Andrzej Hunt [Sun, 25 Apr 2021 14:16:12 +0000 (14:16 +0000)]
branch: FREE_AND_NULL instead of NULL'ing real_ref
real_ref was previously populated by dwim_ref(), which allocates new
memory. We need to make sure to free real_ref when discarding it.
(real_ref is already being freed at the end of create_branch() - but
if we discard it early then it will leak.)
This fixes the following leak found while running t0002-t0099:
Direct leak of 5 byte(s) in 1 object(s) allocated from:
#0 0x486954 in strdup /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3
#1 0xdd6484 in xstrdup wrapper.c:29:14
#2 0xc0f658 in expand_ref refs.c:671:12
#3 0xc0ecf1 in repo_dwim_ref refs.c:644:22
#4 0x8b1184 in dwim_ref ./refs.h:162:9
#5 0x8b0b02 in create_branch branch.c:284:10
#6 0x550cbb in update_refs_for_switch builtin/checkout.c:1046:4
#7 0x54e275 in switch_branches builtin/checkout.c:1274:2
#8 0x548828 in checkout_branch builtin/checkout.c:1668:9
#9 0x541306 in checkout_main builtin/checkout.c:2025:9
#10 0x5395fa in cmd_checkout builtin/checkout.c:2077:8
#11 0x4d02a8 in run_builtin git.c:467:11
#12 0x4cbfe9 in handle_builtin git.c:719:3
#13 0x4cf04f in run_argv git.c:808:4
#14 0x4cb85a in cmd_main git.c:939:19
#15 0x820cf6 in main common-main.c:52:11
#16 0x7f30bd9dd349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Andrzej Hunt [Sun, 25 Apr 2021 14:16:11 +0000 (14:16 +0000)]
bloom: clear each bloom_key after use
fill_bloom_key() allocates memory into bloom_key, we need to clean that
up once the key is no longer needed.
This leak was found while running t0002-t0099. Although this leak is
happening in code being called from a test-helper, the same code is also
used in various locations around git, and can therefore happen during
normal usage too. Gabor's analysis shows that peak-memory usage during
'git commit-graph write' is reduced on the order of 10% for a selection
of larger repos (along with an even larger reduction if we override
modified path bloom filter limits):
https://lore.kernel.org/git/20210411072651.GF2947267@szeder.dev/
LSAN output:
Direct leak of 308 byte(s) in 11 object(s) allocated from:
#0 0x49a5e2 in calloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
#1 0x6f4032 in xcalloc wrapper.c:140:8
#2 0x4f2905 in fill_bloom_key bloom.c:137:28
#3 0x4f34c1 in get_or_compute_bloom_filter bloom.c:284:4
#4 0x4cb484 in get_bloom_filter_for_commit t/helper/test-bloom.c:43:11
#5 0x4cb072 in cmd__bloom t/helper/test-bloom.c:97:3
#6 0x4ca7ef in cmd_main t/helper/test-tool.c:121:11
#7 0x4caace in main common-main.c:52:11
#8 0x7f798af95349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 308 byte(s) leaked in 11 allocation(s).
Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Andrzej Hunt [Sun, 25 Apr 2021 14:16:10 +0000 (14:16 +0000)]
ls-files: free max_prefix when done
common_prefix() returns a new string, which we store in max_prefix -
this string needs to be freed to avoid a leak. This leak is happening
in cmd_ls_files, hence is of no real consequence - an UNLEAK would be
just as good, but we might as well free the string properly.
Leak found while running t0002, see output below:
Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x49a85d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x9ab1b4 in do_xmalloc wrapper.c:41:8
#2 0x9ab248 in do_xmallocz wrapper.c:75:8
#3 0x9ab22a in xmallocz wrapper.c:83:9
#4 0x9ab2d7 in xmemdupz wrapper.c:99:16
#5 0x78d6a4 in common_prefix dir.c:191:15
#6 0x5aca48 in cmd_ls_files builtin/ls-files.c:669:16
#7 0x4cd92d in run_builtin git.c:453:11
#8 0x4cb5fa in handle_builtin git.c:704:3
#9 0x4ccf57 in run_argv git.c:771:4
#10 0x4caf49 in cmd_main git.c:902:19
#11 0x69ce2e in main common-main.c:52:11
#12 0x7f64d4d94349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Andrzej Hunt [Sun, 25 Apr 2021 14:16:09 +0000 (14:16 +0000)]
wt-status: fix multiple small leaks
rev.prune_data is populated (in multiple functions) via copy_pathspec,
and therefore needs to be cleared after running the diff in those
functions.
rev(_info).pending is populated indirectly via setup_revisions, and also
needs to be cleared once diffing is done.
These leaks were found while running t0008 or t0021. The rev.prune_data
leaks are small (80B) but noisy, hence I won't bother including their
logs - the rev.pending leaks are bigger, and can happen early in the
course of other commands, and therefore possibly more valuable to fix -
see example log from a rebase below:
Direct leak of 2048 byte(s) in 1 object(s) allocated from:
#0 0x49ab79 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0x9ac2a6 in xrealloc wrapper.c:126:8
#2 0x83da03 in add_object_array_with_path object.c:337:3
#3 0x8f5d8a in add_pending_object_with_path revision.c:329:2
#4 0x8ea50b in add_pending_object_with_mode revision.c:336:2
#5 0x8ea4fd in add_pending_object revision.c:342:2
#6 0x8ea610 in add_head_to_pending revision.c:354:2
#7 0x9b55f5 in has_uncommitted_changes wt-status.c:2474:2
#8 0x9b58c4 in require_clean_work_tree wt-status.c:2553:6
#9 0x606bcc in cmd_rebase builtin/rebase.c:1970:6
#10 0x4cd91d in run_builtin git.c:467:11
#11 0x4cb5f3 in handle_builtin git.c:719:3
#12 0x4ccf47 in run_argv git.c:808:4
#13 0x4caf49 in cmd_main git.c:939:19
#14 0x69dc0e in main common-main.c:52:11
#15 0x7f2d18909349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 5 byte(s) in 1 object(s) allocated from:
#0 0x486834 in strdup ../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3
#1 0x9ac048 in xstrdup wrapper.c:29:14
#2 0x83da8d in add_object_array_with_path object.c:349:17
#3 0x8f5d8a in add_pending_object_with_path revision.c:329:2
#4 0x8ea50b in add_pending_object_with_mode revision.c:336:2
#5 0x8ea4fd in add_pending_object revision.c:342:2
#6 0x8ea610 in add_head_to_pending revision.c:354:2
#7 0x9b55f5 in has_uncommitted_changes wt-status.c:2474:2
#8 0x9b58c4 in require_clean_work_tree wt-status.c:2553:6
#9 0x606bcc in cmd_rebase builtin/rebase.c:1970:6
#10 0x4cd91d in run_builtin git.c:467:11
#11 0x4cb5f3 in handle_builtin git.c:719:3
#12 0x4ccf47 in run_argv git.c:808:4
#13 0x4caf49 in cmd_main git.c:939:19
#14 0x69dc0e in main common-main.c:52:11
#15 0x7f2d18909349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 2053 byte(s) leaked in 2 allocation(s).
Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Andrzej Hunt [Sun, 25 Apr 2021 14:16:08 +0000 (14:16 +0000)]
revision: free remainder of old commit list in limit_list
limit_list() iterates over the original revs->commits list, and consumes
many of its entries via pop_commit. However we might stop iterating over
the list early (e.g. if we realise that the rest of the list is
uninteresting). If we do stop iterating early, list will be pointing to
the unconsumed portion of revs->commits - and we need to free this list
to avoid a leak. (revs->commits itself will be an invalid pointer: it
will have been free'd during the first pop_commit.)
However the list pointer is later reused to iterate over our new list,
but only for the limiting_can_increase_treesame() branch. We therefore
need to introduce a new variable for that branch - and while we're here
we can rename the original list to original_list as that makes its
purpose more obvious.
This leak was found while running t0090. It's not likely to be very
impactful, but it can happen quite early during some checkout
invocations, and hence seems to be worth fixing:
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x49a85d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x9ac084 in do_xmalloc wrapper.c:41:8
#2 0x9ac05a in xmalloc wrapper.c:62:9
#3 0x7175d6 in commit_list_insert commit.c:540:33
#4 0x71800f in commit_list_insert_by_date commit.c:604:9
#5 0x8f8d2e in process_parents revision.c:1128:5
#6 0x8f2f2c in limit_list revision.c:1418:7
#7 0x8f210e in prepare_revision_walk revision.c:3577:7
#8 0x514170 in orphaned_commit_warning builtin/checkout.c:1185:6
#9 0x512f05 in switch_branches builtin/checkout.c:1250:3
#10 0x50f8de in checkout_branch builtin/checkout.c:1646:9
#11 0x50ba12 in checkout_main builtin/checkout.c:2003:9
#12 0x5086c0 in cmd_checkout builtin/checkout.c:2055:8
#13 0x4cd91d in run_builtin git.c:467:11
#14 0x4cb5f3 in handle_builtin git.c:719:3
#15 0x4ccf47 in run_argv git.c:808:4
#16 0x4caf49 in cmd_main git.c:939:19
#17 0x69dc0e in main common-main.c:52:11
#18 0x7faaabd0e349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 48 byte(s) in 3 object(s) allocated from:
#0 0x49a85d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x9ac084 in do_xmalloc wrapper.c:41:8
#2 0x9ac05a in xmalloc wrapper.c:62:9
#3 0x717de6 in commit_list_append commit.c:1609:35
#4 0x8f1f9b in prepare_revision_walk revision.c:3554:12
#5 0x514170 in orphaned_commit_warning builtin/checkout.c:1185:6
#6 0x512f05 in switch_branches builtin/checkout.c:1250:3
#7 0x50f8de in checkout_branch builtin/checkout.c:1646:9
#8 0x50ba12 in checkout_main builtin/checkout.c:2003:9
#9 0x5086c0 in cmd_checkout builtin/checkout.c:2055:8
#10 0x4cd91d in run_builtin git.c:467:11
#11 0x4cb5f3 in handle_builtin git.c:719:3
#12 0x4ccf47 in run_argv git.c:808:4
#13 0x4caf49 in cmd_main git.c:939:19
#14 0x69dc0e in main common-main.c:52:11
#15 0x7faaabd0e349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:03:01 +0000 (01:03 +0000)]
hex: print objects using the hash algorithm member
Now that all code paths correctly set the hash algorithm member of
struct object_id, write an object's hex representation using the hash
algorithm member embedded in it.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:03:00 +0000 (01:03 +0000)]
hex: default to the_hash_algo on zero algorithm value
There are numerous places in the codebase where we assume we can
initialize data by zeroing all its bytes. However, when we do that with
a struct object_id, it leaves the structure with a zero value for the
algorithm, which is invalid.
We could forbid this pattern and require that all struct object_id
instances be initialized using oidclr, but this seems burdensome and
it's unnatural to most C programmers. Instead, if the algorithm is
zero, assume we wanted to use the default hash algorithm instead.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:59 +0000 (01:02 +0000)]
builtin/pack-objects: avoid using struct object_id for pack hash
We use struct object_id for the names of objects. It isn't intended to
be used for other hash values that don't name objects such as the pack
hash.
Because struct object_id will soon need to have its algorithm member
set, using it in this code path would mean that we didn't set that
member, only the hash member, which would result in a crash. For both
of these reasons, switch to using an unsigned char array of size
GIT_MAX_RAWSZ.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:58 +0000 (01:02 +0000)]
commit-graph: don't store file hashes as struct object_id
The idea behind struct object_id is that it is supposed to represent the
identifier of a standard Git object or a special pseudo-object like the
all-zeros object ID. In this case, we have file hashes, which, while
similar, are distinct from the identifiers of objects.
Switch these code paths to use an unsigned char array. This is both
more logically consistent and it means that we need not set the
algorithm identifier for the struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:57 +0000 (01:02 +0000)]
builtin/show-index: set the algorithm for object IDs
In most cases, when we load the hash of an object into a struct
object_id, we load it using one of the oid* or *_oid_hex functions.
However, for git show-index, we read it in directly using fread. As a
consequence, set the algorithm correctly so the objects can be used
correctly both now and in the future.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:56 +0000 (01:02 +0000)]
hash: provide per-algorithm null OIDs
Up until recently, object IDs did not have an algorithm member, only a
hash. Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms. Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.
Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:55 +0000 (01:02 +0000)]
hash: set, copy, and use algo field in struct object_id
Now that struct object_id has an algorithm field, we should populate it.
This will allow us to handle object IDs in any supported algorithm and
distinguish between them. Ensure that the field is written whenever we
write an object ID by storing it explicitly every time we write an
object. Set values for the empty blob and tree values as well.
In addition, use the algorithm field to compare object IDs. Note that
because we zero-initialize struct object_id in many places throughout
the codebase, we default to the default algorithm in cases where the
algorithm field is zero rather than explicitly initialize all of those
locations.
This leads to a branch on every comparison, but the alternative is to
compare the entire buffer each time and padding the buffer for SHA-1.
That alternative ranges up to 3.9% worse than this approach on the perf
t0001, t1450, and t1451.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:54 +0000 (01:02 +0000)]
builtin/pack-redundant: avoid casting buffers to struct object_id
Now that we need our instances of struct object_id to be zero padded, we
can no longer cast unsigned char buffers to be pointers to struct
object_id. This file reads data out of the pack objects and then
inserts it directly into a linked list item which is a pointer to struct
object_id. Instead, let's have the linked list item hold its own struct
object_id and copy the data into it.
In addition, since these are not really pointers to struct object_id,
stop passing them around as such, and call them what they really are:
pointers to unsigned char.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:53 +0000 (01:02 +0000)]
Use the final_oid_fn to finalize hashing of object IDs
When we're hashing a value which is going to be an object ID, we want to
zero-pad that value if necessary. To do so, use the final_oid_fn
instead of the final_fn anytime we're going to create an object ID to
ensure we perform this operation.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:52 +0000 (01:02 +0000)]
hash: add a function to finalize object IDs
To avoid the penalty of having to branch in hash comparison functions,
we'll want to always compare the full hash member in a struct object_id,
which will require that SHA-1 object IDs be zero-padded. To do so, add
a function which finalizes a hash context and writes it into an object
ID that performs this padding.
Move the definition of struct object_id and the constant definitions
higher up so we they are available for us to use.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:51 +0000 (01:02 +0000)]
http-push: set algorithm when reading object ID
In most places in the codebase, we use oidread to properly read an
object ID into a struct object_id. However, in the HTTP code, we end up
needing to parse a loose object path with a slash in it, so we can't do
that. Let's instead explicitly set the algorithm in this function so we
can rely on it in the future.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:50 +0000 (01:02 +0000)]
Always use oidread to read into struct object_id
In the future, we'll want oidread to automatically set the hash
algorithm member for an object ID we read into it, so ensure we use
oidread instead of hashcpy everywhere we're copying a hash value into a
struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Mon, 26 Apr 2021 01:02:49 +0000 (01:02 +0000)]
hash: add an algo member to struct object_id
Now that we're working with multiple hash algorithms in the same repo,
it's best if we label each object ID with its algorithm so we can
determine how to format a given object ID. Add a member called algo to
struct object_id.
Performance testing on object ID-heavy workloads doesn't reveal a clear
change in performance. Out of performance tests t0001 and t1450, there
are slight variations in performance both up and down, but all
measurements are within the margin of error.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
pretty tests: give --date/format tests a better description
Change the description for the --date/format equivalency tests added
in 466fb6742d7 (pretty: provide a strict ISO 8601 date format,
2014-08-29) and 0df621172d8 (pretty: provide short date format,
2019-11-19) to be more meaningful.
This allows us to reword the comment added in the former commit to
refer to both tests, and any other future test, such as the in-flight
--date=human format being proposed in [1].
Change a needlessly complex test for the %aI/%cI date
formats (iso-strict) added in 466fb6742d7 (pretty: provide a strict
ISO 8601 date format, 2014-08-29) to instead use the same pattern used
to test %as/%cs since 0df621172d8 (pretty: provide short date format,
2019-11-19).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Denton Liu [Thu, 22 Apr 2021 10:00:51 +0000 (03:00 -0700)]
git-completion.bash: use $__git_cmd_idx in more places
With the introduction of the $__git_cmd_idx variable in e94fb44042
(git-completion.bash: pass $__git_subcommand_idx from __git_main(),
2021-03-24), completion functions were able to know the index at which
the git command is listed, allowing them to skip options that are given
to the underlying git itself, not the corresponding command (e.g.
`-C asdf` in `git -C asdf branch`).
While most of the changes here are self-explanatory, some bear further
explanation.
For the __git_find_on_cmdline() and __git_find_last_on_cmdline() pair of
functions, these functions are only ever called in the context of a git
command completion function. These functions will only care about words
after the command so we can safely ignore the words before this.
For _git_worktree(), this change is technically a no-op (once the
__git_find_last_on_cmdline change is also applied). It was in poor style
to have hard-coded on the index right after `worktree`. In case
`git worktree` were to ever learn to accept options, the current
situation would be inflexible.
Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Denton Liu [Thu, 22 Apr 2021 10:00:50 +0000 (03:00 -0700)]
git-completion.bash: rename to $__git_cmd_idx
In e94fb44042 (git-completion.bash: pass $__git_subcommand_idx from
__git_main(), 2021-03-24), the $__git_subcommand_idx variable was
introduced. Naming it after the index of the subcommand is needlessly
confusing as, when this variable is used, it is in the completion
functions for commands (e.g. _git_remote()) where for `git remote add`,
the `remote` is referred to as the command and `add` is referred to as
the subcommand.
Rename this variable so that it's obvious it's about git commands. While
we're at it, shorten up its name so that it's still readable without
being a handful to type.
Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
t1300: fix unset of GIT_CONFIG_NOSYSTEM leaking into subsequent tests
In order to test whether the new GIT_CONFIG_SYSTEM environment variable
behaves as expected, we unset GIT_CONFIG_NOSYSTEM in one of our tests in
t1300. But because tests are not executed in a subshell, this unset
leaks into all subsequent tests and may thus cause them to fail in some
environments. These failures are easily reproducable with `make
prefix=/root test`.
Fix the issue by not using `sane_unset GIT_CONFIG_NOSYSTEM`, but instead
just manually add it to the environment of the two command invocations
which need it.
Reported-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Wed, 21 Apr 2021 00:23:36 +0000 (17:23 -0700)]
Merge branch 'ab/usage-error-docs'
Documentation updates, with unrelated comment updates, too.
* ab/usage-error-docs:
api docs: document that BUG() emits a trace2 error event
api docs: document BUG() in api-error-handling.txt
usage.c: don't copy/paste the same comment three times
When "git pack-objects" makes a literal copy of a part of existing
packfile using the reachability bitmaps, its update to the progress
meter was broken.
* jk/pack-objects-bitmap-progress-fix:
pack-objects: update "nr_seen" progress based on pack-reused count
Junio C Hamano [Wed, 21 Apr 2021 00:23:34 +0000 (17:23 -0700)]
Merge branch 'ab/userdiff-tests'
A bit of code clean-up and a lot of test clean-up around userdiff
area.
* ab/userdiff-tests:
blame tests: simplify userdiff driver test
blame tests: don't rely on t/t4018/ directory
userdiff: remove support for "broken" tests
userdiff tests: list builtin drivers via test-tool
userdiff tests: explicitly test "default" pattern
userdiff: add and use for_each_userdiff_driver()
userdiff style: normalize pascal regex declaration
userdiff style: declare patterns with consistent style
userdiff style: re-order drivers in alphabetical order
Denton Liu [Tue, 20 Apr 2021 09:19:47 +0000 (02:19 -0700)]
git-completion.bash: separate some commands onto their own line
In e94fb44042 (git-completion.bash: pass $__git_subcommand_idx from
__git_main(), 2021-03-24), a line was introduced which contained
multiple statements. This is difficult to read so break it into multiple
lines.
While we're at it, follow this convention for the rest of the
__git_main() and break up lines that contain multiple statements.
Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
AFAICT parsing the output of `git diff --name-only master...feature`
is the intended way of programmatically getting the list of files
modified
by a feature branch. It is impossible to parse text unless you know what
encoding it is in. The output encoding of diff --name-only and
ZheNing Hu [Tue, 20 Apr 2021 16:52:11 +0000 (16:52 +0000)]
ref-filter: reuse output buffer
When we use `git for-each-ref`, every ref will allocate
its own output strbuf and error strbuf. But we can reuse
the final strbuf for each step ref's output. The error
buffer will also be reused, despite the fact that the git
will exit when `format_ref_array_item()` return a non-zero
value and output the contents of the error buffer.
The performance for `git for-each-ref` on the Git repository
itself with performance testing tool `hyperfine` changes from
23.7 ms ± 0.9 ms to 22.2 ms ± 1.0 ms. Optimization is relatively
minor.
At the same time, we apply this optimization to `git tag -l`
and `git branch -l`.
This approach is similar to the one used by 79ed0a5
(cat-file: use a single strbuf for all output, 2018-08-14)
to speed up the cat-file builtin.
Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Jeff King <peff@peff.net> Helped-by: René Scharfe <l.s.r@web.de> Signed-off-by: ZheNing Hu <adlternative@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
ZheNing Hu [Mon, 19 Apr 2021 11:28:44 +0000 (11:28 +0000)]
ref-filter: get rid of show_ref_array_item
Inlining the exported function `show_ref_array_item()`,
which is not providing the right level of abstraction,
simplifies the API and can unlock improvements at the
former call sites.
Helped-by: René Scharfe <l.s.r@web.de> Signed-off-by: ZheNing Hu <adlternative@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
config: allow overriding of global and system configuration
In order to have git run in a fully controlled environment without any
misconfiguration, it may be desirable for users or scripts to override
global- and system-level configuration files. We already have a way of
doing this, which is to unset both HOME and XDG_CONFIG_HOME environment
variables and to set `GIT_CONFIG_NOGLOBAL=true`. This is quite kludgy,
and unsetting the first two variables likely has an impact on other
executables spawned by such a script.
The obvious way to fix this would be to introduce `GIT_CONFIG_NOGLOBAL`
as an equivalent to `GIT_CONFIG_NOSYSTEM`. But in the past, it has
turned out that this design is inflexible: we cannot test system-level
parsing of the git configuration in our test harness because there is no
way to change its location, so all tests run with `GIT_CONFIG_NOSYSTEM`
set.
Instead of doing the same mistake with `GIT_CONFIG_NOGLOBAL`, introduce
two new variables `GIT_CONFIG_GLOBAL` and `GIT_CONFIG_SYSTEM`:
- If unset, git continues to use the usual locations.
- If set to a specific path, we skip reading the normal
configuration files and instead take the path. By setting the path
to `/dev/null`, no configuration will be loaded for the respective
level.
This implements the usecase where we want to execute code in a sanitized
environment without any potential misconfigurations via `/dev/null`, but
is more flexible and allows for more usecases than simply adding
`GIT_CONFIG_NOGLOBAL`.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
config: unify code paths to get global config paths
There's two callsites which assemble global config paths, once in the
config loading code and once in the git-config(1) builtin. We're about
to implement a way to override global config paths via an environment
variable which would require us to adjust both sites.
Unify both code paths into a single `git_global_config()` function which
returns both paths for `~/.gitconfig` and the XDG config file. This will
make the subsequent patch which introduces the new envvar easier to
implement.
No functional changes are expected from this patch.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `git_etc_gitconfig()` function retrieves the system-level path of
the configuration file. We're about to introduce a way to override it
via an environment variable, at which point the name of this function
would start to become misleading.
Rename the function to `git_system_config()` as a preparatory step.
While at it, the function is also refactored to pass memory ownership to
the caller. This is done to better match semantics of
`git_global_config()`, which is going to be introduced in the next
commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When providing an object filter, it is currently impossible to also
filter provided items. E.g. when executing `git rev-list HEAD` , the
commit this reference points to will be treated as user-provided and is
thus excluded from the filtering mechanism. This makes it harder than
necessary to properly use the new `--filter=object:type` filter given
that even if the user wants to only see blobs, he'll still see commits
of provided references.
Improve this by introducing a new `--filter-provided-objects` option
to the git-rev-parse(1) command. If given, then all user-provided
references will be subject to filtering.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the user has multiple objects filters specified, then this is
internally represented by having a "combined" filter. These combined
filters aren't yet supported by bitmap indices and can thus not be
accelerated.
Fix this by implementing support for these combined filters. The
implementation is quite trivial: when there's a combined filter, we
simply recurse into `filter_bitmap()` for all of the sub-filters.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The preceding commit has added a new object filter for git-rev-list(1)
which allows to filter objects by type. Implement the equivalent filter
for packfile bitmaps so that we can answer these queries fast.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
While it already is possible to filter objects by some criteria in
git-rev-list(1), it is not yet possible to filter out only a specific
type of objects. This makes some filters less useful. The `blob:limit`
filter for example filters blobs such that only those which are smaller
than the given limit are returned. But it is unfit to ask only for these
smallish blobs, given that git-rev-list(1) will continue to print tags,
commits and trees.
Now that we have the infrastructure in place to also filter tags and
commits, we can improve this situation by implementing a new filter
which selects objects based on their type. Above query can thus
trivially be implemented with the following command:
Furthermore, this filter allows to optimize for certain other cases: if
for example only tags or commits have been selected, there is no need to
walk down trees.
The new filter is not yet supported in bitmaps. This is going to be
implemented in a subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make parallel checkout configurable by introducing two new settings:
checkout.workers and checkout.thresholdForParallelism. The first defines
the number of workers (where one means sequential checkout), and the
second defines the minimum number of entries to attempt parallel
checkout.
To decide the default value for checkout.workers, the parallel version
was benchmarked during three operations in the linux repo, with cold
cache: cloning v5.8, checking out v5.8 from v2.6.15 (checkout I) and
checking out v5.8 from v5.7 (checkout II). The four tables below show
the mean run times and standard deviations for 5 runs in: a local file
system on SSD, a local file system on HDD, a Linux NFS server, and
Amazon EFS (all on Linux). Each parallel checkout test was executed with
the number of workers that brings the best overall results in that
environment.
Local SSD:
Sequential 10 workers Speedup
Clone 8.805 s ± 0.043 s 3.564 s ± 0.041 s 2.47 ± 0.03
Checkout I 9.678 s ± 0.057 s 4.486 s ± 0.050 s 2.16 ± 0.03
Checkout II 5.034 s ± 0.072 s 3.021 s ± 0.038 s 1.67 ± 0.03
Local HDD:
Sequential 10 workers Speedup
Clone 32.288 s ± 0.580 s 30.724 s ± 0.522 s 1.05 ± 0.03
Checkout I 54.172 s ± 7.119 s 54.429 s ± 6.738 s 1.00 ± 0.18
Checkout II 40.465 s ± 2.402 s 38.682 s ± 1.365 s 1.05 ± 0.07
Linux NFS server (v4.1, on EBS, single availability zone):
Sequential 32 workers Speedup
Clone 240.368 s ± 6.347 s 57.349 s ± 0.870 s 4.19 ± 0.13
Checkout I 242.862 s ± 2.215 s 58.700 s ± 0.904 s 4.14 ± 0.07
Checkout II 65.751 s ± 1.577 s 23.820 s ± 0.407 s 2.76 ± 0.08
EFS (v4.1, replicated over multiple availability zones):
Sequential 32 workers Speedup
Clone 922.321 s ± 2.274 s 210.453 s ± 3.412 s 4.38 ± 0.07
Checkout I 1011.300 s ± 7.346 s 297.828 s ± 0.964 s 3.40 ± 0.03
Checkout II 294.104 s ± 1.836 s 126.017 s ± 1.190 s 2.33 ± 0.03
The above benchmarks show that parallel checkout is most effective on
repositories located on an SSD or over a distributed file system. For
local file systems on spinning disks, and/or older machines, the
parallelism does not always bring a good performance. For this reason,
the default value for checkout.workers is one, a.k.a. sequential
checkout.
To decide the default value for checkout.thresholdForParallelism,
another benchmark was executed in the "Local SSD" setup, where parallel
checkout showed to be beneficial. This time, we compared the runtime of
a `git checkout -f`, with and without parallelism, after randomly
removing an increasing number of files from the Linux working tree. The
"sequential fallback" column below corresponds to the executions where
checkout.workers was 10 but checkout.thresholdForParallelism was equal
to the number of to-be-updated files plus one (so that we end up writing
sequentially). Each test case was sampled 15 times, and each sample had
a randomly different set of files removed. Here are the results:
sequential fallback 10 workers speedup
10 files 772.3 ms ± 12.6 ms 769.0 ms ± 13.6 ms 1.00 ± 0.02
20 files 780.5 ms ± 15.8 ms 775.2 ms ± 9.2 ms 1.01 ± 0.02
50 files 806.2 ms ± 13.8 ms 767.4 ms ± 8.5 ms 1.05 ± 0.02
100 files 833.7 ms ± 21.4 ms 750.5 ms ± 16.8 ms 1.11 ± 0.04
200 files 897.6 ms ± 30.9 ms 730.5 ms ± 14.7 ms 1.23 ± 0.05
500 files 1035.4 ms ± 48.0 ms 677.1 ms ± 22.3 ms 1.53 ± 0.09
1000 files 1244.6 ms ± 35.6 ms 654.0 ms ± 38.3 ms 1.90 ± 0.12
2000 files 1488.8 ms ± 53.4 ms 658.8 ms ± 23.8 ms 2.26 ± 0.12
From the above numbers, 100 files seems to be a reasonable default value
for the threshold setting.
Note: Up to 1000 files, we observe a drop in the execution time of the
parallel code with an increase in the number of files. This is a rather
odd behavior, but it was observed in multiple repetitions. Above 1000
files, the execution time increases according to the number of files, as
one would expect.
About the test environments: Local SSD tests were executed on an
i7-7700HQ (4 cores with hyper-threading) running Manjaro Linux. Local
HDD tests were executed on an Intel(R) Xeon(R) E3-1230 (also 4 cores
with hyper-threading), HDD Seagate Barracuda 7200.14 SATA 3.1, running
Debian. NFS and EFS tests were executed on an Amazon EC2 c5n.xlarge
instance, with 4 vCPUs. The Linux NFS server was running on a m6g.large
instance with 2 vCPUSs and a 1 TB EBS GP2 volume. Before each timing,
the linux repository was removed (or checked out back to its previous
state), and `sync && sysctl vm.drop_caches=3` was executed.
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use multiple worker processes to distribute the queued entries and call
write_pc_item() in parallel for them. The items are distributed
uniformly in contiguous chunks. This minimizes the chances of two
workers writing to the same directory simultaneously, which could affect
performance due to lock contention in the kernel. Work stealing (or any
other format of re-distribution) is not implemented yet.
The protocol between the main process and the workers is quite simple.
They exchange binary messages packed in pkt-line format, and use
PKT-FLUSH to mark the end of input (from both sides). The main process
starts the communication by sending N pkt-lines, each corresponding to
an item that needs to be written. These packets contain all the
necessary information to load, smudge, and write the blob associated
with each item. Then it waits for the worker to send back N pkt-lines
containing the results for each item. The resulting packet must contain:
the identification number of the item that it refers to, the status of
the operation, and the lstat() data gathered after writing the file (iff
the operation was successful).
For now, checkout always uses a hardcoded value of 2 workers, only to
demonstrate that the parallel checkout framework correctly divides and
writes the queued entries. The next patch will add user configurations
and define a more reasonable default, based on tests with the said
settings.
Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
unpack-trees: add basic support for parallel checkout
This new interface allows us to enqueue some of the entries being
checked out to later uncompress them, apply in-process filters, and
write out the files in parallel. For now, the parallel checkout
machinery is enabled by default and there is no user configuration, but
run_parallel_checkout() just writes the queued entries in sequence
(without spawning additional workers). The next patch will actually
implement the parallelism and, later, we will make it configurable.
Note that, to avoid potential data races, not all entries are eligible
for parallel checkout. Also, paths that collide on disk (e.g.
case-sensitive paths in case-insensitive file systems), are detected by
the parallel checkout code and skipped, so that they can be safely
sequentially handled later. The collision detection works like the
following:
- If the collision was at basename (e.g. 'a/b' and 'a/B'), the framework
detects it by looking for EEXIST and EISDIR errors after an
open(O_CREAT | O_EXCL) failure.
- If the collision was at dirname (e.g. 'a/b' and 'A'), it is detected
at the has_dirs_only_path() check, which is done for the leading path
of each item in the parallel checkout queue.
Both verifications rely on the fact that, before enqueueing an entry for
parallel checkout, checkout_entry() makes sure that there is no file at
the entry's path and that its leading components are all real
directories. So, any later change in these conditions indicates that
there was a collision (either between two parallel-eligible entries or
between an eligible and an ineligible one).
After all parallel-eligible entries have been processed, the collided
(and thus, skipped) entries are sequentially fed to checkout_entry()
again. This is similar to the way the current code deals with
collisions, overwriting the previously checked out entries with the
subsequent ones. The only difference is that, since we no longer create
the files in the same order that they appear on index, we are not able
to determine which of the colliding entries will survive on disk (for
the classic code, it is always the last entry).
Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Split set_diff_merges() into separate parsing and execution functions,
the former to be reused for parsing of configuration values later in
the patch series.
Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the notion of default diff format for merges, and the option
"on" to select it. The default format is "separate" and can't yet
be changed, so effectively "on" is just a synonym for "separate"
for now. Add corresponding test to t4013.
This is in preparation for introducing log.diffMerges configuration
option that will let --diff-merges=on to be configured to any
supported format.
Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Fri, 16 Apr 2021 20:53:34 +0000 (13:53 -0700)]
Merge branch 'en/ort-readiness'
Plug the ort merge backend throughout the rest of the system, and
start testing it as a replacement for the recursive backend.
* en/ort-readiness:
Add testing with merge-ort merge strategy
t6423: mark remaining expected failure under merge-ort as such
Revert "merge-ort: ignore the directory rename split conflict for now"
merge-recursive: add a bunch of FIXME comments documenting known bugs
merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict
t: mark several submodule merging tests as fixed under merge-ort
merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries
t6428: new test for SKIP_WORKTREE handling and conflicts
merge-ort: support subtree shifting
merge-ort: let renormalization change modify/delete into clean delete
merge-ort: have ll_merge() use a special attr_index for renormalization
merge-ort: add a special minimal index just for renormalization
merge-ort: use STABLE_QSORT instead of QSORT where required
Junio C Hamano [Fri, 16 Apr 2021 20:53:33 +0000 (13:53 -0700)]
Merge branch 'en/ort-perf-batch-10'
Various rename detection optimization to help "ort" merge strategy
backend.
* en/ort-perf-batch-10:
diffcore-rename: determine which relevant_sources are no longer relevant
merge-ort: record the reason that we want a rename for a file
diffcore-rename: add computation of number of unknown renames
diffcore-rename: check if we have enough renames for directories early on
diffcore-rename: only compute dir_rename_count for relevant directories
merge-ort: record the reason that we want a rename for a directory
merge-ort, diffcore-rename: tweak dirs_removed and relevant_source type
diffcore-rename: take advantage of "majority rules" to skip more renames
Ville Skyttä [Fri, 16 Apr 2021 19:19:39 +0000 (22:19 +0300)]
completion: avoid aliased command lookup error in nounset mode
Aliased command lookup accesses the `list` variable before it has been
set, causing an error in "nounset" mode. Initialize to an empty string
to avoid that.
If a remote has the skipFetchAll setting enabled, then that remote is
not intended for frequent fetching. It makes sense to not fetch that
data during the 'prefetch' maintenance task. Skip that remote in the
iteration without error. The skip_default_update member is initialized
in remote.c:handle_config() as part of initializing the 'struct remote'.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'prefetch' maintenance task previously forced the following refspec
for each remote:
+refs/heads/*:refs/prefetch/<remote>/*
If a user has specified a more strict refspec for the remote, then this
prefetch task downloads more objects than necessary.
The previous change introduced the '--prefetch' option to 'git fetch'
which manipulates the remote's refspec to place all resulting refs into
refs/prefetch/, with further partitioning based on the destinations of
those refspecs.
Update the documentation to be more generic about the destination refs.
Do not mention custom refspecs explicitly, as that does not need to be
highlighted in this documentation. The important part of placing refs in
refs/prefetch/ remains.
Reported-by: Tom Saeger <tom.saeger@oracle.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The --prefetch option will be used by the 'prefetch' maintenance task
instead of sending refspecs explicitly across the command-line. The
intention is to modify the refspec to place all results in
refs/prefetch/ instead of anywhere else.
Create helper method filter_prefetch_refspec() to modify a given refspec
to fit the rules expected of the prefetch task:
* Negative refspecs are preserved.
* Refspecs without a destination are removed.
* Refspecs whose source starts with "refs/tags/" are removed.
* Other refspecs are placed within "refs/prefetch/".
Finally, we add the 'force' option to ensure that prefetch refs are
replaced as necessary.
There are some interesting cases that are worth testing.
An earlier version of this change dropped the "i--" from the loop that
deletes a refspec item and shifts the remaining entries down. This
allowed some refspecs to not be modified. The subtle part about the
first --prefetch test is that the "refs/tags/*" refspec appears directly
before the "refs/heads/bogus/*" refspec. Without that "i--", this
ordering would remove the "refs/tags/*" refspec and leave the last one
unmodified, placing the result in "refs/heads/*".
It is possible to have an empty refspec. This is typically the case for
remotes other than the origin, where users want to fetch a specific tag
or branch. To correctly test this case, we need to further remove the
upstream remote for the local branch. Thus, we are testing a refspec
that will be deleted, leaving nothing to fetch.
Helped-by: Tom Saeger <tom.saeger@oracle.com> Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Apparently this is not supported with Microsoft's Universal C Runtime.
So let's not actually do that.
Instead, just return success because we _know_ that we expect the `NUL`
device to be present.
Side note: it is possible to turn off the "Null device driver" and
thereby disable `NUL`. Too many things are broken if this driver is
disabled, therefore it is not worth bothering to try to detect its
presence when `access()` is called.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
On write() errors, packet_write() dies with the same error message that
is already printed by its callee, packet_write_gently(). This produces
an unnecessarily verbose and repetitive output:
In addition to that, packet_write_gently() does not always fulfill its
caller expectation that errno will be properly set before a non-zero
return. In particular, that is not the case for a "data exceeds max
packet size" error. So, in this case, packet_write() will call
die_errno() and print an strerror(errno) message that might be totally
unrelated to the actual error.
Fix both those issues by turning packet_write() and
packet_write_gently() into wrappers to a common lower level function
that doesn't print the error message, but instead returns it on a buffer
for the caller to die() or error() as appropriate.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Thu, 15 Apr 2021 20:36:00 +0000 (13:36 -0700)]
Merge branch 'jz/apply-run-3way-first'
"git apply --3way" has always been "to fall back to 3-way merge
only when straight application fails". Swap the order of falling
back so that 3-way is always attempted first (only when the option
is given, of course) and then straight patch application is used as
a fallback when it fails.
* jz/apply-run-3way-first:
git-apply: try threeway first when "--3way" is used
transport: respect verbosity when setting upstream
A command such as `git push -qu origin feature` will print "Branch
'feature' set up to track remote branch 'feature' from 'origin'." even
when --quiet is passed. In this case it's because install_branch_config() is
always called with BRANCH_CONFIG_VERBOSE.
struct transport keeps track of the desired verbosity. Fix the above
issue by passing BRANCH_CONFIG_VERBOSE conditionally based on that.
Signed-off-by: Øystein Walle <oystwa@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Wed, 14 Apr 2021 23:51:17 +0000 (16:51 -0700)]
doc: clarify "do not capitalize the first word" rule
The same "do not capitalize the first word" rule is applied to both
our patch titles and error messages, but the existing description
was fuzzy in two aspects.
* For error messages, it was not said that this was only about the
first word that begins the sentence.
* For both, it was not clear when a capital letter there was not an
error. We avoid capitalizing the first word when the only reason
you would capitalize it is because it happens to be the first
word in the sentence. If a proper noun, which is usually spelled
in capital letters, happens to come at the beginning of the
sentence, it should be kept in capital letters.
A sparse-index loads the name-hash data for its entries, including the
sparse-directory entries. If a caller asks for a path that is contained
within a sparse-directory entry, we need to expand to a full index and
recalculate the name hash table before returning the result. Insert
calls to expand_to_path() to protect against this case.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some users of the index API have a specific path they are looking for,
but choose to use index_file_exists() to rely on the name-hash hashtable
instead of doing binary search with index_name_pos(). These users only
need to know a yes/no answer, not a position within the cache array.
When the index is sparse, the name-hash hash table does not contain the
full list of paths within sparse directories. It _does_ contain the
directory names for the sparse-directory entries.
Create a helper function, expand_to_path(), for intended use with the
name-hash hashtable functions. The integration with name-hash.c will
follow in a later change.
The solution here is to use ensure_full_index() when we determine that
the requested path is within a sparse directory entry. This will
populate the name-hash hashtable as the index is recomputed from
scratch.
There may be cases where the caller is trying to find an untracked path
that is not in the index but also is not within a sparse directory
entry. We want to minimize the overhead for these requests. If we used
index_name_pos() to find the insertion order of the path, then we could
determine from that position if a sparse-directory exists. (In fact,
just calling index_name_pos() in that case would lead to expanding the
index to a full index.) However, this takes O(log N) time where N is the
number of cache entries.
To keep the performance of this call based mostly on the input string,
use index_file_exists() to look for the ancestors of the path. Using the
heuristic that a sparse directory is likely to have a small number of
parent directories, we start from the bottom and build up. Use a string
buffer to allow mutating the path name to terminate after each slash for
each hashset test.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Sparse directory entries represent a directory that is outside the
sparse-checkout definition. These are not paths to blobs, so should not
be added to the name_hash table. Instead, they should be added to the
directory hashtable when 'ignore_case' is true.
Add a condition to avoid placing sparse directories into the name_hash
hashtable. This avoids filling the table with extra entries that will
never be queried.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before iterating over all index entries, ensure that a sparse index is
expanded to a full index to avoid unexpected behavior. This case could
be integrated later by ensuring that we walk the tree in the
sparse-directory entry, but the current behavior is only expecting
blobs. Save this integration for later when it can be properly tested.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before iterating over all cache entries, ensure that a sparse index is
expanded to a full one so we do not miss blobs to scan. Later, this can
integrate more carefully with sparse indexes with proper testing.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before we iterate over all cache entries, ensure that the index is not
sparse. This loop in checkout_all() might be safe to iterate over a
sparse index, but let's put this protection here until it can be
carefully tested.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Soon we will insert ensure_full_index() calls across the codebase.
Instead of also adding include statements for sparse-index.h, let's just
use the fact that anything that cares about the index already has
cache.h in its includes.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache: expand on query into sparse-directory entry
Callers to index_name_pos() or index_name_stage_pos() have a specific
path in mind. If that happens to be a path with an ancestor being a
sparse-directory entry, it can lead to unexpected results.
In the case that we did not find the requested path, check to see if the
position _before_ the inserted position is a sparse directory entry that
matches the initial segment of the input path (including the directory
separator at the end of the directory name). If so, then expand the
index to be a full index and search again. This expansion will only
happen once per index read.
Future enhancements could be more careful to expand only the necessary
sparse directory entry, but then we would have a special "not fully
sparse, but also not fully expanded" mode that could affect writing the
index to file. Since this only occurs if a specific file is requested
outside of the sparse checkout definition, this is unlikely to be a
common situation.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
*: remove 'const' qualifier for struct index_state
Several methods specify that they take a 'struct index_state' pointer
with the 'const' qualifier because they intend to only query the data,
not change it. However, we will be introducing a step very low in the
method stack that might modify a sparse-index to become a full index in
the case that our queries venture inside a sparse-directory entry.
This change only removes the 'const' qualifiers that are necessary for
the following change which will actually modify the implementation of
index_name_stage_pos().
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
projects / thirdparty / git.git / log
