blame.c: Properly initialize strbuf after calling, textconv_object()
[git/dscho.git] / replace_object.c
blobeb59604fd39e2beaf7d43802499c27305ac92132
1 #include "cache.h"
2 #include "sha1-lookup.h"
3 #include "refs.h"
5 static struct replace_object {
6 unsigned char sha1[2][20];
7 } **replace_object;
9 static int replace_object_alloc, replace_object_nr;
11 static const unsigned char *replace_sha1_access(size_t index, void *table)
13 struct replace_object **replace = table;
14 return replace[index]->sha1[0];
17 static int replace_object_pos(const unsigned char *sha1)
19 return sha1_pos(sha1, replace_object, replace_object_nr,
20 replace_sha1_access);
23 static int register_replace_object(struct replace_object *replace,
24 int ignore_dups)
26 int pos = replace_object_pos(replace->sha1[0]);
28 if (0 <= pos) {
29 if (ignore_dups)
30 free(replace);
31 else {
32 free(replace_object[pos]);
33 replace_object[pos] = replace;
35 return 1;
37 pos = -pos - 1;
38 if (replace_object_alloc <= ++replace_object_nr) {
39 replace_object_alloc = alloc_nr(replace_object_alloc);
40 replace_object = xrealloc(replace_object,
41 sizeof(*replace_object) *
42 replace_object_alloc);
44 if (pos < replace_object_nr)
45 memmove(replace_object + pos + 1,
46 replace_object + pos,
47 (replace_object_nr - pos - 1) *
48 sizeof(*replace_object));
49 replace_object[pos] = replace;
50 return 0;
53 static int register_replace_ref(const char *refname,
54 const unsigned char *sha1,
55 int flag, void *cb_data)
57 /* Get sha1 from refname */
58 const char *slash = strrchr(refname, '/');
59 const char *hash = slash ? slash + 1 : refname;
60 struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
62 if (strlen(hash) != 40 || get_sha1_hex(hash, repl_obj->sha1[0])) {
63 free(repl_obj);
64 warning("bad replace ref name: %s", refname);
65 return 0;
68 /* Copy sha1 from the read ref */
69 hashcpy(repl_obj->sha1[1], sha1);
71 /* Register new object */
72 if (register_replace_object(repl_obj, 1))
73 die("duplicate replace ref: %s", refname);
75 return 0;
78 static void prepare_replace_object(void)
80 static int replace_object_prepared;
82 if (replace_object_prepared)
83 return;
85 for_each_replace_ref(register_replace_ref, NULL);
86 replace_object_prepared = 1;
89 /* We allow "recursive" replacement. Only within reason, though */
90 #define MAXREPLACEDEPTH 5
92 const unsigned char *lookup_replace_object(const unsigned char *sha1)
94 int pos, depth = MAXREPLACEDEPTH;
95 const unsigned char *cur = sha1;
97 if (!read_replace_refs)
98 return sha1;
100 prepare_replace_object();
102 /* Try to recursively replace the object */
103 do {
104 if (--depth < 0)
105 die("replace depth too high for object %s",
106 sha1_to_hex(sha1));
108 pos = replace_object_pos(cur);
109 if (0 <= pos)
110 cur = replace_object[pos]->sha1[1];
111 } while (0 <= pos);
113 return cur;