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author | Junio C Hamano <gitster@pobox.com> | 2021-03-01 23:02:56 +0100 |
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committer | Junio C Hamano <gitster@pobox.com> | 2021-03-01 23:02:56 +0100 |
commit | 12bd17521c732ea6de47ec5fd9621a2bca451fe6 (patch) | |
tree | 385480a0dfd083c1dcce8485eabbe6b1d062fee6 /Documentation/gitdiffcore.txt | |
parent | Merge branch 'jh/fsmonitor-prework' (diff) | |
parent | merge-ort: call diffcore_rename() directly (diff) | |
download | git-12bd17521c732ea6de47ec5fd9621a2bca451fe6.tar.xz git-12bd17521c732ea6de47ec5fd9621a2bca451fe6.zip |
Merge branch 'en/diffcore-rename'
Performance optimization work on the rename detection continues.
* en/diffcore-rename:
merge-ort: call diffcore_rename() directly
gitdiffcore doc: mention new preliminary step for rename detection
diffcore-rename: guide inexact rename detection based on basenames
diffcore-rename: complete find_basename_matches()
diffcore-rename: compute basenames of source and dest candidates
t4001: add a test comparing basename similarity and content similarity
diffcore-rename: filter rename_src list when possible
diffcore-rename: no point trying to find a match better than exact
Diffstat (limited to 'Documentation/gitdiffcore.txt')
-rw-r--r-- | Documentation/gitdiffcore.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/gitdiffcore.txt b/Documentation/gitdiffcore.txt index 2bd1220477..1c7269655f 100644 --- a/Documentation/gitdiffcore.txt +++ b/Documentation/gitdiffcore.txt @@ -169,6 +169,26 @@ a similarity score different from the default of 50% by giving a number after the "-M" or "-C" option (e.g. "-M8" to tell it to use 8/10 = 80%). +Note that when rename detection is on but both copy and break +detection are off, rename detection adds a preliminary step that first +checks if files are moved across directories while keeping their +filename the same. If there is a file added to a directory whose +contents is sufficiently similar to a file with the same name that got +deleted from a different directory, it will mark them as renames and +exclude them from the later quadratic step (the one that pairwise +compares all unmatched files to find the "best" matches, determined by +the highest content similarity). So, for example, if a deleted +docs/ext.txt and an added docs/config/ext.txt are similar enough, they +will be marked as a rename and prevent an added docs/ext.md that may +be even more similar to the deleted docs/ext.txt from being considered +as the rename destination in the later step. For this reason, the +preliminary "match same filename" step uses a bit higher threshold to +mark a file pair as a rename and stop considering other candidates for +better matches. At most, one comparison is done per file in this +preliminary pass; so if there are several remaining ext.txt files +throughout the directory hierarchy after exact rename detection, this +preliminary step will be skipped for those files. + Note. When the "-C" option is used with `--find-copies-harder` option, 'git diff-{asterisk}' commands feed unmodified filepairs to diffcore mechanism as well as modified ones. This lets the copy |