summaryrefslogtreecommitdiff
path: root/tree-diff.c
blob: 37d235e06e2cbfbd761fd02d7e73648a14a60daf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 * Helper functions for tree diff generation
 */
#include "cache.h"
#include "diff.h"
#include "tree.h"
 
static char *malloc_base(const char *base, const char *path, int pathlen)
{
	int baselen = strlen(base);
	char *newbase = xmalloc(baselen + pathlen + 2);
	memcpy(newbase, base, baselen);
	memcpy(newbase + baselen, path, pathlen);
	memcpy(newbase + baselen + pathlen, "/", 2);
	return newbase;
}
 
static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
		       const char *base);
 
static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	unsigned mode1, mode2;
	const char *path1, *path2;
	const unsigned char *sha1, *sha2;
	int cmp, pathlen1, pathlen2;
 
	sha1 = tree_entry_extract(t1, &path1, &mode1);
	sha2 = tree_entry_extract(t2, &path2, &mode2);
 
	pathlen1 = strlen(path1);
	pathlen2 = strlen(path2);
	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
	if (cmp < 0) {
		show_entry(opt, "-", t1, base);
		return -1;
	}
	if (cmp > 0) {
		show_entry(opt, "+", t2, base);
		return 1;
	}
	if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2)
		return 0;
 
	/*
	 * If the filemode has changed to/from a directory from/to a regular
	 * file, we need to consider it a remove and an add.
	 */
	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
		show_entry(opt, "-", t1, base);
		show_entry(opt, "+", t2, base);
		return 0;
	}
 
	if (opt->recursive && S_ISDIR(mode1)) {
		int retval;
		char *newbase = malloc_base(base, path1, pathlen1);
		if (opt->tree_in_recursive)
			opt->change(opt, mode1, mode2,
				    sha1, sha2, base, path1);
		retval = diff_tree_sha1(sha1, sha2, newbase, opt);
		free(newbase);
		return retval;
	}
 
	opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
	return 0;
}
 
static int interesting(struct tree_desc *desc, const char *base, struct diff_options *opt)
{
	const char *path;
	unsigned mode;
	int i;
	int baselen, pathlen;
 
	if (!opt->nr_paths)
		return 1;
 
	(void)tree_entry_extract(desc, &path, &mode);
 
	pathlen = strlen(path);
	baselen = strlen(base);
 
	for (i=0; i < opt->nr_paths; i++) {
		const char *match = opt->paths[i];
		int matchlen = opt->pathlens[i];
 
		if (baselen >= matchlen) {
			/* If it doesn't match, move along... */
			if (strncmp(base, match, matchlen))
				continue;
 
			/* The base is a subdirectory of a path which was specified. */
			return 1;
		}
 
		/* Does the base match? */
		if (strncmp(base, match, baselen))
			continue;
 
		match += baselen;
		matchlen -= baselen;
 
		if (pathlen > matchlen)
			continue;
 
		if (matchlen > pathlen) {
			if (match[pathlen] != '/')
				continue;
			if (!S_ISDIR(mode))
				continue;
		}
 
		if (strncmp(path, match, pathlen))
			continue;
 
		return 1;
	}
	return 0; /* No matches */
}
 
/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base)
{
	while (desc->size) {
		if (interesting(desc, base, opt))
			show_entry(opt, prefix, desc, base);
		update_tree_entry(desc);
	}
}
 
/* A file entry went away or appeared */
static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
		       const char *base)
{
	unsigned mode;
	const char *path;
	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
 
	if (opt->recursive && S_ISDIR(mode)) {
		char type[20];
		char *newbase = malloc_base(base, path, strlen(path));
		struct tree_desc inner;
		void *tree;
 
		tree = read_sha1_file(sha1, type, &inner.size);
		if (!tree || strcmp(type, tree_type))
			die("corrupt tree sha %s", sha1_to_hex(sha1));
 
		inner.buf = tree;
		show_tree(opt, prefix, &inner, newbase);
 
		free(tree);
		free(newbase);
	} else {
		opt->add_remove(opt, prefix[0], mode, sha1, base, path);
	}
}
 
int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	while (t1->size | t2->size) {
		if (opt->nr_paths && t1->size && !interesting(t1, base, opt)) {
			update_tree_entry(t1);
			continue;
		}
		if (opt->nr_paths && t2->size && !interesting(t2, base, opt)) {
			update_tree_entry(t2);
			continue;
		}
		if (!t1->size) {
			show_entry(opt, "+", t2, base);
			update_tree_entry(t2);
			continue;
		}
		if (!t2->size) {
			show_entry(opt, "-", t1, base);
			update_tree_entry(t1);
			continue;
		}
		switch (compare_tree_entry(t1, t2, base, opt)) {
		case -1:
			update_tree_entry(t1);
			continue;
		case 0:
			update_tree_entry(t1);
			/* Fallthrough */
		case 1:
			update_tree_entry(t2);
			continue;
		}
		die("git-diff-tree: internal error");
	}
	return 0;
}
 
int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
{
	void *tree1, *tree2;
	struct tree_desc t1, t2;
	int retval;
 
	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
	if (!tree1)
		die("unable to read source tree (%s)", sha1_to_hex(old));
	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
	if (!tree2)
		die("unable to read destination tree (%s)", sha1_to_hex(new));
	t1.buf = tree1;
	t2.buf = tree2;
	retval = diff_tree(&t1, &t2, base, opt);
	free(tree1);
	free(tree2);
	return retval;
}
 
int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
{
	int retval;
	void *tree;
	struct tree_desc empty, real;
 
	tree = read_object_with_reference(new, tree_type, &real.size, NULL);
	if (!tree)
		die("unable to read root tree (%s)", sha1_to_hex(new));
	real.buf = tree;
 
	empty.size = 0;
	empty.buf = "";
	retval = diff_tree(&empty, &real, base, opt);
	free(tree);
	return retval;
}
 
static int count_paths(const char **paths)
{
	int i = 0;
	while (*paths++)
		i++;
	return i;
}
 
void diff_tree_release_paths(struct diff_options *opt)
{
	free(opt->pathlens);
}
 
void diff_tree_setup_paths(const char **p, struct diff_options *opt)
{
	opt->nr_paths = 0;
	opt->pathlens = NULL;
	opt->paths = NULL;
 
	if (p) {
		int i;
 
		opt->paths = p;
		opt->nr_paths = count_paths(p);
		if (opt->nr_paths == 0) {
			opt->pathlens = NULL;
			return;
		}
		opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
		for (i=0; i < opt->nr_paths; i++)
			opt->pathlens[i] = strlen(p[i]);
	}
}