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<title>git/object.c, branch v2.30.2</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/git/git.git/
</subtitle>
<id>https://git.shady.money/git/atom?h=v2.30.2</id>
<link rel='self' href='https://git.shady.money/git/atom?h=v2.30.2'/>
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<updated>2020-11-21T23:14:38Z</updated>
<entry>
<title>Merge branch 'en/strmap'</title>
<updated>2020-11-21T23:14:38Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2020-11-21T23:14:38Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=bf0a430f70b53f94454692c9ae8ddadd18891aaa'/>
<id>urn:sha1:bf0a430f70b53f94454692c9ae8ddadd18891aaa</id>
<content type='text'>
A specialization of hashmap that uses a string as key has been
introduced.  Hopefully it will see wider use over time.

* en/strmap:
  shortlog: use strset from strmap.h
  Use new HASHMAP_INIT macro to simplify hashmap initialization
  strmap: take advantage of FLEXPTR_ALLOC_STR when relevant
  strmap: enable allocations to come from a mem_pool
  strmap: add a strset sub-type
  strmap: split create_entry() out of strmap_put()
  strmap: add functions facilitating use as a string-&gt;int map
  strmap: enable faster clearing and reusing of strmaps
  strmap: add more utility functions
  strmap: new utility functions
  hashmap: provide deallocation function names
  hashmap: introduce a new hashmap_partial_clear()
  hashmap: allow re-use after hashmap_free()
  hashmap: adjust spacing to fix argument alignment
  hashmap: add usage documentation explaining hashmap_free[_entries]()
</content>
</entry>
<entry>
<title>hashmap: provide deallocation function names</title>
<updated>2020-11-02T20:15:50Z</updated>
<author>
<name>Elijah Newren</name>
<email>newren@gmail.com</email>
</author>
<published>2020-11-02T18:55:05Z</published>
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<id>urn:sha1:6da1a258142ac2422c8c57c54b92eaed3c86226e</id>
<content type='text'>
hashmap_free(), hashmap_free_entries(), and hashmap_free_() have existed
for a while, but aren't necessarily the clearest names, especially with
hashmap_partial_clear() being added to the mix and lazy-initialization
now being supported.  Peff suggested we adopt the following names[1]:

  - hashmap_clear() - remove all entries and de-allocate any
    hashmap-specific data, but be ready for reuse

  - hashmap_clear_and_free() - ditto, but free the entries themselves

  - hashmap_partial_clear() - remove all entries but don't deallocate
    table

  - hashmap_partial_clear_and_free() - ditto, but free the entries

This patch provides the new names and converts all existing callers over
to the new naming scheme.

[1] https://lore.kernel.org/git/20201030125059.GA3277724@coredump.intra.peff.net/

Signed-off-by: Elijah Newren &lt;newren@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>object: allow clear_commit_marks_all to handle any repo</title>
<updated>2020-10-31T17:46:34Z</updated>
<author>
<name>René Scharfe</name>
<email>l.s.r@web.de</email>
</author>
<published>2020-10-31T12:46:08Z</published>
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<id>urn:sha1:cd8888452cd0e09c9efdc22da729023ae255b54b</id>
<content type='text'>
Allow callers to specify the repository to use.  Rename the function to
repo_clear_commit_marks to document its new scope.  No functional change
intended.

Signed-off-by: René Scharfe &lt;l.s.r@web.de&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>object: drop parsed_object_pool-&gt;commit_count</title>
<updated>2020-06-17T21:37:14Z</updated>
<author>
<name>Abhishek Kumar</name>
<email>abhishekkumar8222@gmail.com</email>
</author>
<published>2020-06-17T09:14:08Z</published>
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<id>urn:sha1:6da43d937ca96d277556fa92c5a664fb1cbcc8ac</id>
<content type='text'>
14ba97f8 (alloc: allow arbitrary repositories for alloc functions,
2018-05-15) introduced parsed_object_pool-&gt;commit_count to keep count of
commits per repository and was used to assign commit-&gt;index.

However, commit-slab code requires commit-&gt;index values to be unique
and a global count would be correct, rather than a per-repo count.

Let's introduce a static counter variable, `parsed_commits_count` to
keep track of parsed commits so far.

As commit_count has no use anymore, let's also drop it from the struct.

Signed-off-by: Abhishek Kumar &lt;abhishekkumar8222@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'jk/object-filter-with-bitmap'</title>
<updated>2020-03-02T23:07:18Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2020-03-02T23:07:18Z</published>
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<id>urn:sha1:0df82d99dae85dbd4f667e95020a146ea0167975</id>
<content type='text'>
The object reachability bitmap machinery and the partial cloning
machinery were not prepared to work well together, because some
object-filtering criteria that partial clones use inherently rely
on object traversal, but the bitmap machinery is an optimization
to bypass that object traversal.  There however are some cases
where they can work together, and they were taught about them.

* jk/object-filter-with-bitmap:
  rev-list --count: comment on the use of count_right++
  pack-objects: support filters with bitmaps
  pack-bitmap: implement BLOB_LIMIT filtering
  pack-bitmap: implement BLOB_NONE filtering
  bitmap: add bitmap_unset() function
  rev-list: use bitmap filters for traversal
  pack-bitmap: basic noop bitmap filter infrastructure
  rev-list: allow commit-only bitmap traversals
  t5310: factor out bitmap traversal comparison
  rev-list: allow bitmaps when counting objects
  rev-list: make --count work with --objects
  rev-list: factor out bitmap-optimized routines
  pack-bitmap: refuse to do a bitmap traversal with pathspecs
  rev-list: fallback to non-bitmap traversal when filtering
  pack-bitmap: fix leak of haves/wants object lists
  pack-bitmap: factor out type iterator initialization
</content>
</entry>
<entry>
<title>Merge branch 'mt/use-passed-repo-more-in-funcs'</title>
<updated>2020-02-14T20:54:22Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2020-02-14T20:54:22Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=78e67cda42a440f216fc4cbfd8a9e190c5eece5a'/>
<id>urn:sha1:78e67cda42a440f216fc4cbfd8a9e190c5eece5a</id>
<content type='text'>
Some codepaths were given a repository instance as a parameter to
work in the repository, but passed the_repository instance to its
callees, which has been cleaned up (somewhat).

* mt/use-passed-repo-more-in-funcs:
  sha1-file: allow check_object_signature() to handle any repo
  sha1-file: pass git_hash_algo to hash_object_file()
  sha1-file: pass git_hash_algo to write_object_file_prepare()
  streaming: allow open_istream() to handle any repo
  pack-check: use given repo's hash_algo at verify_packfile()
  cache-tree: use given repo's hash_algo at verify_one()
  diff: make diff_populate_filespec() honor its repo argument
</content>
</entry>
<entry>
<title>pack-bitmap: fix leak of haves/wants object lists</title>
<updated>2020-02-13T17:08:58Z</updated>
<author>
<name>Jeff King</name>
<email>peff@peff.net</email>
</author>
<published>2020-02-13T02:16:33Z</published>
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<id>urn:sha1:acac50dd8c2c9725841b3e9143d78c6345dc076c</id>
<content type='text'>
When we do a bitmap-aware revision traversal, we create an object_list
for each of the "haves" and "wants" tips. After creating the result
bitmaps these are no longer needed or used, but we never free the list
memory.

Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>sha1-file: allow check_object_signature() to handle any repo</title>
<updated>2020-01-31T18:45:39Z</updated>
<author>
<name>Matheus Tavares</name>
<email>matheus.bernardino@usp.br</email>
</author>
<published>2020-01-30T20:32:23Z</published>
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<id>urn:sha1:b98d18858187eb926912d5199533a6d2a14d5007</id>
<content type='text'>
Some callers of check_object_signature() can work on arbitrary
repositories, but the repo does not get passed to this function.
Instead, the_repository is always used internally. To fix possible
inconsistencies, allow the function to receive a struct repository and
make those callers pass on the repo being handled.

Signed-off-by: Matheus Tavares &lt;matheus.bernardino@usp.br&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>replace-object: make replace operations thread-safe</title>
<updated>2020-01-17T21:52:14Z</updated>
<author>
<name>Matheus Tavares</name>
<email>matheus.bernardino@usp.br</email>
</author>
<published>2020-01-16T02:39:52Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=b1fc9da1c84a94ef03eb07df361f3ec43006b39f'/>
<id>urn:sha1:b1fc9da1c84a94ef03eb07df361f3ec43006b39f</id>
<content type='text'>
replace-object functions are very close to being thread-safe: the only
current racy section is the lazy initialization at
prepare_replace_object(). The following patches will protect some object
reading operations to be called threaded, but before that, replace
functions must be protected. To do so, add a mutex to struct
raw_object_store and acquire it before lazy initializing the
replace_map. This won't cause any noticeable performance drop as the
mutex will no longer be used after the replace_map is initialized.

Later, when the replace functions are called in parallel, thread
debuggers might point our use of the added replace_map_initialized flag
as a data race. However, as this boolean variable is initialized as
false and it's only updated once, there's no real harm. It's perfectly
fine if the value is updated right after a thread read it in
replace-map.h:lookup_replace_object() (there'll only be a performance
penalty for the affected threads at that moment). We could cease the
debugger warning protecting the variable reading at the said function.
However, this would negatively affect performance for all threads
calling it, at any time, so it's not really worthy since the warning
doesn't represent a real problem. Instead, to make sure we don't get
false positives (at ThreadSanitizer, at least) an entry for the
respective function is added to .tsan-suppressions.

Signed-off-by: Matheus Tavares &lt;matheus.bernardino@usp.br&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>packfile.c: speed up loading lots of packfiles</title>
<updated>2019-12-03T15:59:45Z</updated>
<author>
<name>Colin Stolley</name>
<email>cstolley@runbox.com</email>
</author>
<published>2019-11-27T22:24:53Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=ec48540fe8c387cf7424d5387ddbd53e89bb9d51'/>
<id>urn:sha1:ec48540fe8c387cf7424d5387ddbd53e89bb9d51</id>
<content type='text'>
When loading packfiles on start-up, we traverse the internal packfile
list once per file to avoid reloading packfiles that have already
been loaded. This check runs in quadratic time, so for poorly
maintained repos with a large number of packfiles, it can be pretty
slow.

Add a hashmap containing the packfile names as we load them so that
the average runtime cost of checking for already-loaded packs becomes
constant.

Add a perf test to p5303 to show speed-up.

The existing p5303 test runtimes are dominated by other factors and do
not show an appreciable speed-up. The new test in p5303 clearly exposes
a speed-up in bad cases. In this test we create 10,000 packfiles and
measure the start-up time of git rev-parse, which does little else
besides load in the packs.

Here are the numbers for the new p5303 test:

Test                         HEAD^             HEAD
---------------------------------------------------------------------
5303.12: load 10,000 packs   1.03(0.92+0.10)   0.12(0.02+0.09) -88.3%

Signed-off-by: Colin Stolley &lt;cstolley@runbox.com&gt;
Helped-by: Jeff King &lt;peff@peff.net&gt;
[jc: squashed the change to call hashmap in install_packed_git() by peff]
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
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