Commit Graph

12 Commits

Author SHA1 Message Date
Jeff King
2bed2d47b4 repack: simplify handling of --write-bitmap-index
We previously needed to pass --no-write-bitmap-index
explicitly to pack-objects to override its reading of
pack.writebitmaps from the config. Now that it no longer
does so, we can assume that bitmaps are off by default, and
only turn them on when necessary. This also lets us avoid a
confusing tri-state flag for write_bitmaps.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 14:04:06 -07:00
Jeff King
d078d85bc3 repack: s/write_bitmap/&s/ in code
The config name is "writeBitmaps", so the internal variable
missing the plural is unnecessarily confusing to write.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 14:01:30 -07:00
Jeff King
3198b89fb2 repack: respect pack.writebitmaps
The config option to turn on bitmaps is read all the way
down in the plumbing of pack-objects. This makes it hard for
other options in the porcelain of repack to make decisions
based on the bitmap setting. For example,
repack.packKeptObjects tries to kick in by default only when
bitmaps are turned on. But it can't do so reliably because
it doesn't yet know whether we are using bitmaps.

This patch teaches repack to respect pack.writebitmaps. It
means we pass a redundant command-line flag to pack-objects,
but that's OK; it shouldn't affect the outcome.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 14:01:08 -07:00
Jeff King
64d3dc9468 repack: do not accidentally pack kept objects by default
Commit ee34a2b (repack: add `repack.packKeptObjects` config
var, 2014-03-03) added a flag which could duplicate kept
objects, but did not mean to turn it on by default. Instead,
the option is tied by default to the decision to write
bitmaps, like:

  if (pack_kept_objects < 0)
	  pack_kept_objects = write_bitmap;

after which we expect pack_kept_objects to be a boolean 0 or
1.  However, that assignment neglects that write_bitmap is
_also_ a tri-state with "-1" as the default, and with
neither option given, we accidentally turn the option on.

This patch is the minimal fix to restore the desired
behavior for the default state. Further patches will fix the
more complicated cases.

Note the update to t7700. It failed to turn on bitmaps,
meaning we were actually confirming the wrong behavior!

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:58:43 -07:00
Jeff King
ee34a2bead repack: add repack.packKeptObjects config var
The git-repack command always passes `--honor-pack-keep`
to pack-objects. This has traditionally been a good thing,
as we do not want to duplicate those objects in a new pack,
and we are not going to delete the old pack.

However, when bitmaps are in use, it is important for a full
repack to include all reachable objects, even if they may be
duplicated in a .keep pack. Otherwise, we cannot generate
the bitmaps, as the on-disk format requires the set of
objects in the pack to be fully closed.

Even if the repository does not generally have .keep files,
a simultaneous push could cause a race condition in which a
.keep file exists at the moment of a repack. The repack may
try to include those objects in one of two situations:

  1. The pushed .keep pack contains objects that were
     already in the repository (e.g., blobs due to a revert of
     an old commit).

  2. Receive-pack updates the refs, making the objects
     reachable, but before it removes the .keep file, the
     repack runs.

In either case, we may prefer to duplicate some objects in
the new, full pack, and let the next repack (after the .keep
file is cleaned up) take care of removing them.

This patch introduces both a command-line and config option
to disable the `--honor-pack-keep` option.  By default, it
is triggered when pack.writeBitmaps (or `--write-bitmap-index`
is turned on), but specifying it explicitly can override the
behavior (e.g., in cases where you prefer .keep files to
bitmaps, but only when they are present).

Note that this option just disables the pack-objects
behavior. We still leave packs with a .keep in place, as we
do not necessarily know that we have duplicated all of their
objects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-03 12:21:49 -08:00
Vicent Marti
5cf2741c5a repack: consider bitmaps when performing repacks
Since `pack-objects` will write a `.bitmap` file next to the `.pack` and
`.idx` files, this commit teaches `git-repack` to consider the new
bitmap indexes (if they exist) when performing repack operations.

This implies moving old bitmap indexes out of the way if we are
repacking a repository that already has them, and moving the newly
generated bitmap indexes into the `objects/pack` directory, next to
their corresponding packfiles.

Since `git repack` is now capable of handling these `.bitmap` files,
a normal `git gc` run on a repository that has `pack.writebitmaps` set
to true in its config file will generate bitmap indexes as part of the
garbage collection process.

Alternatively, `git repack` can be called with the `-b` switch to
explicitly generate bitmap indexes if you are experimenting
and don't want them on all the time.

Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30 12:19:23 -08:00
Jeff King
b77fcd1edc repack: handle optional files created by pack-objects
We ask pack-objects to pack to a set of temporary files, and
then rename them into place. Some files that pack-objects
creates may be optional (like a .bitmap file), in which case
we would not want to call rename(). We already call stat()
and make the chmod optional if the file cannot be accessed.
We could simply skip the rename step in this case, but that
would be a minor regression in noticing problems with
non-optional files (like the .pack and .idx files).

Instead, we can now annotate extensions as optional, and
skip them if they don't exist (and otherwise rely on
rename() to barf).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30 12:19:23 -08:00
Jeff King
42a02d8529 repack: turn exts array into array-of-struct
This is slightly more verbose, but will let us annotate the
extensions with further options in future commits.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30 12:19:23 -08:00
Jeff King
b328c2166e repack: stop using magic number for ARRAY_SIZE(exts)
We have a static array of extensions, but hardcode the size
of the array in our loops. Let's pull out this magic number,
which will make it easier to change.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30 12:19:23 -08:00
Stefan Beller
0b63c6a5b7 repack: improve warnings about failure of renaming and removing files
Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-17 13:34:57 -07:00
Stefan Beller
ffc9329f48 repack: retain the return value of pack-objects
During the review process of the previous commit (repack: rewrite the
shell script in C), Johannes Sixt proposed to retain any exit codes from
the sub-process, which makes it probably more obvious in case of failure.

As the commit before should behave as close to the original shell
script, the proposed change is put in this extra commit.
The infrastructure however was already setup in the previous commit.
(Having a local 'ret' variable)

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-17 13:34:56 -07:00
Stefan Beller
a1bbc6c017 repack: rewrite the shell script in C
The motivation of this patch is to get closer to a goal of being
able to have a core subset of git functionality built in to git.
That would mean

 * people on Windows could get a copy of at least the core parts
   of Git without having to install a Unix-style shell

 * people using git in on servers with chrooted environments
   do not need to worry about standard tools lacking for shell
   scripts.

This patch is meant to be mostly a literal translation of the
git-repack script; the intent is that later patches would start using
more library facilities, but this patch is meant to be as close to a
no-op as possible so it doesn't do that kind of thing.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-17 13:34:50 -07:00