application that due to underlying database schema
> changes etc only even compiles and runs for a given 2 week moving
> window.
>
> Thus if someone started a branch say 1 month ago, works on it one and
> off, and then merges it back into the mainline it becomes impossible
> to bisect that code if it has a problem. You either have to:
>
> * Revert the whole merge * Manually eyeball the code to see where
> the error might be * Brute-force manually bisect it by checking out
> only the files altered in those commits instead of the commit at a
> given data. Usually individual files are still compatible with the
> new code.
>
> But the whole reason this is a problem is because people don't rebase
> their branches before merging them in, unintentionally causing
> problems.
>
> So before I write a hook to do this, is there anything that
> implements a hook that:
>
> * Checks if you're pushing a merge commit * If so, is that merge
> based off and old version of $MAINBRANCH * Is the base of that
> branch more than N days old? * If so reject the push
It sounds like you're saying that people should rebase before merging to
main. That means their merge would be a fast-forward. You could just
reject anyone who has not done a current rebase. Then you could use
this technique from the pre-rebase.sample hook to enforce up-to-date
rebases:
only_in_main='git rev-list "^$topic" main'
if test -z "$only-in-main"
then
exit 0
else
echo >&2 "error: please rebase on main before merging to main."
exit 1
fi
v/r,
neal
^ permalink raw reply
* Re: [PATCH] Implement fast hash-collision detection
From: Bill Zaumen @ 2011-12-02 2:59 UTC (permalink / raw)
To: Jeff King; +Cc: git, gitster, pclouds, spearce, torvalds
In-Reply-To: <20111201052615.GA22141@sigill.intra.peff.net>
On Thu, 2011-12-01 at 00:26 -0500, Jeff King wrote:
> Cryptographically speaking, I think that claim is sound, and you can
> certainly construct attack scenarios where this detection would help.
> However, quantifying the effectiveness is difficult. What is the
> likelihood of a malicious collided-object replacement being detected
> without your scheme? What is it with it?
>
> There are many questions that factor into guessing the latter.
>
> How often does Linus fetch from his own kernel.org repository? He would
> usually push, I would think. Even if he does fetch, he wouldn't be
> getting the old objects that he already has. I guess this is the reason
> for your digest-of-digests for each commit object sent?
Yes, - the digest of digests is used to check things that would not be
sent.
>
> But what about
> objects that are no longer in current commits, but are in older ones?
That's a good question, of course. After Linus pushes a commit, he'll
notify others, and if some fetch before the repository is hacked,
they will detect an error on a subsequent fetch. For fetches, the
server reports a series of commits, and the client responds with 'have'
for those it has, with the CRCs added so the server can check for a
mismatch. I made minimal changes to fetch-pack.c and upload-pack.c:
just adding the CRC fields to the messages already sent. The server
asks about more commits than it actually transfers, but all the ones
it asks about are tested. One could send additional 'have' replies
if necessary (for ones the server didn't mention) but I didn't do
that, partly for simplicity but also because I was looking at the
fetch-pack.c and update-pack.c code for the first time. If desired,
such changes can be added.
I also do some similar checking when a commit is pushed - the server
tells the client the last commit it has and the client will send the
CRCs in its reply to allow the server to cross check those. I didn't
mention that before because only the latest is really checked. Again,
I just changed a message format (backwards compatible, of course),
but additional checking could be added if desired.
You could also add options to check tips of branches and all commits
that have tags (e.g., a v1.0 tag) All of that simply requires more
work on commands such as fetch-pack, upload-pack, send-pack and
receive-pack.
> What about the server being more clever about hiding the replacement
> object? E.g., instead of just breaking into kernel.org and inserting a
> replacement object, the attacker runs a malicious git-daemon that
> returns the bogus object to cloners, but the real object to fetchers.
That's really a server-security issue, not a git one. Perhaps
repositories should be configured so that all the executables are on
read-only partitions. It's an important question in general of
course, but it is probably useful to distinguish attacks that put
bad data on a server from ones that install new software.
>
> > It's also possible to write some additional commands to (for example)
> > fetch the SHA-1 hashes and CRCs from all remote repositories you use
> > and compare these to make sure they are all consistent, something that
> > can be run ocassionally.
>
> But we can already do that. Assume you have an existing repo "foo". To
> verify the copy at git://example.com/foo.git, do a fresh clone to
> "bar", and then compare the objects in "foo" to "bar", either byte-wise
> or by digest.
Of course, but that is an expensive operation - in the case of Git
transferring some 50 MBytes of data per repository. A command to
fetch the SHA-1 ID and a CRC or message digest for each object would
not only run faster, but should put a much lower load on the server.
Getting back to the birthday attack question (this is an area where
your comments were very useful for me), there's a case I didn't
consider.
Suppose two developers bounce code back and forth by email and one of
them commits it, but the other developer is a bad guy. The bad guy
would then have had an opportunity to use a birthday attack by sending
back subtly modified code (e.g., changes to how comments are formated,
additional blank lines, etc.) He can even put a humorous comment at
the end of the file such as "the first 200 Chinese characters I learned"
and then include the Chinese characters (I've tested this with gcc -
the Chinese characters, represented in Unicode, print in an editor and
are ignored by the compiler.) Unicode is a lot closer to binary data
so you have a lot of bits you can alter in a small amount of space,
with each character requiring multiple bytes to represent it. The
comment will look silly but innocuous. I think Linus Torvalds once
suggested being suspicious of anything that looked like "line noise"
in a patch. Non-western unicode characters can serve the same function
but look legitimate, at least to people who don't know the language
and when coupled with some "social engineering" to set expectations.
As an example of how this attack might work, without breaking into a
system, assume two programmers collaborating on a project both have
write-access to the same shared repository.
1. The project is using Java, with a rule that all classes and methods
that are protected or public be documented (so javadoc can create API
documentation).
2. Programmer A emails some Java source code to programmer B with a
request to edit the comments to improve them or fix any obvious
mistakes.
3. Programmer B fixes the comments, but also creates a modified file
with the same SHA-1 hash as the correct file in order to add some bugs
or security flaws.
4. Programmer B creates a branch from an earlier version, adds some
tests, puts the contents of the modified file into the directory tree
under an obscure name, adds it and does a commit. B then pushes it,
creating a new remote branch.
5. Programmer B then tells Programmer A that he'll have the modified
file back quickly, but could he please fetch his new remote branch
and run a test, and answer some questions about what happens as B needs
that information to finish his review of the documentation.
6. Programmer A tells B the results, so B knows that A has fetched the
remote branch, an B then sends A the corrected file (not the modified
one). Programmer A reviews the file, notes that everything seems OK,
specifically that only comments were changed, and runs commit -a
followed by a push. Because Git tries to be smart, it will (I think)
notice from the SHA-1 hashes and from the remote branches that the
server already has the object so there is no need to send it.
8. Programmer B fetches the changes, deletes his temporary branch, both
locally and on the shared repository. He tells A that the temporary
branch is deleted so that B should run "git branch update --prune ..."
So what happens? Hopefully someone finds the problem, either through a
source-code review or some QA testing, but regardless Programmer A may
get the blame as the evidence of any tampering has pretty much been
erased. In the worst case, a release with a security hole goes out.
Why would Programmer B do that? Maybe he's leaving the company because
he's hard to work with and is blaming Programmer A for the problem, and
wants to "get back" at Programmer A by harming his career. But in any
case he didn't have to break into the repository to get the effect he
wanted. At least is is extremely hard to do in terms of computational
resources.
Bill
^ permalink raw reply
* Re: Proposal: create meaningful aliases for git reset's hard/soft/mixed
From: Thomas Rast @ 2011-12-02 7:26 UTC (permalink / raw)
To: Phil Hord; +Cc: Philippe Vaucher, Junio C Hamano, git, Christian Couder
In-Reply-To: <CABURp0rtCUbJXLHtXv_1g6GRKL3mX-T+3vN1=QO4CUibqXdEMg@mail.gmail.com>
Phil Hord wrote:
>
> Think outside the "reset" command. Like this:
>
> From the "most popular" comment on http://progit.org/2011/07/11/reset.html:
> > I remember them as:
> > --soft -> git uncommit
> > --mixed -> git unadd
> > --hard -> git undo
>
> I don't particular like these names, but conceptually they are helpful.
I think all of these, but the last one in particular, are *very*
dangerous oversimplifications. Doubly so if you then use "undo" with
a revision argument.
--
Thomas Rast
trast@{inf,student}.ethz.ch
^ permalink raw reply
* Re: Proposal: create meaningful aliases for git reset's hard/soft/mixed
From: Miles Bader @ 2011-12-02 7:45 UTC (permalink / raw)
To: Thomas Rast
Cc: Phil Hord, Philippe Vaucher, Junio C Hamano, git,
Christian Couder
In-Reply-To: <201112020826.14114.trast@student.ethz.ch>
Thomas Rast <trast@student.ethz.ch> writes:
>> > I remember them as:
>> > --soft -> git uncommit
>> > --mixed -> git unadd
>> > --hard -> git undo
>>
>> I don't particular like these names, but conceptually they are helpful.
>
> I think all of these, but the last one in particular, are *very*
> dangerous oversimplifications. Doubly so if you then use "undo" with
> a revision argument.
I agree. Not only is it completely wrong when used with a revision
argument, but "undo" is so vague that it's probably useless for _any_
git command, much less one so dangerous as "reset --hard".
-miles
--
Friendship, n. A ship big enough to carry two in fair weather, but only one
in foul.
^ permalink raw reply
* Re: Status after 'git clone --no-checkout' ?
From: norbert.nemec @ 2011-12-02 7:53 UTC (permalink / raw)
To: git
In-Reply-To: <20111201190058.GC2873@sigill.intra.peff.net>
Thanks a lot for this concise explanation -- exactly what I was hoping for!
Am 01.12.11 20:00, schrieb Jeff King:
> On Wed, Nov 30, 2011 at 02:02:22PM +0100, norbert.nemec wrote:
>
>> what exactly is the status after 'git clone --no-checkout'? Is there
>> any straightforward way how one could end up in this state starting
>> from a regularly checked out repository?
>
> You have a HEAD which points to some actual commit, but no index or
> working tree. I don't think there is a particular name for this state.
>
> You can get something similar in an existing repo by deleting all of the
> working tree files and removing .git/index.
>
>> 'git checkout' without any further options serves to move from the
>> aforementioned special state to a regular checked out state.
>> Otherwise it never seems to do anything. Are there any other
>> situations where 'git checkout' on its own would have any effect?
>
> By itself, I don't think so. But you can use "git checkout -f" to
> discard changes in the index and working tree, setting them back to the
> state in HEAD.
>
> At one point, some people used "git checkout" as a no-op, because it
> would print the "ahead/behind" information with respect to the upstream.
> These days, that information is part of "git status", so I suspect
> people use that instead.
>
> -Peff
^ permalink raw reply
* Re: [PATCHv2 0/4] git-p4: small fixes to branches and labels; tests
From: Luke Diamand @ 2011-12-02 8:49 UTC (permalink / raw)
To: Vitor Antunes; +Cc: Pete Wyckoff, git
In-Reply-To: <CAOpHH-XL5OGpnihEgqnXqUUFsMxXn2wSdLadegnC1epg44vs8A@mail.gmail.com>
On 01/12/11 21:59, Vitor Antunes wrote:
> On Dec 1, 2011 4:03 AM, "Pete Wyckoff"<pw@padd.com> wrote:
>> I see your point. P4 labels are the only way that they support
>> tagging, apparently. I'm okay with leaving label support in
>> git-p4. And it will be nice if Luke makes it behave a bit
>> better. But doing heroics to emulate cross-commit tags feels
>> like a lot of work, and the wrong direction.
>
> Agreed. Lets keep it simple.
>
I think I'm going to have to go away and do a bit more work on this. The
existing label code is still quite buggy (or my understanding is
broken). Either way I'd rather get it to the point where it actually
works and passes all its tests.
The two issues I'm seeing are:
- two p4 labels covering the same set of files; only one of them gets
imported.
- if you have a p4 label on a subset of files then it gets dropped
(which is fine) but so do most of the other labels (as far as I can tell).
I think if this could be made to work it would actually be really useful
though.
(Pete - I've found your previous email; not sure why I didn't see it
before. I'll roll that change in with what I'm doing).
Regards!
Luke
^ permalink raw reply
* Re: Anyone have a commit hook for forbidding old branches from being merged in?
From: Ævar Arnfjörð Bjarmason @ 2011-12-02 11:27 UTC (permalink / raw)
To: Neal Kreitzinger; +Cc: Git Mailing List
In-Reply-To: <4ED82BCA.5080909@gmail.com>
On Fri, Dec 2, 2011 at 02:37, Neal Kreitzinger <nkreitzinger@gmail.com> wrote:
> It sounds like you're saying that people should rebase before merging to
> main. That means their merge would be a fast-forward. You could just
> reject anyone who has not done a current rebase. Then you could use this
> technique from the pre-rebase.sample hook to enforce up-to-date rebases:
That would be an overly invasive change to people's workflows. It's
fine if you merge something in as long as the initial merge base isn't
N days older than the current state of the mainline.
^ permalink raw reply
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