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Commit | Line | Data |
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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? | |
8 | static int nr_paths = 0; | |
9 | static const char **paths = NULL; | |
10 | static int *pathlens = NULL; | |
11 | ||
12 | static 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 | ||
24 | static 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 | ||
40 | static 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 | ||
50 | static int show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base); | |
51 | ||
52 | static 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 | ||
102 | static 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 */ | |
156 | static 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 */ | |
166 | static 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 | ||
194 | int 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 | ||
231 | int 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 | ||
251 | static int count_paths(const char **paths) | |
252 | { | |
253 | int i = 0; | |
254 | while (*paths++) | |
255 | i++; | |
256 | return i; | |
257 | } | |
258 | ||
259 | void diff_tree_setup_paths(const char **p) | |
260 | { | |
261 | if (p) { | |
262 | int i; | |
263 | ||
264 | paths = p; | |
265 | nr_paths = count_paths(paths); | |
266 | pathlens = xmalloc(nr_paths * sizeof(int)); | |
267 | for (i=0; i<nr_paths; i++) | |
268 | pathlens[i] = strlen(paths[i]); | |
269 | } | |
270 | } |