1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 /*
18  * Compute the differences between two blobs and write unified diff text
19  * to the provided output FILE. Two const char * diff header labels may
20  * be provided which will be used to identify each blob in the diff output.
21  * If a label is NULL, use the blob's SHA1 checksum instead.
22  * The number of context lines to show in the diff must be specified as well.
23  * Whitespace differences may optionally be ignored.
24  */
25 const struct got_error *got_diff_blob(struct got_blob_object *,
26     struct got_blob_object *, const char *, const char *, int, int, FILE *);
27 
28 /*
29  * Compute the differences between a blob and a file and write unified diff
30  * text to the provided output file. The file's size must be provided, as
31  * well as a const char * diff header label which identifies the file.
32  * An optional const char * diff header label for the blob may be provided, too.
33  * The number of context lines to show in the diff must be specified as well.
34  * Whitespace differences may optionally be ignored.
35  */
36 const struct got_error *got_diff_blob_file(struct got_blob_object *,
37     const char *, FILE *, size_t, const char *, int, int, FILE *);
38 
39 /*
40  * A callback function invoked to handle the differences between two blobs
41  * when diffing trees with got_diff_tree(). This callback receives two blobs,
42  * their respective IDs, and two corresponding paths within the diffed trees.
43  * The first blob contains content from the old side of the diff, and
44  * the second blob contains content on the new side of the diff.
45  * The set of arguments relating to either blob may be NULL to indicate
46  * that no content is present on its respective side of the diff.
47  * File modes from relevant tree objects which contain the blobs may
48  * also be passed. These will be zero if not available.
49  */
50 typedef const struct got_error *(*got_diff_blob_cb)(void *,
51     struct got_blob_object *, struct got_blob_object *,
52     struct got_object_id *, struct got_object_id *,
53     const char *, const char *, mode_t, mode_t, struct got_repository *);
54 
55 /*
56  * A pre-defined implementation of got_diff_blob_cb() which appends unidiff
57  * output to a file. The caller must allocate and fill in the argument
58  * structure.
59  */
60 struct got_diff_blob_output_unidiff_arg {
61 	FILE *outfile;		/* Unidiff text will be written here. */
62 	int diff_context;	/* Sets the number of context lines. */
63 	int ignore_whitespace;	/* Ignore whitespace differences. */
64 };
65 const struct got_error *got_diff_blob_output_unidiff(void *,
66     struct got_blob_object *, struct got_blob_object *,
67     struct got_object_id *, struct got_object_id *,
68     const char *, const char *, mode_t, mode_t, struct got_repository *);
69 
70 /*
71  * Compute the differences between two trees and invoke the provided
72  * got_diff_blob_cb() callback when content differs.
73  * Diffing of blob content can be suppressed by passing zero for the
74  * 'diff_content' parameter. The callback will then only receive blob
75  * object IDs and diff labels, but NULL pointers instead of blob objects.
76  */
77 const struct got_error *got_diff_tree(struct got_tree_object *,
78     struct got_tree_object *, const char *, const char *,
79     struct got_repository *, got_diff_blob_cb cb, void *cb_arg, int);
80 
81 /*
82  * A pre-defined implementation of got_diff_blob_cb() which collects a list
83  * of file paths that differ between two trees.
84  * The caller must allocate and initialize a got_pathlist_head * argument.
85  * Data pointers of entries added to the path list will point to a struct
86  * got_diff_changed_path object.
87  * The caller is expected to free both the path and data pointers of all
88  * entries on the path list.
89  */
90 struct got_diff_changed_path {
91 	/*
92 	 * The modification status of this path. It can be GOT_STATUS_ADD,
93 	 * GOT_STATUS_DELETE, GOT_STATUS_MODIFY, or GOT_STATUS_MODE_CHANGE.
94 	 */
95 	int status;
96 };
97 const struct got_error *got_diff_tree_collect_changed_paths(void *,
98     struct got_blob_object *, struct got_blob_object *,
99     struct got_object_id *, struct got_object_id *,
100     const char *, const char *, mode_t, mode_t, struct got_repository *);
101 
102 /*
103  * Diff two objects, assuming both objects are blobs. Two const char * diff
104  * header labels may be provided which will be used to identify each blob in
105  * the diff output. If a label is NULL, use the blob's SHA1 checksum instead.
106  * The number of context lines to show in the diff must be specified as well.
107  * Write unified diff text to the provided output FILE.
108  */
109 const struct got_error *got_diff_objects_as_blobs(struct got_object_id *,
110     struct got_object_id *, const char *, const char *, int, int,
111     struct got_repository *, FILE *);
112 
113 /*
114  * Diff two objects, assuming both objects are trees. Two const char * diff
115  * header labels may be provided which will be used to identify each blob in
116  * the trees. If a label is NULL, use the blob's SHA1 checksum instead.
117  * The number of context lines to show in diffs must be specified.
118  * Write unified diff text to the provided output FILE.
119  */
120 const struct got_error *got_diff_objects_as_trees(struct got_object_id *,
121     struct got_object_id *, char *, char *, int, int,
122     struct got_repository *, FILE *);
123 
124 /*
125  * Diff two objects, assuming both objects are commits.
126  * The number of context lines to show in diffs must be specified.
127  * Write unified diff text to the provided output FILE.
128  */
129 const struct got_error *got_diff_objects_as_commits(struct got_object_id *,
130     struct got_object_id *, int, int, struct got_repository *, FILE *);
131 
132 #define GOT_DIFF_MAX_CONTEXT	64