Commit Graph

394 Commits

Author SHA1 Message Date
Junio C Hamano
2a978f8273 Merge branch 'jc/object-names-are-not-sha-1'
A few end-user facing messages have been updated to be
hash-algorithm agnostic.

* jc/object-names-are-not-sha-1:
  messages: avoid SHA-1 in end-user facing messages
2020-08-19 16:14:52 -07:00
Junio C Hamano
4279000d3e messages: avoid SHA-1 in end-user facing messages
There are still a handful mentions of SHA-1 when we meant the
(hexadecimal) object names in end-user facing messages.  Rewrite
them.

I was hoping that this can mostly be s/SHA-1/object name/, but
a few messages needed rephrasing to keep the result readable.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-14 09:33:37 -07:00
Junio C Hamano
d1a8a8979d Merge branch 'jt/has_object'
A new helper function has_object() has been introduced to make it
easier to mark object existence checks that do and don't want to
trigger lazy fetches, and a few such checks are converted using it.

* jt/has_object:
  fsck: do not lazy fetch known non-promisor object
  pack-objects: no fetch when allow-{any,promisor}
  apply: do not lazy fetch when applying binary
  sha1-file: introduce no-lazy-fetch has_object()
2020-08-13 14:13:39 -07:00
Junio C Hamano
46b225f153 Merge branch 'jk/strvec'
The argv_array API is useful for not just managing argv but any
"vector" (NULL-terminated array) of strings, and has seen adoption
to a certain degree.  It has been renamed to "strvec" to reduce the
barrier to adoption.

* jk/strvec:
  strvec: rename struct fields
  strvec: drop argv_array compatibility layer
  strvec: update documention to avoid argv_array
  strvec: fix indentation in renamed calls
  strvec: convert remaining callers away from argv_array name
  strvec: convert more callers away from argv_array name
  strvec: convert builtin/ callers away from argv_array name
  quote: rename sq_dequote_to_argv_array to mention strvec
  strvec: rename files from argv-array to strvec
  argv-array: rename to strvec
  argv-array: use size_t for count and alloc
2020-08-10 10:23:57 -07:00
Jonathan Tan
ee47243d76 pack-objects: no fetch when allow-{any,promisor}
The options --missing=allow-{any,promisor} were introduced in caf3827e2f
("rev-list: add list-objects filtering support", 2017-11-22) with the
following note in the commit message:

    This patch introduces handling of missing objects to help
    debugging and development of the "partial clone" mechanism,
    and once the mechanism is implemented, for a power user to
    perform operations that are missing-object aware without
    incurring the cost of checking if a missing link is expected.

The idea that these options are missing-object aware (and thus do not
need to lazily fetch objects, unlike unaware commands that assume that
all objects are present) are assumed in later commits such as 07ef3c6604
("fetch test: use more robust test for filtered objects", 2020-01-15).

However, the current implementations of these options use
has_object_file(), which indeed lazily fetches missing objects. Teach
these implementations not to do so. Also, update the documentation of
these options to be clearer.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-06 13:01:03 -07:00
Jeff King
d70a9eb611 strvec: rename struct fields
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").

Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-30 19:18:06 -07:00
Jeff King
22f9b7f3f5 strvec: convert builtin/ callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts all of the files in builtin/ to keep the diff to a
manageable size.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

and then selectively staging files with "git add builtin/". We'll deal
with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King
dbbcd44fb4 strvec: rename files from argv-array to strvec
This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe 's/argv-array.h/strvec.h/'

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:17 -07:00
Jonathan Tan
e00549aa9b pack-objects: prefetch objects to be packed
When an object to be packed is noticed to be missing, prefetch all
to-be-packed objects in one batch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-21 14:29:42 -07:00
Jonathan Tan
8d5cf95735 pack-objects: refactor to oid_object_info_extended
Use oid_object_info_extended() instead of oid_object_info() because a
subsequent commit needs to specify an additional flag here.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-21 14:29:42 -07:00
Jonathan Tan
dd4b732df7 upload-pack: send part of packfile response as uri
Teach upload-pack to send part of its packfile response as URIs.

An administrator may configure a repository with one or more
"uploadpack.blobpackfileuri" lines, each line containing an OID, a pack
hash, and a URI. A client may configure fetch.uriprotocols to be a
comma-separated list of protocols that it is willing to use to fetch
additional packfiles - this list will be sent to the server. Whenever an
object with one of those OIDs would appear in the packfile transmitted
by upload-pack, the server may exclude that object, and instead send the
URI. The client will then download the packs referred to by those URIs
before performing the connectivity check.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-10 18:06:34 -07:00
Junio C Hamano
896833b268 Merge branch 'tb/shallow-cleanup'
Code cleanup.

* tb/shallow-cleanup:
  shallow: use struct 'shallow_lock' for additional safety
  shallow.h: document '{commit,rollback}_shallow_file'
  shallow: extract a header file for shallow-related functions
  commit: make 'commit_graft_pos' non-static
2020-05-13 12:19:18 -07:00
Taylor Blau
120ad2b0f1 shallow: extract a header file for shallow-related functions
There are many functions in commit.h that are more related to shallow
repositories than they are to any sort of generic commit machinery.
Likely this began when there were only a few shallow-related functions,
and commit.h seemed a reasonable enough place to put them.

But, now there are a good number of shallow-related functions, and
placing them all in 'commit.h' doesn't make sense.

This patch extracts a 'shallow.h', which takes all of the declarations
from 'commit.h' for functions which already exist in 'shallow.c'. We
will bring the remaining shallow-related functions defined in 'commit.c'
in a subsequent patch.

For now, move only the ones that already are implemented in 'shallow.c',
and update the necessary includes.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-30 14:19:13 -07:00
Denton Liu
203c85339f Use OPT_CALLBACK and OPT_CALLBACK_F
In the codebase, there are many options which use OPTION_CALLBACK in a
plain ol' struct definition. However, we have the OPT_CALLBACK and
OPT_CALLBACK_F macros which are meant to abstract these plain struct
definitions away. These macros are useful as they semantically signal to
developers that these are just normal callback option with nothing fancy
happening.

Replace plain struct definitions of OPTION_CALLBACK with OPT_CALLBACK or
OPT_CALLBACK_F where applicable. The heavy lifting was done using the
following (disgusting) shell script:

	#!/bin/sh

	do_replacement () {
		tr '\n' '\r' |
			sed -e 's/{\s*OPTION_CALLBACK,\s*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\s*0,\(\s*[^[:space:]}]*\)\s*}/OPT_CALLBACK(\1,\2,\3,\4,\5,\6)/g' |
			sed -e 's/{\s*OPTION_CALLBACK,\s*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\(\s*[^[:space:]}]*\)\s*}/OPT_CALLBACK_F(\1,\2,\3,\4,\5,\6,\7)/g' |
			tr '\r' '\n'
	}

	for f in $(git ls-files \*.c)
	do
		do_replacement <"$f" >"$f.tmp"
		mv "$f.tmp" "$f"
	done

The result was manually inspected and then reformatted to match the
style of the surrounding code. Finally, using
`git grep OPTION_CALLBACK \*.c`, leftover results which were not handled
by the script were manually transformed.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-28 10:47:10 -07:00
Junio C Hamano
a768f866e9 Merge branch 'jk/oid-array-cleanups'
Code cleanup.

* jk/oid-array-cleanups:
  oidset: stop referring to sha1-array
  ref-filter: stop referring to "sha1 array"
  bisect: stop referring to sha1_array
  test-tool: rename sha1-array to oid-array
  oid_array: rename source file from sha1-array
  oid_array: use size_t for iteration
  oid_array: use size_t for count and allocation
2020-04-22 13:42:49 -07:00
Jeff King
fe299ec5ae oid_array: rename source file from sha1-array
We renamed the actual data structure in 910650d2f8 (Rename sha1_array to
oid_array, 2017-03-31), but the file is still called sha1-array. Besides
being slightly confusing, it makes it more annoying to grep for leftover
occurrences of "sha1" in various files, because the header is included
in so many places.

Let's complete the transition by renaming the source and header files
(and fixing up a few comment references).

I kept the "-" in the name, as that seems to be our style; cf.
fc1395f4a4 (sha1_file.c: rename to use dash in file name, 2018-04-10).
We also have oidmap.h and oidset.h without any punctuation, but those
are "struct oidmap" and "struct oidset" in the code. We _could_ make
this "oidarray" to match, but somehow it looks uglier to me because of
the length of "array" (plus it would be a very invasive patch for little
gain).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 10:59:08 -07:00
Junio C Hamano
9fadedd637 Merge branch 'ds/default-pack-use-sparse-to-true'
The 'pack.useSparse' configuration variable now defaults to 'true',
enabling an optimization that has been experimental since Git 2.21.

* ds/default-pack-use-sparse-to-true:
  pack-objects: flip the use of GIT_TEST_PACK_SPARSE
  config: set pack.useSparse=true by default
2020-03-29 09:32:51 -07:00
Junio C Hamano
f8cb64e3d4 Merge branch 'bc/sha-256-part-1-of-4'
SHA-256 transition continues.

* bc/sha-256-part-1-of-4: (22 commits)
  fast-import: add options for rewriting submodules
  fast-import: add a generic function to iterate over marks
  fast-import: make find_marks work on any mark set
  fast-import: add helper function for inserting mark object entries
  fast-import: permit reading multiple marks files
  commit: use expected signature header for SHA-256
  worktree: allow repository version 1
  init-db: move writing repo version into a function
  builtin/init-db: add environment variable for new repo hash
  builtin/init-db: allow specifying hash algorithm on command line
  setup: allow check_repository_format to read repository format
  t/helper: make repository tests hash independent
  t/helper: initialize repository if necessary
  t/helper/test-dump-split-index: initialize git repository
  t6300: make hash algorithm independent
  t6300: abstract away SHA-1-specific constants
  t: use hash-specific lookup tables to define test constants
  repository: require a build flag to use SHA-256
  hex: add functions to parse hex object IDs in any algorithm
  hex: introduce parsing variants taking hash algorithms
  ...
2020-03-26 17:11:20 -07:00
Derrick Stolee
2d657ab95f pack-objects: flip the use of GIT_TEST_PACK_SPARSE
The environment variable GIT_TEST_PACK_SPARSE was previously used
to allow testing the --sparse option for "git pack-objects" in
the test suite. This allowed interesting cases of "git push" to
also test this algorithm.

Since pack.useSparse is now true by default, we do not need this
variable to _enable_ the --sparse option, but instead to _disable_
it. This flips how we work with the variable a bit.

When checking for the variable, default to a value of -1 for
"unset". If unset, then take the default from the repo settings,
which is currently 1. Then, the --[no-]sparse command-line option
will override either of these settings.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-20 14:22:32 -07:00
Junio C Hamano
e8e71848ea Merge branch 'jk/nth-packed-object-id'
Code cleanup to use "struct object_id" more by replacing use of
"char *sha1"

* jk/nth-packed-object-id:
  packfile: drop nth_packed_object_sha1()
  packed_object_info(): use object_id internally for delta base
  packed_object_info(): use object_id for returning delta base
  pack-check: push oid lookup into loop
  pack-check: convert "internal error" die to a BUG()
  pack-bitmap: use object_id when loading on-disk bitmaps
  pack-objects: use object_id struct in pack-reuse code
  pack-objects: convert oe_set_delta_ext() to use object_id
  pack-objects: read delta base oid into object_id struct
  nth_packed_object_oid(): use customary integer return
2020-03-05 10:43:03 -08:00
Junio C Hamano
0df82d99da Merge branch 'jk/object-filter-with-bitmap'
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
2020-03-02 15:07:18 -08:00
Jeff King
f66d4e0250 pack-objects: use object_id struct in pack-reuse code
When the pack-reuse code is dumping an OFS_DELTA entry to a client that
doesn't support it, we re-write it as a REF_DELTA. To do so, we use
nth_packed_object_sha1() to get the oid, but that function is soon going
away in favor of the more type-safe nth_packed_object_id(). Let's switch
now in preparation.

Note that this does incur an extra hash copy (from the pack idx mmap to
the object_id and then to the output, rather than straight from mmap to
the output). But this is not worth worrying about. It's probably not
measurable even when it triggers, and this is fallback code that we
expect to trigger very rarely (since everybody supports OFS_DELTA these
days anyway).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:53 -08:00
Jeff King
a93c141dde pack-objects: convert oe_set_delta_ext() to use object_id
We already store an object_id internally, and now our sole caller also
has one. Let's stop passing around the internal hash array, which adds a
bit of type safety.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:52 -08:00
Jeff King
3f83fd5e44 pack-objects: read delta base oid into object_id struct
When we're considering reusing an on-disk delta, we get the oid of the
base as a pointer to unsigned char bytes of the hash, either into the
packfile itself (for REF_DELTA) or into the pack idx (using the revindex
to convert the offset into an index entry).

Instead, we'd prefer to use a more type-safe object_id as much as
possible. We can get the pack idx using nth_packed_object_id() instead.
For the packfile bytes, we can copy them out using oidread().

This doesn't even incur an extra copy overall, since the next thing we'd
always do with that pointer is pass it to can_reuse_delta(), which needs
an object_id anyway (and called oidread() itself). So this patch also
converts that function to take the object_id directly.

Note that we did previously use NULL as a sentinel value when the object
isn't a delta. We could probably get away with using the null oid for
this, but instead we'll use an explicit boolean flag, which should make
things more obvious for people reading the code later.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:52 -08:00
Jeff King
0763671b8e nth_packed_object_oid(): use customary integer return
Our nth_packed_object_sha1() function returns NULL for error. So when we
wrapped it with nth_packed_object_oid(), we kept the same semantics. But
it's a bit funny, because the caller actually passes in an out
parameter, and the pointer we return is just that same struct they
passed to us (or NULL).

It's not too terrible, but it does make the interface a little
non-idiomatic. Let's switch to our usual "0 for success, negative for
error" return value. Most callers either don't check it, or are
trivially converted. The one that requires the biggest change is
actually improved, as we can ditch an extra aliased pointer variable.

Since we are changing the interface in a subtle way that the compiler
wouldn't catch, let's also change the name to catch any topics in
flight. We can drop the 'o' and make it nth_packed_object_id(). That's
slightly shorter, but also less redundant since the 'o' stands for
"object" already.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:42 -08:00
brian m. carlson
207899137d builtin/pack-objects: make hash agnostic
Avoid hard-coding a hash size, instead preferring to use the_hash_algo.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 09:33:11 -08:00
Junio C Hamano
78e67cda42 Merge branch 'mt/use-passed-repo-more-in-funcs'
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
2020-02-14 12:54:22 -08:00
Junio C Hamano
a14aebeac3 Merge branch 'jk/packfile-reuse-cleanup'
The way "git pack-objects" reuses objects stored in existing pack
to generate its result has been improved.

* jk/packfile-reuse-cleanup:
  pack-bitmap: don't rely on bitmap_git->reuse_objects
  pack-objects: add checks for duplicate objects
  pack-objects: improve partial packfile reuse
  builtin/pack-objects: introduce obj_is_packed()
  pack-objects: introduce pack.allowPackReuse
  csum-file: introduce hashfile_total()
  pack-bitmap: simplify bitmap_has_oid_in_uninteresting()
  pack-bitmap: uninteresting oid can be outside bitmapped packfile
  pack-bitmap: introduce bitmap_walk_contains()
  ewah/bitmap: introduce bitmap_word_alloc()
  packfile: expose get_delta_base()
  builtin/pack-objects: report reused packfile objects
2020-02-14 12:54:19 -08:00
Jeff King
3ab3185f99 pack-objects: support filters with bitmaps
Just as rev-list recently learned to combine filters and bitmaps, let's
do the same for pack-objects. The infrastructure is all there; we just
need to pass along our filter options, and the pack-bitmap code will
decide to use bitmaps or not.

This unsurprisingly makes things faster for partial clones of large
repositories (here we're cloning linux.git):

  Test                               HEAD^               HEAD
  ------------------------------------------------------------------------------
  5310.11: simulated partial clone   38.94(37.28+5.87)   11.06(11.27+4.07) -71.6%

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14 10:46:22 -08:00
Jeff King
6663ae0a08 pack-bitmap: basic noop bitmap filter infrastructure
Currently you can't use object filters with bitmaps, but we plan to
support at least some filters with bitmaps. Let's introduce some
infrastructure that will help us do that:

  - prepare_bitmap_walk() now accepts a list_objects_filter_options
    parameter (which can be NULL for no filtering; all the current
    callers pass this)

  - we'll bail early if the filter is incompatible with bitmaps (just as
    we would if there were no bitmaps at all). Currently all filters are
    incompatible.

  - we'll filter the resulting bitmap; since there are no supported
    filters yet, this is always a noop.

There should be no behavior change yet, but we'll support some actual
filters in a future patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14 10:46:22 -08:00
Jeff King
4eb707ebd6 rev-list: allow commit-only bitmap traversals
Ever since we added reachability bitmap support, we've been able to use
it with rev-list to get the full list of objects, like:

  git rev-list --objects --use-bitmap-index --all

But you can't do so without --objects, since we weren't ready to just
show the commits. However, the internals of the bitmap code are mostly
ready for this: they avoid opening up trees when walking to fill in the
bitmaps. We just need to actually pass in the rev_info to
traverse_bitmap_commit_list() so it knows which types to bother
triggering our callback for.

For completeness, the perf test now covers both the existing --objects
case, as well as the new commits-only behavior (the objects one got way
faster when we introduced bitmaps, but obviously isn't improved now).

Here are numbers for linux.git:

  Test                         HEAD^               HEAD
  ------------------------------------------------------------------------
  5310.7: rev-list (commits)   8.29(8.10+0.19)       1.76(1.72+0.04) -78.8%
  5310.8: rev-list (objects)   8.06(7.94+0.12)       8.14(7.94+0.13) +1.0%

That run was cheating a little, as I didn't have any commit-graph in the
repository, and we'd built it by default these days when running git-gc.
Here are numbers with a commit-graph:

  Test                         HEAD^               HEAD
  ------------------------------------------------------------------------
  5310.7: rev-list (commits)   0.70(0.58+0.12)     0.51(0.46+0.04) -27.1%
  5310.8: rev-list (objects)   6.20(6.09+0.10)     6.27(6.16+0.11) +1.1%

Still an improvement, but a lot less impressive.

We could have the perf script remove any commit-graph to show the
out-sized effect, but it probably makes sense to leave it in what would
be a more typical setup.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14 10:46:22 -08:00
Matheus Tavares
c8123e72f6 streaming: allow open_istream() to handle any repo
Some callers of open_istream() at archive-tar.c and archive-zip.c are
capable of working on arbitrary repositories but the repo struct is not
passed down to open_istream(), which uses the_repository internally. For
now, that's not a problem since the said callers are only being called
with the_repository. But to be consistent and avoid future problems,
let's allow open_istream() to receive a struct repository and use that
instead of the_repository. This parameter addition will also be used in
a future patch to make sha1-file.c:check_object_signature() be able to
work on arbitrary repos.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 10:45:39 -08:00
Jeff King
92fb0db94c pack-objects: add checks for duplicate objects
Additional checks are added in have_duplicate_entry() and
obj_is_packed() to avoid duplicate objects in the reuse
bitmap. It was probably buggy to not have such a check
before.

Git as a client would never both asks for a tag by sha1 and
specify "include-tag", but libgit2 will, so a libgit2 client
cloning from a Git server would trigger the bug.

If a client both asks for a tag by sha1 and specifies
"include-tag", we may end up including the tag in the reuse
bitmap (due to the first thing), and then later adding it to
the packlist (due to the second). This results in duplicate
objects in the pack, which git chokes on. We should notice
that we are already including it when doing the include-tag
portion, and avoid adding it to the packlist.

The simplest place to fix this is right in add_ref_tag(),
where we could avoid peeling the tag at all if we know that
we are already including it. However, this pushes the check
instead into have_duplicate_entry(). This fixes not only
this case, but also means that we cannot have any similar
problems lurking in other code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 10:51:50 -08:00
Jeff King
bb514de356 pack-objects: improve partial packfile reuse
The old code to reuse deltas from an existing packfile
just tried to dump a whole segment of the pack verbatim.
That's faster than the traditional way of actually adding
objects to the packing list, but it didn't kick in very
often. This new code is really going for a middle ground:
do _some_ per-object work, but way less than we'd
traditionally do.

The general strategy of the new code is to make a bitmap
of objects from the packfile we'll include, and then
iterate over it, writing out each object exactly as it is
in our on-disk pack, but _not_ adding it to our packlist
(which costs memory, and increases the search space for
deltas).

One complication is that if we're omitting some objects,
we can't set a delta against a base that we're not
sending. So we have to check each object in
try_partial_reuse() to make sure we have its delta.

About performance, in the worst case we might have
interleaved objects that we are sending or not sending,
and we'd have as many chunks as objects. But in practice
we send big chunks.

For instance, packing torvalds/linux on GitHub servers
now reused 6.5M objects, but only needed ~50k chunks.

Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 10:51:50 -08:00
Jeff King
ff483026a9 builtin/pack-objects: introduce obj_is_packed()
Let's refactor the way we check if an object is packed by
introducing obj_is_packed(). This function is now a simple
wrapper around packlist_find(), but it will evolve in a
following commit.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 10:51:50 -08:00
Jeff King
e704fc7978 pack-objects: introduce pack.allowPackReuse
Let's make it possible to configure if we want pack reuse or not.

The main reason it might not be wanted is probably debugging and
performance testing, though pack reuse _might_ cause larger packs,
because we wouldn't consider the reused objects as bases for
finding new deltas.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 10:51:50 -08:00
Elijah Newren
15beaaa3d1 Fix spelling errors in code comments
Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-10 16:00:54 +09:00
Junio C Hamano
d8ce144e11 Merge branch 'jk/misc-uninitialized-fixes'
Various fixes to codepaths gcc 9 had trouble following dataflow.

* jk/misc-uninitialized-fixes:
  pack-objects: drop packlist index_pos optimization
  test-read-cache: drop namelen variable
  diff-delta: set size out-parameter to 0 for NULL delta
  bulk-checkin: zero-initialize hashfile_checkpoint
  pack-objects: use object_id in packlist_alloc()
  git-am: handle missing "author" when parsing commit
2019-09-30 13:19:30 +09:00
Junio C Hamano
128666753b Merge branch 'jk/drop-release-pack-memory'
xmalloc() used to have a mechanism to ditch memory and address
space resources as the last resort upon seeing an allocation
failure from the underlying malloc(), which made the code complex
and thread-unsafe with dubious benefit, as major memory resource
users already do limit their uses with various other mechanisms.
It has been simplified away.

* jk/drop-release-pack-memory:
  packfile: drop release_pack_memory()
2019-09-18 11:50:08 -07:00
Jeff King
bab28d9f97 builtin/pack-objects: report reused packfile objects
To see when packfile reuse kicks in or not, it is useful to
show reused packfile objects statistics in the output of
upload-pack.

Helped-by: James Ramsay <james@jramsay.com.au>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-13 14:40:33 -07:00
Junio C Hamano
f4f8dfe127 Merge branch 'ds/feature-macros'
A mechanism to affect the default setting for a (related) group of
configuration variables is introduced.

* ds/feature-macros:
  repo-settings: create feature.experimental setting
  repo-settings: create feature.manyFiles setting
  repo-settings: parse core.untrackedCache
  commit-graph: turn on commit-graph by default
  t6501: use 'git gc' in quiet mode
  repo-settings: consolidate some config settings
2019-09-09 12:26:36 -07:00
Jeff King
3a37876b5d pack-objects: drop packlist index_pos optimization
Once upon a time, the code to add an object to our packing list in
pack-objects all lived in a single function. It computed the position
within the hash table once, then used it to check if the object was
already present, and if not, to add it.

Later, in 2834bc27c1 (pack-objects: refactor the packing list,
2013-10-24), this was split into two functions: packlist_find() and
packlist_alloc(). We ended up with an "index_pos" variable that gets
passed through several functions to make it from one to the other.

The resulting code is rather confusing to follow. The "index_pos"
variable is sometimes undefined, if we don't yet have a hash table. This
works out in practice because in that case packlist_alloc() won't use it
at all, since it will have to create/grow the hash table. But it's hard
to verify that, and it does cause gcc 9.2.1's -Wmaybe-uninitialized to
complain when compiled with "-flto -O3" (rightfully, since we do pass
the uninitialized value as a function parameter, even if nobody ends up
using it).

All of this is to save computing the hash index again when we're
inserting into the hash table, which I found doesn't make a measurable
difference in the program runtime (which is not surprising, since we're
doing all kinds of other heavyweight things for each object).

Let's just drop this index_pos variable entirely, simplifying the code
(and pleasing the compiler).

We might be better still refactoring this custom hash table to use one
of our existing implementations (an oidmap, or a kh_oid_map). I stopped
short of that here, but this would be the likely first step towards that
anyway.

Reported-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-06 11:03:42 -07:00
Jeff King
f1cbd033e2 pack-objects: use object_id in packlist_alloc()
The only caller of packlist_alloc() already has a "struct object_id",
and we immediately copy the hash they pass us into our own object_id.
Let's avoid the unnecessary round-trip to a raw sha1 pointer.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-06 11:03:39 -07:00
Derrick Stolee
7211b9e753 repo-settings: consolidate some config settings
There are a few important config settings that are not loaded
during git_default_config. These are instead loaded on-demand.

Centralize these config options to a single scan, and store
all of the values in a repo_settings struct. The values for
each setting are initialized as negative to indicate "unset".

This centralization will be particularly important in a later
change to introduce "meta" config settings that change the
defaults for these config settings.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-13 13:33:54 -07:00
Jeff King
9827d4c185 packfile: drop release_pack_memory()
Long ago, in 97bfeb34df (Release pack windows before reporting out of
memory., 2006-12-24), we taught xmalloc() and friends to try unmapping
pack windows when malloc() failed. It's unlikely that his helps a lot in
practice, and it has some downsides. First, the downsides:

  1. It makes xmalloc() not thread-safe. We've worked around this in
     pack-objects.c, which installs its own locking version of the
     try_to_free_routine(). But other threaded code doesn't.

  2. It makes the system as a whole harder to reason about. Functions
     which allocate heap memory under the hood may have farther-reaching
     effects than expected.

That might be worth the tradeoff if there's a benefit. But in practice,
it seems unlikely. We're generally dealing with mmap'd files, so the OS
is going to do a much better job at responding to memory pressure by
dropping individual pages (the exception is systems with NO_MMAP, but
even there the OS can probably respond just as well with swapping).

So the only thing we're really freeing is address space. On 64-bit
systems, we have plenty of that to go around. On 32-bit systems, it
could possibly help. But around the same time we made two other changes:
77ccc5bbd1 (Introduce new config option for mmap limit., 2006-12-23) and
60bb8b1453 (Fully activate the sliding window pack access., 2006-12-23).
Together that means that a 32-bit system should have no more than 256MB
total of packed-git mmaps at one time, split between a few 32MB windows.
It's unlikely we have any address space problems since then, but we
don't have any data since the features were all added at the same time.

Likewise, xmmap() will try to free memory. At first glance, it seems
like we'd need this (when we try to mmap a new window, we might need to
close an old one to save address space on a 32-bit system). But we're
saved again by core.packedGitLimit: if we're going to exceed our 256MB
limit, we'll close an existing window before we even call mmap().

So it seems unlikely that this feature is actually doing anything
useful. And while we don't have reports of it harming anything (probably
because it rarely if ever kicks in), it would be nice to simplify the
system overall. This patch drops the whole try_to_free system from
xmalloc(), as well as the manual pack memory release in xmmap().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-13 12:21:33 -07:00
Jeff King
25575015ca repack: silence warnings when auto-enabled bitmaps cannot be built
Depending on various config options, a full repack may not be able to
build a reachability bitmap index (e.g., if pack.packSizeLimit forces us
to write multiple packs). In these cases pack-objects may write a
warning to stderr.

Since 36eba0323d (repack: enable bitmaps by default on bare repos,
2019-03-14), we may generate these warnings even when the user did not
explicitly ask for bitmaps. This has two downsides:

  - it can be confusing, if they don't know what bitmaps are

  - a daemonized auto-gc will write this to its log file, and the
    presence of the warning may suppress further auto-gc (until
    gc.logExpiry has elapsed)

Let's have repack communicate to pack-objects that the choice to turn on
bitmaps was not made explicitly by the user, which in turn allows
pack-objects to suppress these warnings.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-31 13:15:51 -07:00
Junio C Hamano
1eb0a12ec3 Merge branch 'nd/tree-walk-with-repo'
The tree-walk API learned to pass an in-core repository
instance throughout more codepaths.

* nd/tree-walk-with-repo:
  t7814: do not generate same commits in different repos
  Use the right 'struct repository' instead of the_repository
  match-trees.c: remove the_repo from shift_tree*()
  tree-walk.c: remove the_repo from get_tree_entry_follow_symlinks()
  tree-walk.c: remove the_repo from get_tree_entry()
  tree-walk.c: remove the_repo from fill_tree_descriptor()
  sha1-file.c: remove the_repo from read_object_with_reference()
2019-07-19 11:30:21 -07:00
Junio C Hamano
a7db4c193d Merge branch 'jk/oidhash'
Code clean-up to remove hardcoded SHA-1 hash from many places.

* jk/oidhash:
  hashmap: convert sha1hash() to oidhash()
  hash.h: move object_id definition from cache.h
  khash: rename oid helper functions
  khash: drop sha1-specific map types
  pack-bitmap: convert khash_sha1 maps into kh_oid_map
  delta-islands: convert island_marks khash to use oids
  khash: rename kh_oid_t to kh_oid_set
  khash: drop broken oid_map typedef
  object: convert create_object() to use object_id
  object: convert internal hash_obj() to object_id
  object: convert lookup_object() to use object_id
  object: convert lookup_unknown_object() to use object_id
  pack-objects: convert locate_object_entry_hash() to object_id
  pack-objects: convert packlist_find() to use object_id
  pack-bitmap-write: convert some helpers to use object_id
  upload-pack: rename a "sha1" variable to "oid"
  describe: fix accidental oid/hash type-punning
2019-07-09 15:25:43 -07:00
Junio C Hamano
a4c8352e1e Merge branch 'jk/delta-islands-progress-fix'
The codepath to compute delta islands used to spew progress output
without giving the callers any way to squelch it, which has been
fixed.

* jk/delta-islands-progress-fix:
  delta-islands: respect progress flag
2019-07-09 15:25:43 -07:00
Nguyễn Thái Ngọc Duy
d3b4705ab8 sha1-file.c: remove the_repo from read_object_with_reference()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-27 12:45:17 -07:00