Simplify "diff-tree" output, and only keep track of one single name-base.
[git/git.git] / diff-tree.c
... / ...
CommitLineData
1#include "cache.h"
2
3static int recursive = 0;
4
5static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
6
7static void update_tree_entry(void **bufp, unsigned long *sizep)
8{
9 void *buf = *bufp;
10 unsigned long size = *sizep;
11 int len = strlen(buf) + 1 + 20;
12
13 if (size < len)
14 usage("corrupt tree file");
15 *bufp = buf + len;
16 *sizep = size - len;
17}
18
19static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
20{
21 int len = strlen(tree)+1;
22 const unsigned char *sha1 = tree + len;
23 const char *path = strchr(tree, ' ');
24
25 if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
26 usage("corrupt tree file");
27 *pathp = path+1;
28 return sha1;
29}
30
31static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
32{
33 unsigned mode;
34 const char *path;
35 const unsigned char *sha1 = extract(tree, size, &path, &mode);
36 printf("%s%o %s %s%s%c", prefix, mode, sha1_to_hex(sha1), base, path, 0);
37}
38
39static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
40{
41 unsigned mode1, mode2;
42 const char *path1, *path2;
43 const unsigned char *sha1, *sha2;
44 int cmp, pathlen1, pathlen2;
45 char old_sha1_hex[50];
46
47 sha1 = extract(tree1, size1, &path1, &mode1);
48 sha2 = extract(tree2, size2, &path2, &mode2);
49
50 pathlen1 = strlen(path1);
51 pathlen2 = strlen(path2);
52 cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
53 if (cmp < 0) {
54 show_file("-", tree1, size1, base);
55 return -1;
56 }
57 if (cmp > 0) {
58 show_file("+", tree2, size2, base);
59 return 1;
60 }
61 if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
62 return 0;
63 if (recursive && S_ISDIR(mode1) && S_ISDIR(mode2)) {
64 int retval;
65 int baselen = strlen(base);
66 char *newbase = malloc(baselen + pathlen1 + 2);
67 memcpy(newbase, base, baselen);
68 memcpy(newbase + baselen, path1, pathlen1);
69 memcpy(newbase + baselen + pathlen1, "/", 2);
70 retval = diff_tree_sha1(sha1, sha2, newbase);
71 free(newbase);
72 return retval;
73 }
74
75 strcpy(old_sha1_hex, sha1_to_hex(sha1));
76 printf("*%o->%o %s->%s %s%s%c", mode1, mode2, old_sha1_hex, sha1_to_hex(sha2), base, path1, 0);
77 return 0;
78}
79
80static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
81{
82 while (size1 | size2) {
83 if (!size1) {
84 show_file("+", tree2, size2, base);
85 update_tree_entry(&tree2, &size2);
86 continue;
87 }
88 if (!size2) {
89 show_file("-", tree1, size1, base);
90 update_tree_entry(&tree1, &size1);
91 continue;
92 }
93 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
94 case -1:
95 update_tree_entry(&tree1, &size1);
96 continue;
97 case 0:
98 update_tree_entry(&tree1, &size1);
99 /* Fallthrough */
100 case 1:
101 update_tree_entry(&tree2, &size2);
102 continue;
103 }
104 usage("diff-tree: internal error");
105 }
106 return 0;
107}
108
109static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
110{
111 void *tree1, *tree2;
112 unsigned long size1, size2;
113 char type[20];
114 int retval;
115
116 tree1 = read_sha1_file(old, type, &size1);
117 if (!tree1 || strcmp(type, "tree"))
118 usage("unable to read source tree");
119 tree2 = read_sha1_file(new, type, &size2);
120 if (!tree2 || strcmp(type, "tree"))
121 usage("unable to read destination tree");
122 retval = diff_tree(tree1, size1, tree2, size2, base);
123 free(tree1);
124 free(tree2);
125 return retval;
126}
127
128int main(int argc, char **argv)
129{
130 unsigned char old[20], new[20];
131
132 while (argc > 3) {
133 char *arg = argv[1];
134 argv++;
135 argc--;
136 if (!strcmp(arg, "-R")) {
137 recursive = 1;
138 continue;
139 }
140 usage("diff-tree [-R] <tree sha1> <tree sha1>");
141 }
142
143 if (argc != 3 || get_sha1_hex(argv[1], old) || get_sha1_hex(argv[2], new))
144 usage("diff-tree <tree sha1> <tree sha1>");
145 return diff_tree_sha1(old, new, "");
146}