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2022-02-17Merge branch 'jz/rev-list-exclude-first-parent-only'Libravatar Junio C Hamano1-1/+2
"git log" and friends learned an option --exclude-first-parent-only to propagate UNINTERESTING bit down only along the first-parent chain, just like --first-parent option shows commits that lack the UNINTERESTING bit only along the first-parent chain. * jz/rev-list-exclude-first-parent-only: git-rev-list: add --exclude-first-parent-only flag
2022-02-16Merge branch 'en/remerge-diff'Libravatar Junio C Hamano1-1/+5
"git log --remerge-diff" shows the difference from mechanical merge result and the result that is actually recorded in a merge commit. * en/remerge-diff: diff-merges: avoid history simplifications when diffing merges merge-ort: mark conflict/warning messages from inner merges as omittable show, log: include conflict/warning messages in --remerge-diff headers diff: add ability to insert additional headers for paths merge-ort: format messages slightly different for use in headers merge-ort: mark a few more conflict messages as omittable merge-ort: capture and print ll-merge warnings in our preferred fashion ll-merge: make callers responsible for showing warnings log: clean unneeded objects during `log --remerge-diff` show, log: provide a --remerge-diff capability
2022-02-02log: clean unneeded objects during `log --remerge-diff`Libravatar Elijah Newren1-0/+3
The --remerge-diff option will need to create new blobs and trees representing the "automatic merge" state. If one is traversing a long project history, one can easily get hundreds of thousands of loose objects generated during `log --remerge-diff`. However, none of those loose objects are needed after we have completed our diff operation; they can be summarily deleted. Add a new helper function to tmp_objdir to discard all the contained objects, and call it after each merge is handled. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02show, log: provide a --remerge-diff capabilityLibravatar Elijah Newren1-1/+2
When this option is specified, we remerge all (two parent) merge commits and diff the actual merge commit to the automatically created version, in order to show how users removed conflict markers, resolved the different conflict versions, and potentially added new changes outside of conflict regions in order to resolve semantic merge problems (or, possibly, just to hide other random changes). This capability works by creating a temporary object directory and marking it as the primary object store. This makes it so that any blobs or trees created during the automatic merge are easily removable afterwards by just deleting all objects from the temporary object directory. There are a few ways that this implementation is suboptimal: * `log --remerge-diff` becomes slow, because the temporary object directory can fill with many loose objects while running * the log output can be muddied with misplaced "warning: cannot merge binary files" messages, since ll-merge.c unconditionally writes those messages to stderr while running instead of allowing callers to manage them. * important conflict and warning messages are simply dropped; thus for conflicts like modify/delete or rename/rename or file/directory which are not representable with content conflict markers, there may be no way for a user of --remerge-diff to know that there had been a conflict which was resolved (and which possibly motivated other changes in the merge commit). * when fixing the previous issue, note that some unimportant conflict and warning messages might start being included. We should instead make sure these remain dropped. Subsequent commits will address these issues. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-12git-rev-list: add --exclude-first-parent-only flagLibravatar Jerry Zhang1-1/+2
It is useful to know when a branch first diverged in history from some integration branch in order to be able to enumerate the user's local changes. However, these local changes can include arbitrary merges, so it is necessary to ignore this merge structure when finding the divergence point. In order to do this, teach the "rev-list" family to accept "--exclude-first-parent-only", which restricts the traversal of excluded commits to only follow first parent links. -A-----E-F-G--main \ / / B-C-D--topic In this example, the goal is to return the set {B, C, D} which represents a topic branch that has been merged into main branch. `git rev-list topic ^main` will end up returning no commits since excluding main will end up traversing the commits on topic as well. `git rev-list --exclude-first-parent-only topic ^main` however will return {B, C, D} as desired. Add docs for the new flag, and clarify the doc for --first-parent to indicate that it applies to traversing the set of included commits only. Signed-off-by: Jerry Zhang <jerry@skydio.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-17log: let --invert-grep only invert --grepLibravatar René Scharfe1-2/+0
The option --invert-grep is documented to filter out commits whose messages match the --grep filters. However, it also affects the header matches (--author, --committer), which is not intended. Move the handling of that option to grep.c, as only the code there can distinguish between matches in the header from those in the message body. If --invert-grep is given then enable extended expressions (not the regex type, we just need git grep's --not to work), negate the body patterns and check if any of them match by piggy-backing on the collect_hits mechanism of grep_source_1(). Collecting the matches in struct grep_opt is a bit iffy, but with "last_shown" we have a precedent for writing state information to that struct. Reported-by: Dotan Cohen <dotancohen@gmail.com> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-06Merge branch 'jt/add-submodule-odb-clean-up'Libravatar Junio C Hamano1-1/+0
More code paths that use the hack to add submodule's object database to the set of alternate object store have been cleaned up. * jt/add-submodule-odb-clean-up: revision: remove "submodule" from opt struct repository: support unabsorbed in repo_submodule_init submodule: remove unnecessary unabsorbed fallback
2021-09-09revision: remove "submodule" from opt structLibravatar Jonathan Tan1-1/+0
Clean up a TODO in revision.h by removing the "submodule" field from struct setup_revision_opt. This field is only used to specify the ref store to use, so use rev_info->repo to determine the ref store instead. The only users of this field are merge-ort.c and merge-recursive.c. However, both these files specify the superproject as rev_info->repo and the submodule as setup_revision_opt->submodule. In order to be able to pass the submodule as rev_info->repo, all commits must be parsed with the submodule explicitly specified; this patch does that as well. (An incremental solution in which only some commits are parsed with explicit submodule will not work, because if the same commit is parsed twice in different repositories, there will be 2 heap-allocated object structs corresponding to that commit, and any flag set by the revision walking mechanism on one of them will not be reflected onto the other.) Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05revision: separate walk and unsorted flagsLibravatar Patrick Steinhardt1-5/+2
The `--no-walk` flag supports two modes: either it sorts the revisions given as input input or it doesn't. This is reflected in a single `no_walk` flag, which reflects one of the three states "walk", "don't walk but without sorting" and "don't walk but with sorting". Split up the flag into two separate bits, one indicating whether we should walk or not and one indicating whether the input should be sorted or not. This will allow us to more easily introduce a new flag `--unsorted-input`, which only impacts the sorting bit. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22Merge branch 'bc/rev-list-without-commit-line'Libravatar Junio C Hamano1-1/+2
"git rev-list" learns to omit the "commit <object-name>" header lines from the output with the `--no-commit-header` option. * bc/rev-list-without-commit-line: rev-list: add option for --pretty=format without header
2021-07-12rev-list: add option for --pretty=format without headerLibravatar brian m. carlson1-1/+2
In general, we encourage users to use plumbing commands, like git rev-list, over porcelain commands, like git log, when scripting. However, git rev-list has one glaring problem that prevents it from being used in certain cases: when --pretty is used with a custom format, it always prints out a line containing "commit" and the object ID. This makes it unsuitable for many scripting needs, and forces users to use git log instead. While we can't change this behavior for backwards compatibility, we can add an option to suppress this behavior, so let's do so, and call it "--no-commit-header". Additionally, add the corresponding positive option to switch it back on. Note that this option doesn't affect the built-in formats, only custom formats. This is exactly the same behavior as users already have from git log and is what most users will be used to. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-08Merge branch 'jk/bitmap-tree-optim'Libravatar Junio C Hamano1-0/+1
Avoid duplicated work while building reachability bitmaps. * jk/bitmap-tree-optim: bitmaps: don't recurse into trees already in the bitmap
2021-06-15bitmaps: don't recurse into trees already in the bitmapLibravatar Jeff King1-0/+1
If an object is already mentioned in a reachability bitmap we are building, then by definition so are all of the objects it can reach. We have an optimization to stop traversing commits when we see they are already in the bitmap, but we don't do the same for trees. It's generally unavoidable to recurse into trees for commits not yet covered by bitmaps (since most commits generally do have unique top-level trees). But they usually have subtrees that are shared with other commits (i.e., all of the subtrees the commit _didn't_ touch). And some of those commits (and their trees) may be covered by the bitmap. Usually this isn't _too_ big a deal, because we'll visit those subtrees only once in total for the whole walk. But if you have a large number of unbitmapped commits, and if your tree is big, then you may end up opening a lot of sub-trees for no good reason. We can use the same optimization we do for commits here: when we are about to open a tree, see if it's in the bitmap (either the one we are building, or the "seen" bitmap which covers the UNINTERESTING side of the bitmap when doing a set-difference). This works especially well because we'll visit all commits before hitting any trees. So even in a history like: A -- B if "A" has a bitmap on disk but "B" doesn't, we'll already have OR-ed in the results from A before looking at B's tree (so we really will only look at trees touched by B). For most repositories, the timings produced by p5310 are unspectacular. Here's linux.git: Test HEAD^ HEAD -------------------------------------------------------------------- 5310.4: simulated clone 6.00(5.90+0.10) 5.98(5.90+0.08) -0.3% 5310.5: simulated fetch 2.98(5.45+0.18) 2.85(5.31+0.18) -4.4% 5310.7: rev-list (commits) 0.32(0.29+0.03) 0.33(0.30+0.03) +3.1% 5310.8: rev-list (objects) 1.48(1.44+0.03) 1.49(1.44+0.05) +0.7% Any improvement there is within the noise (the +3.1% on test 7 has to be noise, since we are not recursing into trees, and thus the new code isn't even run). The results for git.git are likewise uninteresting. But here are numbers from some other real-world repositories (that are not public). This one's tree is comparable in size to linux.git, but has ~16k refs (and so less complete bitmap coverage): Test HEAD^ HEAD ------------------------------------------------------------------------- 5310.4: simulated clone 38.34(39.86+0.74) 33.95(35.53+0.76) -11.5% 5310.5: simulated fetch 2.29(6.31+0.35) 2.20(5.97+0.41) -3.9% 5310.7: rev-list (commits) 0.99(0.86+0.13) 0.96(0.85+0.11) -3.0% 5310.8: rev-list (objects) 11.32(11.04+0.27) 6.59(6.37+0.21) -41.8% And here's another with a very large tree (~340k entries), and a fairly large number of refs (~10k): Test HEAD^ HEAD ------------------------------------------------------------------------- 5310.3: simulated clone 53.83(54.71+1.54) 39.77(40.76+1.50) -26.1% 5310.4: simulated fetch 19.91(20.11+0.56) 19.79(19.98+0.67) -0.6% 5310.6: rev-list (commits) 0.54(0.44+0.11) 0.51(0.43+0.07) -5.6% 5310.7: rev-list (objects) 24.32(23.59+0.73) 9.85(9.49+0.36) -59.5% This patch provides substantial improvements in these larger cases, and have any drawbacks for smaller ones (the cost of the bitmap check is quite small compared to an actual tree traversal). Note that we have to add a version of revision.c's include_check callback which handles non-commits. We could possibly consolidate this into a single callback for all objects types, as there's only one user of the feature which would need converted (pack-bitmap.c:should_include). That would in theory let us avoid duplicating any logic. But when I tried it, the code ended up much worse to read, with lots of repeated "if it's a commit do this, otherwise do that". Having two separate callbacks splits that naturally, and matches the existing split of show_commit/show_object callbacks. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-14Merge branch 'so/log-m-implies-p'Libravatar Junio C Hamano1-1/+1
The "-m" option in "git log -m" that does not specify which format, if any, of diff is desired did not have any visible effect; it now implies some form of diff (by default "--patch") is produced. * so/log-m-implies-p: diff-merges: let "-m" imply "-p" diff-merges: rename "combined_imply_patch" to "merges_imply_patch" stash list: stop passing "-m" to "git log" git-svn: stop passing "-m" to "git rev-list" diff-merges: move specific diff-index "-m" handling to diff-index t4013: test "git diff-index -m" t4013: test "git diff-tree -m" t4013: test "git log -m --stat" t4013: test "git log -m --raw" t4013: test that "-m" alone has no effect in "git log"
2021-05-21diff-merges: rename "combined_imply_patch" to "merges_imply_patch"Libravatar Sergey Organov1-1/+1
This is refactoring change in preparation for the next commit that will let -m imply -p. The old name doesn't match the intention to let not only -c/-cc imply -p, but also -m, that is not a "combined" format, so we rename the flag accordingly. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-10revision: mark commit parents as NOT_USER_GIVENLibravatar Patrick Steinhardt1-3/+0
The NOT_USER_GIVEN flag of an object marks whether a flag was explicitly provided by the user or not. The most important use case for this is when filtering objects: only objects that were not explicitly requested will get filtered. The flag is currently only set for blobs and trees, which has been fine given that there are no filters for tags or commits currently. We're about to extend filtering capabilities to add object type filter though, which requires us to set up the NOT_USER_GIVEN flag correctly -- if it's not set, the object wouldn't get filtered at all. Mark unseen commit parents as NOT_USER_GIVEN when processing parents. Like this, explicitly provided parents stay user-given and thus unfiltered, while parents which get loaded as part of the graph walk can be filtered. This commit shouldn't have any user-visible impact yet as there is no logic to filter commits yet. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-02Merge branch 'zh/format-patch-fractional-reroll-count'Libravatar Junio C Hamano1-1/+1
"git format-patch -v<n>" learned to allow a reroll count that is not an integer. * zh/format-patch-fractional-reroll-count: format-patch: allow a non-integral version numbers
2021-03-23format-patch: allow a non-integral version numbersLibravatar ZheNing Hu1-1/+1
The `-v<n>` option of `format-patch` can give nothing but an integral iteration number to patches in a series.  Some people, however, prefer to mark a new iteration with only a small fixup with a non integral iteration number (e.g. an "oops, that was wrong" fix-up patch for v4 iteration may be labeled as "v4.1"). Allow `format-patch` to take such a non-integral iteration number. `<n>` can be any string, such as '3.1' or '4rev2'. In the case where it is a non-integral value, the "Range-diff" and "Interdiff" headers will not include the previous version. Signed-off-by: ZheNing Hu <adlternative@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22revision: learn '--no-kept-objects'Libravatar Taylor Blau1-0/+4
A future caller will want to be able to perform a reachability traversal which terminates when visiting an object found in a kept pack. The closest existing option is '--honor-pack-keep', but this isn't quite what we want. Instead of halting the traversal midway through, a full traversal is always performed, and the results are only trimmed afterwords. Besides needing to introduce a new flag (since culling results post-facto can be different than halting the traversal as it's happening), there is an additional wrinkle handling the distinction in-core and on-disk kept packs. That is: what kinds of kept pack should stop the traversal? Introduce '--no-kept-objects[=<on-disk|in-core>]' to specify which kinds of kept packs, if any, should stop a traversal. This can be useful for callers that want to perform a reachability analysis, but want to leave certain packs alone (for e.g., when doing a geometric repack that has some "large" packs which are kept in-core that it wants to leave alone). Note that this option is not guaranteed to produce exactly the set of objects that aren't in kept packs, since it's possible the traversal order may end up in a situation where a non-kept ancestor was "cut off" by a kept object (at which point we would stop traversing). But, we don't care about absolute correctness here, since this will eventually be used as a purely additive guide in an upcoming new repack mode. Explicitly avoid documenting this new flag, since it is only used internally. In theory we could avoid even adding it rev-list, but being able to spell this option out on the command-line makes some special cases easier to test without promising to keep it behaving consistently forever. Those tricky cases are exercised in t6114. Signed-off-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05Merge branch 'so/log-diff-merge'Libravatar Junio C Hamano1-2/+7
"git log" learned a new "--diff-merges=<how>" option. * so/log-diff-merge: (32 commits) t4013: add tests for --diff-merges=first-parent doc/git-show: include --diff-merges description doc/rev-list-options: document --first-parent changes merges format doc/diff-generate-patch: mention new --diff-merges option doc/git-log: describe new --diff-merges options diff-merges: add '--diff-merges=1' as synonym for 'first-parent' diff-merges: add old mnemonic counterparts to --diff-merges diff-merges: let new options enable diff without -p diff-merges: do not imply -p for new options diff-merges: implement new values for --diff-merges diff-merges: make -m/-c/--cc explicitly mutually exclusive diff-merges: refactor opt settings into separate functions diff-merges: get rid of now empty diff_merges_init_revs() diff-merges: group diff-merge flags next to each other inside 'rev_info' diff-merges: split 'ignore_merges' field diff-merges: fix -m to properly override -c/--cc t4013: add tests for -m failing to override -c/--cc t4013: support test_expect_failure through ':failure' magic diff-merges: revise revs->diff flag handling diff-merges: handle imply -p on -c/--cc logic for log.c ...
2020-12-21diff-merges: let new options enable diff without -pLibravatar Sergey Organov1-0/+1
New options don't have any visible effect unless -p is either given or implied, as unlike -c/-cc we don't imply -p with --diff-merges. To fix this, this patch adds new functionality by letting new options enable output of diffs for merge commits only. Add 'merges_need_diff' field and set it whenever diff output for merges is enabled by any of the new options. Extend diff output logic accordingly, to output diffs for merges when 'merges_need_diff' is set even when no -p has been provided. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21diff-merges: do not imply -p for new optionsLibravatar Sergey Organov1-0/+1
Add 'combined_imply_patch' field and set it only for old --cc/-c options, then imply -p if this flag is set instead of implying -p whenever 'combined_merge' flag is set. We don't want new --diff-merge options to imply -p, to make it possible to enable output of diffs for merges independently from non-merge commits. At the same time we want to preserve behavior of old --c/-c/-m options and their interactions with --first-parent, to stay backward-compatible. This patch is first step in this direction: it separates old "--cc/-c imply -p" logic from the rest of the options. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21diff-merges: group diff-merge flags next to each other inside 'rev_info'Libravatar Sergey Organov1-2/+3
The relevant flags were somewhat scattered over definition of 'struct rev_info'. Rearrange them to group them together. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21diff-merges: split 'ignore_merges' fieldLibravatar Sergey Organov1-1/+2
'ignore_merges' was 3-way field that served two distinct purposes that we now assign to 2 new independent flags: 'separate_merges', and 'explicit_diff_merges'. 'separate_merges' tells that we need to output diff format containing separate diff for every parent (as opposed to 'combine_merges'). 'explicit_diff_merges' tells that at least one of diff-merges options has been explicitly specified on the command line, so no defaults should apply. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21diff-merges: introduce revs->first_parent_merges flagLibravatar Sergey Organov1-0/+1
This new field allows us to separate format of diff for merges from 'first_parent_only' flag which primary purpose is limiting history traversal. This change further localizes diff format selection logic into the diff-merges.c file. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: move diff merges functions to its own diff-merges.cLibravatar Sergey Organov1-3/+0
Create separate diff-merges.c and diff-merges.h files, and move all the code related to handling of diff merges there. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: provide implementation for diff merges tweaksLibravatar Sergey Organov1-0/+3
Use these implementations from show_setup_revisions_tweak() and log_setup_revisions_tweak() in builtin/log.c. This completes moving of management of diff merges parameters to a single place, where we can finally observe them simultaneously. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-09format-patch: make output filename configurableLibravatar Junio C Hamano1-0/+1
For the past 15 years, we've used the hardcoded 64 as the length limit of the filename of the output from the "git format-patch" command. Since the value is shorter than the 80-column terminal, it could grow without line wrapping a bit. At the same time, since the value is longer than half of the 80-column terminal, we could fit two or more of them in "ls" output on such a terminal if we allowed to lower it. Introduce a new command line option --filename-max-length=<n> and a new configuration variable format.filenameMaxLength to override the hardcoded default. While we are at it, remove a check that the name of output directory does not exceed PATH_MAX---this check is pointless in that by the time control reaches the function, the caller would already have done an equivalent of "mkdir -p", so if the system does not like an overly long directory name, the control wouldn't have reached here, and otherwise, we know that the system allowed the output directory to exist. In the worst case, we will get an error when we try to open the output file and handle the error correctly anyway. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31revision: add separate field for "-m" of "diff-index -m"Libravatar Sergey Organov1-0/+1
Add separate 'match_missing' field for diff-index to use and set it when we encounter "-m" option. This field won't then be cleared when another meaning of "-m" is reverted (e.g., by "--no-diff-merges"), nor it will be affected by future option(s) that might drive 'ignore_merges' field. Use this new field from diff-lib:do_oneway_diff() instead of reusing 'ignore_merges' field. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17Merge branch 'jk/log-fp-implies-m'Libravatar Junio C Hamano1-1/+1
"git log --first-parent -p" showed patches only for single-parent commits on the first-parent chain; the "--first-parent" option has been made to imply "-m". Use "--no-diff-merges" to restore the previous behaviour to omit patches for merge commits. * jk/log-fp-implies-m: doc/git-log: clarify handling of merge commit diffs doc/git-log: move "-t" into diff-options list doc/git-log: drop "-r" diff option doc/git-log: move "Diff Formatting" from rev-list-options log: enable "-m" automatically with "--first-parent" revision: add "--no-diff-merges" option to counteract "-m" log: drop "--cc implies -m" logic
2020-07-30Merge branch 'ds/commit-graph-bloom-updates' into masterLibravatar Junio C Hamano1-2/+4
Updates to the changed-paths bloom filter. * ds/commit-graph-bloom-updates: commit-graph: check all leading directories in changed path Bloom filters revision: empty pathspecs should not use Bloom filters revision.c: fix whitespace commit-graph: check chunk sizes after writing commit-graph: simplify chunk writes into loop commit-graph: unify the signatures of all write_graph_chunk_*() functions commit-graph: persist existence of changed-paths bloom: fix logic in get_bloom_filter() commit-graph: change test to die on parse, not load commit-graph: place bloom_settings in context
2020-07-29revision: add "--no-diff-merges" option to counteract "-m"Libravatar Jeff King1-1/+1
The "-m" option sets revs->ignore_merges to "0", but there's no way to undo it. This probably isn't something anybody overly cares about, since "1" is already the default, but it will serve as an escape hatch when we flip the default for ignore_merges to "0" in more situations. We'll also add a few extra niceties: - initialize the value to "-1" to indicate "not set", and then resolve it to the normal 0/1 bool in setup_revisions(). This lets any tweak functions, as well as setup_revisions() itself, avoid clobbering the user's preference (which until now they couldn't actually express). - since we now have --no-diff-merges, let's add the matching --diff-merges, which is just a synonym for "-m". Then we don't even need to document --no-diff-merges separately; it countermands the long form of "-m" in the usual way. The new test shows that this behaves just the same as the current behavior without "-m". Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-01commit-graph: check all leading directories in changed path Bloom filtersLibravatar SZEDER Gábor1-2/+4
The file 'dir/subdir/file' can only be modified if its leading directories 'dir' and 'dir/subdir' are modified as well. So when checking modified path Bloom filters looking for commits modifying a path with multiple path components, then check not only the full path in the Bloom filters, but all its leading directories as well. Take care to check these paths in "deepest first" order, because it's the full path that is least likely to be modified, and the Bloom filter queries can short circuit sooner. This can significantly reduce the average false positive rate, by about an order of magnitude or three(!), and can further speed up pathspec-limited revision walks. The table below compares the average false positive rate and runtime of git rev-list HEAD -- "$path" before and after this change for 5000+ randomly* selected paths from each repository: Average false Average Average positive rate runtime runtime before after before after difference ------------------------------------------------------------------ git 3.220% 0.7853% 0.0558s 0.0387s -30.6% linux 2.453% 0.0296% 0.1046s 0.0766s -26.8% tensorflow 2.536% 0.6977% 0.0594s 0.0420s -29.2% *Path selection was done with the following pipeline: git ls-tree -r --name-only HEAD | sort -R | head -n 5000 The improvements in runtime are much smaller than the improvements in average false positive rate, as we are clearly reaching diminishing returns here. However, all these timings depend on that accessing tree objects is reasonably fast (warm caches). If we had a partial clone and the tree objects had to be fetched from a promisor remote, e.g.: $ git clone --filter=tree:0 --bare file://.../webkit.git webkit.notrees.git $ git -C webkit.git -c core.modifiedPathBloomFilters=1 \ commit-graph write --reachable $ cp webkit.git/objects/info/commit-graph webkit.notrees.git/objects/info/ $ git -C webkit.notrees.git -c core.modifiedPathBloomFilters=1 \ rev-list HEAD -- "$path" then checking all leading path component can reduce the runtime from over an hour to a few seconds (and this is with the clone and the promisor on the same machine). This adjusts the tracing values in t4216-log-bloom.sh, which provides a concrete way to notice the improvement. Helped-by: Taylor Blau <me@ttaylorr.com> Helped-by: René Scharfe <l.s.r@web.de> Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-24revision: reallocate TOPO_WALK object flagsLibravatar René Scharfe1-3/+4
The bit fields in struct object have an unfortunate layout. Here's what pahole reports on x86_64 GNU/Linux: struct object { unsigned int parsed:1; /* 0: 0 4 */ unsigned int type:3; /* 0: 1 4 */ /* XXX 28 bits hole, try to pack */ /* Force alignment to the next boundary: */ unsigned int :0; unsigned int flags:29; /* 4: 0 4 */ /* XXX 3 bits hole, try to pack */ struct object_id oid; /* 8 32 */ /* size: 40, cachelines: 1, members: 4 */ /* sum members: 32 */ /* sum bitfield members: 33 bits, bit holes: 2, sum bit holes: 31 bits */ /* last cacheline: 40 bytes */ }; Notice the 1+3+29=33 bits in bit fields and 28+3=31 bits in holes. There are holes inside the flags bit field as well -- while some object flags are used for more than one purpose, 22, 23 and 24 are still free. Use 23 and 24 instead of 27 and 28 for TOPO_WALK_EXPLORED and TOPO_WALK_INDEGREE. This allows us to reduce FLAG_BITS by one so that all bitfields combined fit into a single 32-bit slot: struct object { unsigned int parsed:1; /* 0: 0 4 */ unsigned int type:3; /* 0: 1 4 */ unsigned int flags:28; /* 0: 4 4 */ struct object_id oid; /* 4 32 */ /* size: 36, cachelines: 1, members: 4 */ /* last cacheline: 36 bytes */ }; With this tight packing the size of struct object is reduced by 10%. Other architectures probably benefit as well. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-01Merge branch 'gs/commit-graph-path-filter'Libravatar Junio C Hamano1-0/+11
Introduce an extension to the commit-graph to make it efficient to check for the paths that were modified at each commit using Bloom filters. * gs/commit-graph-path-filter: bloom: ignore renames when computing changed paths commit-graph: add GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS test flag t4216: add end to end tests for git log with Bloom filters revision.c: add trace2 stats around Bloom filter usage revision.c: use Bloom filters to speed up path based revision walks commit-graph: add --changed-paths option to write subcommand commit-graph: reuse existing Bloom filters during write commit-graph: write Bloom filters to commit graph file commit-graph: examine commits by generation number commit-graph: examine changed-path objects in pack order commit-graph: compute Bloom filters for changed paths diff: halt tree-diff early after max_changes bloom.c: core Bloom filter implementation for changed paths. bloom.c: introduce core Bloom filter constructs bloom.c: add the murmur3 hash implementation commit-graph: define and use MAX_NUM_CHUNKS
2020-04-22Merge branch 'ds/revision-show-pulls'Libravatar Junio C Hamano1-1/+5
"git log" learned "--show-pulls" that helps pathspec limited history views; a merge commit that takes the whole change from a side branch, which is normally omitted from the output, is shown in addition to the commits that introduce real changes. * ds/revision-show-pulls: revision: --show-pulls adds helpful merges
2020-04-10revision: --show-pulls adds helpful mergesLibravatar Derrick Stolee1-1/+5
The default file history simplification of "git log -- <path>" or "git rev-list -- <path>" focuses on providing the smallest set of commits that first contributed a change. The revision walk greatly restricts the set of walked commits by visiting only the first TREESAME parent of a merge commit, when one exists. This means that portions of the commit-graph are not walked, which can be a performance benefit, but can also "hide" commits that added changes but were ignored by a merge resolution. The --full-history option modifies this by walking all commits and reporting a merge commit as "interesting" if it has _any_ parent that is not TREESAME. This tends to be an over-representation of important commits, especially in an environment where most merge commits are created by pull request completion. Suppose we have a commit A and we create a commit B on top that changes our file. When we merge the pull request, we create a merge commit M. If no one else changed the file in the first-parent history between M and A, then M will not be TREESAME to its first parent, but will be TREESAME to B. Thus, the simplified history will be "B". However, M will appear in the --full-history mode. However, suppose that a number of topics T1, T2, ..., Tn were created based on commits C1, C2, ..., Cn between A and M as follows: A----C1----C2--- ... ---Cn----M------P1---P2--- ... ---Pn \ \ \ \ / / / / \ \__.. \ \/ ..__T1 / Tn \ \__.. /\ ..__T2 / \_____________________B \____________________/ If the commits T1, T2, ... Tn did not change the file, then all of P1 through Pn will be TREESAME to their first parent, but not TREESAME to their second. This means that all of those merge commits appear in the --full-history view, with edges that immediately collapse into the lower history without introducing interesting single-parent commits. The --simplify-merges option was introduced to remove these extra merge commits. By noticing that the rewritten parents are reachable from their first parents, those edges can be simplified away. Finally, the commits now look like single-parent commits that are TREESAME to their "only" parent. Thus, they are removed and this issue does not cause issues anymore. However, this also ends up removing the commit M from the history view! Even worse, the --simplify-merges option requires walking the entire history before returning a single result. Many Git users are using Git alongside a Git service that provides code storage alongside a code review tool commonly called "Pull Requests" or "Merge Requests" against a target branch. When these requests are accepted and merged, they typically create a merge commit whose first parent is the previous branch tip and the second parent is the tip of the topic branch used for the request. This presents a valuable order to the parents, but also makes that merge commit slightly special. Users may want to see not only which commits changed a file, but which pull requests merged those commits into their branch. In the previous example, this would mean the users want to see the merge commit "M" in addition to the single- parent commit "C". Users are even more likely to want these merge commits when they use pull requests to merge into a feature branch before merging that feature branch into their trunk. In some sense, users are asking for the "first" merge commit to bring in the change to their branch. As long as the parent order is consistent, this can be handled with the following rule: Include a merge commit if it is not TREESAME to its first parent, but is TREESAME to a later parent. These merges look like the merge commits that would result from running "git pull <topic>" on a main branch. Thus, the option to show these commits is called "--show-pulls". This has the added benefit of showing the commits created by closing a pull request or merge request on any of the Git hosting and code review platforms. To test these options, extend the standard test example to include a merge commit that is not TREESAME to its first parent. It is surprising that that option was not already in the example, as it is instructive. In particular, this extension demonstrates a common issue with file history simplification. When a user resolves a merge conflict using "-Xours" or otherwise ignoring one side of the conflict, they create a TREESAME edge that probably should not be TREESAME. This leads users to become frustrated and complain that "my change disappeared!" In my experience, showing them history with --full-history and --simplify-merges quickly reveals the problematic merge. As mentioned, this option is expensive to compute. The --show-pulls option _might_ show the merge commit (usually titled "resolving conflicts") more quickly. Of course, this depends on the user having the correct parent order, which is backwards when using "git pull master" from a topic branch. There are some special considerations when combining the --show-pulls option with --simplify-merges. This requires adding a new PULL_MERGE object flag to store the information from the initial TREESAME comparisons. This helps avoid dropping those commits in later filters. This is covered by a test, including how the parents can be simplified. Since "struct object" has already ruined its 32-bit alignment by using 33 bits across parsed, type, and flags member, let's not make it worse. PULL_MERGE is used in revision.c with the same value (1u<<15) as REACHABLE in commit-graph.c. The REACHABLE flag is only used when writing a commit-graph file, and a revision walk using --show-pulls does not happen in the same process. Care must be taken in the future to ensure this remains the case. Update Documentation/rev-list-options.txt with significant details around this option. This requires updating the example in the History Simplification section to demonstrate some of the problems with TREESAME second parents. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-07format-patch: teach --no-encode-email-headersLibravatar Emma Brooks1-1/+2
When commit subjects or authors have non-ASCII characters, git format-patch Q-encodes them so they can be safely sent over email. However, if the patch transfer method is something other than email (web review tools, sneakernet), this only serves to make the patch metadata harder to read without first applying it (unless you can decode RFC 2047 in your head). git am as well as some email software supports non-Q-encoded mail as described in RFC 6531. Add --[no-]encode-email-headers and format.encodeEmailHeaders to let the user control this behavior. Signed-off-by: Emma Brooks <me@pluvano.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-06revision.c: use Bloom filters to speed up path based revision walksLibravatar Garima Singh1-0/+11
Revision walk will now use Bloom filters for commits to speed up revision walks for a particular path (for computing history for that path), if they are present in the commit-graph file. We load the Bloom filters during the prepare_revision_walk step, currently only when dealing with a single pathspec. Extending it to work with multiple pathspecs can be explored and built on top of this series in the future. While comparing trees in rev_compare_trees(), if the Bloom filter says that the file is not different between the two trees, we don't need to compute the expensive diff. This is where we get our performance gains. The other response of the Bloom filter is '`:maybe', in which case we fall back to the full diff calculation to determine if the path was changed in the commit. We do not try to use Bloom filters when the '--walk-reflogs' option is specified. The '--walk-reflogs' option does not walk the commit ancestry chain like the rest of the options. Incorporating the performance gains when walking reflog entries would add more complexity, and can be explored in a later series. Performance Gains: We tested the performance of `git log -- <path>` on the git repo, the linux and some internal large repos, with a variety of paths of varying depths. On the git and linux repos: - we observed a 2x to 5x speed up. On a large internal repo with files seated 6-10 levels deep in the tree: - we observed 10x to 20x speed ups, with some paths going up to 28 times faster. Helped-by: Derrick Stolee <dstolee@microsoft.com Helped-by: SZEDER Gábor <szeder.dev@gmail.com> Helped-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Garima Singh <garima.singh@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-25Merge branch 'dl/format-patch-notes-config-fixup'Libravatar Junio C Hamano1-1/+1
"git format-patch" can take a set of configured format.notes values to specify which notes refs to use in the log message part of the output. The behaviour of this was not consistent with multiple --notes command line options, which has been corrected. * dl/format-patch-notes-config-fixup: notes.h: fix typos in comment notes: break set_display_notes() into smaller functions config/format.txt: clarify behavior of multiple format.notes format-patch: move git_config() before repo_init_revisions() format-patch: use --notes behavior for format.notes notes: extract logic into set_display_notes() notes: create init_display_notes() helper notes: rename to load_display_notes()
2019-12-16Merge branch 'hw/doc-in-header'Libravatar Junio C Hamano1-0/+59
* hw/doc-in-header: trace2: move doc to trace2.h submodule-config: move doc to submodule-config.h tree-walk: move doc to tree-walk.h trace: move doc to trace.h run-command: move doc to run-command.h parse-options: add link to doc file in parse-options.h credential: move doc to credential.h argv-array: move doc to argv-array.h cache: move doc to cache.h sigchain: move doc to sigchain.h pathspec: move doc to pathspec.h revision: move doc to revision.h attr: move doc to attr.h refs: move doc to refs.h remote: move doc to remote.h and refspec.h sha1-array: move doc to sha1-array.h merge: move doc to ll-merge.h graph: move doc to graph.h and graph.c dir: move doc to dir.h diff: move doc to diff.h and diffcore.h
2019-12-13notes: break set_display_notes() into smaller functionsLibravatar Denton Liu1-1/+1
In 8164c961e1 (format-patch: use --notes behavior for format.notes, 2019-12-09), we introduced set_display_notes() which was a monolithic function with three mutually exclusive branches. Break the function up into three small and simple functions that each are only responsible for one task. This family of functions accepts an `int *show_notes` instead of returning a value suitable for assignment to `show_notes`. This is for two reasons. First of all, this guarantees that the external `show_notes` variable changes in lockstep with the `struct display_notes_opt`. Second, this prompts future developers to be careful about doing something meaningful with this value. In fact, a NULL check is intentionally omitted because causing a segfault here would tell the future developer that they are meant to use the value for something meaningful. One alternative was making the family of functions accept a `struct rev_info *` instead of the `struct display_notes_opt *`, since the former contains the `show_notes` field as well. This does not work because we have to call git_config() before repo_init_revisions(). However, if we had a `struct rev_info`, we'd need to initialize it before it gets assigned values from git_config(). As a result, we break the circular dependency by having standalone `int show_notes` and `struct display_notes_opt notes_opt` variables which temporarily hold values from git_config() until the values are copied over to `rev`. To implement this change, we need to get a pointer to `rev_info::show_notes`. Unfortunately, this is not possible with bitfields and only direct-assignment is possible. Change `rev_info::show_notes` to a non-bitfield int so that we can get its address. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-20revision: make get_revision_mark() return const pointerLibravatar Denton Liu1-2/+2
get_revision_mark() used to return a `char *`, even though all of the strings it was returning were string literals. Make get_revision_mark() return a `const char *` so that callers won't be tempted to modify the returned string. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-18revision: move doc to revision.hLibravatar Heba Waly1-0/+59
Move the documentation from Documentation/technical/api-revision-walking.txt to revision.h as it's easier for the developers to find the usage information beside the code instead of looking for it in another doc file. Also documentation/technical/api-revision-walking.txt is removed because the information it has is now redundant and it'll be hard to keep it up to date and synchronized with the documentation in the header file. Signed-off-by: Heba Waly <heba.waly@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-07Merge branch 'en/combined-all-paths'Libravatar Junio C Hamano1-0/+1
Output from "diff --cc" did not show the original paths when the merge involved renames. A new option adds the paths in the original trees to the output. * en/combined-all-paths: log,diff-tree: add --combined-all-paths option
2019-02-07log,diff-tree: add --combined-all-paths optionLibravatar Elijah Newren1-0/+1
The combined diff format for merges will only list one filename, even if rename or copy detection is active. For example, with raw format one might see: ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM describe.c ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM bar.sh ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR phooey.c This doesn't let us know what the original name of bar.sh was in the first parent, and doesn't let us know what either of the original names of phooey.c were in either of the parents. In contrast, for non-merge commits, raw format does provide original filenames (and a rename score to boot). In order to also provide original filenames for merge commits, add a --combined-all-paths option (which must be used with either -c or --cc, and is likely only useful with rename or copy detection active) so that we can print tab-separated filenames when renames are involved. This transforms the above output to: ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM desc.c desc.c desc.c ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM foo.sh bar.sh bar.sh ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR fooey.c fuey.c phooey.c Further, in patch format, this changes the from/to headers so that instead of just having one "from" header, we get one for each parent. For example, instead of having --- a/phooey.c +++ b/phooey.c we would see --- a/fooey.c --- a/fuey.c +++ b/phooey.c Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-06Merge branch 'ds/push-sparse-tree-walk'Libravatar Junio C Hamano1-0/+2
"git pack-objects" learned another algorithm to compute the set of objects to send, that trades the resulting packfile off to save traversal cost to favor small pushes. * ds/push-sparse-tree-walk: pack-objects: create GIT_TEST_PACK_SPARSE pack-objects: create pack.useSparse setting revision: implement sparse algorithm list-objects: consume sparse tree walk revision: add mark_tree_uninteresting_sparse
2019-01-17revision: add mark_tree_uninteresting_sparseLibravatar Derrick Stolee1-0/+2
In preparation for a new algorithm that walks fewer trees when creating a pack from a set of revisions, create a method that takes an oidset of tree oids and marks reachable objects as UNINTERESTING. The current implementation uses the existing mark_tree_uninteresting to recursively walk the trees and blobs. This will walk the same number of trees as the old mechanism. To ensure that mark_tree_uninteresting walks the tree, we need to remove the UNINTERESTING flag before calling the method. This implementation will be replaced entirely in a later commit. There is one new assumption in this approach: we are also given the oids of the interesting trees. This implementation does not use those trees at the moment, but we will use them in a later rewrite of this method. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14Merge branch 'md/exclude-promisor-objects-fix-cleanup'Libravatar Junio C Hamano1-2/+2
Code clean-up. * md/exclude-promisor-objects-fix-cleanup: revision.c: put promisor option in specialized struct
2018-12-06revision.c: put promisor option in specialized structLibravatar Matthew DeVore1-2/+2
Put the allow_exclude_promisor_objects flag in setup_revision_opt. When it was in rev_info, it was unclear when it was used, since rev_info is passed to functions that don't use the flag. This resulted in unnecessary setting of the flag in prune.c, so fix that as well. Signed-off-by: Matthew DeVore <matvore@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>