summaryrefslogtreecommitdiff
path: root/Documentation/technical/api-diff.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/technical/api-diff.txt')
-rw-r--r--Documentation/technical/api-diff.txt174
1 files changed, 0 insertions, 174 deletions
diff --git a/Documentation/technical/api-diff.txt b/Documentation/technical/api-diff.txt
deleted file mode 100644
index 30fc0e9c93..0000000000
--- a/Documentation/technical/api-diff.txt
+++ /dev/null
@@ -1,174 +0,0 @@
-diff API
-========
-
-The diff API is for programs that compare two sets of files (e.g. two
-trees, one tree and the index) and present the found difference in
-various ways. The calling program is responsible for feeding the API
-pairs of files, one from the "old" set and the corresponding one from
-"new" set, that are different. The library called through this API is
-called diffcore, and is responsible for two things.
-
-* finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and
- changes that touch a string (`-S`), as specified by the caller.
-
-* outputting the differences in various formats, as specified by the
- caller.
-
-Calling sequence
-----------------
-
-* Prepare `struct diff_options` to record the set of diff options, and
- then call `repo_diff_setup()` to initialize this structure. This
- sets up the vanilla default.
-
-* Fill in the options structure to specify desired output format, rename
- detection, etc. `diff_opt_parse()` can be used to parse options given
- from the command line in a way consistent with existing git-diff
- family of programs.
-
-* Call `diff_setup_done()`; this inspects the options set up so far for
- internal consistency and make necessary tweaking to it (e.g. if
- textual patch output was asked, recursive behaviour is turned on);
- the callback set_default in diff_options can be used to tweak this more.
-
-* As you find different pairs of files, call `diff_change()` to feed
- modified files, `diff_addremove()` to feed created or deleted files,
- or `diff_unmerge()` to feed a file whose state is 'unmerged' to the
- API. These are thin wrappers to a lower-level `diff_queue()` function
- that is flexible enough to record any of these kinds of changes.
-
-* Once you finish feeding the pairs of files, call `diffcore_std()`.
- This will tell the diffcore library to go ahead and do its work.
-
-* Calling `diff_flush()` will produce the output.
-
-
-Data structures
----------------
-
-* `struct diff_filespec`
-
-This is the internal representation for a single file (blob). It
-records the blob object name (if known -- for a work tree file it
-typically is a NUL SHA-1), filemode and pathname. This is what the
-`diff_addremove()`, `diff_change()` and `diff_unmerge()` synthesize and
-feed `diff_queue()` function with.
-
-* `struct diff_filepair`
-
-This records a pair of `struct diff_filespec`; the filespec for a file
-in the "old" set (i.e. preimage) is called `one`, and the filespec for a
-file in the "new" set (i.e. postimage) is called `two`. A change that
-represents file creation has NULL in `one`, and file deletion has NULL
-in `two`.
-
-A `filepair` starts pointing at `one` and `two` that are from the same
-filename, but `diffcore_std()` can break pairs and match component
-filespecs with other filespecs from a different filepair to form new
-filepair. This is called 'rename detection'.
-
-* `struct diff_queue`
-
-This is a collection of filepairs. Notable members are:
-
-`queue`::
-
- An array of pointers to `struct diff_filepair`. This
- dynamically grows as you add filepairs;
-
-`alloc`::
-
- The allocated size of the `queue` array;
-
-`nr`::
-
- The number of elements in the `queue` array.
-
-
-* `struct diff_options`
-
-This describes the set of options the calling program wants to affect
-the operation of diffcore library with.
-
-Notable members are:
-
-`output_format`::
- The output format used when `diff_flush()` is run.
-
-`context`::
- Number of context lines to generate in patch output.
-
-`break_opt`, `detect_rename`, `rename-score`, `rename_limit`::
- Affects the way detection logic for complete rewrites, renames
- and copies.
-
-`abbrev`::
- Number of hexdigits to abbreviate raw format output to.
-
-`pickaxe`::
- A constant string (can and typically does contain newlines to
- look for a block of text, not just a single line) to filter out
- the filepairs that do not change the number of strings contained
- in its preimage and postimage of the diff_queue.
-
-`flags`::
- This is mostly a collection of boolean options that affects the
- operation, but some do not have anything to do with the diffcore
- library.
-
-`touched_flags`::
- Records whether a flag has been changed due to user request
- (rather than just set/unset by default).
-
-`set_default`::
- Callback which allows tweaking the options in diff_setup_done().
-
-BINARY, TEXT;;
- Affects the way how a file that is seemingly binary is treated.
-
-FULL_INDEX;;
- Tells the patch output format not to use abbreviated object
- names on the "index" lines.
-
-FIND_COPIES_HARDER;;
- Tells the diffcore library that the caller is feeding unchanged
- filepairs to allow copies from unmodified files be detected.
-
-COLOR_DIFF;;
- Output should be colored.
-
-COLOR_DIFF_WORDS;;
- Output is a colored word-diff.
-
-NO_INDEX;;
- Tells diff-files that the input is not tracked files but files
- in random locations on the filesystem.
-
-ALLOW_EXTERNAL;;
- Tells output routine that it is Ok to call user specified patch
- output routine. Plumbing disables this to ensure stable output.
-
-QUIET;;
- Do not show any output.
-
-REVERSE_DIFF;;
- Tells the library that the calling program is feeding the
- filepairs reversed; `one` is two, and `two` is one.
-
-EXIT_WITH_STATUS;;
- For communication between the calling program and the options
- parser; tell the calling program to signal the presence of
- difference using program exit code.
-
-HAS_CHANGES;;
- Internal; used for optimization to see if there is any change.
-
-SILENT_ON_REMOVE;;
- Affects if diff-files shows removed files.
-
-RECURSIVE, TREE_IN_RECURSIVE;;
- Tells if tree traversal done by tree-diff should recursively
- descend into a tree object pair that are different in preimage
- and postimage set.
-
-(JC)