git/diff.h, branch v2.30.2

Merge branch 'mk/diff-ignore-regex'

2020-11-02T21:17:44Z

"git diff" family of commands learned the "-I" option to ignore hunks whose changed lines all match the given pattern. * mk/diff-ignore-regex: diff: add -I that ignores matching changes merge-base, xdiff: zero out xpparam_t structures

Merge branch 'dl/diff-merge-base'

2020-11-02T21:17:39Z

"git diff A...B" learned "git diff --merge-base A B", which is a longer short-hand to say the same thing. * dl/diff-merge-base: contrib/completion: complete `git diff --merge-base` builtin/diff-tree: learn --merge-base builtin/diff-index: learn --merge-base t4068: add --merge-base tests diff-lib: define diff_get_merge_base() diff-lib: accept option flags in run_diff_index() contrib/completion: extract common diff/difftool options git-diff.txt: backtick quote command text git-diff-index.txt: make --cached description a proper sentence t4068: remove unnecessary >tmp

diff: add -I that ignores matching changes

2020-10-20T19:53:26Z

Add a new diff option that enables ignoring changes whose all lines (changed, removed, and added) match a given regular expression. This is similar to the -I/--ignore-matching-lines option in standalone diff utilities and can be used e.g. to ignore changes which only affect code comments or to look for unrelated changes in commits containing a large number of automatically applied modifications (e.g. a tree-wide string replacement). The difference between -G/-S and the new -I option is that the latter filters output on a per-change basis. Use the 'ignore' field of xdchange_t for marking a change as ignored or not. Since the same field is used by --ignore-blank-lines, identical hunk emitting rules apply for --ignore-blank-lines and -I. These two options can also be used together in the same git invocation (they are complementary to each other). Rename xdl_mark_ignorable() to xdl_mark_ignorable_lines(), to indicate that it is logically a "sibling" of xdl_mark_ignorable_regex() rather than its "parent". Signed-off-by: Michał Kępień Signed-off-by: Junio C Hamano

Merge branch 'so/combine-diff-simplify'

2020-10-05T21:01:51Z

Code simplification. * so/combine-diff-simplify: diff: get rid of redundant 'dense' argument

Merge branch 'tb/bloom-improvements'

2020-09-29T21:01:20Z

"git commit-graph write" learned to limit the number of bloom filters that are computed from scratch with the --max-new-filters option. * tb/bloom-improvements: commit-graph: introduce 'commitGraph.maxNewFilters' builtin/commit-graph.c: introduce '--max-new-filters=' commit-graph: rename 'split_commit_graph_opts' bloom: encode out-of-bounds filters as non-empty bloom/diff: properly short-circuit on max_changes bloom: use provided 'struct bloom_filter_settings' bloom: split 'get_bloom_filter()' in two commit-graph.c: store maximum changed paths commit-graph: respect 'commitGraph.readChangedPaths' t/helper/test-read-graph.c: prepare repo settings commit-graph: pass a 'struct repository *' in more places t4216: use an '&&'-chain commit-graph: introduce 'get_bloom_filter_settings()'

diff: get rid of redundant 'dense' argument

2020-09-29T18:54:53Z

Get rid of 'dense' argument that is redundant for every function that has 'struct rev_info *rev' argument as well, as the value of 'dense' passed is always taken from 'rev->dense_combined_merges' field. The only place where this was not the case is in 'submodule.c' where 'diff_tree_combined_merge()' was called with '1' for 'dense' argument. However, at that call the 'revs' instance used is local to the function, and we now just set 'revs->dense_combined_merges' to 1 in this local instance. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

builtin/diff-index: learn --merge-base

2020-09-21T04:30:26Z

There is currently no easy way to take the diff between the working tree or index and the merge base between an arbitrary commit and HEAD. Even diff's `...` notation doesn't allow this because it only works between commits. However, the ability to do this would be desirable to a user who would like to see all the changes they've made on a branch plus uncommitted changes without taking into account changes made in the upstream branch. Teach diff-index and diff (with one commit) the --merge-base option which allows a user to use the merge base of a commit and HEAD as the "before" side. Signed-off-by: Denton Liu Signed-off-by: Junio C Hamano

diff-lib: define diff_get_merge_base()

2020-09-21T04:30:26Z

In a future commit, we will be using this function to implement --merge-base functionality in various diff commands. Signed-off-by: Denton Liu Signed-off-by: Junio C Hamano

diff-lib: accept option flags in run_diff_index()

2020-09-21T04:30:26Z

In a future commit, we will teach run_diff_index() to accept more options via flag bits. For now, change `cached` into a flag in the `option` bitfield. The behaviour should remain exactly the same. Signed-off-by: Denton Liu Signed-off-by: Junio C Hamano

bloom/diff: properly short-circuit on max_changes

2020-09-17T16:31:25Z

Commit e3696980 (diff: halt tree-diff early after max_changes, 2020-03-30) intended to create a mechanism to short-circuit a diff calculation after a certain number of paths were modified. By incrementing a "num_changes" counter throughout the recursive ll_diff_tree_paths(), this was supposed to match the number of changes that would be written into the changed-path Bloom filters. Unfortunately, this was not implemented correctly and instead misses simple cases like file modifications. This then does not stop very large changed-path filters from being written (unless they add or remove many files). To start, change the implementation in ll_diff_tree_paths() to instead use the global diff_queue_diff struct's 'nr' member as the count. This is a way to simplify the logic instead of making more mistakes in the complicated diff code. This has a drawback: the diff_queue_diff struct only lists the paths corresponding to blob changes, not their leading directories. Thus, get_or_compute_bloom_filter() needs an additional check to see if the hashmap with the leading directories becomes too large. One reason why this was not caught by test cases was that the test in t4216-log-bloom.sh that was supposed to check this "too many changes" condition only checked this on the initial commit of a repository. The old logic counted these values correctly. Update this test in a few ways: 1. Use GIT_TEST_BLOOM_SETTINGS_MAX_CHANGED_PATHS to reduce the limit, allowing smaller commits to engage with this logic. 2. Create several interesting cases of edits, adds, removes, and mode changes (in the second commit). By testing both sides of the inequality with the *_MAX_CHANGED_PATHS variable, we can see that the count is exactly correct, so none of these changes are missed or over-counted. 3. Use the trace2 data value filter_found_large to verify that these commits are on the correct side of the limit. Another way to verify the behavior is correct is through performance tests. By testing on my local copies of the Git repository and the Linux kernel repository, I could measure the effect of these short-circuits when computing a fresh commit-graph file with changed-path Bloom filters using the command GIT_TEST_BLOOM_SETTINGS_MAX_CHANGED_PATHS=N time \ git commit-graph write --reachable --changed-paths and reporting the wall time and resulting commit-graph size. For Git, the results are | | N=1 | N=10 | N=512 | |--------|----------------|----------------|----------------| | HEAD~1 | 10.90s 9.18MB | 11.11s 9.34MB | 11.31s 9.35MB | | HEAD | 9.21s 8.62MB | 11.11s 9.29MB | 11.29s 9.34MB | For Linux, the results are | | N=1 | N=20 | N=512 | |--------|----------------|---------------|---------------| | HEAD~1 | 61.28s 64.3MB | 76.9s 72.6MB | 77.6s 72.6MB | | HEAD | 49.44s 56.3MB | 68.7s 65.9MB | 69.2s 65.9MB | Naturally, the improvement becomes much less as the limit grows, as fewer commits satisfy the short-circuit. Reported-by: SZEDER Gábor Signed-off-by: Derrick Stolee Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano