Commit Graph

63024 Commits

Author SHA1 Message Date
Ævar Arnfjörð Bjarmason
7367d88261 archive: stop passing "stage" through read_tree_recursive()
The "stage" variable being passed around in the archive code has only
ever been an elaborate way to hardcode the value "0".

This code was added in its original form in e4fbbfe9ec (Add
git-zip-tree, 2006-08-26), at which point a hardcoded "0" would be
passed down through read_tree_recursive() to write_zip_entry().

It was then diligently added to the "struct directory" in
ed22b4173b (archive: support filtering paths with glob, 2014-09-21),
but we were still not doing anything except passing it around as-is.

Let's stop doing that in the code internal to archive.c, we'll still
feed "0" to read_tree_recursive() itself, but won't use it. That we're
providing it at all to read_tree_recursive() will be changed in a
follow-up commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 16:09:26 -07:00
Ævar Arnfjörð Bjarmason
9614ad3ce0 ls-files: refactor away read_tree()
Refactor away the read_tree() function into its only user,
overlay_tree_on_index().

First, change read_one_entry_opt() to use the strbuf parameter
read_tree_recursive() passes down in place. This finishes up a partial
refactoring started in 6a0b0b6de9 (tree.c: update read_tree_recursive
callback to pass strbuf as base, 2014-11-30).

Moving the rest into overlay_tree_on_index() makes this index juggling
we're doing easier to read.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 16:09:26 -07:00
Ævar Arnfjörð Bjarmason
fcc7c12f11 ls-files: don't needlessly pass around stage variable
Now that read_tree() has been moved to ls-files.c we can get rid of
the stage != 1 case that'll never happen.

Let's not use read_tree_recursive() as a pass-through to pass "stage =
1" either. For now we'll pass an unused "stage = 0" for consistency
with other read_tree_recursive() callers, that argument will be
removed in a follow-up commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 16:09:26 -07:00
Ævar Arnfjörð Bjarmason
eefadd18e1 tree.c API: move read_tree() into builtin/ls-files.c
Since the read_tree() API was added around the same time as
read_tree_recursive() in 94537c78a8 (Move "read_tree()" to
"tree.c"[...], 2005-04-22) and b12ec373b8 ([PATCH] Teach read-tree
about commit objects, 2005-04-20) things have gradually migrated over
to the read_tree_recursive() version.

Now builtin/ls-files.c is the last user of this code, let's move all
the relevant code there. This allows for subsequent simplification of
it, and an eventual move to read_tree_recursive().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 16:09:25 -07:00
Ævar Arnfjörð Bjarmason
8de78218c5 ls-files tests: add meaningful --with-tree tests
Add tests for "ls-files --with-tree". There was effectively no
coverage for any normal usage of this command, only the tests added in
54e1abce90 (Add test case for ls-files --with-tree, 2007-10-03) for
an obscure bug.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 16:09:25 -07:00
Ævar Arnfjörð Bjarmason
dcc0a86f2f show tests: add test for "git show <tree>"
Add missing tests for showing a tree with "git show". Let's test for
showing a tree, two trees, and that doing so doesn't recurse.

The only tests for this code added in 5d7eeee2ac (git-show: grok
blobs, trees and tags, too, 2006-12-14) were the tests in
t7701-repack-unpack-unreachable.sh added in ccc1297226 (repack:
modify behavior of -A option to leave unreferenced objects unpacked,
2008-05-09).

Let's add this common mode of operation to the "show" tests
themselves. It's more obvious, and the tests in
t7701-repack-unpack-unreachable.sh happily pass if we start buggily
emitting trees recursively.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 16:09:25 -07:00
Elijah Newren
f3b964a07e Add testing with merge-ort merge strategy
In preparation for switching from merge-recursive to merge-ort as the
default strategy, have the testsuite default to running with merge-ort.
Keep coverage of the recursive backend by having the linux-gcc job run
with it.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
259490e572 t6423: mark remaining expected failure under merge-ort as such
When we started on merge-ort, thousands of tests failed when run with
the GIT_TEST_MERGE_ALGORITHM=ort flag; with so many, it didn't make
sense to flip all their test expectations.  The ones in t6409, t6418,
and the submodule tests are being handled by an independent in-flight
topic ("Complete merge-ort implemenation...almost").  The ones in
t6423 were left out of the other series because other ongoing series
that this commit depends upon were addressing those.  Now that we only
have one remaining test failure in t6423, let's mark it as such.

This remaining test will be fixed by a future optimization series, but
since merge-recursive doesn't pass this test either, passing it is not
necessary for declaring merge-ort ready for general use.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
41376b58e6 Revert "merge-ort: ignore the directory rename split conflict for now"
This reverts commit 5ced7c3da0, which was
put in place as a temporary measure to avoid optimizations unstably
erroring out on no destination having a majority of the necessary
renames for directories that had no new files and thus no need for
directory rename detection anyway.  Now that optimizations are in place
to prevent us from trying to compute directory rename count computations
for directories that do not need it, we can undo this temporary measure.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
816147e7ba merge-recursive: add a bunch of FIXME comments documenting known bugs
The plan is to just delete merge-recursive, but not until everyone is
comfortable with merge-ort as a replacement.  Given that I haven't
switched all callers of merge-recursive over yet (e.g. git-am still uses
merge-recursive), maybe there's some value documenting known bugs in the
algorithm in case we end up keeping it or someone wants to dig it up in
the future.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
5291828df8 merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict
There are a variety of questions users might ask while resolving
conflicts:
  * What changes have been made since the previous (first) parent?
  * What changes are staged?
  * What is still unstaged? (or what is still conflicted?)
  * What changes did I make to resolve conflicts so far?
The first three of these have simple answers:
  * git diff HEAD
  * git diff --cached
  * git diff
There was no way to answer the final question previously.  Adding one
is trivial in merge-ort, since it works by creating a tree representing
what should be written to the working copy complete with conflict
markers.  Simply write that tree to .git/AUTO_MERGE, allowing users to
answer the fourth question with
  * git diff AUTO_MERGE

I avoided using a name like "MERGE_AUTO", because that would be
merge-specific (much like MERGE_HEAD, REBASE_HEAD, REVERT_HEAD,
CHERRY_PICK_HEAD) and I wanted a name that didn't change depending on
which type of operation the merge was part of.

Ensure that paths which clean out other temporary operation-specific
files (e.g. CHERRY_PICK_HEAD, MERGE_MSG, rebase-merge/ state directory)
also clean out this AUTO_MERGE file.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
aa2faac03a t: mark several submodule merging tests as fixed under merge-ort
merge-ort handles submodules (and directory/file conflicts in general)
differently than merge-recursive does; it basically puts all the special
handling for different filetypes into one place in the codebase instead
of needing special handling for different filetypes in many different
code paths.  This one code path in merge-ort could perhaps use some work
still (there are still test_expect_failure cases in the testsuite), but
it passes all the tests that merge-recursive does as well as 12
additional ones that merge-recursive fails.  Mark those 12 tests as
test_expect_success under merge-ort.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
66b209b86a merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries
When merge conflicts occur in paths removed by a sparse-checkout, we
need to unsparsify those paths (clear the SKIP_WORKTREE bit), and write
out the conflicted file to the working copy.  In the very unlikely case
that someone manually put a file into the working copy at the location
of the SKIP_WORKTREE file, we need to avoid overwriting whatever edits
they have made and move that file to a different location first.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
8ddc20b896 t6428: new test for SKIP_WORKTREE handling and conflicts
If there is a conflict during a merge for a SKIP_WORKTREE entry, we
expect that file to be written to the working copy and have the
SKIP_WORKTREE bit cleared in the index.  If the user had manually
created a file in the working tree despite SKIP_WORKTREE being set, we
do not want to clobber their changes to that file, but want to move it
out of the way.  Add tests that check for these behaviors.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
3639dfb3a8 merge-ort: support subtree shifting
merge-recursive has some simple code to support subtree shifting; copy
it over to merge-ort.  This fixes t6409.12 under
GIT_TEST_MERGE_ALGORITHM=ort.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
3860220bfa merge-ort: let renormalization change modify/delete into clean delete
When we have a modify/delete conflict, but the only change to the
modification is e.g. change of line endings, then if renormalization is
requested then we should be able to recognize such a case as a
not-modified/delete and resolve the conflict automatically.

This fixes t6418.10 under GIT_TEST_MERGE_ALGORITHM=ort.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
1218b3ab86 merge-ort: have ll_merge() use a special attr_index for renormalization
ll_merge() needs an index when renormalization is requested.  Create one
specifically for just this purpose with just the one needed entry.  This
fixes t6418.4 and t6418.5 under GIT_TEST_MERGE_ALGORITHM=ort.

NOTE 1: Even if the user has a working copy or a real index (which is
not a given as merge-ort can be used in bare repositories), we
explicitly ignore any .gitattributes file from either of these
locations.  merge-ort can be used to merge two branches that are
unrelated to HEAD, so .gitattributes from the working copy and current
index should not be considered relevant.

NOTE 2: Since we are in the middle of merging, there is a risk that
.gitattributes itself is conflicted...leaving us with an ill-defined
situation about how to perform the rest of the merge.  It could be that
the .gitattributes file does not even exist on one of the sides of the
merge, or that it has been modified on both sides.  If it's been
modified on both sides, it's possible that it could itself be merged
cleanly, though it's also possible that it only merges cleanly if you
use the right version of the .gitattributes file to drive the merge.  It
gets kind of complicated.  The only test we ever had that attempted to
test behavior in this area was seemingly unaware of the undefined
behavior, but knew the test wouldn't work for lack of attribute handling
support, marked it as test_expect_failure from the beginning, but
managed to fail for several reasons unrelated to attribute handling.
See commit 6f6e7cfb52 ("t6038: remove problematic test", 2020-08-03) for
details.  So there are probably various ways to improve what
initialize_attr_index() picks in the case of a conflicted .gitattributes
but for now I just implemented something simple -- look for whatever
.gitattributes file we can find in any of the higher order stages and
use it.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
ea305a68fd merge-ort: add a special minimal index just for renormalization
renormalize_buffer() requires an index_state, which is something that
merge-ort does not operate with.  However, all the renormalization code
needs is an index with a .gitattributes file...plus a little bit of
setup.  Create such an index, along with the deallocation and
attr_direction handling.

A subsequent commit will add a function to finish the initialization
of this index.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:40 -07:00
Elijah Newren
72b3091040 merge-ort: use STABLE_QSORT instead of QSORT where required
rename/rename conflict handling depends on the fact that if both sides
renamed the same path, that the one on the MERGE_SIDE1 will appear first
in the combined diff_queue_struct passed to process_renames().  Since we
add all pairs from MERGE_SIDE1 to combined first, and then all pairs
from MERGE_SIDE2, and then sort based on filename, this will only be
true if the sort used is stable.  This was found due to the fact that
Mac, unlike Linux, apparently has a system-defined qsort that is not
stable.

While we are at it, review the other callers of QSORT and add comments
about why they can remain as calls to QSORT instead of being modified
to call STABLE_QSORT.

Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-20 12:35:39 -07:00
Junio C Hamano
ef486a9ecf Merge branch 'tb/git-mv-icase-fix'
Fix a corner case bug in "git mv" on case insensitive systems,
which was introduced in 2.29 timeframe.

* tb/git-mv-icase-fix:
  git mv foo FOO ; git mv foo bar gave an assert
2021-03-19 15:25:40 -07:00
Junio C Hamano
98164e9585 The first batch in 2.32 cycle
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-19 15:25:40 -07:00
Junio C Hamano
bfcc6e2a68 Merge branch 'rs/xcalloc-takes-nelem-first'
Code cleanup.

* rs/xcalloc-takes-nelem-first:
  fix xcalloc() argument order
2021-03-19 15:25:39 -07:00
Junio C Hamano
af107029b1 Merge branch 'ah/make-fuzz-all-doc-update'
Update insn in Makefile comments to run fuzz-all target.

* ah/make-fuzz-all-doc-update:
  Makefile: update 'make fuzz-all' docs to reflect modern clang
2021-03-19 15:25:39 -07:00
Junio C Hamano
c691e918f4 Merge branch 'jk/slimmed-down'
Unused code removal.

* jk/slimmed-down:
  vcs-svn: remove header files as well
2021-03-19 15:25:38 -07:00
Junio C Hamano
92ccd7b752 Merge branch 'rs/calloc-array'
CALLOC_ARRAY() macro replaces many uses of xcalloc().

* rs/calloc-array:
  cocci: allow xcalloc(1, size)
  use CALLOC_ARRAY
  git-compat-util.h: drop trailing semicolon from macro definition
2021-03-19 15:25:38 -07:00
Junio C Hamano
a8a0ac3234 Merge branch 'rs/avoid-null-statement-after-macro-call'
Fix macros that can silently inject unintended null-statements.

* rs/avoid-null-statement-after-macro-call:
  mem-pool: drop trailing semicolon from macro definition
  block-sha1: drop trailing semicolon from macro definition
2021-03-19 15:25:38 -07:00
Junio C Hamano
948e8ac534 Merge branch 'km/config-doc-typofix'
Docfix.

* km/config-doc-typofix:
  config.txt: add missing period
2021-03-19 15:25:38 -07:00
Junio C Hamano
cc930b7472 Merge branch 'jt/clone-unborn-head'
Test fix.

* jt/clone-unborn-head:
  t5606: run clone branch name test with protocol v2
2021-03-19 15:25:38 -07:00
Junio C Hamano
1dd4e74522 Merge branch 'js/fsmonitor-unpack-fix'
The data structure used by fsmonitor interface was not properly
duplicated during an in-core merge, leading to use-after-free etc.

* js/fsmonitor-unpack-fix:
  fsmonitor: do not forget to release the token in `discard_index()`
  fsmonitor: fix memory corruption in some corner cases
2021-03-19 15:25:37 -07:00
Junio C Hamano
35381b13da Merge branch 'jk/bisect-peel-tag-fix'
"git bisect" reimplemented more in C during 2.30 timeframe did not
take an annotated tag as a good/bad endpoint well.  This regression
has been corrected.

* jk/bisect-peel-tag-fix:
  bisect: peel annotated tags to commits
2021-03-19 15:25:37 -07:00
Junio C Hamano
8779c141da Merge branch 'jh/fsmonitor-prework'
The fsmonitor interface read from its input without making sure
there is something to read from.  This bug is new in 2.31
timeframe.

* jh/fsmonitor-prework:
  fsmonitor: avoid global-buffer-overflow READ when checking trivial response
2021-03-19 15:25:37 -07:00
Junio C Hamano
eabacfd9cb Merge branch 'jc/calloc-fix'
Code clean-up.

* jc/calloc-fix:
  xcalloc: use CALLOC_ARRAY() when applicable
2021-03-19 15:25:37 -07:00
Taylor Blau
14e7b8344f builtin/pack-objects.c: ignore missing links with --stdin-packs
When 'git pack-objects --stdin-packs' encounters a commit in a pack, it
marks it as a starting point of a best-effort reachability traversal
that is used to populate the name-hash of the objects listed in the
given packs.

The traversal expects that it should be able to walk the ancestors of
all commits in a pack without issue. Ordinarily this is the case, but it
is possible to having missing parents from an unreachable part of the
repository. In that case, we'd consider any missing objects in the
unreachable portion of the graph to be junk.

This should be handled gracefully: since the traversal is best-effort
(i.e., we don't strictly need to fill in all of the name-hash fields),
we should simply ignore any missing links.

This patch does that (by setting the 'ignore_missing_links' bit on the
rev_info struct), and ensures we don't regress in the future by adding a
test which demonstrates this case.

It is a little over-eager, since it will also ignore missing links in
reachable parts of the packs (which would indicate a corrupted
repository), but '--stdin-packs' is explicitly *not* about reachability.
So this step isn't making anything worse for a repository which contains
packs missing reachable objects (since we never drop objects with
'--stdin-packs').

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-19 11:19:29 -07:00
Bagas Sanjaya
6534d436a2 INSTALL: note on using Asciidoctor to build doc
Note on using Asciidoctor to build documentation suite.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-19 10:49:20 -07:00
Elijah Newren
9bd342137e diffcore-rename: determine which relevant_sources are no longer relevant
As noted a few commits ago ("diffcore-rename: only compute
dir_rename_count for relevant directories"), when a source file rename
is used as part of directory rename detection, we need to increment
counts for each ancestor directory in dirs_removed with value
RELEVANT_FOR_SELF.  However, a few commits ago ("diffcore-rename: check
if we have enough renames for directories early on"), we may have
downgraded all relevant ancestor directories from RELEVANT_FOR_SELF to
RELEVANT_FOR_ANCESTOR.

For a given file, if no ancestor directory is found in dirs_removed with
a value of RELEVANT_FOR_SELF, then we can downgrade
relevant_source[PATH] from RELEVANT_LOCATION to RELEVANT_NO_MORE.  This
means we can skip detecting a rename for that particular path (and any
other paths in the same directory).

For the testcases mentioned in commit 557ac0350d ("merge-ort: begin
performance work; instrument with trace2_region_* calls", 2020-10-28),
this change improves the performance as follows:

                            Before                  After
    no-renames:        5.680 s ±  0.096 s     5.665 s ±  0.129 s
    mega-renames:     13.812 s ±  0.162 s    11.435 s ±  0.158 s
    just-one-mega:   506.0  ms ±  3.9  ms   494.2  ms ±  6.1  ms

While this improvement looks rather modest for these testcases (because
all the previous optimizations were sufficient to nearly remove all time
spent in rename detection already),  consider this alternative testcase
tweaked from the ones in commit 557ac0350d as follows

    <Same initial setup as commit 557ac0350d, then...>
    $ git switch -c add-empty-file v5.5
    $ >drivers/gpu/drm/i915/new-empty-file
    $ git add drivers/gpu/drm/i915/new-empty-file
    $ git commit -m "new file"
    $ git switch 5.4-rename
    $ git cherry-pick --strategy=ort add-empty-file

For this testcase, we see the following improvement:

                            Before                  After
    pick-empty:        1.936 s ±  0.024 s     688.1 ms ±  4.2 ms

So roughly a factor of 3 speedup.  At $DAYJOB, there was a particular
repository and cherry-pick that inspired this optimization; for that
case I saw a speedup factor of 7 with this optimization.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
ec59da6015 merge-ort: record the reason that we want a rename for a file
There are two different reasons we might want a rename for a file -- for
three-way content merging or as part of directory rename detection.
Record the reason.  diffcore-rename will potentially be able to filter
some of the ones marked as needed only for directory rename detection,
if it can determine those directory renames based solely on renames
found via exact rename detection and basename-guided rename detection.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
bf238b7137 diffcore-rename: add computation of number of unknown renames
The previous commit can only be effective if we have a computation of
the number of paths under a given directory which are still have pending
renames, and expected this number to be recorded in the dir_rename_count
map under the key UNKNOWN_DIR.  Add the code necessary to compute these
values.

Note that this change means dir_rename_count might have a directory
whose only entry (for UNKNOWN_DIR) was removed by the time merge-ort
goes to check it.  To account for this, merge-ort needs to check for the
case where the max count is 0.

With this change we are now computing the necessary value for each
directory in dirs_removed, but are not using that value anywhere.  The
next two commits will make use of the values stored in dirs_removed in
order to compute whether each relevant_source (that is needed only for
directory rename detection) has become unnecessary.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
0491d39297 diffcore-rename: check if we have enough renames for directories early on
As noted in the past few commits, if we can determine that a directory
already has enough renames to determine how directory rename detection
will be decided for that directory, then we can mark that directory as
no longer needing any more renames detected for files underneath it.
For such directories, we change the value in the dirs_removed map from
RELEVANT_TO_SELF to RELEVANT_FOR_ANCESTOR.

A subsequent patch will use this information while iterating over the
remaining potential rename sources to mark ones that were only
location_relevant as unneeded if no containing directory is still marked
as RELEVANT_TO_SELF.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
e54385b97a diffcore-rename: only compute dir_rename_count for relevant directories
When one side adds files to a directory that the other side renamed,
directory rename detection is used to either move the new paths to the
newer directory or warn the user about the fact that another path
location might be better.

If a parent of the given directory had new files added to it, any
renames in the current directory are also part of determining where the
parent directory is renamed to.  Thus, naively, we need to record each
rename N times for a path at depth N.  However, we can use the
additional information added to dirs_removed in the last commit to avoid
traversing all N parent directories in many cases.  Let's use an example
to explain how this works.  If we have a path named
   src/old_dir/a/b/file.c
and src/old_dir doesn't exist on one side of history, but the other
added a file named src/old_dir/newfile.c, then if one side renamed
   src/old_dir/a/b/file.c => source/new_dir/a/b/file.c
then this file would affect potential directory rename detection counts
for
   src/old_dir/a/b => source/new_dir/a/b
   src/old_dir/a   => source/new_dir/a
   src/old_dir     => source/new_dir
   src             => source
adding a weight of 1 to each in dir_rename_counts.  However, if src/
exists on both sides of history, then we don't need to track any entries
for it in dir_rename_counts.  That was implemented previously.  What we
are adding now, is that if no new files were added to src/old_dir/a or
src/old_dir/b, then we don't need to have counts in dir_rename_count
for those directories either.

In short, we only need to track counts in dir_rename_count for
directories whose dirs_removed value is RELEVANT_FOR_SELF.  And as soon
as we reach a directory that isn't in dirs_removed (signalled by
returning the default value of NOT_RELEVANT from strintmap_get()), we
can stop looking any further up the directory hierarchy.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Elijah Newren
fb52938eec merge-ort: record the reason that we want a rename for a directory
When one side of history renames a directory, and the other side of
history added files to the old directory, directory rename detection is
used to warn about the location of the added files so the user can
move them to the old directory or keep them with the new one.

This sets up three different types of directories:
  * directories that had new files added to them
  * directories underneath a directory that had new files added to them
  * directories where no new files were added to it or any leading path

Save this information in dirs_removed; the next several commits will
make use of this information.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Elijah Newren
a49b55d52e merge-ort, diffcore-rename: tweak dirs_removed and relevant_source type
As noted in the previous commit, we want to be able to take advantage of
the "majority rules" portion of directory rename detection to avoid
detecting more renames than necessary.  However, for diffcore-rename to
take advantage of that, it needs to know whether a rename source file
was needed for just directory rename detection reasons, or if it is
wanted for potential three-way content merging.  Modify relevant_sources
from a strset to a strintmap, so we can encode additional information.

We also modify dirs_removed from a strset to a strintmap at the same
time because trying to determine what files are needed for directory
rename detection will require us tracking a bit more information for
each directory.

This commit only changes the types of the two variables from strset to
strintmap; it does not actually store any special values yet and for now
only checks for presence of entries in the strintmap.  Thus, the code is
functionally identical to how it behaved before.  Future commits will
start associating values with each key for these two maps.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Elijah Newren
ae1db7b31c diffcore-rename: take advantage of "majority rules" to skip more renames
In directory rename detection (when a directory is removed on one side
of history and the other side adds new files to that directory), we work
to find where the greatest number of files within that directory were
renamed to so that the new files can be moved with the majority of the
files.

Naively, we can just do this by detecting renames for *all* files within
the removed/renamed directory, looking at all the destination
directories where files within that directory were moved, and if there
is more than one such directory then taking the one with the greatest
number of files as the directory where the old directory was renamed to.

However, sometimes there are enough renames from exact rename detection
or basename-guided rename detection that we have enough information to
determine the majority winner already.  Add a function meant to compute
whether particular renames are still needed based on this majority rules
check.  The next several commits will then add the necessary
infrastructure to get the information we need to compute which
additional rename sources we can skip.

An important side note for future further optimization:

There is a possible improvement to this optimization that I have not yet
attempted and will not be included in this series of patches: we could
first check whether exact renames provide enough information for us to
determine directory renames, and avoid doing basename-guided rename
detection on some or all of the RELEVANT_LOCATION files within those
directories.  In effect, this variant would mean doing the
handle_early_known_dir_renames() both after exact rename detection and
again after basename-guided rename detection, though it would also mean
decrementing the number of "unknown" renames for each rename we found
from basename-guided rename detection.  Adding this additional check for
skippable renames right after exact rename detection might turn out to
be valuable, especially for partial clones where it might allow us to
download certain source files entirely.  However, this particular
optimization was actually the last one I did in original implementation
order, and by the time I implemented this idea, every testcase I had was
sufficiently fast that further optimization was unwarranted.  If future
testcases arise that tax rename detection more heavily (or perhaps
partial clones can benefit from avoiding loading more objects), it may
be worth implementing this more involved variant.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Jeff King
27d578d904 t: annotate !PTHREADS tests with !FAIL_PREREQS
Some tests in t5300 and t7810 expect us to complain about a "--threads"
argument when Git is compiled without pthread support. Running these
under GIT_TEST_FAIL_PREREQS produces a confusing failure: we pretend to
the tests that there is no pthread support, so they expect the warning,
but of course the actual build is perfectly happy to respect the
--threads argument.

We never noticed before the recent a926c4b904 (tests: remove most uses
of C_LOCALE_OUTPUT, 2021-02-11), because the tests also were marked as
requiring the C_LOCALE_OUTPUT prerequisite. Which means they'd never
have run in FAIL_PREREQS mode, since it would always pretend that the
locale prereq was not satisfied.

These tests can't possibly work in this mode; it is a mismatch between
what the tests expect and what the build was told to do. So let's just
mark them to be skipped, using the special prereq introduced by
dfe1a17df9 (tests: add a special setup where prerequisites fail,
2019-05-13).

Reported-by: Son Luong Ngoc <sluongng@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:17:30 -07:00
Jeff Hostetler
f59d15bb42 convert: add classification for conv_attrs struct
Create `enum conv_attrs_classification` to express the different ways
that attributes are handled for a blob during checkout.

This will be used in a later commit when deciding whether to add a file
to the parallel or delayed queue during checkout. For now, we can also
use it in get_stream_filter_ca() to simplify the function (as the
classifying logic is the same).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Jeff Hostetler
3e9e82c0d8 convert: add get_stream_filter_ca() variant
Like the previous patch, we will also need to call get_stream_filter()
with a precomputed `struct conv_attrs`, when we add support for parallel
checkout workers. So add the _ca() variant which takes the conversion
attributes struct as a parameter.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Jeff Hostetler
55b4ad0ead convert: add [async_]convert_to_working_tree_ca() variants
Separate the attribute gathering from the actual conversion by adding
_ca() variants of the conversion functions. These variants receive a
precomputed 'struct conv_attrs', not relying, thus, on an index state.
They will be used in a future patch adding parallel checkout support,
for two reasons:

- We will already load the conversion attributes in checkout_entry(),
  before conversion, to decide whether a path is eligible for parallel
  checkout. Therefore, it would be wasteful to load them again later,
  for the actual conversion.

- The parallel workers will be responsible for reading, converting and
  writing blobs to the working tree. They won't have access to the main
  process' index state, so they cannot load the attributes. Instead,
  they will receive the preloaded ones and call the _ca() variant of
  the conversion functions. Furthermore, the attributes machinery is
  optimized to handle paths in sequential order, so it's better to leave
  it for the main process, anyway.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Jeff Hostetler
38e95844e8 convert: make convert_attrs() and convert structs public
Move convert_attrs() declaration from convert.c to convert.h, together
with the conv_attrs struct and the crlf_action enum. This function and
the data structures will be used outside convert.c in the upcoming
parallel checkout implementation. Note that crlf_action is renamed to
convert_crlf_action, which is more appropriate for the global namespace.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Nipunn Koorapati
7e5aa13d2c fsmonitor: add perf test for git diff HEAD
Update the xargs call so that if your large repo contains
symlinks, test-tool chmtime failure does not end the script.

On Linux
Test                                                          this tree           upstream/master
---------------------------------------------------------------------------------------------------------
7519.4: status (fsmonitor=fsmonitor-watchman)                 0.52(0.43+0.10)     0.53(0.49+0.05) +1.9%
7519.5: status -uno (fsmonitor=fsmonitor-watchman)            0.21(0.15+0.07)     0.22(0.13+0.09) +4.8%
7519.6: status -uall (fsmonitor=fsmonitor-watchman)           1.65(0.93+0.71)     1.69(1.03+0.65) +2.4%
7519.7: status (dirty) (fsmonitor=fsmonitor-watchman)         11.99(11.34+1.58)   11.95(11.02+1.79) -0.3%
7519.8: diff (fsmonitor=fsmonitor-watchman)                   0.25(0.17+0.26)     0.25(0.18+0.26) +0.0%
7519.9: diff HEAD (fsmonitor=fsmonitor-watchman)              0.39(0.25+0.34)     0.89(0.35+0.74) +128.2%
7519.10: diff -- 0_files (fsmonitor=fsmonitor-watchman)       0.16(0.13+0.04)     0.16(0.12+0.05) +0.0%
7519.11: diff -- 10_files (fsmonitor=fsmonitor-watchman)      0.16(0.12+0.05)     0.16(0.12+0.05) +0.0%
7519.12: diff -- 100_files (fsmonitor=fsmonitor-watchman)     0.16(0.12+0.05)     0.16(0.12+0.05) +0.0%
7519.13: diff -- 1000_files (fsmonitor=fsmonitor-watchman)    0.16(0.11+0.06)     0.16(0.12+0.05) +0.0%
7519.14: diff -- 10000_files (fsmonitor=fsmonitor-watchman)   0.18(0.13+0.06)     0.17(0.10+0.08) -5.6%
7519.15: add (fsmonitor=fsmonitor-watchman)                   2.25(1.53+0.68)     2.25(1.47+0.74) +0.0%
7519.18: status (fsmonitor=disabled)                          0.88(0.73+1.03)     0.89(0.67+1.08) +1.1%
7519.19: status -uno (fsmonitor=disabled)                     0.45(0.43+0.89)     0.45(0.34+0.98) +0.0%
7519.20: status -uall (fsmonitor=disabled)                    1.88(1.16+1.58)     1.88(1.22+1.51) +0.0%
7519.21: status (dirty) (fsmonitor=disabled)                  7.53(7.05+2.11)     7.53(6.98+2.04) +0.0%
7519.22: diff (fsmonitor=disabled)                            0.42(0.37+0.92)     0.42(0.38+0.91) +0.0%
7519.23: diff HEAD (fsmonitor=disabled)                       0.44(0.41+0.90)     0.44(0.40+0.91) +0.0%
7519.24: diff -- 0_files (fsmonitor=disabled)                 0.13(0.09+0.05)     0.13(0.09+0.05) +0.0%
7519.25: diff -- 10_files (fsmonitor=disabled)                0.13(0.10+0.04)     0.13(0.10+0.04) +0.0%
7519.26: diff -- 100_files (fsmonitor=disabled)               0.13(0.09+0.05)     0.13(0.10+0.04) +0.0%
7519.27: diff -- 1000_files (fsmonitor=disabled)              0.13(0.09+0.06)     0.13(0.09+0.05) +0.0%
7519.28: diff -- 10000_files (fsmonitor=disabled)             0.14(0.11+0.05)     0.14(0.10+0.05) +0.0%
7519.29: add (fsmonitor=disabled)                             2.43(1.61+1.64)     2.43(1.69+1.57) +0.0%

On linux (2.29.2 vs w/ this patch):
nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff 2>&1 | grep lstat
  0.04    0.000063           3        20         6 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff HEAD 2>&1 | grep lstat
 94.98    5.242262          10    523783        13 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff 2>&1 | grep lstat
  0.38    0.000032           5         7         3 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep lstat
 99.44    0.741892           9     81634        10 lstat

On mac (2.29.2 vs w/ this patch):
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff 2>&1 | grep "^lstat64 "
lstat64                                         8
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff HEAD 2>&1 | grep "^lstat64 "
lstat64                                    120242
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff 2>&1 | grep "^lstat64 "
lstat64                                         4
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep "^lstat64 "
lstat64                                      4497

There are still a bunch of lstats - on directories, but not every file. Progress!

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:31:14 -07:00
Nipunn Koorapati
0ec9949f78 fsmonitor: add assertion that fsmonitor is valid to check_removed
Validate that fsmonitor is valid to futureproof against bugs where
check_removed might be called from places that haven't refreshed.

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:31:13 -07:00
Nipunn Koorapati
4f3d6d0261 fsmonitor: skip lstat deletion check during git diff-index
Teach git to honor fsmonitor rather than issuing an lstat
when checking for dirty local deletes. Eliminates O(files)
lstats during `git diff HEAD`

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:31:11 -07:00