git/commit.h, branch v2.18.2

Merge branch 'nd/pack-struct-commit'

2018-05-30T05:04:08Z

Memory optimization. * nd/pack-struct-commit: commit.h: rearrange 'index' to shrink struct commit

Merge branch 'js/deprecate-grafts'

2018-05-23T05:38:17Z

The functionality of "$GIT_DIR/info/grafts" has been superseded by the "refs/replace/" mechanism for some time now, but the internal code had support for it in many places, which has been cleaned up in order to drop support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

commit.h: rearrange 'index' to shrink struct commit

2018-05-13T02:01:48Z

On linux 64-bit architecture, pahole finds that there's a 4 bytes padding after 'index'. Moving it to the end reduces this struct's size from 72 to 64 bytes (because of another 4 bytes padding after graph_pos). On linux 32-bit, the struct size remains 52 bytes like before. Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano

commit: Let the callback of for_each_mergetag return on error

2018-04-26T03:52:57Z

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 Signed-off-by: Junio C Hamano

commit-graph: lazy-load trees for commits

2018-04-11T01:47:16Z

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 Signed-off-by: Junio C Hamano

commit: create get_commit_tree() method

2018-04-11T01:47:16Z

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 Signed-off-by: Junio C Hamano

treewide: rename tree to maybe_tree

2018-04-11T01:47:16Z

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 Signed-off-by: Junio C Hamano

commit: integrate commit graph with commit parsing

2018-04-11T01:43:02Z

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 Signed-off-by: Junio C Hamano

commit: convert commit_tree* to object_id

2018-01-30T18:42:36Z

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 Signed-off-by: Junio C Hamano

Merge branch 'rs/lose-leak-pending'

2018-01-23T21:16:36Z

API clean-up around revision traversal. * rs/lose-leak-pending: commit: remove unused function clear_commit_marks_for_object_array() revision: remove the unused flag leak_pending checkout: avoid using the rev_info flag leak_pending bundle: avoid using the rev_info flag leak_pending bisect: avoid using the rev_info flag leak_pending object: add clear_commit_marks_all() ref-filter: use clear_commit_marks_many() in do_merge_filter() commit: use clear_commit_marks_many() in remove_redundant() commit: avoid allocation in clear_commit_marks_many()