name_ref() is called for each ref and checks if its a better name for
the referenced commit. If that's the case it remembers it and checks if
a name based on it is better for its ancestors as well. This in done in
the the order for_each_ref() imposes on us.
That might not be optimal. If bad names happen to be encountered first
(as defined by is_better_name()), names derived from them may spread to
a lot of commits, only to be replaced by better names later. Setting
better names first can avoid that.
is_better_name() prefers tags, short distances and old references. The
distance is a measure that we need to calculate for each candidate
commit, but the other two properties are not dependent on the
relationships of commits. Sorting the refs by them should yield better
performance than the essentially random order we currently use.
And applying older references first should also help to reduce rework
due to the fact that older commits have less ancestors than newer ones.
So add all details of names to the tip table first, then sort them
to prefer tags and older references and then apply them in this order.
Here's the performance as measures by hyperfine for the Linux repo
before:
Benchmark #1: ./git -C ../linux/ name-rev --all
Time (mean ± σ): 851.1 ms ± 4.5 ms [User: 806.7 ms, System: 44.4 ms]
Range (min … max): 845.9 ms … 859.5 ms 10 runs
... and with this patch:
Benchmark #1: ./git -C ../linux/ name-rev --all
Time (mean ± σ): 736.2 ms ± 8.7 ms [User: 688.4 ms, System: 47.5 ms]
Range (min … max): 726.0 ms … 755.2 ms 10 runs
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Earlier patches in this series moved a couple of conditions from the
recursive name_rev() function into its caller name_ref(), for no other
reason than to make eliminating the recursion a bit easier to follow.
Since the previous patch name_rev() is not recursive anymore, so let's
move all those conditions back into name_rev().
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The name_rev() function calls itself recursively for each interesting
parent of the commit it got as parameter, and, consequently, it can
segfault when processing a deep history if it exhausts the available
stack space. E.g. running 'git name-rev --all' and 'git name-rev
HEAD~100000' in the gcc, gecko-dev, llvm, and WebKit repositories
results in segfaults on my machine ('ulimit -s' reports 8192kB of
stack size limit), and nowadays the former segfaults in the Linux repo
as well (it reached the necessasry depth sometime between v5.3-rc4 and
-rc5).
Eliminate the recursion by inserting the interesting parents into a
LIFO 'prio_queue' [1] and iterating until the queue becomes empty.
Note that the parent commits must be added in reverse order to the
LIFO 'prio_queue', so their relative order is preserved during
processing, i.e. the first parent should come out first from the
queue, because otherwise performance greatly suffers on mergy
histories [2].
The stacksize-limited test 'name-rev works in a deep repo' in
't6120-describe.sh' demonstrated this issue and expected failure. Now
the recursion is gone, so flip it to expect success. Also gone are
the dmesg entries logging the segfault of that segfaulting 'git
name-rev' process on every execution of the test suite.
Note that this slightly changes the order of lines in the output of
'git name-rev --all', usually swapping two lines every 35 lines in
git.git or every 150 lines in linux.git. This shouldn't matter in
practice, because the output has always been unordered anyway.
This patch is best viewed with '--ignore-all-space'.
[1] Early versions of this patch used a 'commit_list', resulting in
~15% performance penalty for 'git name-rev --all' in 'linux.git',
presumably because of the memory allocation and release for each
insertion and removal. Using a LIFO 'prio_queue' has basically no
effect on performance.
[2] We prefer shorter names, i.e. 'v0.1~234' is preferred over
'v0.1^2~5', meaning that usually following the first parent of a
merge results in the best name for its ancestors. So when later
we follow the remaining parent(s) of a merge, and reach an already
named commit, then we usually find that we can't give that commit
a better name, and thus we don't have to visit any of its
ancestors again.
OTOH, if we were to follow the Nth parent of the merge first, then
the name of all its ancestors would include a corresponding '^N'.
Those are not the best names for those commits, so when later we
reach an already named commit following the first parent of that
merge, then we would have to update the name of that commit and
the names of all of its ancestors as well. Consequently, we would
have to visit many commits several times, resulting in a
significant slowdown.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Following the previous patches in this series we can get the value of
'name_rev()'s 'tip_name' parameter from the 'struct rev_name'
associated with the commit as well.
So let's use 'name->tip_name' instead, which makes the patch
eliminating the recursion of name_rev() a bit easier to follow.
Note that at this point we could drop the 'tip_name' parameter as
well, but that parameter will be necessary later, after the recursion
is eliminated.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Following the previous patches in this series we can get the values of
name_rev()'s 'generation' and 'distance' parameters from the 'stuct
rev_name' associated with the commit as well.
Let's simplify the function's signature and remove these two
unnecessary parameters.
Note that at this point we could do the same with the 'tip_name',
'taggerdate' and 'from_tag' parameters as well, but those parameters
will be necessary later, after the recursion is eliminated.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
At the beginning of the recursive name_rev() function it creates a new
'struct rev_name' instance for each previously unvisited commit or, if
this visit results in better name for an already visited commit, then
updates the 'struct rev_name' instance attached to the commit, or
returns early.
Restructure this so it's caller creates or updates the 'struct
rev_name' instance associated with the commit to be passed as
parameter, i.e. both name_ref() before calling name_rev() and
name_rev() itself as it iterates over the parent commits.
This makes eliminating the recursion a bit easier to follow, and the
condition moved to name_ref() will be moved back to name_rev() after
the recursion is eliminated.
This change also plugs the memory leak that was temporarily unplugged
in the earlier "name-rev: pull out deref handling from the recursion"
patch in this series.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
At the beginning of the recursive name_rev() function it parses the
commit it got as parameter, and returns early if the commit is older
than a cutoff limit.
Restructure this so the caller parses the commit and checks its date,
and doesn't invoke name_rev() if the commit to be passed as parameter
is older than the cutoff, i.e. both name_ref() before calling
name_rev() and name_rev() itself as it iterates over the parent
commits.
This makes eliminating the recursion a bit easier to follow, and the
condition moved to name_ref() will be moved back to name_rev() after
the recursion is eliminated.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'if (deref) { ... }' condition near the beginning of the recursive
name_rev() function can only ever be true in the first invocation,
because the 'deref' parameter is always 0 in the subsequent recursive
invocations.
Extract this condition from the recursion into name_rev()'s caller and
drop the function's 'deref' parameter. This makes eliminating the
recursion a bit easier to follow, and it will be moved back into
name_rev() after the recursion is eliminated.
Furthermore, drop the condition that die()s when both 'deref' and
'generation' are non-null (which should have been a BUG() to begin
with).
Note that this change reintroduces the memory leak that was plugged in
in commit 5308224633 (name-rev: avoid leaking memory in the `deref`
case, 2017-05-04), but a later patch (name-rev: restructure
creating/updating 'struct rev_name' instances) in this series will
plug it in again.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a later patch in this series we'll want to do this in two places.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Casting a 'struct object' to 'struct commit' is unnecessary there,
because it's already available in the local 'commit' variable.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_name_rev() basically open-codes strip_suffix() before adding a
string to a strbuf.
Let's use the strbuf right from the beginning, i.e. add the whole
string to the strbuf and then use strbuf_strip_suffix(), making the
code more idiomatic.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Let skip_prefix() advance refname to get rid of two magic numbers.
Signed-off-by: René Scharfe <l.s.r@web.de>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 'git name-rev' is invoked with commit-ish parameters, it tries to
save some work, and doesn't visit commits older than the committer
date of the oldest given commit minus a one day worth of slop. Since
our 'timestamp_t' is an unsigned type, this leads to a timestamp
underflow when the committer date of the oldest given commit is within
a day of the UNIX epoch. As a result the cutoff timestamp ends up
far-far in the future, and 'git name-rev' doesn't visit any commits,
and names each given commit as 'undefined'.
Check whether subtracting the slop from the oldest committer date
would lead to an underflow, and use no cutoff in that case. We don't
have a TIME_MIN constant, dddbad728c (timestamp_t: a new data type for
timestamps, 2017-04-26) didn't add one, so do it now.
Note that the type of the cutoff timestamp variable used to be signed
before 5589e87fd8 (name-rev: change a "long" variable to timestamp_t,
2017-05-20). The behavior was still the same even back then, but the
underflow didn't happen when substracting the slop from the oldest
committer date, but when comparing the signed cutoff timestamp with
unsigned committer dates in name_rev(). IOW, this underflow bug is as
old as 'git name-rev' itself.
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are no callers left of lookup_object() that aren't just passing us
the "hash" member of a "struct object_id". Let's take the whole struct,
which gets us closer to removing all raw sha1 variables. It also
matches the existing conversions of lookup_blob(), etc.
The conversions of callers were done by hand, but they're all mechanical
one-liners.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When this function was extracted in 0041bf6544 (name-rev: refactor logic
to see if a new candidate is a better name, 2017-03-29), it ended up
getting more arguments than it needs.
It's possible we may later use these values to evaluate the name, but
since it's a static function with a single caller, it will be easy to
add them back then.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the_hash_algo when parsing instead of GIT_SHA1_HEXSZ so that this
function works with any size hash. Rename the variable forty to
counter, as this is a better name and is independent of the hash size.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of deref_tag
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow callers of lookup_object to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of parse_object
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's done so that commit->util can be removed. See more explanation in
the commit that removes commit->util.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert find_unique_abbrev and find_unique_abbrev_r to each take a
pointer to struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add some UNLEAKs where we are about to return from `cmd_*`. UNLEAK the
variables in the same order as we've declared them. While addressing
`msg` in builtin/tag.c, convert the existing `strbuf_release()` calls as
well.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Earlier, dddbad728c ("timestamp_t: a new data type for timestamps",
2017-04-26) changed several types to timestamp_t.
5589e87fd8 ("name-rev: change a "long" variable to timestamp_t",
2017-05-20) cleaned up a missed variable, but both missed a _MAX
constant.
Change the remaining constant to the one appropriate for the current
type
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the unused wildopts placeholder struct from being passed to all
wildmatch() invocations, or rather remove all the boilerplate NULL
parameters.
This parameter was added back in commit 9b3497cab9 ("wildmatch: rename
constants and update prototype", 2013-01-01) as a placeholder for
future use. Over 4 years later nothing has made use of it, let's just
remove it. It can be added in the future if we find some reason to
start using such a parameter.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop including config.h by default in cache.h. Instead only include
config.h in those files which require use of the config system.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Earlier dddbad72 ("timestamp_t: a new data type for timestamps",
2017-04-26) updated all in-core variables, fields and function
return values that are used to store "seconds since epoch" to a new
type timestamp_t. Unfortunately one variable "cutoff", which is
used to keep track of the oldest timestamp of commit we saw on the
command line, was "long" and left behind.
Update it to timestamp_t as well.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the `name_rev()` function is asked to dereference the tip name, it
allocates memory. But when it turns out that another tip already
described the commit better than the current one, we forgot to release
the memory.
Pointed out by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert all the uses of unsigned char [20] to struct object_id. Also,
convert some hard-coded integers into constants.
name_rev_line accepts a wide variety of free-form input and only
interprets 40-character hex values, passing through everything else.
Consequently, it is not a good candidate for parse_oid_hex, which is
much stricter.
This change is a prerequisite for converting parse_object.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).
So let's just use a more appropriate data type instead. In preparation
for this, we introduce the new `timestamp_t` data type.
By necessity, this is a very, very large patch, as it has to replace all
timestamps' data type in one go.
As we will use a data type that is not necessarily identical to `time_t`,
we need to be very careful to use `time_t` whenever we interact with the
system functions, and `timestamp_t` everywhere else.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When name-rev needs to format an actual name, we do so into
a fixed-size buffer. That includes the actual ref tip, as
well as any traversal information. Since refs can exceed
1024 bytes, this means you can get a bogus result. E.g.,
doing:
git tag $(perl -e 'print join("/", 1..1024)')
git describe --contains HEAD^
results in ".../282/283", when it should be
".../1023/1024~1".
We can solve this by using a heap buffer. We'll use a
strbuf, which lets us write into the same buffer from our
loop without having to reallocate.
Signed-off-by: Jeff King <peff@peff.net>
"git name-rev" assigned a phony "far in the future" date to tips of
refs that are not pointing at tag objects, and favored names based
on a ref with the oldest date. This made it almost impossible for
an unannotated tags and branches to be counted as a viable base,
which was especially problematic when the command is run with the
"--tags" option. If an unannotated tag that points at an ancient
commit and an annotated tag that points at a much newer commit
reaches the commit that is being named, the old unannotated tag was
ignored.
Update the "taggerdate" field of the rev-name structure, which is
initialized from the tip of ref, to have the committer date if the
object at the tip of ref is a commit, not a tag, so that we can
optionally take it into account when doing "is this name better?"
comparison logic.
When "name-rev" is run without the "--tags" option, the general
expectation is still to name the commit based on a tag if possible,
but use non-tag refs as fallback, and tiebreak among these non-tag
refs by favoring names with shorter hops from the tip. The use of a
phony "far in the future" date in the original code was an effective
way to ensure this expectation is held: a non-tag tip gets the same
"far in the future" timestamp, giving precedence to tags, and among
non-tag tips, names with shorter hops are preferred over longer
hops, without taking the "taggerdate" into account. As we are
taking over the "taggerdate" field to store the committer date for
tips with commits:
(1) keep the original logic when comparing names based on two refs
both of which are from refs/tags/;
(2) favoring a name based on a ref in refs/tags/ hierarchy over
a ref outside the hierarchy;
(3) between two names based on a ref both outside refs/tags/, give
precedence to a name with shorter hops and use "taggerdate"
only to tie-break.
A change to t4202 is a natural consequence. The test creates a
commit on a branch "side" and points at it with an unannotated tag
"refs/tags/side-2". The original code couldn't decide which one to
favor at all, and gave a name based on a branch (simply because
refs/heads/side sorts earlier than refs/tags/side-2). Because the
updated logic is taught to favor refs in refs/tags/ hierarchy, the
the test is updated to expect to see tags/side-2 instead.
[mjg: open-coded the comparisons in is_better_name(), dropping a
helper macro used in the original]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we encounter a new ref that could describe the commit we are
looking at, we compare the name that is formed using that ref and
the name we found so far and pick a better one.
Factor the comparison logic out to a separate helper function, while
keeping the current logic the same (i.e. a name that is based on an
older tag is better, and if two tags of the same age can reach the
commit, the one with fewer number of hops to reach the commit is
better).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend git-name-rev to support excluding refs which match shell patterns
using --exclude. These patterns can be used to limit the scope of refs
by excluding any ref that matches one of the --exclude patterns. A ref
will only be used for naming when it matches at least one --refs pattern
but does not match any of the --exclude patterns. Thus, --exclude
patterns are given precedence over --refs patterns.
For example, suppose you wish to name a series of commits based on an
official release tag of the form "v*" but excluding any pre-release tags
which match "*rc*". You can use the following to do so:
git name-rev --refs="v*" --exclude="*rc*" --all
Add tests and update Documentation for this change.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach git name-rev to take multiple --refs stored as a string list of
patterns. The list of patterns will be matched inclusively, and each ref
only needs to match one pattern to be included. A ref will only be
excluded if it does not match any of the given patterns. Additionally,
if any of the patterns would allow abbreviation, then we will abbreviate
the ref, even if another pattern is more strict and would not have
allowed abbreviation on its own.
Add tests and documentation for this change. The tests expected output
is dynamically generated. This is in order to avoid hard-coding
a commit object name in the test results (as the expected output is to
simply leave the commit object unnamed).
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Apply the semantic patch contrib/coccinelle/qsort.cocci to the code
base, replacing calls of qsort(3) with QSORT. The resulting code is
shorter and supports empty arrays with NULL pointers.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We most likely want the oldest tag that contained the commit to be
reported. So let's remember the taggerdate, and make it more important
than anything else when choosing the best name for a given commit.
Suggested by Linus Torvalds.
Note that we need to update t9903 because it tested for the old behavior
(which preferred the description "b1~1" over "tags/t2~1").
We might want to introduce a --heed-taggerdate option, and make the new
behavior dependent on that, if it turns out that some scripts rely on the
old name-rev method.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert all instances of get_object_hash to use an appropriate reference
to the hash member of the oid member of struct object. This provides no
functional change, as it is essentially a macro substitution.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
struct object is one of the major data structures dealing with object
IDs. Convert it to use struct object_id instead of an unsigned char
array. Convert get_object_hash to refer to the new member as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
René Scharfe