Commit graph

445 commits

Author SHA1 Message Date
Junio C Hamano 00624d608c Merge branch 'sb/object-store-grafts'
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.

* sb/object-store-grafts:
  commit: allow lookup_commit_graft to handle arbitrary repositories
  commit: allow prepare_commit_graft to handle arbitrary repositories
  shallow: migrate shallow information into the object parser
  path.c: migrate global git_path_* to take a repository argument
  cache: convert get_graft_file to handle arbitrary repositories
  commit: convert read_graft_file to handle arbitrary repositories
  commit: convert register_commit_graft to handle arbitrary repositories
  commit: convert commit_graft_pos() to handle arbitrary repositories
  shallow: add repository argument to is_repository_shallow
  shallow: add repository argument to check_shallow_file_for_update
  shallow: add repository argument to register_shallow
  shallow: add repository argument to set_alternate_shallow_file
  commit: add repository argument to lookup_commit_graft
  commit: add repository argument to prepare_commit_graft
  commit: add repository argument to read_graft_file
  commit: add repository argument to register_commit_graft
  commit: add repository argument to commit_graft_pos
  object: move grafts to object parser
  object-store: move object access functions to object-store.h
2018-07-18 12:20:28 -07:00
Junio C Hamano 110240588d Merge branch 'sb/object-store-alloc'
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.

* sb/object-store-alloc:
  alloc: allow arbitrary repositories for alloc functions
  object: allow create_object to handle arbitrary repositories
  object: allow grow_object_hash to handle arbitrary repositories
  alloc: add repository argument to alloc_commit_index
  alloc: add repository argument to alloc_report
  alloc: add repository argument to alloc_object_node
  alloc: add repository argument to alloc_tag_node
  alloc: add repository argument to alloc_commit_node
  alloc: add repository argument to alloc_tree_node
  alloc: add repository argument to alloc_blob_node
  object: add repository argument to grow_object_hash
  object: add repository argument to create_object
  repository: introduce parsed objects field
2018-06-25 13:22:38 -07:00
Junio C Hamano a856e7d69f Merge branch 'ds/commit-graph-lockfile-fix'
Update to ds/generation-numbers topic.

* ds/commit-graph-lockfile-fix:
  commit-graph: fix UX issue when .lock file exists
  commit-graph.txt: update design document
  merge: check config before loading commits
  commit: use generation number in remove_redundant()
  commit: add short-circuit to paint_down_to_common()
  commit: use generation numbers for in_merge_bases()
  ref-filter: use generation number for --contains
  commit-graph: always load commit-graph information
  commit: use generations in paint_down_to_common()
  commit-graph: compute generation numbers
  commit: add generation number to struct commit
  ref-filter: fix outdated comment on in_commit_list
2018-06-25 13:22:36 -07:00
Junio C Hamano b3b2aaf0fd Merge branch 'nd/commit-util-to-slab'
The in-core "commit" object had an all-purpose "void *util" field,
which was tricky to use especially in library-ish part of the
code.  All of the existing uses of the field has been migrated to a
more dedicated "commit-slab" mechanism and the field is eliminated.

* nd/commit-util-to-slab:
  commit.h: delete 'util' field in struct commit
  merge: use commit-slab in merge remote desc instead of commit->util
  log: use commit-slab in prepare_bases() instead of commit->util
  show-branch: note about its object flags usage
  show-branch: use commit-slab for commit-name instead of commit->util
  name-rev: use commit-slab for rev-name instead of commit->util
  bisect.c: use commit-slab for commit weight instead of commit->util
  revision.c: use commit-slab for show_source
  sequencer.c: use commit-slab to associate todo items to commits
  sequencer.c: use commit-slab to mark seen commits
  shallow.c: use commit-slab for commit depth instead of commit->util
  describe: use commit-slab for commit names instead of commit->util
  blame: use commit-slab for blame suspects instead of commit->util
  commit-slab: support shared commit-slab
  commit-slab.h: code split
2018-06-25 13:22:35 -07:00
Junio C Hamano 549ca8aa7c Merge branch 'jk/index-pack-maint'
"index-pack --strict" has been taught to make sure that it runs the
final object integrity checks after making the freshly indexed
packfile available to itself.

* jk/index-pack-maint:
  index-pack: correct install_packed_git() args
  index-pack: handle --strict checks of non-repo packs
  prepare_commit_graft: treat non-repository as a noop
2018-06-13 12:50:46 -07:00
Jeff King 14a9bd2898 prepare_commit_graft: treat non-repository as a noop
The parse_commit_buffer() function consults lookup_commit_graft()
to see if we need to rewrite parents. The latter will look
at $GIT_DIR/info/grafts. If you're outside of a repository,
then this will trigger a BUG() as of b1ef400eec (setup_git_env:
avoid blind fall-back to ".git", 2016-10-20).

It's probably uncommon to actually parse a commit outside of
a repository, but you can see it in action with:

  cd /not/a/git/repo
  git index-pack --strict /some/file.pack

This works fine without --strict, but the fsck checks will
try to parse any commits, triggering the BUG(). We can fix
that by teaching the graft code to behave as if there are no
grafts when we aren't in a repository.

Arguably index-pack (and fsck) are wrong to consider grafts
at all. So another solution is to disable grafts entirely
for those commands. But given that the graft feature is
deprecated anyway, it's not worth even thinking through the
ramifications that might have.

There is one other corner case I considered here. What
should:

  cd /not/a/git/repo
  export GIT_GRAFT_FILE=/file/with/grafts
  git index-pack --strict /some/file.pack

do? We don't have a repository, but the user has pointed us
directly at a graft file, which we could respect. I believe
this case did work that way prior to b1ef400eec. However,
fixing it now would be pretty invasive. Back then we would
just call into setup_git_env() even without a repository.
But these days it actually takes a git_dir argument. So
there would be a fair bit of refactoring of the setup code
involved.

Given the obscurity of this case, plus the fact that grafts
are deprecated and probably shouldn't work under index-pack
anyway, it's not worth pursuing further. This patch at least
un-breaks the common case where you're _not_ using grafts,
but we BUG() anyway trying to even find that out.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-01 11:48:54 +09:00
Junio C Hamano 42c8ce1c49 Merge branch 'bc/object-id'
Conversion from uchar[20] to struct object_id continues.

* bc/object-id: (42 commits)
  merge-one-file: compute empty blob object ID
  add--interactive: compute the empty tree value
  Update shell scripts to compute empty tree object ID
  sha1_file: only expose empty object constants through git_hash_algo
  dir: use the_hash_algo for empty blob object ID
  sequencer: use the_hash_algo for empty tree object ID
  cache-tree: use is_empty_tree_oid
  sha1_file: convert cached object code to struct object_id
  builtin/reset: convert use of EMPTY_TREE_SHA1_BIN
  builtin/receive-pack: convert one use of EMPTY_TREE_SHA1_HEX
  wt-status: convert two uses of EMPTY_TREE_SHA1_HEX
  submodule: convert several uses of EMPTY_TREE_SHA1_HEX
  sequencer: convert one use of EMPTY_TREE_SHA1_HEX
  merge: convert empty tree constant to the_hash_algo
  builtin/merge: switch tree functions to use object_id
  builtin/am: convert uses of EMPTY_TREE_SHA1_BIN to the_hash_algo
  sha1-file: add functions for hex empty tree and blob OIDs
  builtin/receive-pack: avoid hard-coded constants for push certs
  diff: specify abbreviation size in terms of the_hash_algo
  upload-pack: replace use of several hard-coded constants
  ...
2018-05-30 14:04:10 +09:00
Junio C Hamano 352cf6cfe1 Merge branch 'js/deprecate-grafts'
The functionality of "$GIT_DIR/info/grafts" has been superseded by
the "refs/replace/" mechanism for some time now, but the internal
code had support for it in many places, which has been cleaned up
in order to drop support of the "grafts" mechanism.

* js/deprecate-grafts:
  Remove obsolete script to convert grafts to replace refs
  technical/shallow: describe why shallow cannot use replace refs
  technical/shallow: stop referring to grafts
  filter-branch: stop suggesting to use grafts
  Deprecate support for .git/info/grafts
  Add a test for `git replace --convert-graft-file`
  replace: introduce --convert-graft-file
  replace: prepare create_graft() for converting graft files wholesale
  replace: "libify" create_graft() and callees
  replace: avoid using die() to indicate a bug
  commit: Let the callback of for_each_mergetag return on error
  argv_array: offer to split a string by whitespace
2018-05-23 14:38:17 +09:00
Junio C Hamano c89b6e136e Merge branch 'ds/lazy-load-trees'
The code has been taught to use the duplicated information stored
in the commit-graph file to learn the tree object name for a commit
to avoid opening and parsing the commit object when it makes sense
to do so.

* ds/lazy-load-trees:
  coccinelle: avoid wrong transformation suggestions from commit.cocci
  commit-graph: lazy-load trees for commits
  treewide: replace maybe_tree with accessor methods
  commit: create get_commit_tree() method
  treewide: rename tree to maybe_tree
2018-05-23 14:38:13 +09:00
Derrick Stolee 04bc8d1ecc commit: use generation number in remove_redundant()
The static remove_redundant() method is used to filter a list
of commits by removing those that are reachable from another
commit in the list. This is used to remove all possible merge-
bases except a maximal, mutually independent set.

To determine these commits are independent, we use a number of
paint_down_to_common() walks and use the PARENT1, PARENT2 flags
to determine reachability. Since we only care about reachability
and not the full set of merge-bases between 'one' and 'twos', we
can use the 'min_generation' parameter to short-circuit the walk.

When no commit-graph exists, there is no change in behavior.

For a copy of the Linux repository, we measured the following
performance improvements:

git merge-base v3.3 v4.5

Before: 234 ms
 After: 208 ms
 Rel %: -11%

git merge-base v4.3 v4.5

Before: 102 ms
 After:  83 ms
 Rel %: -19%

The experiments above were chosen to demonstrate that we are
improving the filtering of the merge-base set. In the first
example, more time is spent walking the history to find the
set of merge bases before the remove_redundant() call. The
starting commits are closer together in the second example,
therefore more time is spent in remove_redundant(). The relative
change in performance differs as expected.

Reported-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-22 12:36:34 +09:00
Derrick Stolee d7c1ec3efd commit: add short-circuit to paint_down_to_common()
When running 'git branch --contains', the in_merge_bases_many()
method calls paint_down_to_common() to discover if a specific
commit is reachable from a set of branches. Commits with lower
generation number are not needed to correctly answer the
containment query of in_merge_bases_many().

Add a new parameter, min_generation, to paint_down_to_common() that
prevents walking commits with generation number strictly less than
min_generation. If 0 is given, then there is no functional change.

For in_merge_bases_many(), we can pass commit->generation as the
cutoff, and this saves time during 'git branch --contains' queries
that would otherwise walk "around" the commit we are inspecting.

For a copy of the Linux repository, where HEAD is checked out at
v4.13~100, we get the following performance improvement for
'git branch --contains' over the previous commit:

Before: 0.21s
After:  0.13s
Rel %: -38%

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-22 12:36:34 +09:00
Derrick Stolee f9b8908b85 commit: use generation numbers for in_merge_bases()
The containment algorithm for 'git branch --contains' is different
from that for 'git tag --contains' in that it uses is_descendant_of()
instead of contains_tag_algo(). The expensive portion of the branch
algorithm is computing merge bases.

When a commit-graph file exists with generation numbers computed,
we can avoid this merge-base calculation when the target commit has
a larger generation number than the initial commits.

Performance tests were run on a copy of the Linux repository where
HEAD is contained in v4.13 but no earlier tag. Also, all tags were
copied to branches and 'git branch --contains' was tested:

Before: 60.0s
After:   0.4s
Rel %: -99.3%

Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-22 12:36:34 +09:00
Derrick Stolee e2838d85b6 commit-graph: always load commit-graph information
Most code paths load commits using lookup_commit() and then
parse_commit(). In some cases, including some branch lookups, the commit
is parsed using parse_object_buffer() which side-steps parse_commit() in
favor of parse_commit_buffer().

With generation numbers in the commit-graph, we need to ensure that any
commit that exists in the commit-graph file has its generation number
loaded.

Create new load_commit_graph_info() method to fill in the information
for a commit that exists only in the commit-graph file. Call it from
parse_commit_buffer() after loading the other commit information from
the given buffer. Only fill this information when specified by the
'check_graph' parameter.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-22 12:36:34 +09:00
Derrick Stolee 3afc679b3c commit: use generations in paint_down_to_common()
Define compare_commits_by_gen_then_commit_date(), which uses generation
numbers as a primary comparison and commit date to break ties (or as a
comparison when both commits do not have computed generation numbers).

Since the commit-graph file is closed under reachability, we know that
all commits in the file have generation at most GENERATION_NUMBER_MAX
which is less than GENERATION_NUMBER_INFINITY.

This change does not affect the number of commits that are walked during
the execution of paint_down_to_common(), only the order that those
commits are inspected. In the case that commit dates violate topological
order (i.e. a parent is "newer" than a child), the previous code could
walk a commit twice: if a commit is reached with the PARENT1 bit, but
later is re-visited with the PARENT2 bit, then that PARENT2 bit must be
propagated to its parents. Using generation numbers avoids this extra
effort, even if it is somewhat rare.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-22 12:36:34 +09:00
Nguyễn Thái Ngọc Duy e2e5ac2303 merge: use commit-slab in merge remote desc instead of commit->util
It's done so that commit->util can be removed. See more explanation in
the commit that removes commit->util.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-21 14:07:20 +09:00
Stefan Beller b9dbddf6da commit: allow lookup_commit_graft to handle arbitrary repositories
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Stefan Beller 2f6c767fd4 commit: allow prepare_commit_graft to handle arbitrary repositories
Move the global variable 'commit_graft_prepared' into the object
pool and convert the function prepare_commit_graft to work
an arbitrary repositories.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Stefan Beller 0437a2e365 cache: convert get_graft_file to handle arbitrary repositories
This conversion was done without the #define trick used in the earlier
series refactoring to have better repository access, because this function
is easy to review, as all lines are converted and it has only one caller.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Brandon Williams d0e5dd0ed4 commit: convert read_graft_file to handle arbitrary repositories
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Brandon Williams a3b78e833b commit: convert register_commit_graft to handle arbitrary repositories
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Brandon Williams e808656c46 commit: convert commit_graft_pos() to handle arbitrary repositories
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Stefan Beller c88134870e shallow: add repository argument to is_repository_shallow
Add a repository argument to allow callers of is_repository_shallow
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Jonathan Nieder 1f93ecd1ab commit: add repository argument to lookup_commit_graft
Add a repository argument to allow callers of lookup_commit_graft to
be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Jonathan Nieder 3ee37656ee commit: add repository argument to prepare_commit_graft
Add a repository argument to allow the caller of prepare_commit_graft
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Jonathan Nieder 02ba3e1a05 commit: add repository argument to read_graft_file
Add a repository argument to allow the caller of read_graft_file to be
more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Jonathan Nieder 3f5787f806 commit: add repository argument to register_commit_graft
Add a repository argument to allow callers of register_commit_graft to
be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Jonathan Nieder be479e801d commit: add repository argument to commit_graft_pos
Add a repository argument to allow callers of commit_graft_pos to be
more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Jonathan Nieder 6a1a79fd14 object: move grafts to object parser
Grafts are only meaningful in the context of a single repository.
Therefore they cannot be global.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Stefan Beller cbd53a2193 object-store: move object access functions to object-store.h
This should make these functions easier to find and cache.h less
overwhelming to read.

In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file

As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise.  It would be better to #include wherever
identifiers from the header are used.  That can happen later
when we have better tooling for it.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Stefan Beller 14ba97f81c alloc: allow arbitrary repositories for alloc functions
We have to convert all of the alloc functions at once, because alloc_report
uses a funky macro for reporting. It is better for the sake of mechanical
conversion to convert multiple functions at once rather than changing the
structure of the reporting function.

We record all memory allocation in alloc.c, and free them in
clear_alloc_state, which is called for all repositories except
the_repository.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:16:50 +09:00
Stefan Beller 8ba0e5ec57 alloc: add repository argument to alloc_commit_node
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-09 12:12:36 +09:00
Stefan Beller 68f95d382b object: add repository argument to create_object
Add a repository argument to allow the callers of create_object
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-09 12:12:36 +09:00
Junio C Hamano b10edb2df5 Merge branch 'ds/commit-graph'
Precompute and store information necessary for ancestry traversal
in a separate file to optimize graph walking.

* ds/commit-graph:
  commit-graph: implement "--append" option
  commit-graph: build graph from starting commits
  commit-graph: read only from specific pack-indexes
  commit: integrate commit graph with commit parsing
  commit-graph: close under reachability
  commit-graph: add core.commitGraph setting
  commit-graph: implement git commit-graph read
  commit-graph: implement git-commit-graph write
  commit-graph: implement write_commit_graph()
  commit-graph: create git-commit-graph builtin
  graph: add commit graph design document
  commit-graph: add format document
  csum-file: refactor finalize_hashfile() method
  csum-file: rename hashclose() to finalize_hashfile()
2018-05-08 15:59:20 +09:00
brian m. carlson 26ea3e7dca commit: convert uses of get_sha1_hex to get_oid_hex
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 13:59:51 +09:00
Johannes Schindelin f9f99b3f7d Deprecate support for .git/info/grafts
The grafts feature was a convenient way to "stitch together" ancient
history to the fresh start of linux.git.

Its implementation is, however, not up to Git's standards, as there are
too many ways where it can lead to surprising and unwelcome behavior.

For example, when pushing from a repository with active grafts, it is
possible to miss commits that have been "grafted out", resulting in a
broken state on the other side.

Also, the grafts feature is limited to "rewriting" commits' list of
parents, it cannot replace anything else.

The much younger feature implemented as `git replace` set out to remedy
those limitations and dangerous bugs.

Seeing as `git replace` is pretty mature by now (since 4228e8bc98
(replace: add --graft option, 2014-07-19) it can perform the graft
file's duties), it is time to deprecate support for the graft file, and
to retire it eventually.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-30 11:12:31 +09:00
Johannes Schindelin fef461ea5d commit: Let the callback of for_each_mergetag return on error
This is yet another patch to be filed under the keyword "libification".

There is one subtle change in behavior here, where a `git log` that has
been asked to show the mergetags would now stop reporting the mergetags
upon the first failure, whereas previously, it would have continued to the
next mergetag, if any.

In practice, that change should not matter, as it is 1) uncommon to
perform octopus merges using multiple tags as merge heads, and 2) when the
user asks to be shown those tags, they really should be there.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-26 12:52:57 +09:00
Derrick Stolee 7b8a21dba1 commit-graph: lazy-load trees for commits
The commit-graph file provides quick access to commit data, including
the OID of the root tree for each commit in the graph. When performing
a deep commit-graph walk, we may not need to load most of the trees
for these commits.

Delay loading the tree object for a commit loaded from the graph
until requested via get_commit_tree(). Do not lazy-load trees for
commits not in the graph, since that requires duplicate parsing
and the relative peformance improvement when trees are not needed
is small.

On the Linux repository, performance tests were run for the following
command:

    git log --graph --oneline -1000

    Before: 0.92s
    After:  0.66s
    Rel %: -28.3%

Adding '-- kernel/' to the command requires loading the root tree
for every commit that is walked. There was no measureable performance
change as a result of this patch.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-11 10:47:16 +09:00
Derrick Stolee 5bb03de102 commit: create get_commit_tree() method
While walking the commit graph, we load struct commit objects into
the object cache. During this process, we also load struct tree
objects for the root tree of each of these commits. We load these
objects even if we are only computing commit reachability information,
such as a merge base or ahead/behind information.

Create get_commit_tree() as a first step to removing direct
references to the 'maybe_tree' member of struct commit.

Create get_commit_tree_oid() as a shortcut for several references
to "&commit->maybe_tree->object.oid" in the codebase.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-11 10:47:16 +09:00
Derrick Stolee 891435d55d treewide: rename tree to maybe_tree
Using the commit-graph file to walk commit history removes the large
cost of parsing commits during the walk. This exposes a performance
issue: lookup_tree() takes a large portion of the computation time,
even when Git never uses those trees.

In anticipation of lazy-loading these trees, rename the 'tree' member
of struct commit to 'maybe_tree'. This serves two purposes: it hints
at the future role of possibly being NULL even if the commit has a
valid tree, and it allows for unambiguous transformation from simple
member access (i.e. commit->maybe_tree) to method access.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-11 10:47:16 +09:00
Junio C Hamano 2d5792f071 Merge branch 'bw/c-plus-plus' into ds/lazy-load-trees
* bw/c-plus-plus: (37 commits)
  replace: rename 'new' variables
  trailer: rename 'template' variables
  tempfile: rename 'template' variables
  wrapper: rename 'template' variables
  environment: rename 'namespace' variables
  diff: rename 'template' variables
  environment: rename 'template' variables
  init-db: rename 'template' variables
  unpack-trees: rename 'new' variables
  trailer: rename 'new' variables
  submodule: rename 'new' variables
  split-index: rename 'new' variables
  remote: rename 'new' variables
  ref-filter: rename 'new' variables
  read-cache: rename 'new' variables
  line-log: rename 'new' variables
  imap-send: rename 'new' variables
  http: rename 'new' variables
  entry: rename 'new' variables
  diffcore-delta: rename 'new' variables
  ...
2018-04-11 10:46:32 +09:00
Derrick Stolee 177722b344 commit: integrate commit graph with commit parsing
Teach Git to inspect a commit graph file to supply the contents of a
struct commit when calling parse_commit_gently(). This implementation
satisfies all post-conditions on the struct commit, including loading
parents, the root tree, and the commit date.

If core.commitGraph is false, then do not check graph files.

In test script t5318-commit-graph.sh, add output-matching conditions on
read-only graph operations.

By loading commits from the graph instead of parsing commit buffers, we
save a lot of time on long commit walks. Here are some performance
results for a copy of the Linux repository where 'master' has 678,653
reachable commits and is behind 'origin/master' by 59,929 commits.

| Command                          | Before | After  | Rel % |
|----------------------------------|--------|--------|-------|
| log --oneline --topo-order -1000 |  8.31s |  0.94s | -88%  |
| branch -vv                       |  1.02s |  0.14s | -86%  |
| rev-list --all                   |  5.89s |  1.07s | -81%  |
| rev-list --all --objects         | 66.15s | 58.45s | -11%  |

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-11 10:43:02 +09:00
brian m. carlson b4f5aca40e sha1_file: convert read_sha1_file to struct object_id
Convert read_sha1_file to take a pointer to struct object_id and rename
it read_object_file.  Do the same for read_sha1_file_extended.

Convert one use in grep.c to use the new function without any other code
change, since the pointer being passed is a void pointer that is already
initialized with a pointer to struct object_id.  Update the declaration
and definitions of the modified functions, and apply the following
semantic patch to convert the remaining callers:

@@
expression E1, E2, E3;
@@
- read_sha1_file(E1.hash, E2, E3)
+ read_object_file(&E1, E2, E3)

@@
expression E1, E2, E3;
@@
- read_sha1_file(E1->hash, E2, E3)
+ read_object_file(E1, E2, E3)

@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1.hash, E2, E3, E4)
+ read_object_file_extended(&E1, E2, E3, E4)

@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1->hash, E2, E3, E4)
+ read_object_file_extended(E1, E2, E3, E4)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14 09:23:50 -07:00
brian m. carlson e816caa07b sha1_file: convert assert_sha1_type to object_id
Convert this function to take a pointer to struct object_id and rename
it to assert_oid_type.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14 09:23:49 -07:00
Junio C Hamano 169c9c0169 Merge branch 'bw/c-plus-plus'
Avoid using identifiers that clash with C++ keywords.  Even though
it is not a goal to compile Git with C++ compilers, changes like
this help use of code analysis tools that targets C++ on our
codebase.

* bw/c-plus-plus: (37 commits)
  replace: rename 'new' variables
  trailer: rename 'template' variables
  tempfile: rename 'template' variables
  wrapper: rename 'template' variables
  environment: rename 'namespace' variables
  diff: rename 'template' variables
  environment: rename 'template' variables
  init-db: rename 'template' variables
  unpack-trees: rename 'new' variables
  trailer: rename 'new' variables
  submodule: rename 'new' variables
  split-index: rename 'new' variables
  remote: rename 'new' variables
  ref-filter: rename 'new' variables
  read-cache: rename 'new' variables
  line-log: rename 'new' variables
  imap-send: rename 'new' variables
  http: rename 'new' variables
  entry: rename 'new' variables
  diffcore-delta: rename 'new' variables
  ...
2018-03-06 14:54:07 -08:00
Brandon Williams 258c03eb45 commit: rename 'new' variables
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-22 10:08:05 -08:00
Junio C Hamano 8be8342b4c Merge branch 'po/object-id'
Conversion from uchar[20] to struct object_id continues.

* po/object-id:
  sha1_file: rename hash_sha1_file_literally
  sha1_file: convert write_loose_object to object_id
  sha1_file: convert force_object_loose to object_id
  sha1_file: convert write_sha1_file to object_id
  notes: convert write_notes_tree to object_id
  notes: convert combine_notes_* to object_id
  commit: convert commit_tree* to object_id
  match-trees: convert splice_tree to object_id
  cache: clear whole hash buffer with oidclr
  sha1_file: convert hash_sha1_file to object_id
  dir: convert struct sha1_stat to use object_id
  sha1_file: convert pretend_sha1_file to object_id
2018-02-15 14:55:43 -08:00
Brandon Williams debca9d2fe object: rename function 'typename' to 'type_name'
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 13:10:05 -08:00
Junio C Hamano cbf0240f82 Merge branch 'sg/cocci-move-array'
Code clean-up.

* sg/cocci-move-array:
  Use MOVE_ARRAY
2018-02-13 13:39:13 -08:00
Patryk Obara a09c985eae sha1_file: convert write_sha1_file to object_id
Convert the definition and declaration of write_sha1_file to
struct object_id and adjust usage of this function.

This commit also converts static function write_sha1_file_prepare, as it
is closely related.

Rename these functions to write_object_file and
write_object_file_prepare respectively.

Replace sha1_to_hex, hashcpy and hashclr with their oid equivalents
wherever possible.

Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-30 10:42:36 -08:00
Patryk Obara 5078f34459 commit: convert commit_tree* to object_id
Convert the definitions and declarations of commit_tree and
commit_tree_extended to use struct object_id and adjust all usages of
these functions.

Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-30 10:42:36 -08:00