Commit Graph

58683 Commits

Author SHA1 Message Date
Matthew Rogers
a5cb4204b6 config: make scope_name non-static and rename it
To prepare for the upcoming --show-scope option, we require the ability
to convert a config_scope enum to a string.  As this was originally
implemented as a static function 'scope_name()' in
t/helper/test-config.c, we expose it via config.h and give it a less
ambiguous name 'config_scope_name()'

Signed-off-by: Matthew Rogers <mattr94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 10:32:18 -08:00
Johannes Schindelin
30183894ea ci: ignore rubygems warning in the "Documentation" job
A recent update in the Linux VM images used by Azure Pipelines surfaced
a new problem in the "Documentation" job. Apparently, this warning
appears 396 times on `stderr` when running `make doc`:

/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb:10: warning: constant Gem::ConfigMap is deprecated

This problem was already reported to the `rubygems` project via
https://github.com/rubygems/rubygems/issues/3068.

As there is nothing Git can do about this warning, and as the
"Documentation" job reports this warning as a failure, let's just
silence it and move on.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:52:27 -08:00
René Scharfe
7a9f8ca805 parse-options: simplify parse_options_dup()
Simplify parse_options_dup() by making it a trivial wrapper of
parse_options_concat() by making use of the facts that the latter
duplicates its input as well and that appending an empty set is a no-op.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:45:49 -08:00
René Scharfe
c84078573e parse-options: const parse_options_concat() parameters
Document the fact that the function doesn't modify the two option arrays
passed to it by adding the keyword const to each parameter.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:44:58 -08:00
René Scharfe
f904f9025f parse-options: factor out parse_options_count()
Add a helper function to count the number of options (excluding the
final OPT_END()) and use it to simplify parse_options_dup() and
parse_options_concat().

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:43:25 -08:00
René Scharfe
a277d0a67f parse-options: use COPY_ARRAY in parse_options_concat()
Use COPY_ARRAY to copy whole arrays instead of iterating through the
elements.  That's shorter, simpler and bit more efficient.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:42:43 -08:00
René Scharfe
517b60564e mailinfo: don't insert header prefix for handle_content_type()
handle_content_type() only cares about the value after "Content-Type: ";
there is no need to insert that string for it.

Suggested-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:27:13 -08:00
René Scharfe
a91cc7fad0 strbuf: add and use strbuf_insertstr()
Add a function for inserting a C string into a strbuf.  Use it
throughout the source to get rid of magic string length constants and
explicit strlen() calls.

Like strbuf_addstr(), implement it as an inline function to avoid the
implicit strlen() calls to cause runtime overhead.

Helped-by: Taylor Blau <me@ttaylorr.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:04:45 -08:00
Johannes Berg
eb31044ff7 pack-format: correct multi-pack-index description
The description of the multi-pack-index contains a small bug,
if all offsets are < 2^32 then there will be no LOFF chunk,
not only if they're all < 2^31 (since the highest bit is only
needed as the "LOFF-escape" when that's actually needed.)

Correct this, and clarify that in that case only offsets up
to 2^31-1 can be stored in the OOFF chunk.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:01:48 -08:00
Martin Ågren
9299f84921 diff-options.txt: avoid "regex" overload in example
When we exemplify the difference between `-G` and `-S` (using
`--pickaxe-regex`), we do so using an example diff and git-diff
invocation involving "regexec", "regexp", "regmatch", ...

The example is correct, but we can make it easier to untangle by
avoiding writing "regex.*" unless it's really needed to make our point.

Use some made-up, non-regexy words instead.

Reported-by: Adam Dinwoodie <adam@dinwoodie.org>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-09 09:25:24 -08:00
Masaya Suzuki
7378ec90e1 doc: describe Git bundle format
The bundle format was not documented. Describe the format with ABNF and
explain the meaning of each part.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 12:47:02 -08:00
brian m. carlson
f3037657e8 t6024: update for SHA-256
To make this test work with SHA-256, compute two of the items in the
conflicted index entry.  The other entry is a conflict within a conflict
and computing it is difficult, so use test_oid_cache to specify the
proper values for both hash algorithms.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:31 -08:00
brian m. carlson
edf04243b2 t6006: make hash size independent
Instead of hard-coding the length of an object ID when creating a tree,
compute it for the hash in use using the translation tables.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:31 -08:00
brian m. carlson
5db24dcffd t6000: abstract away SHA-1-specific constants
Adjust the test so that it computes variables for object IDs instead of
using hard-coded hashes.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:31 -08:00
brian m. carlson
d341e0805d t5703: make test work with SHA-256
This test used an object ID which was 40 hex characters in length,
causing the test not only not to pass, but to hang, when run with
SHA-256 as the hash.  Change this value to a fixed dummy object ID using
test_oid_init and test_oid.

Furthermore, ensure we extract an object ID of the appropriate length
using cut with fields instead of a fixed length.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:31 -08:00
brian m. carlson
88ed241a7e t5607: make hash size independent
Use $OID_REGEX instead of a hard-coded regular expression.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
48c10cc0e6 t5318: update for SHA-256
Switch two tests to use $ZERO_OID to represent the all-zeros object ID.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
f7ae8e69b6 t5515: make test hash independent
This test contains a large number of data files, mostly using the same
object ID values for refs. Instead of producing two separate sets of
test files, keep the test files using SHA-1 and translate them on the
fly by replacing the SHA-1 values with the values for the current hash
algorithm in use.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
e70649bb66 t5321: make test hash independent
Use the proper pack constants defined in lib-pack.sh to make this test
work with SHA-256.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
a30f93b143 t5313: make test hash independent
Make this test hash independent by computing the length of the object
offsets and looking up values which will hash to object IDs with the
right properties.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
a79eec220b t5309: make test hash independent
Use the proper pack constants defined in lib-pack.sh to make this test
work with SHA-256.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
796d1383a3 t5302: make hash size independent
Compute the length of object IDs and pack offsets instead of hard-coding
constants.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
417e45e5e3 t4060: make test work with SHA-256
In this test, there are two main types of object IDs we see in the
diffs: the ones for the submodules, which we care about, and the ones
for the individual files, which are unrelated to what we're testing.
Much of the test already computes the former, so extend the rest of the
test to do so as well.  Add a diff comparison function that normalizes
the differences in the latter, since they're not explicitly what we're
testing.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
dfa5f53e78 t4211: add test cases for SHA-256
There are already files containing example output for SHA-1.  Add test
files providing example output for SHA-256 as well and adjust the test
to look up the appropriate ones based on the algorithm in use.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
f743e8f5b3 t4211: move SHA-1-specific test cases into a directory
In preparation for adding SHA-256 support to this test, let's move the
SHA-1-specific expected output into a directory called "sha1".  This
will allow us to add a similar directory for SHA-256 as well.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:30 -08:00
brian m. carlson
72f936b120 t4013: make test hash independent
This test produces a large number of diff formats and compares the
output with test files that have content specific to SHA-1. Since we are
more interested in the format of the diffs, and not their specific
values, which are tested elsewhere, add a function which uses sed to
transform these specific object IDs into generic ones of the right size,
which we can then compare.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
brian m. carlson
5df0f11f07 t3311: make test work with SHA-256
Replace the hard-coded SHA-1 constants with the use of test_oid to look
up an appropriate constant for each hash algorithm.  In addition, adjust
the fanout checks to look for either zero or one slashes in the filename
without needing to check for an explicit length.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
brian m. carlson
07877f393c t3310: make test work with SHA-256
Replace the hard-coded SHA-1 constants with the use of test_oid to look
up an appropriate constant for each hash algorithm.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
brian m. carlson
6025e898d6 t3309: make test work with SHA-256
Replace the hard-coded SHA-1 constants with the use of test_oid to look
up an appropriate constant for each hash algorithm.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
brian m. carlson
7b1a1822fe t3308: make test work with SHA-256
Replace the hard-coded SHA-1 constants with the use of test_oid to look
up an appropriate constant for each hash algorithm.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
brian m. carlson
94db7e3e93 t3206: make hash size independent
Fix the one assertion in this test that still uses SHA-1 to use test_oid
to be independent of the hash.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
brian m. carlson
db12505c2c t/lib-pack: support SHA-256
Update the support routines for generating packs to support both SHA-1
and SHA-256.  Compute the trailing pack checksum and its length
correctly depending on the algorithm, and look up the object names based
on the algorithm as well.  Ensure we initialize the algorithm facts so
that our callers need not do so.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:07:29 -08:00
Emily Shaffer
303b3c1c46 submodule: add newline on invalid submodule error
Since 'err' contains output for multiple submodules and is printed all
at once by fetch_populated_submodules(), errors for each submodule
should be newline separated for readability. The same strbuf is added to
with a newline in the other half of the conditional where this error is
detected, so make the two consistent.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:05:45 -08:00
Heba Waly
887a0fd573 add: change advice config variables used by the add API
advice.addNothing config variable is used to control the visibility of
two advice messages in the add library. This config variable is
replaced by two new variables, whose names are more clear and relevant
to the two cases.

Also add the two new variables to the documentation.

Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-06 11:08:00 -08:00
Junio C Hamano
de93cc14ab The third batch for 2.26
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-05 14:35:00 -08:00
Junio C Hamano
ea46d9097b Merge branch 'mt/sparse-checkout-doc-update'
Doc update.

* mt/sparse-checkout-doc-update:
  completion: add support for sparse-checkout
  doc: sparse-checkout: mention --cone option
2020-02-05 14:35:00 -08:00
Junio C Hamano
ff5134b2ff Merge branch 'pb/recurse-submodule-in-worktree-fix'
The "--recurse-submodules" option of various subcommands did not
work well when run in an alternate worktree, which has been
corrected.

* pb/recurse-submodule-in-worktree-fix:
  submodule.c: use get_git_dir() instead of get_git_common_dir()
  t2405: clarify test descriptions and simplify test
  t2405: use git -C and test_commit -C instead of subshells
  t7410: rename to t2405-worktree-submodule.sh
2020-02-05 14:35:00 -08:00
Junio C Hamano
b5c71cc33d Merge branch 'es/fetch-show-failed-submodules-atend'
A fetch that is told to recursively fetch updates in submodules
inevitably produces reams of output, and it becomes hard to spot
error messages.  The command has been taught to enumerate
submodules that had errors at the end of the operation.

* es/fetch-show-failed-submodules-atend:
  fetch: emphasize failure during submodule fetch
2020-02-05 14:34:59 -08:00
Junio C Hamano
7ab963e122 Merge branch 'en/fill-directory-fixes-more'
Corner case bugs in "git clean" that stems from a (necessarily for
performance reasons) awkward calling convention in the directory
enumeration API has been corrected.

* en/fill-directory-fixes-more:
  dir: point treat_leading_path() warning to the right place
  dir: restructure in a way to avoid passing around a struct dirent
  dir: treat_leading_path() and read_directory_recursive(), round 2
  clean: demonstrate a bug with pathspecs
2020-02-05 14:34:59 -08:00
Junio C Hamano
f52ab33616 Merge branch 'bc/hash-independent-tests-part-7'
Preparation of test scripts for the day when the object names will
use SHA-256 continues.

* bc/hash-independent-tests-part-7:
  t5604: make hash independent
  t5601: switch into repository to hash object
  t5562: use $ZERO_OID
  t5540: make hash size independent
  t5537: make hash size independent
  t5530: compute results based on object length
  t5512: abstract away SHA-1-specific constants
  t5510: make hash size independent
  t5504: make hash algorithm independent
  t5324: make hash size independent
  t5319: make test work with SHA-256
  t5319: change invalid offset for SHA-256 compatibility
  t5318: update for SHA-256
  t4300: abstract away SHA-1-specific constants
  t4204: make hash size independent
  t4202: abstract away SHA-1-specific constants
  t4200: make hash size independent
  t4134: compute appropriate length constant
  t4066: compute index line in diffs
  t4054: make hash-size independent
2020-02-05 14:34:59 -08:00
Junio C Hamano
25794d6ce9 Merge branch 'km/submodule-add-errmsg'
Improve error message generation for "git submodule add".

* km/submodule-add-errmsg:
  submodule add: show 'add --dry-run' stderr when aborting
2020-02-05 14:34:59 -08:00
Junio C Hamano
d0e70cd32e Merge branch 'am/checkout-file-and-ref-ref-ambiguity'
"git checkout X" did not correctly fail when X is not a local
branch but could name more than one remote-tracking branches
(i.e. to be dwimmed as the starting point to create a corresponding
local branch), which has been corrected.

* am/checkout-file-and-ref-ref-ambiguity:
  checkout: don't revert file on ambiguous tracking branches
  parse_branchname_arg(): extract part as new function
2020-02-05 14:34:58 -08:00
Junio C Hamano
76c57fedfa Merge branch 'js/add-p-leftover-bits'
The final leg of rewriting "add -i/-p" in C.

* js/add-p-leftover-bits:
  ci: include the built-in `git add -i` in the `linux-gcc` job
  built-in add -p: handle Escape sequences more efficiently
  built-in add -p: handle Escape sequences in interactive.singlekey mode
  built-in add -p: respect the `interactive.singlekey` config setting
  terminal: add a new function to read a single keystroke
  terminal: accommodate Git for Windows' default terminal
  terminal: make the code of disable_echo() reusable
  built-in add -p: handle diff.algorithm
  built-in add -p: support interactive.diffFilter
  t3701: adjust difffilter test
2020-02-05 14:34:58 -08:00
Junio C Hamano
9a5315edfd Merge branch 'js/patch-mode-in-others-in-c'
The effort to move "git-add--interactive" to C continues.

* js/patch-mode-in-others-in-c:
  commit --interactive: make it work with the built-in `add -i`
  built-in add -p: implement the "worktree" patch modes
  built-in add -p: implement the "checkout" patch modes
  built-in stash: use the built-in `git add -p` if so configured
  legacy stash -p: respect the add.interactive.usebuiltin setting
  built-in add -p: implement the "stash" and "reset" patch modes
  built-in add -p: prepare for patch modes other than "stage"
2020-02-05 14:34:58 -08:00
Junio C Hamano
381e8e9de1 Merge branch 'dl/test-must-fail-fixes'
Test clean-up.

* dl/test-must-fail-fixes:
  t1507: inline full_name()
  t1507: run commands within test_expect_success
  t1507: stop losing return codes of git commands
  t1501: remove use of `test_might_fail cp`
  t1409: use test_path_is_missing()
  t1409: let sed open its own input file
  t1307: reorder `nongit test_must_fail`
  t1306: convert `test_might_fail rm` to `rm -f`
  t0020: use ! check_packed_refs_marked
  t0020: don't use `test_must_fail has_cr`
  t0003: don't use `test_must_fail attr_check`
  t0003: use test_must_be_empty()
  t0003: use named parameters in attr_check()
  t0000: replace test_must_fail with run_sub_test_lib_test_err()
  t/lib-git-p4: use test_path_is_missing()
2020-02-05 14:34:57 -08:00
Jacques Bodin-Hullin
395518cf7a parse-options: lose an unnecessary space in an error message
Signed-off-by: Jacques Bodin-Hullin <j.bodinhullin@monsieurbiz.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-05 10:49:29 -08:00
René Scharfe
079f970971 name-rev: sort tip names before applying
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>
2020-02-05 10:36:33 -08:00
René Scharfe
2d53975488 name-rev: release unused name strings
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>
2020-02-05 10:24:15 -08:00
René Scharfe
977dc1912b name-rev: generate name strings only if they are better
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>
2020-02-05 10:24:15 -08:00
René Scharfe
1c56fc2084 name-rev: pre-size buffer in get_parent_name()
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>
2020-02-05 10:24:15 -08:00