* maint-2.19: (34 commits)
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
...
* maint-2.18: (33 commits)
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
...
* maint-2.17: (32 commits)
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
...
* maint-2.16: (31 commits)
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
...
* maint-2.15: (29 commits)
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
clone --recurse-submodules: prevent name squatting on Windows
is_ntfs_dotgit(): only verify the leading segment
...
* maint-2.14: (28 commits)
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
clone --recurse-submodules: prevent name squatting on Windows
is_ntfs_dotgit(): only verify the leading segment
test-path-utils: offer to run a protectNTFS/protectHFS benchmark
...
When creating a directory on Windows whose path ends in a space or a
period (or chains thereof), the Win32 API "helpfully" trims those. For
example, `mkdir("abc ");` will return success, but actually create a
directory called `abc` instead.
This stems back to the DOS days, when all file names had exactly 8
characters plus exactly 3 characters for the file extension, and the
only way to have shorter names was by padding with spaces.
Sadly, this "helpful" behavior is a bit inconsistent: after a successful
`mkdir("abc ");`, a `mkdir("abc /def")` will actually _fail_ (because
the directory `abc ` does not actually exist).
Even if it would work, we now have a serious problem because a Git
repository could contain directories `abc` and `abc `, and on Windows,
they would be "merged" unintentionally.
As these paths are illegal on Windows, anyway, let's disallow any
accesses to such paths on that Operating System.
For practical reasons, this behavior is still guarded by the
config setting `core.protectNTFS`: it is possible (and at least two
regression tests make use of it) to create commits without involving the
worktree. In such a scenario, it is of course possible -- even on
Windows -- to create such file names.
Among other consequences, this patch disallows submodules' paths to end
in spaces on Windows (which would formerly have confused Git enough to
try to write into incorrect paths, anyway).
While this patch does not fix a vulnerability on its own, it prevents an
attack vector that was exploited in demonstrations of a number of
recently-fixed security bugs.
The regression test added to `t/t7417-submodule-path-url.sh` reflects
that attack vector.
Note that we have to adjust the test case "prevent git~1 squatting on
Windows" in `t/t7415-submodule-names.sh` because of a very subtle issue.
It tries to clone two submodules whose names differ only in a trailing
period character, and as a consequence their git directories differ in
the same way. Previously, when Git tried to clone the second submodule,
it thought that the git directory already existed (because on Windows,
when you create a directory with the name `b.` it actually creates `b`),
but with this patch, the first submodule's clone will fail because of
the illegal name of the git directory. Therefore, when cloning the
second submodule, Git will take a different code path: a fresh clone
(without an existing git directory). Both code paths fail to clone the
second submodule, both because the the corresponding worktree directory
exists and is not empty, but the error messages are worded differently.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The config setting `core.protectNTFS` is specifically designed to work
not only on Windows, but anywhere, to allow for repositories hosted on,
say, Linux servers to be protected against NTFS-specific attack vectors.
As a consequence, `is_ntfs_dotgit()` manually splits backslash-separated
paths (but does not do the same for paths separated by forward slashes),
under the assumption that the backslash might not be a valid directory
separator on the _current_ Operating System.
However, the two callers, `verify_path()` and `fsck_tree()`, are
supposed to feed only individual path segments to the `is_ntfs_dotgit()`
function.
This causes a lot of duplicate scanning (and very inefficient scanning,
too, as the inner loop of `is_ntfs_dotgit()` was optimized for
readability rather than for speed.
Let's simplify the design of `is_ntfs_dotgit()` by putting the burden of
splitting the paths by backslashes as directory separators on the
callers of said function.
Consequently, the `verify_path()` function, which already splits the
path by directory separators, now treats backslashes as directory
separators _explicitly_ when `core.protectNTFS` is turned on, even on
platforms where the backslash is _not_ a directory separator.
Note that we have to repeat some code in `verify_path()`: if the
backslash is not a directory separator on the current Operating System,
we want to allow file names like `\`, but we _do_ want to disallow paths
that are clearly intended to cause harm when the repository is cloned on
Windows.
The `fsck_tree()` function (the other caller of `is_ntfs_dotgit()`) now
needs to look for backslashes in tree entries' names specifically when
`core.protectNTFS` is turned on. While it would be tempting to
completely disallow backslashes in that case (much like `fsck` reports
names containing forward slashes as "full paths"), this would be
overzealous: when `core.protectNTFS` is turned on in a non-Windows
setup, backslashes are perfectly valid characters in file names while we
_still_ want to disallow tree entries that are clearly designed to
exploit NTFS-specific behavior.
This simplification will make subsequent changes easier to implement,
such as turning `core.protectNTFS` on by default (not only on Windows)
or protecting against attack vectors involving NTFS Alternate Data
Streams.
Incidentally, this change allows for catching malicious repositories
that contain tree entries of the form `dir\.gitmodules` already on the
server side rather than only on the client side (and previously only on
Windows): in contrast to `is_ntfs_dotgit()`, the
`is_ntfs_dotgitmodules()` function already expects the caller to split
the paths by directory separators.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
CI updates.
* js/azure-pipelines-msvc:
ci: also build and test with MS Visual Studio on Azure Pipelines
ci: really use shallow clones on Azure Pipelines
tests: let --immediate and --write-junit-xml play well together
test-tool run-command: learn to run (parts of) the testsuite
vcxproj: include more generated files
vcxproj: only copy `git-remote-http.exe` once it was built
msvc: work around a bug in GetEnvironmentVariable()
msvc: handle DEVELOPER=1
msvc: ignore some libraries when linking
compat/win32/path-utils.h: add #include guards
winansi: use FLEX_ARRAY to avoid compiler warning
msvc: avoid using minus operator on unsigned types
push: do not pretend to return `int` from `die_push_simple()`
"git stash" learned to write refreshed index back to disk.
* tg/stash-refresh-index:
stash: make sure to write refreshed cache
merge: use refresh_and_write_cache
factor out refresh_and_write_cache function
MSVC complains about this with `-Wall`, which can be taken as a sign
that this is indeed a real bug. The symptom is:
C4146: unary minus operator applied to unsigned type, result
still unsigned
Let's avoid this warning in the minimal way, e.g. writing `-1 -
<unsigned value>` instead of `-<unsigned value> - 1`.
Note that the change in the `estimate_cache_size()` function is
needed because MSVC considers the "return type" of the `sizeof()`
operator to be `size_t`, i.e. unsigned, and therefore it cannot be
negated using the unary minus operator.
Even worse, that arithmetic is doing extra work, in vain. We want to
calculate the entry extra cache size as the difference between the
size of the `cache_entry` structure minus the size of the
`ondisk_cache_entry` structure, padded to the appropriate alignment
boundary.
To that end, we start by assigning that difference to the `per_entry`
variable, and then abuse the `len` parameter of the
`align_padding_size()` macro to take the negative size of the ondisk
entry size. Essentially, we try to avoid passing the already calculated
difference to that macro by passing the operands of that difference
instead, when the macro expects operands of an addition:
#define align_padding_size(size, len) \
((size + (len) + 8) & ~7) - (size + len)
Currently, we pass A and -B to that macro instead of passing A - B and
0, where A - B is already stored in the `per_entry` variable, ready to
be used.
This is neither necessary, nor intuitive. Let's fix this, and have code
that is both easier to read and that also does not trigger MSVC's
warning.
While at it, we take care of reporting overflows (which are unlikely,
but hey, defensive programming is good!).
We _also_ take pains of casting the unsigned value to signed: otherwise,
the signed operand (i.e. the `-1`) would be cast to unsigned before
doing the arithmetic.
Helped-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Getting the lock for the index, refreshing it and then writing it is a
pattern that happens more than once throughout the codebase, and isn't
trivial to get right. Factor out the refresh_and_write_cache function
from builtin/am.c to read-cache.c, so it can be re-used in other
places in a subsequent commit.
Note that we return different error codes for failing to refresh the
cache, and failing to write the index. The current caller only cares
about failing to write the index. However for other callers we're
going to convert in subsequent patches we will need this distinction.
Helped-by: Martin Ågren <martin.agren@gmail.com>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A mechanism to affect the default setting for a (related) group of
configuration variables is introduced.
* ds/feature-macros:
repo-settings: create feature.experimental setting
repo-settings: create feature.manyFiles setting
repo-settings: parse core.untrackedCache
commit-graph: turn on commit-graph by default
t6501: use 'git gc' in quiet mode
repo-settings: consolidate some config settings
The core.untrackedCache config setting is slightly complicated,
so clarify its use and centralize its parsing into the repo
settings.
The default value is "keep" (returned as -1), which persists the
untracked cache if it exists.
If the value is set as "false" (returned as 0), then remove the
untracked cache if it exists.
If the value is set as "true" (returned as 1), then write the
untracked cache and persist it.
Instead of relying on magic values of -1, 0, and 1, split these
options into an enum. This allows the use of "-1" as a
default value. After parsing the config options, if the value is
unset we can initialize it to UNTRACKED_CACHE_KEEP.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few important config settings that are not loaded
during git_default_config. These are instead loaded on-demand.
Centralize these config options to a single scan, and store
all of the values in a repo_settings struct. The values for
each setting are initialized as negative to indicate "unset".
This centralization will be particularly important in a later
change to introduce "meta" config settings that change the
defaults for these config settings.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up to avoid signed integer overlaps during binary search.
* rs/avoid-overflow-in-midpoint-computation:
cleanup: fix possible overflow errors in binary search, part 2
do_read_index() mmaps the index, or tries to die with an error message
on failure. It should call xmmap_gently(), which returns MAP_FAILED,
rather than xmmap(), which dies with its own error message.
An easy way to cause this mmap to fail is by setting $GIT_INDEX_FILE to
a path to a directory and then invoking any command that reads from the
index.
Signed-off-by: Varun Naik <vcnaik94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up to avoid signed integer overlaps during binary search.
* rs/avoid-overflow-in-midpoint-computation:
cleanup: fix possible overflow errors in binary search, part 2
The data collected by fsmonitor was not properly written back to
the on-disk index file, breaking t7519 tests occasionally, which
has been corrected.
* js/fsmonitor-unflake:
mark_fsmonitor_valid(): mark the index as changed if needed
fill_stat_cache_info(): prepare for an fsmonitor fix
* jk/unused-params-final-batch:
verify-commit: simplify parameters to run_gpg_verify()
show-branch: drop unused parameter from show_independent()
rev-list: drop unused void pointer from finish_commit()
remove_all_fetch_refspecs(): drop unused "remote" parameter
receive-pack: drop unused "commands" from prepare_shallow_update()
pack-objects: drop unused rev_info parameters
name-rev: drop unused parameters from is_better_name()
mktree: drop unused length parameter
wt-status: drop unused status parameter
read-cache: drop unused parameter from threaded load
clone: drop dest parameter from copy_alternates()
submodule: drop unused prefix parameter from some functions
builtin: consistently pass cmd_* prefix to parse_options
cmd_{read,write}_tree: rename "unused" variable that is used
Calculating the sum of two array indexes to find the midpoint between
them can overflow, i.e. code like this is unsafe for big arrays:
mid = (first + last) >> 1;
Make sure the intermediate value stays within the boundaries instead,
like this:
mid = first + ((last - first) >> 1);
The loop condition of the binary search makes sure that 'last' is
always greater than 'first', so this is safe as long as 'first' is
not negative. And that can be verified easily using the pre-context
of each change, except for name-hash.c, so add an assertion to that
effect there.
The unsafe calculations were found with:
git grep '(.*+.*) *>> *1'
This is a continuation of 19716b21a4 (cleanup: fix possible overflow
errors in binary search, 2017-10-08).
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Without this bug fix, t7519's four "status doesn't detect unreported
modifications" test cases would fail occasionally (and, oddly enough,
*a lot* more frequently on Windows).
The reason is that these test cases intentionally use the side effect of
`git status` to re-write the index if any updates were detected: they
first clean the worktree, run `git status` to update the index as well
as show the output to the casual reader, then make the worktree dirty
again and expect no changes to reported if running with a mocked
fsmonitor hook.
The problem with this strategy was that the index was written during
said `git status` on the clean worktree for the *wrong* reason: not
because the index was marked as changed (it wasn't), but because the
recorded mtimes were racy with the index' own mtime.
As the mtime granularity on Windows is 100 nanoseconds (see e.g.
https://docs.microsoft.com/en-us/windows/desktop/SysInfo/file-times),
the mtimes of the files are often enough *not* racy with the index', so
that that `git status` call currently does not always update the index
(including the fsmonitor extension), causing the test case to fail.
The obvious fix: if we change *any* index entry's `CE_FSMONITOR_VALID`
flag, we should also mark the index as changed. That will cause the
index to be written upon `git status`, *including* an updated fsmonitor
extension.
Side note: Even though the reader might think that the t7519 issue
should be *much* more prevalent on Linux, given that the ext4 filesystem
(that seems to be used by every Linux distribution) stores mtimes in
nanosecond precision. However, ext4 uses `current_kernel_time()` (see
https://unix.stackexchange.com/questions/11599#comment762968_11599; it
is *amazingly* hard to find any proper source of information about such
ext4 questions) whose accuracy seems to depend on many factors but is
safely worse than the 100-nanosecond granularity of NTFS (again, it is
*horribly* hard to find anything remotely authoritative about this
question). So it seems that the racy index condition that hid the bug
fixed by this patch simply is a lot more likely on Linux than on
Windows. But not impossible ;-)
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We will need to pass down the `struct index_state` to
`mark_fsmonitor_valid()` for an upcoming bug fix, and this here function
calls that there function, so we need to extend the signature of
`fill_stat_cache_info()` first.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The fsmonitor interface got out of sync after the in-core index
file gets discarded, which has been corrected.
* js/fsmonitor-refresh-after-discarding-index:
fsmonitor: force a refresh after the index was discarded
fsmonitor: demonstrate that it is not refreshed after discard_index()
The load_cache_entries_threaded() function takes a src_offset parameter
that it doesn't use. This has been there since its inception in
77ff1127a4 (read-cache: load cache entries on worker threads,
2018-10-10).
Digging on the mailing list, that parameter was part of an earlier
iteration of the series[1], but became unnecessary when the code
switched to using the IEOT extension.
[1] https://public-inbox.org/git/20180906210227.54368-5-benpeart@microsoft.com/
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a trivial bug that's been here since the shared/do_write_index
tracing was added in 42fee7a388 ("trace2:data: add trace2
instrumentation to index read/write", 2019-02-22). We should have
enter/leave points, not two enter/enter points. This resulted in an
"enter" event without a corresponding "leave" event.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running "git add" on a repository created inside the current
repository is an explicit indication that the user wants to add it
as a submodule, but when the HEAD of the inner repository is on an
unborn branch, it cannot be added as a submodule. Worse, the files
in its working tree can be added as if they are a part of the outer
repository, which is not what the user wants. These problems are
being addressed.
* km/empty-repo-is-still-a-repo:
add: error appropriately on repository with no commits
dir: do not traverse repositories with no commits
submodule: refuse to add repository with no commits
With this change, the `index_state` struct becomes the new home for the
flag that says whether the fsmonitor hook has been run, i.e. it is now
per-index.
It also gets re-set when the index is discarded, fixing the bug
demonstrated by the "test_expect_failure" test added in the preceding
commit. In that case fsmonitor-enabled Git would miss updates under
certain circumstances, see that preceding commit for details.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from unsigned char[20] to struct object_id continues.
* bc/hash-transition-16: (35 commits)
gitweb: make hash size independent
Git.pm: make hash size independent
read-cache: read data in a hash-independent way
dir: make untracked cache extension hash size independent
builtin/difftool: use parse_oid_hex
refspec: make hash size independent
archive: convert struct archiver_args to object_id
builtin/get-tar-commit-id: make hash size independent
get-tar-commit-id: parse comment record
hash: add a function to lookup hash algorithm by length
remote-curl: make hash size independent
http: replace sha1_to_hex
http: compute hash of downloaded objects using the_hash_algo
http: replace hard-coded constant with the_hash_algo
http-walker: replace sha1_to_hex
http-push: remove remaining uses of sha1_to_hex
http-backend: allow 64-character hex names
http-push: convert to use the_hash_algo
builtin/pull: make hash-size independent
builtin/am: make hash size independent
...
A new hook "post-index-change" is called when the on-disk index
file changes, which can help e.g. a virtualized working tree
implementation.
* bp/post-index-change-hook:
read-cache: add post-index-change hook
The previous commit made 'git add' abort when given a repository that
doesn't have a commit checked out. However, the output upon failure
isn't appropriate:
% git add repo
warning: adding embedded git repository: repo
hint: You've added another git repository inside your current repository.
hint: [...]
error: unable to index file 'repo/'
fatal: adding files failed
The hint doesn't apply in this case, and the error message doesn't
tell the user why 'repo' couldn't be added to the index.
Provide better output by teaching add_to_index() to error when given a
git directory where HEAD can't be resolved. To avoid the embedded
repository warning and hint, call check_embedded_repo() only after
add_file_to_index() succeeds because, in general, its output doesn't
make sense if adding to the index fails.
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Index entries are structured with a variety of fields up front, followed
by a hash and one or two flags fields. Because the hash field is stored
in the middle of the structure, it's difficult to use one fixed-size
structure that easily allows access to the hash and flags fields.
Adjust the structure to hold the maximum amount of data that may be
needed using a member called "data" and read and write this field
independently in the various places that need to read and write the
structure.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A more structured way to obtain execution trace has been added.
* jh/trace2:
trace2: add for_each macros to clang-format
trace2: t/helper/test-trace2, t0210.sh, t0211.sh, t0212.sh
trace2:data: add subverb for rebase
trace2:data: add subverb to reset command
trace2:data: add subverb to checkout command
trace2:data: pack-objects: add trace2 regions
trace2:data: add trace2 instrumentation to index read/write
trace2:data: add trace2 hook classification
trace2:data: add trace2 transport child classification
trace2:data: add trace2 sub-process classification
trace2:data: add editor/pager child classification
trace2:data: add trace2 regions to wt-status
trace2: collect Windows-specific process information
trace2: create new combined trace facility
trace2: Documentation/technical/api-trace2.txt
"git checkout --no-overlay" can be used to trigger a new mode of
checking out paths out of the tree-ish, that allows paths that
match the pathspec that are in the current index and working tree
and are not in the tree-ish.
* tg/checkout-no-overlay:
revert "checkout: introduce checkout.overlayMode config"
checkout: introduce checkout.overlayMode config
checkout: introduce --{,no-}overlay option
checkout: factor out mark_cache_entry_for_checkout function
checkout: clarify comment
read-cache: add invalidate parameter to remove_marked_cache_entries
entry: support CE_WT_REMOVE flag in checkout_entry
entry: factor out unlink_entry function
move worktree tests to t24*
Add trace2 events to measure reading and writing the index.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a post-index-change hook that is invoked after the index is written in
do_write_locked_index().
This hook is meant primarily for notification, and cannot affect
the outcome of git commands that trigger the index write.
The hook is passed a flag to indicate whether the working directory was
updated or not and a flag indicating if a skip-worktree bit could have
changed. These flags enable the hook to optimize its response to the
index change notification.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since commit 7db118303a (unpack_trees: fix breakage when o->src_index !=
o->dst_index - 2018-04-23) and changes in merge code to use separate
index_state for source and destination, when doing a merge with split
index activated, we may run into this line in unpack_trees():
o->result.split_index = init_split_index(&o->result);
This is by itself not wrong. But this split index information is not
fully populated (and it's only so when move_cache_to_base_index() is
called, aka force splitting the index, or loading index_state from a
file). Both "base_oid" and "base" in this case remain null.
So when writing the main index down, we link to this index with null
oid (default value after init_split_index()), which also means "no split
index" internally. This triggers an incorrect base index refresh:
warning: could not freshen shared index '.../sharedindex.0{40}'
This patch makes sure we will not refresh null base_oid (because the
file is never there). It also makes sure not to write "link" extension
with null base_oid in the first place (no point having it at
all). Read code already has protection against null base_oid.
There is also another side fix in remove_split_index() that causes a
crash when doing "git update-index --no-split-index" when base_oid in
the index file is null. In this case we will not load
istate->split_index->base but we dereference it anyway and are rewarded
with a segfault. This should not happen anymore, but it's still wrong to
dereference a potential NULL pointer, especially when we do check for
NULL pointer in the next code.
Reported-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The assumption to work on the single "in-core index" instance has
been reduced from the library-ish part of the codebase.
* nd/the-index-final:
cache.h: flip NO_THE_INDEX_COMPATIBILITY_MACROS switch
read-cache.c: remove the_* from index_has_changes()
merge-recursive.c: remove implicit dependency on the_repository
merge-recursive.c: remove implicit dependency on the_index
sha1-name.c: remove implicit dependency on the_index
read-cache.c: replace update_index_if_able with repo_&
read-cache.c: kill read_index()
checkout: avoid the_index when possible
repository.c: replace hold_locked_index() with repo_hold_locked_index()
notes-utils.c: remove the_repository references
grep: use grep_opt->repo instead of explict repo argument
Commit 9e5da3d055 (add: use separate ADD_CACHE_RENORMALIZE flag,
2019-01-17) switched out using HASH_RENORMALIZE in our flags field for a
new ADD_CACHE_RENORMALIZE flag. However, it forgot to convert one of the
checks for HASH_RENORMALIZE into the new flag, which totally broke "git
add --renormalize".
To make matters even more confusing, the resulting code would racily
pass the tests! The forgotten check was responsible for defeating the
up-to-date check of the index entry. That meant that "git add
--renormalize" would refuse to renormalize things that appeared
stat-clean. But most of the time the test commands run fast enough that
the file mtime is the same as the index mtime. And thus we err on the
conservative side and re-hash the file, which is what "--renormalize"
would have wanted.
But if you're unlucky and cross that one-second boundary between writing
the file and writing the index (which is more likely to happen on a slow
or heavily-loaded system), then the file appears stat-clean. And
"--renormalize" would effectively do nothing.
The fix is straightforward: convert this check to use the right flag.
Noticed-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git add --ignore-errors" did not work as advertised and instead
worked as an unintended synonym for "git add --renormalize", which
has been fixed.
* jk/add-ignore-errors-bit-assignment-fix:
add: use separate ADD_CACHE_RENORMALIZE flag
By default, index compat macros are off from now on, because they
could hide the_index dependency.
Only those in builtin can use it.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 9472935d81 (add: introduce "--renormalize", 2017-11-16) taught
git-add to pass HASH_RENORMALIZE to add_to_index(), which then passes
the flag along to index_path(). However, the flags taken by
add_to_index() and the ones taken by index_path() are distinct
namespaces. We cannot take HASH_* flags in add_to_index(), because they
overlap with the ADD_CACHE_* flags we already take (in this case,
HASH_RENORMALIZE conflicts with ADD_CACHE_IGNORE_ERRORS).
We can solve this by adding a new ADD_CACHE_RENORMALIZE flag, and using
it to set HASH_RENORMALIZE within add_to_index(). In order to make it
clear that these two flags come from distinct sets, let's also change
the name "newflags" in the function to "hash_flags".
Reported-by: Dmitriy Smirnov <dmitriy.smirnov@jetbrains.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
read_index() shares the same problem as hold_locked_index(): it
assumes $GIT_DIR/index. Move all call sites to repo_read_index()
instead. read_index_preload() and read_index_unmerged() are also
killed as a consequence.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
hold_locked_index() assumes the index path at $GIT_DIR/index. This is
not good for places that take an arbitrary index_state instead of
the_index, which is basically everywhere except builtin/.
Replace it with repo_hold_locked_index(). hold_locked_index() remains
as a wrapper around repo_hold_locked_index() to reduce changes in builtin/
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
More _("i18n") markings.
* nd/i18n:
fsck: mark strings for translation
fsck: reduce word legos to help i18n
parse-options.c: mark more strings for translation
parse-options.c: turn some die() to BUG()
parse-options: replace opterror() with optname()
repack: mark more strings for translation
remote.c: mark messages for translation
remote.c: turn some error() or die() to BUG()
reflog: mark strings for translation
read-cache.c: add missing colon separators
read-cache.c: mark more strings for translation
read-cache.c: turn die("internal error") to BUG()
attr.c: mark more string for translation
archive.c: mark more strings for translation
alias.c: mark split_cmdline_strerror() strings for translation
git.c: mark more strings for translation
When marking cache entries for removal, and later removing them all at
once using 'remove_marked_cache_entries()', cache entries currently
have to be invalidated manually in the cache tree and in the untracked
cache.
Add an invalidate flag to the function. With the flag set, the
function will take care of invalidating the path in the cache tree and
in the untracked cache.
Note that the current callsites already do the invalidation properly
in other places, so we're just passing 0 from there to keep the status
quo.
This will be useful in a subsequent commit.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We indent with TABs and sometimes for fine alignment, TABs followed by
spaces, but never all spaces (unless the indentation is less than 8
columns). Indenting with spaces slips through in some places. Fix
them.
Imported code and compat/ are left alone on purpose. The former should
remain as close as upstream as possible. The latter pretty much has
separate maintainers, it's up to them to decide.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The way .git/index and .git/sharedindex* files were initially
created gave these files different perm bits until they were
adjusted for shared repository settings. This was made consistent.
* cc/shared-index-permbits:
read-cache: make the split index obey umask settings
If a user explicitly sets
[index]
threads = true
to read the index using multiple threads, ensure that index writes
include the offset table by default to make that possible. This
ensures that the user's intent of turning on threading is respected.
In other words, permit the following configurations:
- index.threads and index.recordOffsetTable unspecified: do not write
the offset table yet (to avoid alarming the user with "ignoring IEOT
extension" messages when an older version of Git accesses the
repository) but do make use of multiple threads to read the index if
the supporting offset table is present.
This can also be requested explicitly by setting index.threads=true,
0, or >1 and index.recordOffsetTable=false.
- index.threads=false or 1: do not write the offset table, and do not
make use of the offset table.
One can set index.recordOffsetTable=false as well, to be more
explicit.
- index.threads=true, 0, or >1 and index.recordOffsetTable unspecified:
write the offset table and make use of threads at read time.
This can also be requested by setting index.threads=true, 0, >1, or
unspecified and index.recordOffsetTable=true.
Fortunately the complication is temporary: once most Git installations
have upgraded to a version with support for the IEOT and EOIE
extensions, we can flip the defaults for index.recordEndOfIndexEntries
and index.recordOffsetTable to true and eliminate the settings.
Helped-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As with EOIE, popular versions of Git do not support the new IEOT
extension yet. When accessing a Git repository written by a more
modern version of Git, they correctly ignore the unrecognized section,
but in the process they loudly warn
ignoring IEOT extension
resulting in confusion for users. Introduce the index extension more
gently by not writing it yet in this first version with support for
it. Soon, once sufficiently many users are running a modern version
of Git, we can flip the default so users benefit from this index
extension by default.
Introduce a '[index] recordOffsetTable' configuration variable to
control whether the new index extension is written.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 3b1d9e04 (eoie: add End of Index Entry (EOIE) extension,
2018-10-10) Git defaults to writing the new EOIE section when writing
out an index file. Usually that is a good thing because it improves
threaded performance, but when a Git repository is shared with older
versions of Git, it produces a confusing warning:
$ git status
ignoring EOIE extension
HEAD detached at 371ed0defa
nothing to commit, working tree clean
Let's introduce the new index extension more gently. First we'll roll
out the new version of Git that understands it, and then once
sufficiently many users are using such a version, we can flip the
default to writing it by default.
Introduce a '[index] recordEndOfIndexEntries' configuration variable
to allow interested users to benefit from this index extension early.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the split index write out its .git/sharedindex_* files with the
same permissions as .git/index. This only changes the behavior when
core.sharedRepository isn't set, i.e. the user's umask settings will
be respected.
This hasn't been the case ever since the split index was originally
implemented in c18b80a0e8 ("update-index: new options to
enable/disable split index mode", 2014-06-13). A mkstemp()-like
function has always been used to create it. First mkstemp() itself,
and then later our own mkstemp()-like in
f6ecc62dbf ("write_shared_index(): use tempfile module", 2015-08-10)
A related bug was fixed in df801f3f9f ("read-cache: use shared perms
when writing shared index", 2017-06-25). Since then the split index
has respected core.sharedRepository.
However, using that setting should not be required simply to make git
obey the user's umask setting. It's intended for the use-case of
overriding whatever that umask is set to. This fixes cases where the
user has e.g. set his umask to 022 on a shared server in anticipation
of other user's needing to run "status", "log" etc. in his repository.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".
* nd/pthreads:
Clean up pthread_create() error handling
read-cache.c: initialize copy_len to shut up gcc 8
read-cache.c: reduce branching based on HAVE_THREADS
read-cache.c: remove #ifdef NO_PTHREADS
pack-objects: remove #ifdef NO_PTHREADS
preload-index.c: remove #ifdef NO_PTHREADS
grep: clean up num_threads handling
grep: remove #ifdef NO_PTHREADS
attr.c: remove #ifdef NO_PTHREADS
name-hash.c: remove #ifdef NO_PTHREADS
index-pack: remove #ifdef NO_PTHREADS
send-pack.c: move async's #ifdef NO_PTHREADS back to run-command.c
run-command.h: include thread-utils.h instead of pthread.h
thread-utils: macros to unconditionally compile pthreads API
The helper function to refresh the cached stat information in the
in-core index has learned to perform the lstat() part of the
operation in parallel on multi-core platforms.
* bp/refresh-index-using-preload:
refresh_index: remove unnecessary calls to preload_index()
speed up refresh_index() by utilizing preload_index()
This case is more interesting than other boring "remove the_repo"
commits because while we need access to the object database, we cannot
simply use r->index because unpack-trees.c can operate on a temporary
index, not $GIT_DIR/index. Ideally we should be able to pass an object
database to lookup_tree() but that ship has sailed.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
typechange_fmt and added_fmt should have a colon before "needs
update". Align the statements to make it easier to read and see. Also
drop the unnecessary ().
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a couple other improvements on these strings as well:
- add missing colon (as separator)
- quote paths
- provide more information on error messages
- keep first word in lowercase
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was reported that when building with NO_PTHREADS=1,
-Wmaybe-uninitialized is triggered. Just initialize the variable from
the beginning to shut the compiler up (because this warning is enabled
in config.dev)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a faithful conversion with no attempt to clean up whatsoever.
Code indentation is left broken. There will be another commit to clean
it up and un-indent if we just indent now. It's just more code noise.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Speed up refresh_index() by utilizing preload_index() to do most of the work
spread across multiple threads. This works because most cache entries will
get marked CE_UPTODATE so that refresh_cache_ent() can bail out early when
called from within refresh_index().
On a Windows repo with ~200K files, this drops refresh times from 6.64
seconds to 2.87 seconds for a savings of 57%.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The codepath to support the experimental split-index mode had
remaining "racily clean" issues fixed.
* sg/split-index-racefix:
split-index: BUG() when cache entry refers to non-existing shared entry
split-index: smudge and add racily clean cache entries to split index
split-index: don't compare cached data of entries already marked for split index
split-index: count the number of deleted entries
t1700-split-index: date back files to avoid racy situations
split-index: add tests to demonstrate the racy split index problem
t1700-split-index: document why FSMONITOR is disabled in this test script
introduced with c46c406ae1 (trace.h: support nested performance tracing)
on Aug 18, 2018 but not affecting maint
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git status" learns to show progress bar when refreshing the index
takes a long time.
* nd/status-refresh-progress:
status: show progress bar if refreshing the index takes too long
A new extension to the index file has been introduced, which allows
the file to be read in parallel.
* bp/read-cache-parallel:
read-cache: load cache entries on worker threads
ieot: add Index Entry Offset Table (IEOT) extension
read-cache: load cache extensions on a worker thread
config: add new index.threads config setting
eoie: add End of Index Entry (EOIE) extension
read-cache: clean up casting and byte decoding
read-cache.c: optimize reading index format v4
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".
* nd/the-index: (23 commits)
revision.c: reduce implicit dependency the_repository
revision.c: remove implicit dependency on the_index
ws.c: remove implicit dependency on the_index
tree-diff.c: remove implicit dependency on the_index
submodule.c: remove implicit dependency on the_index
line-range.c: remove implicit dependency on the_index
userdiff.c: remove implicit dependency on the_index
rerere.c: remove implicit dependency on the_index
sha1-file.c: remove implicit dependency on the_index
patch-ids.c: remove implicit dependency on the_index
merge.c: remove implicit dependency on the_index
merge-blobs.c: remove implicit dependency on the_index
ll-merge.c: remove implicit dependency on the_index
diff-lib.c: remove implicit dependency on the_index
read-cache.c: remove implicit dependency on the_index
diff.c: remove implicit dependency on the_index
grep.c: remove implicit dependency on the_index
diff.c: remove the_index dependency in textconv() functions
blame.c: rename "repo" argument to "r"
combine-diff.c: remove implicit dependency on the_index
...
Ever since the split index feature was introduced [1], refreshing a
split index is prone to a variant of the classic racy git problem.
Consider the following sequence of commands updating the split index
when the shared index contains a racily clean cache entry, i.e. an
entry whose cached stat data matches with the corresponding file in
the worktree and the cached mtime matches that of the index:
echo "cached content" >file
git update-index --split-index --add file
echo "dirty worktree" >file # size stays the same!
# ... wait ...
git update-index --add other-file
Normally, when a non-split index is updated, then do_write_index()
(the function responsible for writing all kinds of indexes, "regular",
split, and shared) recognizes racily clean cache entries, and writes
them with smudged stat data, i.e. with file size set to 0. When
subsequent git commands read the index, they will notice that the
smudged stat data doesn't match with the file in the worktree, and
then go on to check the file's content and notice its dirtiness.
In the above example, however, in the second 'git update-index'
prepare_to_write_split_index() decides which cache entries stored only
in the shared index should be replaced in the new split index. Alas,
this function never looks out for racily clean cache entries, and
since the file's stat data in the worktree hasn't changed since the
shared index was written, it won't be replaced in the new split index.
Consequently, do_write_index() doesn't even get this racily clean
cache entry, and can't smudge its stat data. Subsequent git commands
will then see that the index has more recent mtime than the file and
that the (not smudged) cached stat data still matches with the file in
the worktree, and, ultimately, will erroneously consider the file
clean.
Modify prepare_to_write_split_index() to recognize racily clean cache
entries, and mark them to be added to the split index. Note that
there are two places where it should check raciness: first those cache
entries that are only stored in the shared index, and then those that
have been copied by unpack_trees() from the shared index while it
constructed a new index. This way do_write_index() will get these
racily clean cache entries as well, and will then write them with
smudged stat data to the new split index.
This change makes all tests in 't1701-racy-split-index.sh' pass, so
flip the two 'test_expect_failure' tests to success. Also add the '#'
(as in nr. of trial) to those tests' description that were omitted
when the tests expected failure.
Note that after this change if the index is split when it contains a
racily clean cache entry, then a smudged cache entry will be written
both to the new shared and to the new split indexes. This doesn't
affect regular git commands: as far as they are concerned this is just
an entry in the split index replacing an outdated entry in the shared
index. It did affect a few tests in 't1700-split-index.sh', though,
because they actually check which entries are stored in the split
index; a previous patch in this series has already made the necessary
adjustments in 't1700'. And racily clean cache entries and index
splitting are rare enough to not worry about the resulting duplicated
smudged cache entries, and the additional complexity required to
prevent them is not worth it.
Several tests failed occasionally when the test suite was run with
'GIT_TEST_SPLIT_INDEX=yes'. Here are those that I managed to trace
back to this racy split index problem, starting with those failing
more frequently, with a link to a failing Travis CI build job for
each. The highlighted line [2] shows when the racy file was written,
which is not always in the failing test but in a preceeding setup
test.
t3903-stash.sh:
https://travis-ci.org/git/git/jobs/385542084#L5858
t4024-diff-optimize-common.sh:
https://travis-ci.org/git/git/jobs/386531969#L3174
t4015-diff-whitespace.sh:
https://travis-ci.org/git/git/jobs/360797600#L8215
t2200-add-update.sh:
https://travis-ci.org/git/git/jobs/382543426#L3051
t0090-cache-tree.sh:
https://travis-ci.org/git/git/jobs/416583010#L3679
There might be others, e.g. perhaps 't1000-read-tree-m-3way.sh' and
others using 'lib-read-tree-m-3way.sh', but I couldn't confirm yet.
[1] In the branch leading to the merge commit v2.1.0-rc0~45 (Merge
branch 'nd/split-index', 2014-07-16).
[2] Note that those highlighted lines are in the 'after failure' fold,
and your browser might unhelpfully fold it up before you could
take a good look.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch helps address the CPU cost of loading the index by utilizing
the Index Entry Offset Table (IEOT) to divide loading and conversion of
the cache entries across multiple threads in parallel.
I used p0002-read-cache.sh to generate some performance data:
Test w/100,000 files reduced the time by 32.24%
Test w/1,000,000 files reduced the time by -4.77%
Note that on the 1,000,000 files case, multi-threading the cache entry parsing
does not yield a performance win. This is because the cost to parse the
index extensions in this repo, far outweigh the cost of loading the cache
entries.
The high cost of parsing the index extensions is driven by the cache tree
and the untracked cache extensions. As this is currently the longest pole,
any reduction in this time will reduce the overall index load times so is
worth further investigation in another patch series.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch enables addressing the CPU cost of loading the index by adding
additional data to the index that will allow us to efficiently multi-
thread the loading and conversion of cache entries.
It accomplishes this by adding an (optional) index extension that is a
table of offsets to blocks of cache entries in the index file. To make
this work for V4 indexes, when writing the cache entries, it periodically
"resets" the prefix-compression by encoding the current entry as if the
path name for the previous entry is completely different and saves the
offset of that entry in the IEOT. Basically, with V4 indexes, it
generates offsets into blocks of prefix-compressed entries.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch helps address the CPU cost of loading the index by loading
the cache extensions on a worker thread in parallel with loading the cache
entries.
In some cases, loading the extensions takes longer than loading the
cache entries so this patch utilizes the new EOIE to start the thread to
load the extensions before loading all the cache entries in parallel.
This is possible because the current extensions don't access the cache
entries in the index_state structure so are OK that they don't all exist
yet.
The CACHE_EXT_TREE, CACHE_EXT_RESOLVE_UNDO, and CACHE_EXT_UNTRACKED
extensions don't even get a pointer to the index so don't have access to the
cache entries.
CACHE_EXT_LINK only uses the index_state to initialize the split index.
CACHE_EXT_FSMONITOR only uses the index_state to save the fsmonitor last
update and dirty flags.
I used p0002-read-cache.sh to generate some performance data:
Test w/100,000 files reduced the time by 0.53%
Test w/1,000,000 files reduced the time by 27.78%
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The End of Index Entry (EOIE) is used to locate the end of the variable
length index entries and the beginning of the extensions. Code can take
advantage of this to quickly locate the index extensions without having
to parse through all of the index entries.
The EOIE extension is always written out to the index file including to
the shared index when using the split index feature. Because it is always
written out, the SHA checksums in t/t1700-split-index.sh were updated
to reflect its inclusion.
It is written as an optional extension to ensure compatibility with other
git implementations that do not yet support it. It is always written out
to ensure it is available as often as possible to speed up index operations.
Because it must be able to be loaded before the variable length cache
entries and other index extensions, this extension must be written last.
The signature for this extension is { 'E', 'O', 'I', 'E' }.
The extension consists of:
- 32-bit offset to the end of the index entries
- 160-bit SHA-1 over the extension types and their sizes (but not
their contents). E.g. if we have "TREE" extension that is N-bytes
long, "REUC" extension that is M-bytes long, followed by "EOIE",
then the hash would be:
SHA-1("TREE" + <binary representation of N> +
"REUC" + <binary representation of M>)
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch does a clean up pass to minimize the casting required to work
with the memory mapped index (mmap).
It also makes the decoding of network byte order more consistent by using
get_be32() where possible.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Index format v4 requires some more computation to assemble a path
based on a previous one. The current code is not very efficient
because
- it doubles memory copy, we assemble the final path in a temporary
first before putting it back to a cache_entry
- strbuf_remove() in expand_name_field() is not exactly a good fit
for stripping a part at the end, _setlen() would do the same job
and is much cheaper.
- the open-coded loop to find the end of the string in
expand_name_field() can't beat an optimized strlen()
This patch avoids the temporary buffer and writes directly to the new
cache_entry, which addresses the first two points. The last point
could also be avoided if the total string length fits in the first 12
bits of ce_flags, if not we fall back to strlen().
Running "test-tool read-cache 100" on webkit.git (275k files), reading
v2 only takes 4.226 seconds, while v4 takes 5.711 seconds, 35% more
time. The patch reduces read time on v4 to 4.319 seconds.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A new variant repo_diff_setup() is added that takes 'struct repository *'
and diff_setup() becomes a thin macro around it that is protected by
NO_THE_REPOSITORY_COMPATIBILITY_MACROS, similar to NO_THE_INDEX_....
The plan is these macros will always be defined for all library files
and the macros are only accessible in builtin/
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function calls do_diff_cache() which eventually needs to set this
"istate" to unpack_options->src_index [1]. This is an unfortunate fact
that unpack_trees() _will_ update [2] src_index so we can't really pass a
const index_state there. Just remove 'const'.
[1] Right now diff_cache() in diff-lib.c assigns the_index to
src_index. But the plan is to get rid of the_index, so it should
be 'istate' from here that gets assigned to src_index.
[2] Some transient bits in the source index are touched. Optional
extensions can also be removed. But other than that the source
tree should still be valid.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
spatch transformation to replace boolean uses of !hashcmp() to
newly introduced oideq() is added, and applied, to regain
performance lost due to support of multiple hash algorithms.
* jk/cocci:
show_dirstat: simplify same-content check
read-cache: use oideq() in ce_compare functions
convert hashmap comparison functions to oideq()
convert "hashcmp() != 0" to "!hasheq()"
convert "oidcmp() != 0" to "!oideq()"
convert "hashcmp() == 0" to hasheq()
convert "oidcmp() == 0" to oideq()
introduce hasheq() and oideq()
coccinelle: use <...> for function exclusion
The unpack_trees() API used in checking out a branch and merging
walks one or more trees along with the index. When the cache-tree
in the index tells us that we are walking a tree whose flattened
contents is known (i.e. matches a span in the index), as linearly
scanning a span in the index is much more efficient than having to
open tree objects recursively and listing their entries, the walk
can be optimized, which is done in this topic.
* nd/unpack-trees-with-cache-tree:
Document update for nd/unpack-trees-with-cache-tree
cache-tree: verify valid cache-tree in the test suite
unpack-trees: add missing cache invalidation
unpack-trees: reuse (still valid) cache-tree from src_index
unpack-trees: reduce malloc in cache-tree walk
unpack-trees: optimize walking same trees with cache-tree
unpack-trees: add performance tracing
trace.h: support nested performance tracing
Refreshing the index is usually very fast, but it can still take a
long time sometimes. Cold cache is one. Or copying a repo to a new
place (*). It's good to show something to let the user know "git
status" is not hanging, it's just busy doing something.
(*) In this case, all stat info in the index becomes invalid and git
falls back to rehashing all file content to see if there's any
difference between updating stat info in the index. This is quite
expensive. Even with a repo as small as git.git, it takes 3
seconds.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These functions return the full oidcmp() value, but the
callers really only care whether it is non-zero. We can use
the more strict !oideq(), which a compiler may be able to
optimize further.
This does change the meaning of the return value subtly, but
it's unlikely that anybody would try to use them for
ordering. They're static-local in this file, and they
already return other error values that would confuse an
ordering (e.g., open() failure gives -1).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This rounds out the previous three patches, covering the
inequality logic for the "hash" variant of the functions.
As with the previous three, the accompanying code changes
are the mechanical result of applying the coccinelle patch;
see those patches for more discussion.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the flip side of the previous two patches: checking
for a non-zero oidcmp() can be more strictly expressed as
inequality. Like those patches, we write "!= 0" in the
coccinelle transformation, which covers by isomorphism the
more common:
if (oidcmp(E1, E2))
As with the previous two patches, this patch can be achieved
almost entirely by running "make coccicheck"; the only
differences are manual line-wrap fixes to match the original
code.
There is one thing to note for anybody replicating this,
though: coccinelle 1.0.4 seems to miss the case in
builtin/tag.c, even though it's basically the same as all
the others. Running with 1.0.7 does catch this, so
presumably it's just a coccinelle bug that was fixed in the
interim.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.
The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).
This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.
I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The more library-ish parts of the codebase learned to work on the
in-core index-state instance that is passed in by their callers,
instead of always working on the singleton "the_index" instance.
* nd/no-the-index: (24 commits)
blame.c: remove implicit dependency on the_index
apply.c: remove implicit dependency on the_index
apply.c: make init_apply_state() take a struct repository
apply.c: pass struct apply_state to more functions
resolve-undo.c: use the right index instead of the_index
archive-*.c: use the right repository
archive.c: avoid access to the_index
grep: use the right index instead of the_index
attr: remove index from git_attr_set_direction()
entry.c: use the right index instead of the_index
submodule.c: use the right index instead of the_index
pathspec.c: use the right index instead of the_index
unpack-trees: avoid the_index in verify_absent()
unpack-trees: convert clear_ce_flags* to avoid the_index
unpack-trees: don't shadow global var the_index
unpack-trees: add a note about path invalidation
unpack-trees: remove 'extern' on function declaration
ls-files: correct index argument to get_convert_attr_ascii()
preload-index.c: use the right index instead of the_index
dir.c: remove an implicit dependency on the_index in pathspec code
...
This makes sure that cache-tree is consistent with the index. The main
purpose is to catch potential problems by saving the index in
unpack_trees() but the line in write_index() would also help spot
missing invalidation in other code.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do n-way merge by walking the source index and n trees at the same
time and add merge results to a new temporary index called o->result.
The merge result for any given path could be either
- keep_entry(): same old index entry in o->src_index is reused
- merged_entry(): either a new entry is added, or an existing one updated
- deleted_entry(): one entry from o->src_index is removed
For some reason [1] we keep making sure that the source index's
cache-tree is still valid if used by o->result: for all those
merged/deleted entries, we invalidate the same path in o->src_index,
so only cache-trees covering the "keep_entry" parts remain good.
Because of this, the cache-tree from o->src_index can be perfectly
reused in o->result. And in fact we already rely on this logic to
reuse untracked cache in edf3b90553 (unpack-trees: preserve index
extensions - 2017-05-08). Move the cache-tree to o->result before
doing cache_tree_update() to reduce hashing cost.
Since cache_tree_update() has risen up as one of the most expensive
parts in unpack_trees() after the last few patches. This does help
reduce unpack_trees() time significantly (on webkit.git):
before after
--------------------------------------------------------------------
0.080394752 0.051258167 s: read cache .git/index
0.216010838 0.212106298 s: preload index
0.008534301 0.280521764 s: refresh index
0.251992198 0.218160442 s: traverse_trees
0.377031383 0.374948191 s: check_updates
0.372768105 0.037040114 s: cache_tree_update
1.045887251 0.672031609 s: unpack_trees
0.314983512 0.317456290 s: write index, changed mask = 2e
0.062572653 0.038382654 s: traverse_trees
0.000022544 0.000042731 s: check_updates
0.073795585 0.050930053 s: unpack_trees
0.073807557 0.051099735 s: diff-index
1.938191592 1.614241153 s: git command: git checkout -
[1] I'm pretty sure the reason is an oversight in 34110cd4e3 (Make
'unpack_trees()' have a separate source and destination index -
2008-03-06). That patch aims to _not_ update the source index at
all. The invalidation should have been done on o->result in that
patch. But then there was no cache-tree on o->result even then so
it's pointless to do so.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Performance measurements are listed right now as a flat list, which is
fine when we measure big blocks. But when we start adding more and
more measurements, some of them could be just part of a bigger
measurement and a flat list gives a wrong impression that they are
executed at the same level instead of nested.
Add trace_performance_enter() and trace_performance_leave() to allow
indent these nested measurements. For now it does not help much
because the only nested thing is (lazy) name hash initialization
(e.g. called in diff-index from "git status"). This will help more
because I'm going to add some more tracing that's actually nested.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
