996da0503acfa3e3a0ed0f57a951d0fbc1500fb8
[git/git.git] / Documentation / technical / api-revision-walking.txt
1 revision walking API
2 ====================
3
4 The revision walking API offers functions to build a list of revisions
5 and then iterate over that list.
6
7 Calling sequence
8 ----------------
9
10 The walking API has a given calling sequence: first you need to
11 initialize a rev_info structure, then add revisions to control what kind
12 of revision list do you want to get, finally you can iterate over the
13 revision list.
14
15 Functions
16 ---------
17
18 `init_revisions`::
19
20 Initialize a rev_info structure with default values. The second
21 parameter may be NULL or can be prefix path, and then the `.prefix`
22 variable will be set to it. This is typically the first function you
23 want to call when you want to deal with a revision list. After calling
24 this function, you are free to customize options, like set
25 `.ignore_merges` to 0 if you don't want to ignore merges, and so on. See
26 `revision.h` for a complete list of available options.
27
28 `add_pending_object`::
29
30 This function can be used if you want to add commit objects as revision
31 information. You can use the `UNINTERESTING` object flag to indicate if
32 you want to include or exclude the given commit (and commits reachable
33 from the given commit) from the revision list.
34 +
35 NOTE: If you have the commits as a string list then you probably want to
36 use setup_revisions(), instead of parsing each string and using this
37 function.
38
39 `setup_revisions`::
40
41 Parse revision information, filling in the `rev_info` structure, and
42 removing the used arguments from the argument list. Returns the number
43 of arguments left that weren't recognized, which are also moved to the
44 head of the argument list. The last parameter is used in case no
45 parameter given by the first two arguments.
46
47 `prepare_revision_walk`::
48
49 Prepares the rev_info structure for a walk. You should check if it
50 returns any error (non-zero return code) and if it does not, you can
51 start using get_revision() to do the iteration.
52
53 `get_revision`::
54
55 Takes a pointer to a `rev_info` structure and iterates over it,
56 returning a `struct commit *` each time you call it. The end of the
57 revision list is indicated by returning a NULL pointer.
58
59 Data structures
60 ---------------
61
62 Talk about <revision.h>, things like:
63
64 * two diff_options, one for path limiting, another for output;
65 * remaining functions;
66
67 (Linus, JC, Dscho)