name_rev() assigns a name to a commit and its parents and grandparents
and so on. Commits share their name string with their first parent,
which in turn does the same, recursively to the root. That saves a lot
of allocations. When a better name is found, the old name is replaced,
but its memory is not released. That leakage can become significant.
Can we release these old strings exactly once even though they are
referenced multiple times? Yes, indeed -- we can make use of the fact
that name_rev() visits the ancestors of a commit after it set a new name
for it and tries to update their names as well.
Members of the first ancestral line have the same taggerdate and
from_tag values, but a higher distance value than their child commit at
generation 0. These are the only criteria used by is_better_name().
Lower distance values are considered better, so a name that is better
for a child will also be better for its parent and grandparent etc.
That means we can free(3) an inferior name at generation 0 and rely on
name_rev() to replace all references in ancestors as well.
If we do that then we need to stop using the string pointer alone to
distinguish new empty rev_name slots from initialized ones, though, as
it technically becomes invalid after the free(3) call -- even though its
value is still different from NULL.
We can check the generation value first, as empty slots will have it
initialized to 0, and for the actual generation 0 we'll set a new valid
name right after the create_or_update_name() call that releases the
string.
For the Chromium repo, releasing superceded names reduces the memory
footprint of name-rev --all significantly. Here's the output of GNU
time before:
0.98user 0.48system 0:01.46elapsed 99%CPU (0avgtext+0avgdata 2601812maxresident)k
0inputs+0outputs (0major+571470minor)pagefaults 0swaps
... and with this patch:
1.01user 0.26system 0:01.28elapsed 100%CPU (0avgtext+0avgdata 1559196maxresident)k
0inputs+0outputs (0major+314370minor)pagefaults 0swaps
It also gets faster; hyperfine before:
Benchmark #1: ./git -C ../chromium/src name-rev --all
Time (mean ± σ): 1.534 s ± 0.006 s [User: 1.039 s, System: 0.494 s]
Range (min … max): 1.522 s … 1.542 s 10 runs
... and with this patch:
Benchmark #1: ./git -C ../chromium/src name-rev --all
Time (mean ± σ): 1.338 s ± 0.006 s [User: 1.047 s, System: 0.291 s]
Range (min … max): 1.327 s … 1.346 s 10 runs
For the Linux repo it doesn't pay off; memory usage only gets down from:
0.76user 0.03system 0:00.80elapsed 99%CPU (0avgtext+0avgdata 292848maxresident)k
0inputs+0outputs (0major+44579minor)pagefaults 0swaps
... to:
0.78user 0.03system 0:00.81elapsed 100%CPU (0avgtext+0avgdata 284696maxresident)k
0inputs+0outputs (0major+44892minor)pagefaults 0swaps
The runtime actually increases slightly from:
Benchmark #1: ./git -C ../linux/ name-rev --all
Time (mean ± σ): 828.8 ms ± 5.0 ms [User: 797.2 ms, System: 31.6 ms]
Range (min … max): 824.1 ms … 838.9 ms 10 runs
... to:
Benchmark #1: ./git -C ../linux/ name-rev --all
Time (mean ± σ): 847.6 ms ± 3.4 ms [User: 807.9 ms, System: 39.6 ms]
Range (min … max): 843.4 ms … 854.3 ms 10 runs
Why is that? In the Chromium repo, ca. 44000 free(3) calls in
create_or_update_name() release almost 1GB, while in the Linux repo
240000+ calls release a bit more than 5MB, so the average discarded
name is ca. 1000x longer in the latter.
Overall I think it's the right tradeoff to make, as it helps curb the
memory usage in repositories with big discarded names, and the added
overhead is small.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Leave setting the tip_name member of struct rev_name to callers of
create_or_update_name(). This avoids allocations for names that are
rejected by that function. Here's how this affects the runtime when
working with a fresh clone of Git's own repository; performance numbers
by hyperfine before:
Benchmark #1: ./git -C ../git-pristine/ name-rev --all
Time (mean ± σ): 437.8 ms ± 4.0 ms [User: 422.5 ms, System: 15.2 ms]
Range (min … max): 432.8 ms … 446.3 ms 10 runs
... and with this patch:
Benchmark #1: ./git -C ../git-pristine/ name-rev --all
Time (mean ± σ): 408.5 ms ± 1.4 ms [User: 387.2 ms, System: 21.2 ms]
Range (min … max): 407.1 ms … 411.7 ms 10 runs
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We can calculate the size of new name easily and precisely. Open-code
the xstrfmt() calls and grow the buffers as needed before filling them.
This provides a surprisingly large benefit when working with the
Chromium repository; here are the numbers measured using hyperfine
before:
Benchmark #1: ./git -C ../chromium/src name-rev --all
Time (mean ± σ): 5.822 s ± 0.013 s [User: 5.304 s, System: 0.516 s]
Range (min … max): 5.803 s … 5.837 s 10 runs
... and with this patch:
Benchmark #1: ./git -C ../chromium/src name-rev --all
Time (mean ± σ): 1.527 s ± 0.003 s [User: 1.015 s, System: 0.511 s]
Range (min … max): 1.524 s … 1.535 s 10 runs
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reduce nesting by moving code to come up with a name for the parent into
its own function.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit slab commit_rev_name contains a pointer to a struct rev_name,
and the actual struct is allocated separatly. Avoid that allocation and
pointer indirection by storing the full struct in the commit slab. Use
the tip_name member pointer to determine if the returned struct is
initialized.
Performance in the Linux repository measured with hyperfine before:
Benchmark #1: ./git -C ../linux/ name-rev --all
Time (mean ± σ): 953.5 ms ± 6.3 ms [User: 901.2 ms, System: 52.1 ms]
Range (min … max): 945.2 ms … 968.5 ms 10 runs
... and with this patch:
Benchmark #1: ./git -C ../linux/ name-rev --all
Time (mean ± σ): 851.0 ms ± 3.1 ms [User: 807.4 ms, System: 43.6 ms]
Range (min … max): 846.7 ms … 857.0 ms 10 runs
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Look up the commit slab slot for the commit once using
commit_rev_name_at() and populate it in case it is empty, instead of
checking for emptiness in a separate step using commit_rev_name_peek()
via get_commit_rev_name().
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
name_ref() duplicates the path string and passes it to name_rev(), which
either puts it into a commit slab or ignores it if there is already a
better name, leaking it. Move the duplication to name_rev() and release
the copy in the latter case.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Keep the const qualifier of the first parameter of get_rev_name() even
when casting the object pointer to a commit pointer, and further for the
parameter of get_commit_rev_name(), as all these uses are read-only.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The type alias became unused with bf43abc6e6 (name-rev: use sizeof(*ptr)
instead of sizeof(type) in allocation, 2019-11-12); remove it.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This code was moved straight out of name_rev(). As such, we inherited
the "goto" to jump from an if into an else-if. We also inherited the
fact that "nothing to do -- return NULL" is handled last.
Rewrite the function to first handle the "nothing to do" case. Then we
can handle the conditional allocation early before going on to populate
the struct. No need for goto-ing.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 5d9324e0f4, reversing
changes made to c58ae96fc4.
The topic turns out to be too buggy for real use.
cf. <f2fe7437-8a48-3315-4d3f-8d51fe4bb8f1@gmail.com>
Further tweak to a "no backslash in indexed paths" for Windows port
we applied earlier.
* js/mingw-loosen-overstrict-tree-entry-checks:
mingw: safeguard better against backslashes in file names
In 224c7d70fa (mingw: only test index entries for backslashes, not tree
entries, 2019-12-31), we relaxed the check for backslashes in tree
entries to check only index entries.
However, the code change was incorrect: it was added to
`add_index_entry_with_check()`, not to `add_index_entry()`, so under
certain circumstances it was possible to side-step the protection.
Besides, the description of that commit purported that all index entries
would be checked when in fact they were only checked when being added to
the index (there are code paths that do not do that, constructing
"transient" index entries).
In any case, it was pointed out in one insightful review at
https://github.com/git-for-windows/git/pull/2437#issuecomment-566771835
that it would be a much better idea to teach `verify_path()` to perform
the check for a backslash. This is safer, even if it comes with two
notable drawbacks:
- `verify_path()` cannot say _what_ is wrong with the path, therefore
the user will no longer be told that there was a backslash in the
path, only that the path was invalid.
- The `git apply` command also calls the `verify_path()` function, and
might have been able to handle Windows-style paths (i.e. with
backslashes instead of forward slashes). This will no longer be
possible unless the user (temporarily) sets `core.protectNTFS=false`.
Note that `git add <windows-path>` will _still_ work because
`normalize_path_copy_len()` will convert the backslashes to forward
slashes before hitting the code path that creates an index entry.
The clear advantage is that `verify_path()`'s purpose is to check the
validity of the file name, therefore we naturally tap into all the code
paths that need safeguarding, also implicitly into future code paths.
The benefits of that approach outweigh the downsides, so let's move the
check from `add_index_entry_with_check()` to `verify_path()`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The english term generation is here not used in the sense of "to
generate" but in the sense of "generations of beings".
This corrects the initial translation from cf4c0c25 (l10n: update German
translation, 2018-12-06).
Fixed-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
The whole submoduleAlternateErrorStrategyDie item is interpreted as
being part of the supporting content of the preceding item. This is
because we don't give a double-colon "::" for the separator, but just a
single colon, ":". Let's fix that.
There are a few other matches for [^:]:\s*$ in Documentation/config, but
I didn't spot any similar bugs among them.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since recent updates to the log graph rendering code, drawing
certain merges started triggering an assert on a condition that
would no longer hold true, which has been corrected.
* ds/graph-assert-fix:
graph: fix lack of color in horizontal lines
graph: drop assert() for merge with two collapsing parents
* https://github.com/prati0100/git-gui:
git-gui: allow opening currently selected file in default app
git-gui: allow closing console window with Escape
git gui: fix branch name encoding error
git-gui: revert untracked files by deleting them
git-gui: update status bar to track operations
git-gui: consolidate naming conventions
In some cases, horizontal lines in rendered graphs can lose their
coloring. This is due to a use of graph_line_addch() instead of
graph_line_write_column(). Using a ternary operator to pick the
character is nice for compact code, but we actually need a column to
provide the color.
Add a test to t4215-log-skewed-merges.sh to prevent regression.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "git log --graph" shows a merge commit that has two collapsing
lines, like:
| | | | *
| |_|_|/|
|/| | |/
| | |/|
| |/| |
| * | |
* | | |
we trigger an assert():
graph.c:1228: graph_output_collapsing_line: Assertion
`graph->mapping[i - 3] == target' failed.
The assert was introduced by eaf158f8 ("graph API: Use horizontal
lines for more compact graphs", 2009-04-21), which is quite old.
This assert is trying to say that when we complete a horizontal
line with a single slash, it is because we have reached our target.
It is actually the _second_ collapsing line that hits this assert.
The reason we are in this code path is because we are collapsing
the first line, and in that case we are hitting our target now
that the horizontal line is complete. However, the second line
cannot be a horizontal line, so it will collapse without horizontal
lines. In this case, it is inappropriate to assert that we have
reached our target, as we need to continue for another column
before reaching the target. Dropping the assert is safe here.
The new behavior in 0f0f389f12 (graph: tidy up display of
left-skewed merges, 2019-10-15) caused the behavior change that
made this assertion failure possible. In addition to making the
assert possible, it also changed how multiple edges collapse.
In a larger example, the current code will output a collapse
as follows:
| | | | | | *
| |_|_|_|_|/|\
|/| | | | |/ /
| | | | |/| /
| | | |/| |/
| | |/| |/|
| |/| |/| |
| | |/| | |
| | * | | |
However, the intended collapse should allow multiple horizontal lines
as follows:
| | | | | | *
| |_|_|_|_|/|\
|/| | | | |/ /
| | |_|_|/| /
| |/| | | |/
| | | |_|/|
| | |/| | |
| | * | | |
This behavior is not corrected by this change, but is noted for a later
update.
Helped-by: Jeff King <peff@peff.net>
Reported-by: Bradley Smith <brad@brad-smith.co.uk>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to write split commit-graph file(s) upon fetching computed
bogus value for the parameter used in splitting the resulting
files, which has been corrected.
* ds/commit-graph-set-size-mult:
commit-graph: prefer default size_mult when given zero
"git sparse-checkout list" subcommand learned to give its output in
a more concise form when the "cone" mode is in effect.
* ds/sparse-list-in-cone-mode:
sparse-checkout: document interactions with submodules
sparse-checkout: list directories in cone mode
An earlier update to Git for Windows declared that a tree object is
invalid if it has a path component with backslash in it, which was
overly strict, which has been corrected. The only protection the
Windows users need is to prevent such path (or any path that their
filesystem cannot check out) from entering the index.
* js/mingw-loosen-overstrict-tree-entry-checks:
mingw: only test index entries for backslashes, not tree entries
The sentence wants to talk about the superproject's possesive, not plural form.
Signed-off-by: Thomas Menzel <dev@tomsit.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar to "From:" and "Subject:" already mentioned in the
documentation, "Date:" can also appear as an in-body header
to override the value in the e-mail headers. Document it.
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's core.multiPackIndex, not pack.multiIndex.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This typo was introduced in 94c0956b60 (sparse-checkout: create builtin
with 'list' subcommand, 2019-11-21).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow opening the currently selected file in its default app by clicking
on its name.
* zs/open-current-file:
git-gui: allow opening currently selected file in default app
