Teach tree_entry_interesting() that the tree entries are sorted.
[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"
8e440259 6#include "tree.h"
ac1b3d12 7
304de2d2 8static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
ac1b3d12 9{
ac1b3d12
LT
10 char *newbase = xmalloc(baselen + pathlen + 2);
11 memcpy(newbase, base, baselen);
12 memcpy(newbase + baselen, path, pathlen);
13 memcpy(newbase + baselen + pathlen, "/", 2);
14 return newbase;
15}
16
cf995ede 17static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
304de2d2 18 const char *base, int baselen);
ac1b3d12 19
304de2d2 20static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt)
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LT
21{
22 unsigned mode1, mode2;
23 const char *path1, *path2;
24 const unsigned char *sha1, *sha2;
25 int cmp, pathlen1, pathlen2;
26
50f9a858
LT
27 sha1 = tree_entry_extract(t1, &path1, &mode1);
28 sha2 = tree_entry_extract(t2, &path2, &mode2);
ac1b3d12 29
304de2d2
LT
30 pathlen1 = tree_entry_len(path1, sha1);
31 pathlen2 = tree_entry_len(path2, sha2);
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LT
32 cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
33 if (cmp < 0) {
304de2d2 34 show_entry(opt, "-", t1, base, baselen);
ac1b3d12
LT
35 return -1;
36 }
37 if (cmp > 0) {
304de2d2 38 show_entry(opt, "+", t2, base, baselen);
ac1b3d12
LT
39 return 1;
40 }
a89fccd2 41 if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2)
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LT
42 return 0;
43
44 /*
45 * If the filemode has changed to/from a directory from/to a regular
46 * file, we need to consider it a remove and an add.
47 */
48 if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
304de2d2
LT
49 show_entry(opt, "-", t1, base, baselen);
50 show_entry(opt, "+", t2, base, baselen);
ac1b3d12
LT
51 return 0;
52 }
53
54 if (opt->recursive && S_ISDIR(mode1)) {
55 int retval;
304de2d2 56 char *newbase = malloc_base(base, baselen, path1, pathlen1);
ac1b3d12
LT
57 if (opt->tree_in_recursive)
58 opt->change(opt, mode1, mode2,
59 sha1, sha2, base, path1);
60 retval = diff_tree_sha1(sha1, sha2, newbase, opt);
61 free(newbase);
62 return retval;
63 }
64
65 opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
66 return 0;
67}
68
5d865017
LT
69/*
70 * Is a tree entry interesting given the pathspec we have?
71 *
72 * Return:
73 * - positive for yes
74 * - zero for no
75 * - negative for "no, and no subsequent entries will be either"
76 */
77static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
ac1b3d12
LT
78{
79 const char *path;
304de2d2 80 const unsigned char *sha1;
ac1b3d12
LT
81 unsigned mode;
82 int i;
304de2d2 83 int pathlen;
7d2f667b 84 int never_interesting = -1;
ac1b3d12 85
a8baa7b9 86 if (!opt->nr_paths)
ac1b3d12
LT
87 return 1;
88
304de2d2 89 sha1 = tree_entry_extract(desc, &path, &mode);
ac1b3d12 90
304de2d2 91 pathlen = tree_entry_len(path, sha1);
ac1b3d12 92
7d2f667b 93 for (i = 0; i < opt->nr_paths; i++) {
a8baa7b9
JH
94 const char *match = opt->paths[i];
95 int matchlen = opt->pathlens[i];
7d2f667b 96 int m;
ac1b3d12
LT
97
98 if (baselen >= matchlen) {
99 /* If it doesn't match, move along... */
100 if (strncmp(base, match, matchlen))
101 continue;
102
103 /* The base is a subdirectory of a path which was specified. */
104 return 1;
105 }
106
107 /* Does the base match? */
108 if (strncmp(base, match, baselen))
109 continue;
110
111 match += baselen;
112 matchlen -= baselen;
113
7d2f667b
JH
114 /*
115 * Does match sort strictly earlier than path with their
116 * common parts?
117 */
118 m = strncmp(match, path,
119 (matchlen < pathlen) ? matchlen : pathlen);
120 if (m < 0)
121 continue;
122
123 /*
124 * If we come here even once, that means there is at
125 * least one pathspec that would sort equal to or
126 * later than the path we are currently looking at.
127 * In other words, if we have never reached this point
128 * after iterating all pathspecs, it means all
129 * pathspecs are either outside of base, or inside the
130 * base but sorts strictly earlier than the current
131 * one. In either case, they will never match the
132 * subsequent entries. In such a case, we initialized
133 * the variable to -1 and that is what will be
134 * returned, allowing the caller to terminate early.
135 */
136 never_interesting = 0;
137
ac1b3d12
LT
138 if (pathlen > matchlen)
139 continue;
140
141 if (matchlen > pathlen) {
142 if (match[pathlen] != '/')
143 continue;
144 if (!S_ISDIR(mode))
145 continue;
146 }
147
7d2f667b
JH
148 /*
149 * If common part matched earlier then it is a hit,
150 * because we rejected the case where path is not a
151 * leading directory and is shorter than match.
152 */
153 if (!m)
154 return 1;
ac1b3d12 155 }
7d2f667b 156 return never_interesting; /* No matches */
ac1b3d12
LT
157}
158
159/* A whole sub-tree went away or appeared */
304de2d2 160static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
ac1b3d12
LT
161{
162 while (desc->size) {
5d865017
LT
163 int show = tree_entry_interesting(desc, base, baselen, opt);
164 if (show < 0)
165 break;
166 if (show)
304de2d2 167 show_entry(opt, prefix, desc, base, baselen);
ac1b3d12
LT
168 update_tree_entry(desc);
169 }
170}
171
172/* A file entry went away or appeared */
cf995ede 173static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
304de2d2 174 const char *base, int baselen)
ac1b3d12
LT
175{
176 unsigned mode;
177 const char *path;
50f9a858 178 const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
ac1b3d12
LT
179
180 if (opt->recursive && S_ISDIR(mode)) {
21666f1a 181 enum object_type type;
304de2d2
LT
182 int pathlen = tree_entry_len(path, sha1);
183 char *newbase = malloc_base(base, baselen, path, pathlen);
ac1b3d12
LT
184 struct tree_desc inner;
185 void *tree;
6fda5e51 186 unsigned long size;
ac1b3d12 187
6fda5e51 188 tree = read_sha1_file(sha1, &type, &size);
21666f1a 189 if (!tree || type != OBJ_TREE)
ac1b3d12
LT
190 die("corrupt tree sha %s", sha1_to_hex(sha1));
191
6fda5e51 192 init_tree_desc(&inner, tree, size);
304de2d2 193 show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
ac1b3d12
LT
194
195 free(tree);
196 free(newbase);
cf995ede
DR
197 } else {
198 opt->add_remove(opt, prefix[0], mode, sha1, base, path);
ac1b3d12 199 }
ac1b3d12
LT
200}
201
5d865017
LT
202static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt)
203{
204 while (t->size) {
205 int show = tree_entry_interesting(t, base, baselen, opt);
206 if (!show) {
207 update_tree_entry(t);
208 continue;
209 }
210 /* Skip it all? */
211 if (show < 0)
212 t->size = 0;
213 return;
214 }
215}
216
ac1b3d12
LT
217int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
218{
304de2d2
LT
219 int baselen = strlen(base);
220
5d865017 221 for (;;) {
822cac01
JH
222 if (opt->quiet && opt->has_changes)
223 break;
5d865017
LT
224 if (opt->nr_paths) {
225 skip_uninteresting(t1, base, baselen, opt);
226 skip_uninteresting(t2, base, baselen, opt);
ac1b3d12
LT
227 }
228 if (!t1->size) {
5d865017
LT
229 if (!t2->size)
230 break;
304de2d2 231 show_entry(opt, "+", t2, base, baselen);
ac1b3d12
LT
232 update_tree_entry(t2);
233 continue;
234 }
235 if (!t2->size) {
304de2d2 236 show_entry(opt, "-", t1, base, baselen);
ac1b3d12
LT
237 update_tree_entry(t1);
238 continue;
239 }
304de2d2 240 switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
ac1b3d12
LT
241 case -1:
242 update_tree_entry(t1);
243 continue;
244 case 0:
245 update_tree_entry(t1);
246 /* Fallthrough */
247 case 1:
248 update_tree_entry(t2);
249 continue;
250 }
251 die("git-diff-tree: internal error");
252 }
253 return 0;
254}
255
256int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
257{
258 void *tree1, *tree2;
259 struct tree_desc t1, t2;
6fda5e51 260 unsigned long size1, size2;
ac1b3d12
LT
261 int retval;
262
6fda5e51 263 tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
ac1b3d12
LT
264 if (!tree1)
265 die("unable to read source tree (%s)", sha1_to_hex(old));
6fda5e51 266 tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
ac1b3d12
LT
267 if (!tree2)
268 die("unable to read destination tree (%s)", sha1_to_hex(new));
6fda5e51
LT
269 init_tree_desc(&t1, tree1, size1);
270 init_tree_desc(&t2, tree2, size2);
ac1b3d12
LT
271 retval = diff_tree(&t1, &t2, base, opt);
272 free(tree1);
273 free(tree2);
274 return retval;
275}
276
2b60356d
RS
277int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
278{
279 int retval;
280 void *tree;
6fda5e51 281 unsigned long size;
2b60356d
RS
282 struct tree_desc empty, real;
283
6fda5e51 284 tree = read_object_with_reference(new, tree_type, &size, NULL);
2b60356d
RS
285 if (!tree)
286 die("unable to read root tree (%s)", sha1_to_hex(new));
6fda5e51 287 init_tree_desc(&real, tree, size);
2b60356d 288
6fda5e51 289 init_tree_desc(&empty, "", 0);
2b60356d
RS
290 retval = diff_tree(&empty, &real, base, opt);
291 free(tree);
292 return retval;
293}
294
ac1b3d12
LT
295static int count_paths(const char **paths)
296{
297 int i = 0;
298 while (*paths++)
299 i++;
300 return i;
301}
302
a8baa7b9 303void diff_tree_release_paths(struct diff_options *opt)
ac1b3d12 304{
a8baa7b9
JH
305 free(opt->pathlens);
306}
307
308void diff_tree_setup_paths(const char **p, struct diff_options *opt)
309{
310 opt->nr_paths = 0;
311 opt->pathlens = NULL;
312 opt->paths = NULL;
313
ac1b3d12
LT
314 if (p) {
315 int i;
316
a8baa7b9
JH
317 opt->paths = p;
318 opt->nr_paths = count_paths(p);
319 if (opt->nr_paths == 0) {
320 opt->pathlens = NULL;
7e4a2a84
JH
321 return;
322 }
a8baa7b9
JH
323 opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
324 for (i=0; i < opt->nr_paths; i++)
325 opt->pathlens[i] = strlen(p[i]);
ac1b3d12
LT
326 }
327}