The '--sparse' flag in 'git pack-objects' changes the algorithm
used to enumerate objects to one that is faster for individual
users pushing new objects that change only a small cone of the
working directory. The sparse algorithm is not recommended for a
server, which likely sends new objects that appear across the
entire working directory.
Create a 'pack.useSparse' setting that enables this new algorithm.
This allows 'git push' to use this algorithm without passing a
'--sparse' flag all the way through four levels of run_command()
calls.
If the '--no-sparse' flag is set, then this config setting is
overridden.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When enumerating objects to place in a pack-file during 'git
pack-objects --revs', we discover the "frontier" of commits
that we care about and the boundary with commit we find
uninteresting. From that point, we walk trees to discover which
trees and blobs are uninteresting. Finally, we walk trees from the
interesting commits to find the interesting objects that are
placed in the pack.
This commit introduces a new, "sparse" way to discover the
uninteresting trees. We use the perspective of a single user trying
to push their topic to a large repository. That user likely changed
a very small fraction of the paths in their working directory, but
we spend a lot of time walking all reachable trees.
The way to switch the logic to work in this sparse way is to start
caring about which paths introduce new trees. While it is not
possible to generate a diff between the frontier boundary and all
of the interesting commits, we can simulate that behavior by
inspecting all of the root trees as a whole, then recursing down
to the set of trees at each path.
We already had taken the first step by passing an oidset to
mark_trees_uninteresting_sparse(). We now create a dictionary
whose keys are paths and values are oidsets. We consider the set
of trees that appear at each path. While we inspect a tree, we
add its subtrees to the oidsets corresponding to the tree entry's
path. We also mark trees as UNINTERESTING if the tree we are
parsing is UNINTERESTING.
To actually improve the performance, we need to terminate our
recursion. If the oidset contains only UNINTERESTING trees, then
we do not continue the recursion. This avoids walking trees that
are likely to not be reachable from interesting trees. If the
oidset contains only interesting trees, then we will walk these
trees in the final stage that collects the intersting objects to
place in the pack. Thus, we only recurse if the oidset contains
both interesting and UNINITERESTING trees.
There are a few ways that this is not a universally better option.
First, we can pack extra objects. If someone copies a subtree
from one tree to another, the first tree will appear UNINTERESTING
and we will not recurse to see that the subtree should also be
UNINTERESTING. We will walk the new tree and see the subtree as
a "new" object and add it to the pack. A test is modified to
demonstrate this behavior and to verify that the new logic is
being exercised.
Second, we can have extra memory pressure. If instead of being a
single user pushing a small topic we are a server sending new
objects from across the entire working directory, then we will
gain very little (the recursion will rarely terminate early) but
will spend extra time maintaining the path-oidset dictionaries.
Despite these potential drawbacks, the benefits of the algorithm
are clear. By adding a counter to 'add_children_by_path' and
'mark_tree_contents_uninteresting', I measured the number of
parsed trees for the two algorithms in a variety of repos.
For git.git, I used the following input:
v2.19.0
^v2.19.0~10
Objects to pack: 550
Walked (old alg): 282
Walked (new alg): 130
For the Linux repo, I used the following input:
v4.18
^v4.18~10
Objects to pack: 518
Walked (old alg): 4,836
Walked (new alg): 188
The two repos above are rather "wide and flat" compared to
other repos that I have used in the past. As a comparison,
I tested an old topic branch in the Azure DevOps repo, which
has a much deeper folder structure than the Linux repo.
Objects to pack: 220
Walked (old alg): 22,804
Walked (new alg): 129
I used the number of walked trees the main metric above because
it is consistent across multiple runs. When I ran my tests, the
performance of the pack-objects command with the same options
could change the end-to-end time by 10x depending on the file
system being warm. However, by repeating the same test on repeat
I could get more consistent timing results. The git.git and
Linux tests were too fast overall (less than 0.5s) to measure
an end-to-end difference. The Azure DevOps case was slow enough
to see the time improve from 15s to 1s in the warm case. The
cold case was 90s to 9s in my testing.
These improvements will have even larger benefits in the super-
large Windows repository. In our experiments, we see the
"Enumerate objects" phase of pack-objects taking 60-80% of the
end-to-end time of non-trivial pushes, taking longer than the
network time to send the pack and the server time to verify the
pack.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating a pack-file using 'git pack-objects --revs' we provide
a list of interesting and uninteresting commits. For example, a push
operation would make the local topic branch be interesting and the
known remote refs as uninteresting. We want to discover the set of
new objects to send to the server as a thin pack.
We walk these commits until we discover a frontier of commits such
that every commit walk starting at interesting commits ends in a root
commit or unintersting commit. We then need to discover which
non-commit objects are reachable from uninteresting commits. This
commit walk is not changing during this series.
The mark_edges_uninteresting() method in list-objects.c iterates on
the commit list and does the following:
* If the commit is UNINTERSTING, then mark its root tree and every
object it can reach as UNINTERESTING.
* If the commit is interesting, then mark the root tree of every
UNINTERSTING parent (and all objects that tree can reach) as
UNINTERSTING.
At the very end, we repeat the process on every commit directly
given to the revision walk from stdin. This helps ensure we properly
cover shallow commits that otherwise were not included in the
frontier.
The logic to recursively follow trees is in the
mark_tree_uninteresting() method in revision.c. The algorithm avoids
duplicate work by not recursing into trees that are already marked
UNINTERSTING.
Add a new 'sparse' option to the mark_edges_uninteresting() method
that performs this logic in a slightly different way. As we iterate
over the commits, we add all of the root trees to an oidset. Then,
call mark_trees_uninteresting_sparse() on that oidset. Note that we
include interesting trees in this process. The current implementation
of mark_trees_unintersting_sparse() will walk the same trees as
the old logic, but this will be replaced in a later change.
Add a '--sparse' flag in 'git pack-objects' to call this new logic.
Add a new test script t/t5322-pack-objects-sparse.sh that tests this
option. The tests currently demonstrate that the resulting object
list is the same as the old algorithm. This includes a case where
both algorithms pack an object that is not needed by a remote due to
limits on the explored set of trees. When the sparse algorithm is
changed in a later commit, we will add a test that demonstrates a
change of behavior in some cases.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit d8981c3f88 ("format-patch: do not let its diff-options affect
--range-diff", 2018-11-30) taught `show_range_diff()` to accept a
NULL-pointer as an indication that it should use its own "reasonable
default". That fixed a regression from a5170794 ("Merge branch
'ab/range-diff-no-patch'", 2018-11-18), but unfortunately it introduced
a regression of its own.
In particular, it means we forget the `file` member of the diff options,
so rather than placing a range-diff in the cover-letter, we write it to
stdout. In order to fix this, rewrite the two callers adjusted by
d8981c3f88 to instead create a "dummy" set of diff options where they
only fill in the fields we absolutely require, such as output file and
color.
Modify and extend the existing tests to try and verify that the right
contents end up in the right place.
Don't revert `show_range_diff()`, i.e., let it keep accepting NULL.
Rather than removing what is dead code and figuring out it isn't
actually dead and we've broken 2.20, just leave it for now.
[es: retain diff coloring when going to stdout]
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test framework has been updated to make a bug in the test script
(as opposed to bugs in Git that are discovered by running the
tests) stand out more prominently.
* sg/test-BUG:
tests: send "bug in the test script" errors to the script's stderr
The advice message to tell the user to migrate an existing graft
file to the replace system when a graft file was read was shown
even when "git replace --convert-graft-file" command, which is the
way the message suggests to use, was running, which made little
sense.
* ab/replace-graft-with-replace-advice:
advice: don't pointlessly suggest --convert-graft-file
"git rebase --stat" to transplant a piece of history onto a totally
unrelated history were not working before and silently showed wrong
result. With the recent reimplementation in C, it started to instead
die with an error message, as the original logic was not prepared
to cope with this case. This has now been fixed.
* js/rebase-stat-unrelated-fix:
rebase --stat: fix when rebasing to an unrelated history
When rebasing to a commit history that has no common commits with the
current branch, there is no merge base. In diffstat mode, this means
that we cannot compare to the merge base, but we have to compare to the
empty tree instead.
Also, if running in verbose diffstat mode, we should not output
Changes from <merge-base> to <onto>
as that does not make sense without any merge base.
Note: neither scripted nor built-in versoin of `git rebase` were
prepared for this situation well. We use this opportunity not only to
fix the bug(s), but also to make both versions' output consistent in
this instance. And add a regression test to keep this working in all
eternity.
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The scripted version of "rebase" honored the `GIT_REFLOG_ACTION`,
and some automation scripts expected the reflog entries to be
prefixed with "rebase -i", not "rebase", after running "rebase -i".
This regressed in the reimplementation in C.
Fix that, and add a regression test, both with `GIT_REFLOG_ACTION`
set and unset.
Note: the reflog message for "rebase finished" did *not* honor
GIT_REFLOG_ACTION, and as we are very late in the v2.20.0-rcN phase,
we leave that bug for later (as it seems that that bug has been with
us from the very beginning).
Reported by Ian Jackson.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The advice to run 'git replace --convert-graft-file' added in
f9f99b3f7d ("Deprecate support for .git/info/grafts", 2018-04-29)
didn't add an exception for the 'git replace --convert-graft-file'
codepath itself.
As a result we'd suggest running --convert-graft-file while the user
was running --convert-graft-file, which makes no sense. Before:
$ git replace --convert-graft-file
hint: Support for <GIT_DIR>/info/grafts is deprecated
hint: and will be removed in a future Git version.
hint:
hint: Please use "git replace --convert-graft-file"
hint: to convert the grafts into replace refs.
hint:
hint: Turn this message off by running
hint: "git config advice.graftFileDeprecated false"
Add a check for that case and skip printing the advice while the user
is busy following our advice.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test scripts checking 'git daemon' stop the daemon with a TERM signal,
and the 'stop_git_daemon' helper checks the daemon's exit status to
make sure that it indeed died because of that signal.
This check is bogus since 03c39b3458 (t/lib-git-daemon: use
test_match_signal, 2016-06-24), for two reasons:
- Right after killing 'git daemon', 'stop_git_daemon' saves its exit
status in a variable, but since 03c39b3458 the condition checking
the exit status looks at '$?', which at this point is not the exit
status of 'git daemon', but that of the variable assignment, i.e.
it's always 0.
- The unexpected exit status should abort the whole test script with
'error', but it doesn't, because 03c39b3458 forgot to negate
'test_match_signal's exit status in the condition.
This patch fixes both issues.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code recently added to "git clone" to see if the platform's
filesystem is adequate to check out and use the project code
correctly (e.g. a case smashing filesystem cannot be used for a
project with two files whose paths are different only in case) was
meant to help Windows users, but the test for it was not enabled
for that platform, which has been corrected.
* tb/clone-case-smashing-warning-test:
t5601-99: Enable colliding file detection for MINGW
Some systems do not have perl installed to /usr/bin. Use the variable
from the build settiings, and call perl directly than via shebang.
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit b878579ae7 (clone: report duplicate entries on case-insensitive
filesystems - 2018-08-17) adds a warning to user when cloning a repo
with case-sensitive file names on a case-insensitive file system.
This test has never been enabled for MINGW.
It had been working since day 1, but I forget to report that to the
author.
Enable it after a re-test.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A regression in Git 2.12 era made "git fsck" fall into an infinite
loop while processing truncated loose objects.
* jk/detect-truncated-zlib-input:
cat-file: handle streaming failures consistently
check_stream_sha1(): handle input underflow
t1450: check large blob in trailing-garbage test
Our test scripts can now take the '-V' option as a synonym for the
'--verbose-log' option.
* sg/test-verbose-log:
test-lib: introduce the '-V' short option for '--verbose-log'
Operations on promisor objects make sense in the context of only a
small subset of the commands that internally use the revisions
machinery, but the "--exclude-promisor-objects" option were taken
and led to nonsense results by commands like "log", to which it
didn't make much sense. This has been corrected.
* md/exclude-promisor-objects-fix:
exclude-promisor-objects: declare when option is allowed
Documentation/git-log.txt: do not show --exclude-promisor-objects
"git repack" in a shallow clone did not correctly update the
shallow points in the repository, leading to a repository that
does not pass fsck.
* js/shallow-and-fetch-prune:
repack -ad: prune the list of shallow commits
shallow: offer to prune only non-existing entries
repack: point out a bug handling stale shallow info
The receive.denyCurrentBranch=updateInstead codepath kicked in even
when the push should have been rejected due to other reasons, such
as it does not fast-forward or the update-hook rejects it, which
has been corrected.
* jc/receive-deny-current-branch-fix:
receive: denyCurrentBranch=updateinstead should not blindly update
Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on
Windows would strip initial parts from the paths because they
were not recognized as absolute, which has been corrected.
* js/diff-notice-has-drive-prefix:
diff: don't attempt to strip prefix from absolute Windows paths
A mutex used in "git pack-objects" were not correctly initialized
and this caused "git repack" to dump core on Windows.
* js/pack-objects-mutex-init-fix:
pack-objects (mingw): initialize `packing_data` mutex in the correct spot
pack-objects (mingw): demonstrate a segmentation fault with large deltas
pack-objects: fix typo 'detla' -> 'delta'
The implementation of run_command() API on the UNIX platforms had a
bug that caused a command not on $PATH to be found in the current
directory.
* jk/run-command-notdot:
run-command: mark path lookup errors with ENOENT
"git log --graph" showing an octopus merge sometimes miscounted the
number of display columns it is consuming to show the merge and its
parent commits, which has been corrected.
* np/log-graph-octopus-fix:
log: fix coloring of certain octopus merge shapes
The codepath to support the experimental split-index mode had
remaining "racily clean" issues fixed.
* sg/split-index-racefix:
split-index: BUG() when cache entry refers to non-existing shared entry
split-index: smudge and add racily clean cache entries to split index
split-index: don't compare cached data of entries already marked for split index
split-index: count the number of deleted entries
t1700-split-index: date back files to avoid racy situations
split-index: add tests to demonstrate the racy split index problem
t1700-split-index: document why FSMONITOR is disabled in this test script
A partial clone that is configured to lazily fetch missing objects
will on-demand issue a "git fetch" request to the originating
repository to fill not-yet-obtained objects. The request has been
optimized for requesting a tree object (and not the leaf blob
objects contained in it) by telling the originating repository that
no blobs are needed.
* jt/non-blob-lazy-fetch:
fetch-pack: exclude blobs when lazy-fetching trees
fetch-pack: avoid object flags if no_dependents
The code in "git status" sometimes hit an assertion failure. This
was caused by a structure that was reused without cleaning the data
used for the first run, which has been corrected.
* en/status-multiple-renames-to-the-same-target-fix:
commit: fix erroneous BUG, 'multiple renames on the same target? how?'
The recently introduced commit-graph auxiliary data is incompatible
with mechanisms such as replace & grafts that "breaks" immutable
nature of the object reference relationship. Disable optimizations
based on its use (and updating existing commit-graph) when these
incompatible features are in use in the repository.
* ds/commit-graph-with-grafts:
commit-graph: close_commit_graph before shallow walk
commit-graph: not compatible with uninitialized repo
commit-graph: not compatible with grafts
commit-graph: not compatible with replace objects
test-repository: properly init repo
commit-graph: update design document
refs.c: upgrade for_each_replace_ref to be a each_repo_ref_fn callback
refs.c: migrate internal ref iteration to pass thru repository argument
Recently added "range-diff" had a corner-case bug to cause it
segfault, which has been corrected.
* tg/range-diff-corner-case-fix:
linear-assignment: fix potential out of bounds memory access
"git update-ref" learned to make both "--no-deref" and "--stdin"
work at the same time.
* en/update-ref-no-deref-stdin:
update-ref: allow --no-deref with --stdin
update-ref: fix type of update_flags variable to match its usage
Update error messages given by "git remote" and make them consistent.
* ms/remote-error-message-update:
builtin/remote: quote remote name on error to display empty name
The code to backfill objects in lazily cloned repository did not
work correctly, which has been corrected.
* jt/lazy-object-fetch-fix:
fetch-object: set exact_oid when fetching
fetch-object: unify fetch_object[s] functions
"git rebase" etc. in Git 2.19 fails to abort when given an empty
commit log message as result of editing, which has been corrected.
* en/sequencer-empty-edit-result-aborts:
sequencer: fix --allow-empty-message behavior, make it smarter
"git add ':(attr:foo)'" is not supported and is supposed to be
rejected while the command line arguments are parsed, but we fail
to reject such a command line upfront.
* nd/attr-pathspec-fix:
add: do not accept pathspec magic 'attr'
Further fix for O_APPEND emulation on Windows
* js/mingw-o-append:
mingw: fix mingw_open_append to work with named pipes
t0051: test GIT_TRACE to a windows named pipe
Fix for a long-standing bug that leaves the index file corrupt when
it shrinks during a partial commit.
* jk/reopen-tempfile-truncate:
reopen_tempfile(): truncate opened file
"git rebase -i" did not clear the state files correctly when a run
of "squash/fixup" is aborted and then the user manually amended the
commit instead, which has been corrected.
* js/rebase-i-autosquash-fix:
rebase -i: be careful to wrap up fixup/squash chains
rebase -i --autosquash: demonstrate a problem skipping the last squash
"git interpret-trailers" and its underlying machinery had a buggy
code that attempted to ignore patch text after commit log message,
which triggered in various codepaths that will always get the log
message alone and never get such an input.
* jk/trailer-fixes:
append_signoff: use size_t for string offsets
sequencer: ignore "---" divider when parsing trailers
pretty, ref-filter: format %(trailers) with no_divider option
interpret-trailers: allow suppressing "---" divider
interpret-trailers: tighten check for "---" patch boundary
trailer: pass process_trailer_opts to trailer_info_get()
trailer: use size_t for iterating trailer list
trailer: use size_t for string offsets
The way .git/index and .git/sharedindex* files were initially
created gave these files different perm bits until they were
adjusted for shared repository settings. This was made consistent.
* cc/shared-index-permbits:
read-cache: make the split index obey umask settings
