[PATCH] git-svn: Added 'find-rev' command

[PATCH] git-svn: Added 'find-rev' command

[Adam Roben]

This patch adds a new 'find-rev' command to git-svn that lets you easily
translate between SVN revision numbers and git tree-ish.

Signed-off-by: Adam Roben <aroben@apple.com>
---
 Documentation/git-svn.txt |    5 +++++
 git-svn.perl              |   24 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index a0d34e0..a35b9de 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -159,6 +159,11 @@ New features:
 Any other arguments are passed directly to `git log'
 
 --
+'find-rev'::
+	When given an SVN revision number of the form 'rN', returns the
+	corresponding git commit hash.  When given a tree-ish, returns the
+	corresponding SVN revision number.
+
 'set-tree'::
 	You should consider using 'dcommit' instead of this command.
 	Commit specified commit or tree objects to SVN.  This relies on
diff --git a/git-svn.perl b/git-svn.perl
index 7b5f8ab..4be8576 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -141,6 +141,8 @@ my %cmd = (
 			  'color' => \$Git::SVN::Log::color,
 			  'pager=s' => \$Git::SVN::Log::pager,
 			} ],
+	'find-rev' => [ \&cmd_find_rev, "Translate between SVN revision numbers and tree-ish",
+			{ } ],
 	'rebase' => [ \&cmd_rebase, "Fetch and rebase your working directory",
 			{ 'merge|m|M' => \$_merge,
 			  'verbose|v' => \$_verbose,
@@ -428,6 +430,28 @@ sub cmd_dcommit {
 	command_noisy(@finish, $gs->refname);
 }
 
+sub cmd_find_rev {
+	my $revision_or_hash = shift;
+	my $result;
+	if ($revision_or_hash =~ /^r\d+$/) {
+		my $desired_revision = substr($revision_or_hash, 1);
+		my ($fh, $ctx) = command_output_pipe('rev-list', 'HEAD');
+		while (my $hash = <$fh>) {
+			chomp($hash);
+			my (undef, $rev, undef) = cmt_metadata($hash);
+			if ($rev && $rev eq $desired_revision) {
+				$result = $hash;
+				last;
+			}
+		}
+		command_close_pipe($fh, $ctx);
+	} else {
+		my (undef, $rev, undef) = cmt_metadata($revision_or_hash);
+		$result = $rev;
+	}
+	print "$result\n" if $result;
+}
+
 sub cmd_rebase {
 	command_noisy(qw/update-index --refresh/);
 	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
-- 
1.5.2.rc0.75.g959b-dirty

Re: [PATCH] git-svn: Added 'find-rev' command

[Eric Wong]

Adam Roben <aroben@apple.com> wrote:
> This patch adds a new 'find-rev' command to git-svn that lets you easily
> translate between SVN revision numbers and git tree-ish.

Looks useful.

Acked-by: Eric Wong <normalperson@yhbt.net>

> Signed-off-by: Adam Roben <aroben@apple.com>
> ---
>  Documentation/git-svn.txt |    5 +++++
>  git-svn.perl              |   24 ++++++++++++++++++++++++
>  2 files changed, 29 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
> index a0d34e0..a35b9de 100644
> --- a/Documentation/git-svn.txt
> +++ b/Documentation/git-svn.txt
> @@ -159,6 +159,11 @@ New features:
>  Any other arguments are passed directly to `git log'
>  
>  --
> +'find-rev'::
> +	When given an SVN revision number of the form 'rN', returns the
> +	corresponding git commit hash.  When given a tree-ish, returns the
> +	corresponding SVN revision number.
> +
>  'set-tree'::
>  	You should consider using 'dcommit' instead of this command.
>  	Commit specified commit or tree objects to SVN.  This relies on
> diff --git a/git-svn.perl b/git-svn.perl
> index 7b5f8ab..4be8576 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -141,6 +141,8 @@ my %cmd = (
>  			  'color' => \$Git::SVN::Log::color,
>  			  'pager=s' => \$Git::SVN::Log::pager,
>  			} ],
> +	'find-rev' => [ \&cmd_find_rev, "Translate between SVN revision numbers and tree-ish",
> +			{ } ],
>  	'rebase' => [ \&cmd_rebase, "Fetch and rebase your working directory",
>  			{ 'merge|m|M' => \$_merge,
>  			  'verbose|v' => \$_verbose,
> @@ -428,6 +430,28 @@ sub cmd_dcommit {
>  	command_noisy(@finish, $gs->refname);
>  }
>  
> +sub cmd_find_rev {
> +	my $revision_or_hash = shift;
> +	my $result;
> +	if ($revision_or_hash =~ /^r\d+$/) {
> +		my $desired_revision = substr($revision_or_hash, 1);
> +		my ($fh, $ctx) = command_output_pipe('rev-list', 'HEAD');
> +		while (my $hash = <$fh>) {
> +			chomp($hash);
> +			my (undef, $rev, undef) = cmt_metadata($hash);
> +			if ($rev && $rev eq $desired_revision) {
> +				$result = $hash;
> +				last;
> +			}
> +		}
> +		command_close_pipe($fh, $ctx);
> +	} else {
> +		my (undef, $rev, undef) = cmt_metadata($revision_or_hash);
> +		$result = $rev;
> +	}
> +	print "$result\n" if $result;
> +}
> +
>  sub cmd_rebase {
>  	command_noisy(qw/update-index --refresh/);
>  	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
> -- 
> 1.5.2.rc0.75.g959b-dirty
> 

-- 
Eric Wong

Re: [PATCH] git-svn: Added 'find-rev' command

[Junio C Hamano]

Eric Wong <normalperson@yhbt.net> writes:

> Adam Roben <aroben@apple.com> wrote:
>> This patch adds a new 'find-rev' command to git-svn that lets you easily
>> translate between SVN revision numbers and git tree-ish.
>
> Looks useful.
>
> Acked-by: Eric Wong <normalperson@yhbt.net>

But looks quite wasteful.  Why not run "rev-list -v" or
something instead of running cat-file on revision one-by-one?

Re: [PATCH] git-svn: Added 'find-rev' command

[Eric Wong]

Junio C Hamano <junkio@cox.net> wrote:
> Eric Wong <normalperson@yhbt.net> writes:
> 
> > Adam Roben <aroben@apple.com> wrote:
> >> This patch adds a new 'find-rev' command to git-svn that lets you easily
> >> translate between SVN revision numbers and git tree-ish.
> >
> > Looks useful.
> >
> > Acked-by: Eric Wong <normalperson@yhbt.net>
> 
> But looks quite wasteful.  Why not run "rev-list -v" or
> something instead of running cat-file on revision one-by-one?

Didn't know about "rev-list -v", but I just checked and it still has the
limited-size buffer that --pretty=raw has.

"git-svn log" only runs cat-file if it can't find a git-svn-id: line at
the bottom.  (I used log --abbrev-commit --pretty=raw).

Sorry about the premature Ack, I hadn't had my coffee yet at that point
(and now I'm half awake :x)

Adam:

However, since we're not fetching ranges...

You can do $gs->rev_db_get($rev_nr) to easily find a commit given a
revision.  Bonus points if this works independently of the current HEAD
so you can look up revision numbers on different branches.  (git-svn log
should be made to support this, too)


-- 
Eric Wong

Re: [PATCH] git-svn: Added 'find-rev' command

[Adam Roben]

On Apr 28, 2007, at 3:50 AM, Eric Wong wrote:

> Adam:
>
> However, since we're not fetching ranges...
>
> You can do $gs->rev_db_get($rev_nr) to easily find a commit given a
> revision.  Bonus points if this works independently of the current  
> HEAD
> so you can look up revision numbers on different branches.  (git- 
> svn log
> should be made to support this, too)

    OK, I'll do that and send out a new patch.

-Adam