Merge branches 'bf/doc' and 'db/tartree'
[git/git.git] / tree-diff.c
CommitLineData
ac1b3d12
LT
1/*
2 * Helper functions for tree diff generation
3 */
4#include "cache.h"
5#include "diff.h"
6
7// What paths are we interested in?
8static int nr_paths = 0;
9static const char **paths = NULL;
10static int *pathlens = NULL;
11
12static void update_tree_entry(struct tree_desc *desc)
13{
14 void *buf = desc->buf;
15 unsigned long size = desc->size;
16 int len = strlen(buf) + 1 + 20;
17
18 if (size < len)
19 die("corrupt tree file");
20 desc->buf = buf + len;
21 desc->size = size - len;
22}
23
24static const unsigned char *extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
25{
26 void *tree = desc->buf;
27 unsigned long size = desc->size;
28 int len = strlen(tree)+1;
29 const unsigned char *sha1 = tree + len;
30 const char *path = strchr(tree, ' ');
31 unsigned int mode;
32
33 if (!path || size < len + 20 || sscanf(tree, "%o", &mode) != 1)
34 die("corrupt tree file");
35 *pathp = path+1;
36 *modep = DIFF_FILE_CANON_MODE(mode);
37 return sha1;
38}
39
40static char *malloc_base(const char *base, const char *path, int pathlen)
41{
42 int baselen = strlen(base);
43 char *newbase = xmalloc(baselen + pathlen + 2);
44 memcpy(newbase, base, baselen);
45 memcpy(newbase + baselen, path, pathlen);
46 memcpy(newbase + baselen + pathlen, "/", 2);
47 return newbase;
48}
49
50static int show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base);
51
52static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
53{
54 unsigned mode1, mode2;
55 const char *path1, *path2;
56 const unsigned char *sha1, *sha2;
57 int cmp, pathlen1, pathlen2;
58
59 sha1 = extract(t1, &path1, &mode1);
60 sha2 = extract(t2, &path2, &mode2);
61
62 pathlen1 = strlen(path1);
63 pathlen2 = strlen(path2);
64 cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
65 if (cmp < 0) {
66 show_entry(opt, "-", t1, base);
67 return -1;
68 }
69 if (cmp > 0) {
70 show_entry(opt, "+", t2, base);
71 return 1;
72 }
73 if (!opt->find_copies_harder &&
74 !memcmp(sha1, sha2, 20) && mode1 == mode2)
75 return 0;
76
77 /*
78 * If the filemode has changed to/from a directory from/to a regular
79 * file, we need to consider it a remove and an add.
80 */
81 if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
82 show_entry(opt, "-", t1, base);
83 show_entry(opt, "+", t2, base);
84 return 0;
85 }
86
87 if (opt->recursive && S_ISDIR(mode1)) {
88 int retval;
89 char *newbase = malloc_base(base, path1, pathlen1);
90 if (opt->tree_in_recursive)
91 opt->change(opt, mode1, mode2,
92 sha1, sha2, base, path1);
93 retval = diff_tree_sha1(sha1, sha2, newbase, opt);
94 free(newbase);
95 return retval;
96 }
97
98 opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
99 return 0;
100}
101
102static int interesting(struct tree_desc *desc, const char *base)
103{
104 const char *path;
105 unsigned mode;
106 int i;
107 int baselen, pathlen;
108
109 if (!nr_paths)
110 return 1;
111
112 (void)extract(desc, &path, &mode);
113
114 pathlen = strlen(path);
115 baselen = strlen(base);
116
117 for (i=0; i < nr_paths; i++) {
118 const char *match = paths[i];
119 int matchlen = pathlens[i];
120
121 if (baselen >= matchlen) {
122 /* If it doesn't match, move along... */
123 if (strncmp(base, match, matchlen))
124 continue;
125
126 /* The base is a subdirectory of a path which was specified. */
127 return 1;
128 }
129
130 /* Does the base match? */
131 if (strncmp(base, match, baselen))
132 continue;
133
134 match += baselen;
135 matchlen -= baselen;
136
137 if (pathlen > matchlen)
138 continue;
139
140 if (matchlen > pathlen) {
141 if (match[pathlen] != '/')
142 continue;
143 if (!S_ISDIR(mode))
144 continue;
145 }
146
147 if (strncmp(path, match, pathlen))
148 continue;
149
150 return 1;
151 }
152 return 0; /* No matches */
153}
154
155/* A whole sub-tree went away or appeared */
156static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base)
157{
158 while (desc->size) {
159 if (interesting(desc, base))
160 show_entry(opt, prefix, desc, base);
161 update_tree_entry(desc);
162 }
163}
164
165/* A file entry went away or appeared */
166static int show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base)
167{
168 unsigned mode;
169 const char *path;
170 const unsigned char *sha1 = extract(desc, &path, &mode);
171
172 if (opt->recursive && S_ISDIR(mode)) {
173 char type[20];
174 char *newbase = malloc_base(base, path, strlen(path));
175 struct tree_desc inner;
176 void *tree;
177
178 tree = read_sha1_file(sha1, type, &inner.size);
179 if (!tree || strcmp(type, "tree"))
180 die("corrupt tree sha %s", sha1_to_hex(sha1));
181
182 inner.buf = tree;
183 show_tree(opt, prefix, &inner, newbase);
184
185 free(tree);
186 free(newbase);
187 return 0;
188 }
189
190 opt->add_remove(opt, prefix[0], mode, sha1, base, path);
191 return 0;
192}
193
194int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
195{
196 while (t1->size | t2->size) {
197 if (nr_paths && t1->size && !interesting(t1, base)) {
198 update_tree_entry(t1);
199 continue;
200 }
201 if (nr_paths && t2->size && !interesting(t2, base)) {
202 update_tree_entry(t2);
203 continue;
204 }
205 if (!t1->size) {
206 show_entry(opt, "+", t2, base);
207 update_tree_entry(t2);
208 continue;
209 }
210 if (!t2->size) {
211 show_entry(opt, "-", t1, base);
212 update_tree_entry(t1);
213 continue;
214 }
215 switch (compare_tree_entry(t1, t2, base, opt)) {
216 case -1:
217 update_tree_entry(t1);
218 continue;
219 case 0:
220 update_tree_entry(t1);
221 /* Fallthrough */
222 case 1:
223 update_tree_entry(t2);
224 continue;
225 }
226 die("git-diff-tree: internal error");
227 }
228 return 0;
229}
230
231int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
232{
233 void *tree1, *tree2;
234 struct tree_desc t1, t2;
235 int retval;
236
237 tree1 = read_object_with_reference(old, "tree", &t1.size, NULL);
238 if (!tree1)
239 die("unable to read source tree (%s)", sha1_to_hex(old));
240 tree2 = read_object_with_reference(new, "tree", &t2.size, NULL);
241 if (!tree2)
242 die("unable to read destination tree (%s)", sha1_to_hex(new));
243 t1.buf = tree1;
244 t2.buf = tree2;
245 retval = diff_tree(&t1, &t2, base, opt);
246 free(tree1);
247 free(tree2);
248 return retval;
249}
250
251static int count_paths(const char **paths)
252{
253 int i = 0;
254 while (*paths++)
255 i++;
256 return i;
257}
258
259void diff_tree_setup_paths(const char **p)
260{
261 if (p) {
262 int i;
263
264 paths = p;
265 nr_paths = count_paths(paths);
7e4a2a84
JH
266 if (nr_paths == 0) {
267 pathlens = NULL;
268 return;
269 }
ac1b3d12
LT
270 pathlens = xmalloc(nr_paths * sizeof(int));
271 for (i=0; i<nr_paths; i++)
272 pathlens[i] = strlen(paths[i]);
273 }
274}