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Diffstat (limited to 'Documentation/diffcore.txt')
| -rw-r--r-- | Documentation/diffcore.txt | 78 |
1 files changed, 47 insertions, 31 deletions
diff --git a/Documentation/diffcore.txt b/Documentation/diffcore.txt index 6c474d1..1a6e725 100644 --- a/Documentation/diffcore.txt +++ b/Documentation/diffcore.txt @@ -22,8 +22,8 @@ The git-diff-* family works by first comparing two sets of files: - git-diff-cache compares contents of a "tree" object and the - working directory (when --cached flag is not used) or a - "tree" object and the index file (when --cached flag is + working directory (when '--cached' flag is not used) or a + "tree" object and the index file (when '--cached' flag is used); - git-diff-files compares contents of the index file and the @@ -37,29 +37,31 @@ comparison is passed from these commands to what is internally called "diffcore", in a format similar to what is output when the -p option is not used. E.g. - in-place edit :100644 100644 bcd1234... 0123456... M file0 - create :000000 100644 0000000... 1234567... N file4 - delete :100644 000000 1234567... 0000000... D file5 - unmerged :000000 000000 0000000... 0000000... U file6 +------------------------------------------------ +in-place edit :100644 100644 bcd1234... 0123456... M file0 +create :000000 100644 0000000... 1234567... A file4 +delete :100644 000000 1234567... 0000000... D file5 +unmerged :000000 000000 0000000... 0000000... U file6 +------------------------------------------------ The diffcore mechanism is fed a list of such comparison results (each of which is called "filepair", although at this point each of them talks about a single file), and transforms such a list into another list. There are currently 6 such transformations: - - diffcore-pathspec - - diffcore-break - - diffcore-rename - - diffcore-merge-broken - - diffcore-pickaxe - - diffcore-order +- diffcore-pathspec +- diffcore-break +- diffcore-rename +- diffcore-merge-broken +- diffcore-pickaxe +- diffcore-order -These are applied in sequence. The set of filepairs git-diff-* +These are applied in sequence. The set of filepairs git-diff-\* commands find are used as the input to diffcore-pathspec, and the output from diffcore-pathspec is used as the input to the next transformation. The final result is then passed to the output routine and generates either diff-raw format (see Output -format sections of the manual for git-diff-* commands) or +format sections of the manual for git-diff-\* commands) or diff-patch format. @@ -87,13 +89,17 @@ used to detect a filepair that represents "complete rewrite" and break such filepair into two filepairs that represent delete and create. E.g. If the input contained this filepair: - :100644 100644 bcd1234... 0123456... M file0 +------------------------------------------------ +:100644 100644 bcd1234... 0123456... M file0 +------------------------------------------------ and if it detects that the file "file0" is completely rewritten, it changes it to: - :100644 000000 bcd1234... 0000000... D file0 - :000000 100644 0000000... 0123456... N file0 +------------------------------------------------ +:100644 000000 bcd1234... 0000000... D file0 +:000000 100644 0000000... 0123456... A file0 +------------------------------------------------ For the purpose of breaking a filepair, diffcore-break examines the extent of changes between the contents of the files before @@ -117,14 +123,18 @@ controlled by the -M option (to detect renames) and the -C option (to detect copies as well) to the git-diff-* commands. If the input contained these filepairs: - :100644 000000 0123456... 0000000... D fileX - :000000 100644 0000000... 0123456... N file0 +------------------------------------------------ +:100644 000000 0123456... 0000000... D fileX +:000000 100644 0000000... 0123456... A file0 +------------------------------------------------ and the contents of the deleted file fileX is similar enough to the contents of the created file file0, then rename detection merges these filepairs and creates: - :100644 100644 0123456... 0123456... R100 fileX file0 +------------------------------------------------ +:100644 100644 0123456... 0123456... R100 fileX file0 +------------------------------------------------ When the "-C" option is used, the original contents of modified files and contents of unchanged files are considered as @@ -133,15 +143,19 @@ addition to the deleted files. If the input were like these filepairs, that talk about a modified file fileY and a newly created file file0: - :100644 100644 0123456... 1234567... M fileY - :000000 100644 0000000... 0123456... N file0 +------------------------------------------------ +:100644 100644 0123456... 1234567... M fileY +:000000 100644 0000000... 0123456... A file0 +------------------------------------------------ the original contents of fileY and the resulting contents of file0 are compared, and if they are similar enough, they are changed to: - :100644 100644 0123456... 1234567... M fileY - :100644 100644 0123456... 0123456... C100 fileY file0 +------------------------------------------------ +:100644 100644 0123456... 1234567... M fileY +:100644 100644 0123456... 0123456... C100 fileY file0 +------------------------------------------------ In both rename and copy detection, the same "extent of changes" algorithm used in diffcore-break is used to determine if two @@ -151,11 +165,11 @@ number after "-M" or "-C" option (e.g. "-M8" to tell it to use 8/10 = 80%). Note. When the "-C" option is used with --find-copies-harder -option, git-diff-* commands feed unmodified filepairs to +option, git-diff-\* commands feed unmodified filepairs to diffcore mechanism as well as modified ones. This lets the copy detector consider unmodified files as copy source candidates at the expense of making it slower. Without --find-copies-harder, -git-diff-* commands can detect copies only if the file that was +git-diff-\* commands can detect copies only if the file that was copied happened to have been modified in the same changeset. @@ -186,10 +200,10 @@ material is deleted, the broken pairs are merged back into a single modification) by giving a second number to -B option, like these: - -B50/60 (give 50% "break score" to diffcore-break, use - 60% for diffcore-merge-broken). - -B/60 (the same as above, since diffcore-break defautls to - 50%). +* -B50/60 (give 50% "break score" to diffcore-break, use 60% + for diffcore-merge-broken). + +* -B/60 (the same as above, since diffcore-break defaults to 50%). Note that earlier implementation left a broken pair as a separate creation and deletion patches. This was unnecessary hack and @@ -237,12 +251,14 @@ in the file are output before ones that match a later line, and filepairs that do not match any glob pattern are output last. As an example, typical orderfile for the core GIT probably -should look like this: +would look like this: +------------------------------------------------ README Makefile Documentation *.h *.c t +------------------------------------------------ |