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  */
24 const struct got_error *got_diff_blob(struct got_blob_object *,
25     struct got_blob_object *, const char *, const char *, int, FILE *);
26 
27 /*
28  * Compute the differences between a blob and a file and write unified diff
29  * text to the provided output file. The file's size must be provided, as
30  * well as a const char * diff header label which identifies the file.
31  * An optional const char * diff header label for the blob may be provided, too.
32  * The number of context lines to show in the diff must be specified as well.
33  */
34 const struct got_error *got_diff_blob_file(struct got_blob_object *,
35     const char *, FILE *, size_t, const char *, int, FILE *);
36 
37 /*
38  * A callback function invoked to handle the differences between two blobs
39  * when diffing trees with got_diff_tree(). This callback receives two blobs,
40  * their respective IDs, and two corresponding paths within the diffed trees.
41  * The first blob contains content from the old side of the diff, and
42  * the second blob contains content on the new side of the diff.
43  * The set of arguments relating to either blob may be NULL to indicate
44  * that no content is present on its respective side of the diff.
45  */
46 typedef const struct got_error *(*got_diff_blob_cb)(void *,
47     struct got_blob_object *, struct got_blob_object *,
48     struct got_object_id *, struct got_object_id *,
49     const char *, const char *, struct got_repository *);
50 
51 /*
52  * A pre-defined implementation of got_diff_blob_cb() which appends unidiff
53  * output to a file. The caller must allocate and fill in the argument
54  * structure.
55  */
56 struct got_diff_blob_output_unidiff_arg {
57 	FILE *outfile;		/* Unidiff text will be written here. */
58 	int diff_context;	/* Sets the number of context lines. */
59 };
60 const struct got_error *got_diff_blob_output_unidiff(void *,
61     struct got_blob_object *, struct got_blob_object *,
62     struct got_object_id *, struct got_object_id *,
63     const char *, const char *, struct got_repository *);
64 
65 /*
66  * Compute the differences between two trees and invoke the provided
67  * got_diff_blob_cb() callback when content differs.
68  * Diffing of blob content can be suppressed by passing zero for the
69  * 'diff_content' parameter. The callback will then only receive blob
70  * object IDs and diff labels, but NULL pointers instead of blob objects.
71  */
72 const struct got_error *got_diff_tree(struct got_tree_object *,
73     struct got_tree_object *, const char *, const char *,
74     struct got_repository *, got_diff_blob_cb cb, void *cb_arg, int);
75 
76 /*
77  * Diff two objects, assuming both objects are blobs. Two const char * diff
78  * header labels may be provided which will be used to identify each blob in
79  * the diff output. If a label is NULL, use the blob's SHA1 checksum instead.
80  * The number of context lines to show in the diff must be specified as well.
81  * Write unified diff text to the provided output FILE.
82  */
83 const struct got_error *got_diff_objects_as_blobs(struct got_object_id *,
84     struct got_object_id *, const char *, const char *, int,
85     struct got_repository *, FILE *);
86 
87 /*
88  * Diff two objects, assuming both objects are trees. Two const char * diff
89  * header labels may be provided which will be used to identify each blob in
90  * the trees. If a label is NULL, use the blob's SHA1 checksum instead.
91  * The number of context lines to show in diffs must be specified.
92  * Write unified diff text to the provided output FILE.
93  */
94 const struct got_error *got_diff_objects_as_trees(struct got_object_id *,
95     struct got_object_id *, char *, char *, int, struct got_repository *, FILE *);
96 
97 /*
98  * Diff two objects, assuming both objects are commits.
99  * The number of context lines to show in diffs must be specified.
100  * Write unified diff text to the provided output FILE.
101  */
102 const struct got_error *got_diff_objects_as_commits(struct got_object_id *,
103     struct got_object_id *, int, struct got_repository *, FILE *);
104 
105 #define GOT_DIFF_MAX_CONTEXT	64