If "fetch --prune" is run with no new refs to fetch, but it has refs
to prune. Then, the header url is not printed as it would if there were
new refs to fetch.
Output before this patch:
$ git fetch --prune remote-with-no-new-refs
x [deleted] (none) -> origin/world
Output after this patch:
$ git fetch --prune remote-with-no-new-refs
From https://github.com/git/git
x [deleted] (none) -> origin/test
Signed-off-by: Tom Miller <jackerran@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The word 'prefix' is currently translated as 'Prefix'
which is not a German word. It should be translated as
'Präfix'.
Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Since 64a99eb4 git gc refuses to run without the --force option if
another gc process on the same repository is already running.
However, if the repository is shared and user A runs git gc on the
repository and while that gc is still running user B runs git gc on
the same repository the gc process run by user A will not be noticed
and the gc run by user B will go ahead and run.
The problem is that the kill(pid, 0) test fails with an EPERM error
since user B is not allowed to signal processes owned by user A
(unless user B is root).
Update the test to recognize an EPERM error as meaning the process
exists and another gc should not be run (unless --force is given).
Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Having a simulated "known breakage" test means that the test
suite will always tell us there is a bug to be fixed, even
though it is only simulated.
The right way to test this is in a sub-test, that can also
check that we provide the correct exit status and output.
Fortunately, we already have such a test (added much later
by 5ebf89e).
We could arguably get rid of the simulated success test
immediately above, as well, as it is also redundant with the
tests added in 5ebf89e. However, it does not have the
annoying behavior of the "known breakage" test. It may also
be easier to debug if the test suite is truly broken, since
it is not a test-within-a-test, as the later tests are.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 517cd55 set HARNESS_ACTIVE unconditionally in
sub-tests, because that value affects the output of
"--verbose". t0000 needs stable output from its sub-tests,
and we may or may not be running under a TAP harness.
That commit made the decision to always set the variable,
since it has another useful side effect, which is
suppressing writes to t/test-results by the sub-tests (which
would just pollute the real results).
Since the last commit, though, the sub-tests have their own
test-results directories, so this is no longer an issue. We
can now update a few comments that are no longer accurate
nor necessary.
We can also revisit the choice of HARNESS_ACTIVE. Since we
must choose one value for stability, it's probably saner to
have it off. This means that future patches could test
things like the test-results writing, or the "--quiet"
option, which is currently ignored when run under a harness.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running t0000 produces more trash directories than expected and does
not clean up after itself:
$ ./t0000-basic.sh
[...]
$ ls -d trash\ directory.*
trash directory.failing-cleanup
trash directory.mixed-results1
trash directory.mixed-results2
trash directory.partial-pass
trash directory.test-verbose
trash directory.test-verbose-only-2
These scratch areas for sub-tests should be under the t0000 trash
directory, but because TEST_OUTPUT_DIRECTORY defaults to
TEST_DIRECTORY, which is exported to help sub-tests find
test-lib.sh, the sub-test trash directories are created under the
toplevel t/ directory instead. Because some of the sub-tests
simulate failures, their trash directories are kept around.
Fix it by explicitly setting TEST_OUTPUT_DIRECTORY appropriately for
sub-tests.
An alternative fix would be to pass the --root parameter that only
specifies where to put the trash directories, which would also work.
However, using TEST_OUTPUT_DIRECTORY is more futureproof in case
tests want to write more output in addition to the test-results/
(which are already suppressed in sub-tests using the HARNESS_ACTIVE
setting) and trash directories.
This fixes a regression introduced by 38b074d (t/test-lib.sh: fix
TRASH_DIRECTORY handling, 2013-04-14). Before that commit, the
TEST_OUTPUT_DIRECTORY setting was not respected consistently so most
tests did their work in a "trash" subdirectory of the current
directory instead of the output dir.
Signed-off-by: Jeff King <peff@peff.net>
Clarified-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The httpd server we set up to test git's http client code
knows about a single account, in which both the username and
password are "user@host" (the unusual use of the "@" here is
to verify that we handle the character correctly when URL
escaped).
This means that we may miss a certain class of errors in
which the username and password are mixed up internally by
git. We can make our tests more robust by having distinct
values for the username and password.
In addition to tweaking the server passwd file and the
client URL, we must teach the "askpass" harness to accept
multiple values. As a bonus, this makes the setup of some
tests more obvious; when we are expecting git to ask
only about the password, we can seed the username askpass
response with a bogus value.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 31b49d9b65.
That commit taught do_askpass to hand ownership of our
buffer back to the caller rather than simply return a
pointer into our internal strbuf. What it failed to notice,
though, was that our internal strbuf is static, because we
are trying to emulate the getpass() interface.
By handing off ownership, we created a memory leak that
cannot be solved. Sometimes git_prompt returns a static
buffer from getpass() (or our smarter git_terminal_prompt
wrapper), and sometimes it returns an allocated string from
do_askpass.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add an entry into the table of supported OSes. Do not set _XOPEN_SOURCE
(contrary to OpenBSD) because that disables the u_short and u_long
typedefs, which are used unconditionally in various other header files.
Signed-off-by: Benny Siegert <bsiegert@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enum names SHORT/MEDIUM/FULL were too broad to be descriptive. And
they clashed with built-in symbols on platforms like Windows.
Clarify by giving them REPLACE_FORMAT_ prefix.
Rename 'full' format in "git replace --format=<name>" to 'long', to
match others (i.e. 'short' and 'medium').
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No code ever used this symbol since the command was introduced at
9f613ddd (Add git-for-each-ref: helper for language bindings,
2006-09-15).
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we use pack bitmaps rather than walking the object
graph, we end up with the list of objects to include in the
packfile, but we do not know the path at which any tree or
blob objects would be found.
In a recently packed repository, this is fine. A fetch would
use the paths only as a heuristic in the delta compression
phase, and a fully packed repository should not need to do
much delta compression.
As time passes, though, we may acquire more objects on top
of our large bitmapped pack. If clients fetch frequently,
then they never even look at the bitmapped history, and all
works as usual. However, a client who has not fetched since
the last bitmap repack will have "have" tips in the
bitmapped history, but "want" newer objects.
The bitmaps themselves degrade gracefully in this
circumstance. We manually walk the more recent bits of
history, and then use bitmaps when we hit them.
But we would also like to perform delta compression between
the newer objects and the bitmapped objects (both to delta
against what we know the user already has, but also between
"new" and "old" objects that the user is fetching). The lack
of pathnames makes our delta heuristics much less effective.
This patch adds an optional cache of the 32-bit name_hash
values to the end of the bitmap file. If present, a reader
can use it to match bitmapped and non-bitmapped names during
delta compression.
Here are perf results for p5310:
Test origin/master HEAD^ HEAD
-------------------------------------------------------------------------------------------------
5310.2: repack to disk 36.81(37.82+1.43) 47.70(48.74+1.41) +29.6% 47.75(48.70+1.51) +29.7%
5310.3: simulated clone 30.78(29.70+2.14) 1.08(0.97+0.10) -96.5% 1.07(0.94+0.12) -96.5%
5310.4: simulated fetch 3.16(6.10+0.08) 3.54(10.65+0.06) +12.0% 1.70(3.07+0.06) -46.2%
5310.6: partial bitmap 36.76(43.19+1.81) 6.71(11.25+0.76) -81.7% 4.08(6.26+0.46) -88.9%
You can see that the time spent on an incremental fetch goes
down, as our delta heuristics are able to do their work.
And we save time on the partial bitmap clone for the same
reason.
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>
This adds a few basic perf tests for the pack bitmap code to
show off its improvements. The tests are:
1. How long does it take to do a repack (it gets slower
with bitmaps, since we have to do extra work)?
2. How long does it take to do a clone (it gets faster
with bitmaps)?
3. How does a small fetch perform when we've just
repacked?
4. How does a clone perform when we haven't repacked since
a week of pushes?
Here are results against linux.git:
Test origin/master this tree
-----------------------------------------------------------------------
5310.2: repack to disk 33.64(32.64+2.04) 67.67(66.75+1.84) +101.2%
5310.3: simulated clone 30.49(29.47+2.05) 1.20(1.10+0.10) -96.1%
5310.4: simulated fetch 3.49(6.79+0.06) 5.57(22.35+0.07) +59.6%
5310.6: partial bitmap 36.70(43.87+1.81) 8.18(21.92+0.73) -77.7%
You can see that we do take longer to repack, but we do way
better for further clones. A small fetch performs a bit
worse, as we spend way more time on delta compression (note
the heavy user CPU time, as we have 8 threads) due to the
lack of name hashes for the bitmapped objects.
The final test shows how the bitmaps degrade over time
between packs. There's still a significant speedup over the
non-bitmap case, but we don't do quite as well (we have to
spend time accessing the "new" objects the old fashioned
way, including delta compression).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we can read and write bitmaps, we can exercise them
with some basic functionality tests. These tests aren't
particularly useful for seeing the benefit, as the test
repo is too small for it to make a difference. However, we
can at least check that using bitmaps does not break anything.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Count-objects will report any "garbage" files in the packs
directory, including files whose extensions it does not
know (case 1), and files whose matching ".pack" file is
missing (case 2). Without having learned about ".bitmap"
files, the current code reports all such files as garbage
(case 1), even if their pack exists. Instead, they should be
treated as case 2.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
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>
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>
This commit extends more the functionality of `pack-objects` by allowing
it to write out a `.bitmap` index next to any written packs, together
with the `.idx` index that currently gets written.
If bitmap writing is enabled for a given repository (either by calling
`pack-objects` with the `--write-bitmap-index` flag or by having
`pack.writebitmaps` set to `true` in the config) and pack-objects is
writing a packfile that would normally be indexed (i.e. not piping to
stdout), we will attempt to write the corresponding bitmap index for the
packfile.
Bitmap index writing happens after the packfile and its index has been
successfully written to disk (`finish_tmp_packfile`). The process is
performed in several steps:
1. `bitmap_writer_set_checksum`: this call stores the partial
checksum for the packfile being written; the checksum will be
written in the resulting bitmap index to verify its integrity
2. `bitmap_writer_build_type_index`: this call uses the array of
`struct object_entry` that has just been sorted when writing out
the actual packfile index to disk to generate 4 type-index bitmaps
(one for each object type).
These bitmaps have their nth bit set if the given object is of
the bitmap's type. E.g. the nth bit of the Commits bitmap will be
1 if the nth object in the packfile index is a commit.
This is a very cheap operation because the bitmap writing code has
access to the metadata stored in the `struct object_entry` array,
and hence the real type for each object in the packfile.
3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap
index for one of the packfiles we're trying to repack, this call
will efficiently rebuild the existing bitmaps so they can be
reused on the new index. All the existing bitmaps will be stored
in a `reuse` hash table, and the commit selection phase will
prioritize these when selecting, as they can be written directly
to the new index without having to perform a revision walk to
fill the bitmap. This can greatly speed up the repack of a
repository that already has bitmaps.
4. `bitmap_writer_select_commits`: if bitmap writing is enabled for
a given `pack-objects` run, the sequence of commits generated
during the Counting Objects phase will be stored in an array.
We then use that array to build up the list of selected commits.
Writing a bitmap in the index for each object in the repository
would be cost-prohibitive, so we use a simple heuristic to pick
the commits that will be indexed with bitmaps.
The current heuristics are a simplified version of JGit's
original implementation. We select a higher density of commits
depending on their age: the 100 most recent commits are always
selected, after that we pick 1 commit of each 100, and the gap
increases as the commits grow older. On top of that, we make sure
that every single branch that has not been merged (all the tips
that would be required from a clone) gets their own bitmap, and
when selecting commits between a gap, we tend to prioritize the
commit with the most parents.
Do note that there is no right/wrong way to perform commit
selection; different selection algorithms will result in
different commits being selected, but there's no such thing as
"missing a commit". The bitmap walker algorithm implemented in
`prepare_bitmap_walk` is able to adapt to missing bitmaps by
performing manual walks that complete the bitmap: the ideal
selection algorithm, however, would select the commits that are
more likely to be used as roots for a walk in the future (e.g.
the tips of each branch, and so on) to ensure a bitmap for them
is always available.
5. `bitmap_writer_build`: this is the computationally expensive part
of bitmap generation. Based on the list of commits that were
selected in the previous step, we perform several incremental
walks to generate the bitmap for each commit.
The walks begin from the oldest commit, and are built up
incrementally for each branch. E.g. consider this dag where A, B,
C, D, E, F are the selected commits, and a, b, c, e are a chunk
of simplified history that will not receive bitmaps.
A---a---B--b--C--c--D
\
E--e--F
We start by building the bitmap for A, using A as the root for a
revision walk and marking all the objects that are reachable
until the walk is over. Once this bitmap is stored, we reuse the
bitmap walker to perform the walk for B, assuming that once we
reach A again, the walk will be terminated because A has already
been SEEN on the previous walk.
This process is repeated for C, and D, but when we try to
generate the bitmaps for E, we can reuse neither the current walk
nor the bitmap we have generated so far.
What we do now is resetting both the walk and clearing the
bitmap, and performing the walk from scratch using E as the
origin. This new walk, however, does not need to be completed.
Once we hit B, we can lookup the bitmap we have already stored
for that commit and OR it with the existing bitmap we've composed
so far, allowing us to limit the walk early.
After all the bitmaps have been generated, another iteration
through the list of commits is performed to find the best XOR
offsets for compression before writing them to disk. Because of
the incremental nature of these bitmaps, XORing one of them with
its predecesor results in a minimal "bitmap delta" most of the
time. We can write this delta to the on-disk bitmap index, and
then re-compose the original bitmaps by XORing them again when
loaded.
This is a phase very similar to pack-object's `find_delta` (using
bitmaps instead of objects, of course), except the heuristics
have been greatly simplified: we only check the 10 bitmaps before
any given one to find best compressing one. This gives good
results in practice, because there is locality in the ordering of
the objects (and therefore bitmaps) in the packfile.
6. `bitmap_writer_finish`: the last step in the process is
serializing to disk all the bitmap data that has been generated
in the two previous steps.
The bitmap is written to a tmp file and then moved atomically to
its final destination, using the same process as
`pack-write.c:write_idx_file`.
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>
The bitmap reachability index used to speed up the counting objects
phase during `pack-objects` can also be used to optimize a normal
rev-list if the only thing required are the SHA1s of the objects during
the list (i.e., not the path names at which trees and blobs were found).
Calling `git rev-list --objects --use-bitmap-index [committish]` will
perform an object iteration based on a bitmap result instead of actually
walking the object graph.
These are some example timings for `torvalds/linux` (warm cache,
best-of-five):
$ time git rev-list --objects master > /dev/null
real 0m34.191s
user 0m33.904s
sys 0m0.268s
$ time git rev-list --objects --use-bitmap-index master > /dev/null
real 0m1.041s
user 0m0.976s
sys 0m0.064s
Likewise, using `git rev-list --count --use-bitmap-index` will speed up
the counting operation by building the resulting bitmap and performing a
fast popcount (number of bits set on the bitmap) on the result.
Here are some sample timings of different ways to count commits in
`torvalds/linux`:
$ time git rev-list master | wc -l
399882
real 0m6.524s
user 0m6.060s
sys 0m3.284s
$ time git rev-list --count master
399882
real 0m4.318s
user 0m4.236s
sys 0m0.076s
$ time git rev-list --use-bitmap-index --count master
399882
real 0m0.217s
user 0m0.176s
sys 0m0.040s
This also respects negative refs, so you can use it to count
a slice of history:
$ time git rev-list --count v3.0..master
144843
real 0m1.971s
user 0m1.932s
sys 0m0.036s
$ time git rev-list --use-bitmap-index --count v3.0..master
real 0m0.280s
user 0m0.220s
sys 0m0.056s
Though note that the closer the endpoints, the less it helps. In the
traversal case, we have fewer commits to cross, so we take less time.
But the bitmap time is dominated by generating the pack revindex, which
is constant with respect to the refs given.
Note that you cannot yet get a fast --left-right count of a symmetric
difference (e.g., "--count --left-right master...topic"). The slow part
of that walk actually happens during the merge-base determination when
we parse "master...topic". Even though a count does not actually need to
know the real merge base (it only needs to take the symmetric difference
of the bitmaps), the revision code would require some refactoring to
handle this case.
Additionally, a `--test-bitmap` flag has been added that will perform
the same rev-list manually (i.e. using a normal revwalk) and using
bitmaps, and verify that the results are the same. This can be used to
exercise the bitmap code, and also to verify that the contents of the
.bitmap file are sane.
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>
In this patch, we use the bitmap API to perform the `Counting Objects`
phase in pack-objects, rather than a traditional walk through the object
graph. For a reasonably-packed large repo, the time to fetch and clone
is often dominated by the full-object revision walk during the Counting
Objects phase. Using bitmaps can reduce the CPU time required on the
server (and therefore start sending the actual pack data with less
delay).
For bitmaps to be used, the following must be true:
1. We must be packing to stdout (as a normal `pack-objects` from
`upload-pack` would do).
2. There must be a .bitmap index containing at least one of the
"have" objects that the client is asking for.
3. Bitmaps must be enabled (they are enabled by default, but can be
disabled by setting `pack.usebitmaps` to false, or by using
`--no-use-bitmap-index` on the command-line).
If any of these is not true, we fall back to doing a normal walk of the
object graph.
Here are some sample timings from a full pack of `torvalds/linux` (i.e.
something very similar to what would be generated for a clone of the
repository) that show the speedup produced by various
methods:
[existing graph traversal]
$ time git pack-objects --all --stdout --no-use-bitmap-index \
</dev/null >/dev/null
Counting objects: 3237103, done.
Compressing objects: 100% (508752/508752), done.
Total 3237103 (delta 2699584), reused 3237103 (delta 2699584)
real 0m44.111s
user 0m42.396s
sys 0m3.544s
[bitmaps only, without partial pack reuse; note that
pack reuse is automatic, so timing this required a
patch to disable it]
$ time git pack-objects --all --stdout </dev/null >/dev/null
Counting objects: 3237103, done.
Compressing objects: 100% (508752/508752), done.
Total 3237103 (delta 2699584), reused 3237103 (delta 2699584)
real 0m5.413s
user 0m5.604s
sys 0m1.804s
[bitmaps with pack reuse (what you get with this patch)]
$ time git pack-objects --all --stdout </dev/null >/dev/null
Reusing existing pack: 3237103, done.
Total 3237103 (delta 0), reused 0 (delta 0)
real 0m1.636s
user 0m1.460s
sys 0m0.172s
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>
This function actually does three things:
1. Check whether we've already added the object to our
packing list.
2. Check whether the object meets our criteria for adding.
3. Actually add the object to our packing list.
It's a little hard to see these three phases, because they
happen linearly in the rather long function. Instead, this
patch breaks them up into three separate helper functions.
The result is a little easier to follow, though it
unfortunately suffers from some optimization
interdependencies between the stages (e.g., during step 3 we
use the packing list index from step 1 and the packfile
information from step 2).
More importantly, though, the various parts can be
composed differently, as they will be in the next patch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A bitmap index is a `.bitmap` file that can be found inside
`$GIT_DIR/objects/pack/`, next to its corresponding packfile, and
contains precalculated reachability information for selected commits.
The full specification of the format for these bitmap indexes can be found
in `Documentation/technical/bitmap-format.txt`.
For a given commit SHA1, if it happens to be available in the bitmap
index, its bitmap will represent every single object that is reachable
from the commit itself. The nth bit in the bitmap is the nth object in
the packfile; if it's set to 1, the object is reachable.
By using the bitmaps available in the index, this commit implements
several new functions:
- `prepare_bitmap_git`
- `prepare_bitmap_walk`
- `traverse_bitmap_commit_list`
- `reuse_partial_packfile_from_bitmap`
The `prepare_bitmap_walk` function tries to build a bitmap of all the
objects that can be reached from the commit roots of a given `rev_info`
struct by using the following algorithm:
- If all the interesting commits for a revision walk are available in
the index, the resulting reachability bitmap is the bitwise OR of all
the individual bitmaps.
- When the full set of WANTs is not available in the index, we perform a
partial revision walk using the commits that don't have bitmaps as
roots, and limiting the revision walk as soon as we reach a commit that
has a corresponding bitmap. The earlier OR'ed bitmap with all the
indexed commits can now be completed as this walk progresses, so the end
result is the full reachability list.
- For revision walks with a HAVEs set (a set of commits that are deemed
uninteresting), first we perform the same method as for the WANTs, but
using our HAVEs as roots, in order to obtain a full reachability bitmap
of all the uninteresting commits. This bitmap then can be used to:
a) limit the subsequent walk when building the WANTs bitmap
b) finding the final set of interesting commits by performing an
AND-NOT of the WANTs and the HAVEs.
If `prepare_bitmap_walk` runs successfully, the resulting bitmap is
stored and the equivalent of a `traverse_commit_list` call can be
performed by using `traverse_bitmap_commit_list`; the bitmap version
of this call yields the objects straight from the packfile index
(without having to look them up or parse them) and hence is several
orders of magnitude faster.
As an extra optimization, when `prepare_bitmap_walk` succeeds, the
`reuse_partial_packfile_from_bitmap` call can be attempted: it will find
the amount of objects at the beginning of the on-disk packfile that can
be reused as-is, and return an offset into the packfile. The source
packfile can then be loaded and the bytes up to `offset` can be written
directly to the result without having to consider the entires inside the
packfile individually.
If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files
are available), the `rev_info` struct is left untouched, and can be used
to perform a manual rev-walk using `traverse_commit_list`.
Hence, this new set of functions are a generic API that allows to
perform the equivalent of
git rev-list --objects [roots...] [^uninteresting...]
for any set of commits, even if they don't have specific bitmaps
generated for them.
In further patches, we'll use this bitmap traversal optimization to
speed up the `pack-objects` and `rev-list` commands.
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>
This is the technical documentation for the JGit-compatible Bitmap v1
on-disk format.
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>
EWAH is a word-aligned compressed variant of a bitset (i.e. a data
structure that acts as a 0-indexed boolean array for many entries).
It uses a 64-bit run-length encoding (RLE) compression scheme,
trading some compression for better processing speed.
The goal of this word-aligned implementation is not to achieve
the best compression, but rather to improve query processing time.
As it stands right now, this EWAH implementation will always be more
efficient storage-wise than its uncompressed alternative.
EWAH arrays will be used as the on-disk format to store reachability
bitmaps for all objects in a repository while keeping reasonable sizes,
in the same way that JGit does.
This EWAH implementation is a mostly straightforward port of the
original `javaewah` library that JGit currently uses. The library is
self-contained and has been embedded whole (4 files) inside the `ewah`
folder to ease redistribution.
The library is re-licensed under the GPLv2 with the permission of Daniel
Lemire, the original author. The source code for the C version can
be found on GitHub:
https://github.com/vmg/libewok
The original Java implementation can also be found on GitHub:
https://github.com/lemire/javaewah
[jc: stripped debug-only code per Peff's $gmane/239768]
Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Scripts that use "merge-base --octopus" could do the reducing
themselves, but most of them are expected to want to get the reduced
results without having to do any work themselves.
Tests are taken from a message by Василий Макаров
<einmalfel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
We might want to vet the existing callers of the underlying
get_octopus_merge_bases() and find out if _all_ of them are doing
anything extra (like deduping) because the machinery can return
duplicate results. And if that is the case, then we may want to
move the dedupling down the callchain instead of having it here.
It piggybacks on an unrelated handle_octopus() function only because
there are some similarities between the way they need to preprocess
their input and output their result. There is nothing similar in
the true logic between these two operations.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Support for grafts predates Git's strbuf, and hence it is understandable
that there was a hard-coded line length limit of 1023 characters (which
was chosen a bit awkwardly, given that it is *exactly* one byte short of
aligning with the 41 bytes occupied by a commit name and the following
space or new-line character).
While regular commit histories hardly win comprehensibility in general
if they merge more than twenty-two branches in one go, it is not Git's
business to limit grafts in such a way.
In this particular developer's case, the use case that requires
substantially longer graft lines to be supported is the visualization of
the commits' order implied by their changes: commits are considered to
have an implicit relationship iff exchanging them in an interactive
rebase would result in merge conflicts.
Thusly implied branches tend to be very shallow in general, and the
resulting thicket of implied branches is usually very wide; It is
actually quite common that *most* of the commits in a topic branch have
not even one implied parent, so that a final merge commit has about as
many implied parents as there are commits in said branch.
[jc: squashed in tests by Jonathan]
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* fc/remote-helper-fixes:
remote-hg: test 'shared_path' in a moved clone
remote-hg: add tests for special filenames
remote-hg: fix 'shared path' path
remote-helpers: add extra safety checks
remote-hg: avoid buggy strftime()
Two packfiles that contain the same set of objects have
traditionally been named identically, but that made repacking a
repository that is already fully packed without any cruft with a
different packing parameter cumbersome. Update the convention to
name the packfile after the bytestream representation of the data,
not after the set of objects in it.
* jk/name-pack-after-byte-representation:
pack-objects doc: treat output filename as opaque
pack-objects: name pack files after trailer hash
sha1write: make buffer const-correct
"git diff ../else/where/A ../else/where/B" when ../else/where is
clearly outside the repository, and "git diff --no-index A B", do
not have to look at the index at all, but we used to read the index
unconditionally.
* tg/diff-no-index-refactor:
diff: avoid some nesting
diff: add test for --no-index executed outside repo
diff: don't read index when --no-index is given
diff: move no-index detection to builtin/diff.c
Show the total number of paths and the number of paths shown so far
when "git difftool" prompts to launch an external diff tool, which
would give users some sense of progress.
* zk/difftool-counts:
diff.c: fix some recent whitespace style violations
difftool: display the number of files in the diff queue in the prompt
"git cat-file --batch=", an admittedly useless command, did not
behave very well.
* jk/cat-file-regression-fix:
cat-file: handle --batch format with missing type/size
cat-file: pass expand_data to print_object_or_die
"git rev-parse <revs> -- <paths>" did not implement the usual
disambiguation rules the commands in the "git log" family used in
the same way.
* jk/rev-parse-double-dashes:
rev-parse: be more careful with munging arguments
rev-parse: correctly diagnose revision errors before "--"
Make "git push origin master" update the same ref that would be
updated by our 'master' when "git push origin" (no refspecs) is run
while the 'master' branch is checked out, which makes "git push"
more symmetric to "git fetch" and more usable for the triangular
workflow.
* jc/push-refmap:
push: also use "upstream" mapping when pushing a single ref
push: use remote.$name.push as a refmap
builtin/push.c: use strbuf instead of manual allocation
Subversion serf backend in versions 1.8.5 and below has a bug(*) that the
function creating the descriptor of a file change -- add_file() --
doesn't make a copy of its third argument when storing it on the
returned descriptor. As a result, by the time this field is used (in
transactions of file copying or renaming) it may well be released, and
the memory reused.
One of its possible manifestations is the svn assertion triggering on an
invalid path, with a message
svn_fspath__skip_ancestor: Assertion
`svn_fspath__is_canonical(child_fspath)' failed.
This patch works around this bug, by storing the value to be passed as
the third argument to add_file() in a local variable with the same scope
as the file change descriptor, making sure their lifetime is the same.
* [ew: fixed in Subversion r1553376 as noted by Jonathan Nieder]
Cc: Benjamin Pabst <benjamin.pabst85@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Roman Kagan <rkagan@mail.ru>
It can be useful for debugging or analysis to see which
objects are stored as delta bases on top of others. This
information is available by running `git verify-pack`, but
that is extremely expensive (and is harder than necessary to
parse).
Instead, let's make it available as a cat-file query format,
which makes it fast and simple to get the bases for a subset
of the objects.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A caller of sha1_object_info_extended technically has enough
information to determine the base sha1 from the results of
the call. It knows the pack, offset, and delta type of the
object, which is sufficient to find the base.
However, the functions to do so are not publicly available,
and the code itself is intimate enough with the pack details
that it should be abstracted away. We could add a public
helper to allow callers to query the delta base separately,
but it is simpler and slightly more efficient to optionally
grab it along with the rest of the object_info data.
For cases where the object is not stored as a delta, we
write the null sha1 into the query field. A careful caller
could check "oi.whence == OI_PACKED && oi.u.packed.is_delta"
before looking at the base sha1, but using the null sha1
provides a simple alternative (and gives a better sanity
check for a non-careful caller than simply returning random
bytes).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sha1write function returns an int, but it will always be
"0". The failure-prone parts of the function happen in the
"flush" callback, which cannot pass an error back to us. So
we just end up calling die() during the flush.
Let's just drop the return value altogether, as it only
confuses callers into thinking that it might be useful.
Only one call site actually checked the return value. We can
drop that check, since it just led to a die() anyway.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This behavior was added in 07d7bed (add: don't complain when adding
empty project root - 2009-04-28) then broken by 84b8b5d (remove
match_pathspec() in favor of match_pathspec_depth() -
2013-07-14). Reinstate it.
Noticed-by: Thomas Ferris Nicolaisen <tfnico@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since e71d1378 (remote-hg: fix 'shared path' path, 2013-12-07),
Mercurial 'shared_path' file is correctly updated whenever a clone is
moved. Make sure it keeps working, especially as this is depending on a
private Mercurial file.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git log did not correctly handle decorations when a tag object referenced
another tag object that was no longer a ref, such as when the second tag was
deleted. The commit would not be decorated correctly because parse_object had
not been called on the second tag and therefore its tagged field had not been
filled in, resulting in none of the tags being associated with the relevant
commit.
Call parse_object to fill in this field if it is absent so that the chain of
tags can be dereferenced and the commit can be properly decorated. Include
tests as well to prevent future regressions.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use strcmp() instead of starts_with()/!prefixcmp() to stop accepting
--informative-errors-just-a-little
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff.orderfile acts as a default for the -O command line option.
[sb: split up aw's original patch; rework tests and docs, treat option
as pathname]
Signed-off-by: Anders Waldenborg <anders@0x63.nu>
Signed-off-by: Samuel Bronson <naesten@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
