Commit graph

73007 commits

Author SHA1 Message Date
Junio C Hamano
7b66f5dd8b Merge branch 'mr/rerere-crash-fix'
When .git/rr-cache/ rerere database gets corrupted or rerere is fed to
work on a file with conflicted hunks resolved incompletely, the rerere
machinery got confused and segfaulted, which has been corrected.

* mr/rerere-crash-fix:
  rerere: fix crashes due to unmatched opening conflict markers
2024-04-23 11:52:41 -07:00
Junio C Hamano
fb9f603f3c Merge branch 'rs/imap-send-simplify-cmd-issuing-codepath'
Code simplification.

* rs/imap-send-simplify-cmd-issuing-codepath:
  imap-send: increase command size limit
2024-04-23 11:52:41 -07:00
Junio C Hamano
9cb0bbf0b4 Merge branch 'xx/rfc2822-date-format-in-doc'
Docfix.

* xx/rfc2822-date-format-in-doc:
  Documentation: fix typos describing date format
2024-04-23 11:52:40 -07:00
Junio C Hamano
567293123d Merge branch 'ps/missing-btmp-fix'
GIt 2.44 introduced a regression that makes the updated code to
barf in repositories with multi-pack index written by older
versions of Git, which has been corrected.

* ps/missing-btmp-fix:
  pack-bitmap: gracefully handle missing BTMP chunks
2024-04-23 11:52:40 -07:00
Junio C Hamano
c9f1f88bb0 Merge branch 'la/format-trailer-info'
The code to format trailers have been cleaned up.

* la/format-trailer-info:
  trailer: finish formatting unification
  trailer: begin formatting unification
  format_trailer_info(): append newline for non-trailer lines
  format_trailer_info(): drop redundant unfold_value()
  format_trailer_info(): use trailer_item objects
2024-04-23 11:52:39 -07:00
Junio C Hamano
b258237f4d Merge branch 'dd/t9604-use-posix-timezones'
The cvsimport tests required that the platform understands
traditional timezone notations like CST6CDT, which has been
updated to work on those systems as long as they understand
POSIX notation with explicit tz transition dates.

* dd/t9604-use-posix-timezones:
  t9604: Fix test for musl libc and new Debian
2024-04-23 11:52:39 -07:00
Junio C Hamano
5615be39bc Merge branch 'rj/launch-editor-error-message'
Git writes a "waiting for your editor" message on an incomplete
line after launching an editor, and then append another error
message on the same line if the editor errors out.  It now clears
the "waiting for..." line before giving the error message.

* rj/launch-editor-error-message:
  launch_editor: waiting message on error
2024-04-23 11:52:39 -07:00
Junio C Hamano
7f49008602 Merge branch 'yb/replay-doc-linkfix'
Docfix.

* yb/replay-doc-linkfix:
  Documentation: fix linkgit reference
2024-04-23 11:52:38 -07:00
Junio C Hamano
ec465fcb75 Merge branch 'rs/no-openssl-compilation-fix-on-macos'
Build fix.

* rs/no-openssl-compilation-fix-on-macos:
  git-compat-util: fix NO_OPENSSL on current macOS
2024-04-23 11:52:38 -07:00
Junio C Hamano
050e334979 Merge branch 'ta/fast-import-parse-path-fix'
The way "git fast-import" handles paths described in its input has
been tightened up and more clearly documented.

* ta/fast-import-parse-path-fix:
  fast-import: make comments more precise
  fast-import: forbid escaped NUL in paths
  fast-import: document C-style escapes for paths
  fast-import: improve documentation for path quoting
  fast-import: remove dead strbuf
  fast-import: allow unquoted empty path for root
  fast-import: directly use strbufs for paths
  fast-import: tighten path unquoting
2024-04-23 11:52:37 -07:00
Junio C Hamano
33bbc21c92 Merge branch 'ps/reftable-block-iteration-optim'
The code to iterate over reftable blocks has seen some optimization
to reduce memory allocation and deallocation.

* ps/reftable-block-iteration-optim:
  reftable/block: avoid copying block iterators on seek
  reftable/block: reuse `zstream` state on inflation
  reftable/block: open-code call to `uncompress2()`
  reftable/block: reuse uncompressed blocks
  reftable/reader: iterate to next block in place
  reftable/block: move ownership of block reader into `struct table_iter`
  reftable/block: introduce `block_reader_release()`
  reftable/block: better grouping of functions
  reftable/block: merge `block_iter_seek()` and `block_reader_seek()`
  reftable/block: rename `block_reader_start()`
2024-04-23 11:52:37 -07:00
Patrick Steinhardt
00e10ef10e docs: address typos in Git v2.45 changelog
Address some typos in the Git v2.45 changelog.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-22 08:54:01 -07:00
Patrick Steinhardt
bbeb79789c docs: improve changelog entry for git pack-refs --auto
The changelog entry for the new `git pack-refs --auto` mode only says
that the new flag is useful, but doesn't really say what it does. Add
some more information.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-22 08:54:01 -07:00
Orgad Shaneh
bf3fe4f1a2 docs: remove duplicate entry and fix typo in 2.45 changelog
Signed-off-by: Orgad Shaneh <orgads@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-22 08:53:41 -07:00
Junio C Hamano
ae3196a5ea Git 2.45-rc0
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-19 09:13:47 -07:00
Junio C Hamano
6c69d3a91f Merge branch 'la/mailmap-entry'
Update contact address for Linus Arver.

* la/mailmap-entry:
  mailmap: change primary address for Linus Arver
2024-04-19 09:13:47 -07:00
Junio C Hamano
18dd9301a2 Merge branch 'pf/commitish-committish'
Spellfix.

* pf/commitish-committish:
  typo: replace 'commitish' with 'committish'
2024-04-19 09:13:47 -07:00
Linus Arver
8882ee9d68 mailmap: change primary address for Linus Arver
Linus will lose access to his work email soon.

Signed-off-by: Linus Arver <linusa@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-16 22:25:11 -07:00
Junio C Hamano
21306a098c The twentieth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-16 14:50:31 -07:00
Junio C Hamano
93e3f9df7a Merge branch 'pw/t3428-cleanup'
Test cleanup.

* pw/t3428-cleanup:
  t3428: restore coverage for "apply" backend
  t3428: use test_commit_message
  t3428: modernize test setup
2024-04-16 14:50:31 -07:00
Junio C Hamano
51c15ac1b6 Merge branch 'ba/osxkeychain-updates'
Update osxkeychain backend with features required for the recent
credential subsystem.

* ba/osxkeychain-updates:
  osxkeychain: store new attributes
  osxkeychain: erase matching passwords only
  osxkeychain: erase all matching credentials
  osxkeychain: replace deprecated SecKeychain API
2024-04-16 14:50:30 -07:00
Junio C Hamano
82a31ec324 Merge branch 'jt/reftable-geometric-compaction'
The strategy to compact multiple tables of reftables after many
operations accumulate many entries has been improved to avoid
accumulating too many tables uncollected.

* jt/reftable-geometric-compaction:
  reftable/stack: use geometric table compaction
  reftable/stack: add env to disable autocompaction
  reftable/stack: expose option to disable auto-compaction
2024-04-16 14:50:30 -07:00
Junio C Hamano
2b49e41155 Merge branch 'tb/make-indent-conditional-with-non-spaces'
Adjust to an upcoming changes to GNU make that breaks our Makefiles.

* tb/make-indent-conditional-with-non-spaces:
  Makefile(s): do not enforce "all indents must be done with tab"
  Makefile(s): avoid recipe prefix in conditional statements
2024-04-16 14:50:29 -07:00
Junio C Hamano
a7589384d5 Merge branch 'rs/usage-fallback-to-show-message-format'
vreportf(), which is usede by error() and friends, has been taught
to give the error message printf-format string when its vsnprintf()
call fails, instead of showing nothing useful to identify the
nature of the error.

* rs/usage-fallback-to-show-message-format:
  usage: report vsnprintf(3) failure
2024-04-16 14:50:29 -07:00
Junio C Hamano
107313eb11 Merge branch 'rs/date-mode-pass-by-value'
The codepaths that reach date_mode_from_type() have been updated to
pass "struct date_mode" by value to make them thread safe.

* rs/date-mode-pass-by-value:
  date: make DATE_MODE thread-safe
2024-04-16 14:50:29 -07:00
Junio C Hamano
2d642afb0a Merge branch 'sj/userdiff-c-sharp'
The userdiff patterns for C# has been updated.

Acked-by: Johannes Sixt <j6t@kdbg.org>
cf. <c2154457-3f2f-496e-9b8b-c8ea7257027b@kdbg.org>

* sj/userdiff-c-sharp:
  userdiff: better method/property matching for C#
2024-04-16 14:50:28 -07:00
Junio C Hamano
625ef1c6f1 Merge branch 'tb/t7700-fixup'
Test fix.

* tb/t7700-fixup:
  t/t7700-repack.sh: fix test breakages with `GIT_TEST_MULTI_PACK_INDEX=1 `
2024-04-16 14:50:28 -07:00
Junio C Hamano
92e8388bd3 Merge branch 'jc/local-extern-shell-rules'
Document and apply workaround for a buggy version of dash that
mishandles "local var=val" construct.

* jc/local-extern-shell-rules:
  t1016: local VAR="VAL" fix
  t0610: local VAR="VAL" fix
  t: teach lint that RHS of 'local VAR=VAL' needs to be quoted
  t: local VAR="VAL" (quote ${magic-reference})
  t: local VAR="VAL" (quote command substitution)
  t: local VAR="VAL" (quote positional parameters)
  CodingGuidelines: quote assigned value in 'local var=$val'
  CodingGuidelines: describe "export VAR=VAL" rule
2024-04-16 14:50:27 -07:00
Marcel Röthke
167395bb47 rerere: fix crashes due to unmatched opening conflict markers
When rerere handles a conflict with an unmatched opening conflict marker
in a file with other conflicts, it will fail create a preimage and also
fail allocate the status member of struct rerere_dir. Currently the
status member is allocated after the error handling. This will lead to a
SEGFAULT when the status member is accessed during cleanup of the failed
parse.

Additionally, in subsequent executions of rerere, after removing the
MERGE_RR.lock manually, rerere crashes for a similar reason. MERGE_RR
points to a conflict id that has no preimage, therefore the status
member is not allocated and a SEGFAULT happens when trying to check if a
preimage exists.

Solve this by making sure the status field is allocated correctly and add
tests to prevent the bug from reoccurring.

This does not fix the root cause, failing to parse stray conflict
markers, but I don't think we can do much better than recognizing it,
printing an error, and moving on gracefully.

Signed-off-by: Marcel Röthke <marcel@roethke.info>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-16 08:42:36 -07:00
Junio C Hamano
548fe35913 The ninteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 14:11:44 -07:00
Junio C Hamano
cb25f97eab Merge branch 'jc/t2104-style-fixes'
Test style fixes.

* jc/t2104-style-fixes:
  t2104: style fixes
2024-04-15 14:11:44 -07:00
Junio C Hamano
b415f15b49 Merge branch 'jc/unleak-core-excludesfile'
The variable that holds the value read from the core.excludefile
configuration variable used to leak, which has been corrected.

* jc/unleak-core-excludesfile:
  config: do not leak excludes_file
2024-04-15 14:11:44 -07:00
Junio C Hamano
eba498a774 Merge branch 'jk/libcurl-8.7-regression-workaround'
Fix was added to work around a regression in libcURL 8.7.0 (which has
already been fixed in their tip of the tree).

* jk/libcurl-8.7-regression-workaround:
  remote-curl: add Transfer-Encoding header only for older curl
  INSTALL: bump libcurl version to 7.21.3
  http: reset POSTFIELDSIZE when clearing curl handle
2024-04-15 14:11:44 -07:00
Junio C Hamano
372aabe912 Merge branch 'ps/t0610-umask-fix'
The "shared repository" test in the t0610 reftable test failed
under restrictive umask setting (e.g. 007), which has been
corrected.

* ps/t0610-umask-fix:
  t0610: execute git-pack-refs(1) with specified umask
  t0610: make `--shared=` tests reusable
2024-04-15 14:11:43 -07:00
Junio C Hamano
d75ec4c627 Merge branch 'gt/add-u-commit-i-pathspec-check'
"git add -u <pathspec>" and "git commit [-i] <pathspec>" did not
diagnose a pathspec element that did not match any files in certain
situations, unlike "git add <pathspec>" did.

* gt/add-u-commit-i-pathspec-check:
  builtin/add: error out when passing untracked path with -u
  builtin/commit: error out when passing untracked path with -i
  revision: optionally record matches with pathspec elements
2024-04-15 14:11:43 -07:00
Junio C Hamano
6c142bc846 Merge branch 'ds/fetch-config-parse-microfix'
A config parser callback function fell through instead of returning
after recognising and processing a variable, wasting cycles, which
has been corrected.

* ds/fetch-config-parse-microfix:
  fetch: return when parsing submodule.recurse
2024-04-15 14:11:43 -07:00
Junio C Hamano
ce729ea9ba Merge branch 'rs/apply-reject-fd-leakfix'
A file descriptor leak in an error codepath, used when "git apply
--reject" fails to create the *.rej file, has been corrected.

* rs/apply-reject-fd-leakfix:
  apply: don't leak fd on fdopen() error
2024-04-15 14:11:43 -07:00
Junio C Hamano
c7a9ec4728 Merge branch 'rs/apply-lift-path-length-limit'
"git apply" has been updated to lift the hardcoded pathname length
limit, which in turn allowed a mksnpath() function that is no
longer used.

* rs/apply-lift-path-length-limit:
  path: remove mksnpath()
  apply: avoid fixed-size buffer in create_one_file()
2024-04-15 14:11:42 -07:00
Junio C Hamano
509cc1d413 Merge branch 'ma/win32-unix-domain-socket'
Windows binary used to decide the use of unix-domain socket at
build time, but it learned to make the decision at runtime instead.

* ma/win32-unix-domain-socket:
  Win32: detect unix socket support at runtime
2024-04-15 14:11:42 -07:00
René Scharfe
21b5821acd imap-send: increase command size limit
nfvasprintf() has a 8KB limit, but it's not relevant, as its result is
combined with other strings and added to a 1KB buffer by its caller.
That 1KB limit is not mentioned in RFC 9051, which specifies IMAP.

While 1KB is plenty for user names, passwords and mailbox names,
there's no point in limiting our commands like that.  Call xstrvfmt()
instead of open-coding it and use strbuf to format the command to
send, as we need its length.  Fail hard if it exceeds INT_MAX, because
socket_write() can't take more than that.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 11:34:17 -07:00
Yehezkel Bernat
f412d72c19 Documentation: fix linkgit reference
In git-replay documentation, linkgit to git-rev-parse is missing the
man section, which breaks its rendering.

Add section number as done in other references to this command.

Signed-off-by: Yehezkel Bernat <YehezkelShB@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 11:02:43 -07:00
René Scharfe
44bdba2fa6 git-compat-util: fix NO_OPENSSL on current macOS
b195aa00c1 (git-compat-util: suppress unavoidable Apple-specific
deprecation warnings, 2014-12-16) started to define
__AVAILABILITY_MACROS_USES_AVAILABILITY in git-compat-util.h.  On
current versions it is already defined (e.g. on macOS 14.4.1).  Undefine
it before redefining it to avoid a compilation error.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 11:01:31 -07:00
Patrick Steinhardt
795006fff4 pack-bitmap: gracefully handle missing BTMP chunks
In 0fea6b73f1 (Merge branch 'tb/multi-pack-verbatim-reuse', 2024-01-12)
we have introduced multi-pack verbatim reuse of objects. This series has
introduced a new BTMP chunk, which encodes information about bitmapped
objects in the multi-pack index. Starting with dab60934e3 (pack-bitmap:
pass `bitmapped_pack` struct to pack-reuse functions, 2023-12-14) we use
this information to figure out objects which we can reuse from each of
the packfiles.

One thing that we glossed over though is backwards compatibility with
repositories that do not yet have BTMP chunks in their multi-pack index.
In that case, `nth_bitmapped_pack()` would return an error, which causes
us to emit a warning followed by another error message. These warnings
are visible to users that fetch from a repository:

```
$ git fetch
...
remote: error: MIDX does not contain the BTMP chunk
remote: warning: unable to load pack: 'pack-f6bb7bd71d345ea9fe604b60cab9ba9ece54ffbe.idx', disabling pack-reuse
remote: Enumerating objects: 40, done.
remote: Counting objects: 100% (40/40), done.
remote: Compressing objects: 100% (39/39), done.
remote: Total 40 (delta 5), reused 0 (delta 0), pack-reused 0 (from 0)
...
```

While the fetch succeeds the user is left wondering what they did wrong.
Furthermore, as visible both from the warning and from the reuse stats,
pack-reuse is completely disabled in such repositories.

What is quite interesting is that this issue can even be triggered in
case `pack.allowPackReuse=single` is set, which is the default value.
One could have expected that in this case we fall back to the old logic,
which is to use the preferred packfile without consulting BTMP chunks at
all. But either we fail with the above error in case they are missing,
or we use the first pack in the multi-pack-index. The former case
disables pack-reuse altogether, whereas the latter case may result in
reusing objects from a suboptimal packfile.

Fix this issue by partially reverting the logic back to what we had
before this patch series landed. Namely, in the case where we have no
BTMP chunks or when `pack.allowPackReuse=single` are set, we use the
preferred pack instead of consulting the BTMP chunks.

Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:42:00 -07:00
Patrick Steinhardt
9da5c992dd reftable/block: avoid copying block iterators on seek
When seeking a reftable record in a block we need to position the
iterator _before_ the sought-after record so that the next call to
`block_iter_next()` would yield that record. To achieve this, the loop
that performs the linear seeks to restore the previous position once it
has found the record.

This is done by advancing two `block_iter`s: one to check whether the
next record is our sought-after record, and one that we update after
every iteration. This of course involves quite a lot of copying and also
leads to needless memory allocations.

Refactor the code to get rid of the `next` iterator and the copying this
involves. Instead, we can restore the previous offset such that the call
to `next` will return the correct record.

Next to being simpler conceptually this also leads to a nice speedup.
The following benchmark parser 10k refs out of 100k existing refs via
`git-rev-list --no-walk`:

  Benchmark 1: rev-list: print many refs (HEAD~)
    Time (mean ± σ):     170.2 ms ±   1.7 ms    [User: 86.1 ms, System: 83.6 ms]
    Range (min … max):   166.4 ms … 180.3 ms    500 runs

  Benchmark 2: rev-list: print many refs (HEAD~)
    Time (mean ± σ):     161.6 ms ±   1.6 ms    [User: 78.1 ms, System: 83.0 ms]
    Range (min … max):   158.4 ms … 172.3 ms    500 runs

  Summary
    rev-list: print many refs (HEAD) ran
      1.05 ± 0.01 times faster than rev-list: print many refs (HEAD~)

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:37:59 -07:00
Patrick Steinhardt
ce1f213cc9 reftable/block: reuse zstream state on inflation
When calling `inflateInit()` and `inflate()`, the zlib library will
allocate several data structures for the underlying `zstream` to keep
track of various information. Thus, when inflating repeatedly, it is
possible to optimize memory allocation patterns by reusing the `zstream`
and then calling `inflateReset()` on it to prepare it for the next chunk
of data to inflate.

This is exactly what the reftable code is doing: when iterating through
reflogs we need to potentially inflate many log blocks, but we discard
the `zstream` every single time. Instead, as we reuse the `block_reader`
for each of the blocks anyway, we can initialize the `zstream` once and
then reuse it for subsequent inflations.

Refactor the code to do so, which leads to a significant reduction in
the number of allocations. The following measurements were done when
iterating through 1 million reflog entries. Before:

  HEAP SUMMARY:
      in use at exit: 13,473 bytes in 122 blocks
    total heap usage: 23,028 allocs, 22,906 frees, 162,813,552 bytes allocated

After:

  HEAP SUMMARY:
      in use at exit: 13,473 bytes in 122 blocks
    total heap usage: 302 allocs, 180 frees, 88,352 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:36:09 -07:00
Patrick Steinhardt
15a60b747e reftable/block: open-code call to uncompress2()
The reftable format stores log blocks in a compressed format. Thus,
whenever we want to read such a block we first need to decompress it.
This is done by calling the convenience function `uncompress2()` of the
zlib library, which is a simple wrapper that manages the lifecycle of
the `zstream` structure for us.

While nice for one-off inflation of data, when iterating through reflogs
we will likely end up inflating many such log blocks. This requires us
to reallocate the state of the `zstream` every single time, which adds
up over time. It would thus be great to reuse the `zstream` instead of
discarding it after every inflation.

Open-code the call to `uncompress2()` such that we can start reusing the
`zstream` in the subsequent commit. Note that our open-coded variant is
different from `uncompress2()` in two ways:

  - We do not loop around `inflate()` until we have processed all input.
    As our input is limited by the maximum block size, which is 16MB, we
    should not hit limits of `inflate()`.

  - We use `Z_FINISH` instead of `Z_NO_FLUSH`. Quoting the `inflate()`
    documentation: "inflate() should normally be called until it returns
    Z_STREAM_END or an error. However if all decompression is to be
    performed in a single step (a single call of inflate), the parameter
    flush should be set to Z_FINISH."

    Furthermore, "Z_FINISH also informs inflate to not maintain a
    sliding window if the stream completes, which reduces inflate's
    memory footprint."

Other than that this commit is expected to be functionally equivalent
and does not yet reuse the `zstream`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:36:09 -07:00
Patrick Steinhardt
dd347bbce6 reftable/block: reuse uncompressed blocks
The reftable backend stores reflog entries in a compressed format and
thus needs to uncompress blocks before one can read records from it.
For each reflog block we thus have to allocate an array that we can
decompress the block contents into. This block is being discarded
whenever the table iterator moves to the next block. Consequently, we
reallocate a new array on every block, which is quite wasteful.

Refactor the code to reuse the uncompressed block data when moving the
block reader to a new block. This significantly reduces the number of
allocations when iterating through many compressed blocks. The following
measurements are done with `git reflog list` when listing 100k reflogs.
Before:

  HEAP SUMMARY:
      in use at exit: 13,473 bytes in 122 blocks
    total heap usage: 45,755 allocs, 45,633 frees, 254,779,456 bytes allocated

After:

  HEAP SUMMARY:
      in use at exit: 13,473 bytes in 122 blocks
    total heap usage: 23,028 allocs, 22,906 frees, 162,813,547 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:36:09 -07:00
Patrick Steinhardt
b00bcb7c49 reftable/reader: iterate to next block in place
The table iterator has to iterate towards the next block once it has
yielded all records of the current block. This is done by creating a new
table iterator, initializing it to the next block, releasing the old
iterator and then copying over the data.

Refactor the code to instead advance the table iterator in place. This
is simpler and unlocks some optimizations in subsequent patches. Also,
it allows us to avoid some allocations.

The following measurements show a single matching ref out of 1 million
refs. Before this change:

  HEAP SUMMARY:
      in use at exit: 13,603 bytes in 125 blocks
    total heap usage: 7,235 allocs, 7,110 frees, 301,481 bytes allocated

After:

  HEAP SUMMARY:
      in use at exit: 13,603 bytes in 125 blocks
    total heap usage: 315 allocs, 190 frees, 107,027 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:36:09 -07:00
Patrick Steinhardt
bcdc586db0 reftable/block: move ownership of block reader into struct table_iter
The table iterator allows the caller to iterate through all records in a
reftable table. To do so it iterates through all blocks of the desired
type one by one, where for each block it creates a new block iterator
and yields all its entries.

One of the things that is somewhat confusing in this context is who owns
the block reader that is being used to read the blocks and pass them to
the block iterator. Intuitively, as the table iterator is responsible
for iterating through the blocks, one would assume that this iterator is
also responsible for managing the lifecycle of the reader. And while it
somewhat is, the block reader is ultimately stored inside of the block
iterator.

Refactor the code such that the block reader is instead fully managed by
the table iterator. Instead of passing the reader to the block iterator,
we now only end up passing the block data to it. Despite clearing up the
lifecycle of the reader, it will also allow for better reuse of the
reader in subsequent patches.

The following benchmark prints a single matching ref out of 1 million
refs. Before:

  HEAP SUMMARY:
      in use at exit: 13,603 bytes in 125 blocks
    total heap usage: 6,607 allocs, 6,482 frees, 509,635 bytes allocated

After:

  HEAP SUMMARY:
      in use at exit: 13,603 bytes in 125 blocks
    total heap usage: 7,235 allocs, 7,110 frees, 301,481 bytes allocated

Note that while there are more allocation and free calls now, the
overall number of bytes allocated is significantly lower. The number of
allocations will be reduced significantly by the next patch though.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:36:09 -07:00
Patrick Steinhardt
b371221a60 reftable/block: introduce block_reader_release()
Introduce a new function `block_reader_release()` that releases
resources acquired by the block reader. This function will be extended
in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-15 10:36:09 -07:00