stash: remove now superfluos help for "stash push"
[git.git] / replace_object.c
blobf0b39f06d5dabc3c98c5c083458736a585b4cabb
1 #include "cache.h"
2 #include "sha1-lookup.h"
3 #include "refs.h"
4 #include "commit.h"
6 /*
7  * An array of replacements.  The array is kept sorted by the original
8  * sha1.
9  */
10 static struct replace_object {
11         unsigned char original[20];
12         unsigned char replacement[20];
13 } **replace_object;
15 static int replace_object_alloc, replace_object_nr;
17 static const unsigned char *replace_sha1_access(size_t index, void *table)
19         struct replace_object **replace = table;
20         return replace[index]->original;
23 static int replace_object_pos(const unsigned char *sha1)
25         return sha1_pos(sha1, replace_object, replace_object_nr,
26                         replace_sha1_access);
29 static int register_replace_object(struct replace_object *replace,
30                                    int ignore_dups)
32         int pos = replace_object_pos(replace->original);
34         if (0 <= pos) {
35                 if (ignore_dups)
36                         free(replace);
37                 else {
38                         free(replace_object[pos]);
39                         replace_object[pos] = replace;
40                 }
41                 return 1;
42         }
43         pos = -pos - 1;
44         ALLOC_GROW(replace_object, replace_object_nr + 1, replace_object_alloc);
45         replace_object_nr++;
46         if (pos < replace_object_nr)
47                 memmove(replace_object + pos + 1,
48                         replace_object + pos,
49                         (replace_object_nr - pos - 1) *
50                         sizeof(*replace_object));
51         replace_object[pos] = replace;
52         return 0;
55 static int register_replace_ref(const char *refname,
56                                 const struct object_id *oid,
57                                 int flag, void *cb_data)
59         /* Get sha1 from refname */
60         const char *slash = strrchr(refname, '/');
61         const char *hash = slash ? slash + 1 : refname;
62         struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
64         if (strlen(hash) != 40 || get_sha1_hex(hash, repl_obj->original)) {
65                 free(repl_obj);
66                 warning("bad replace ref name: %s", refname);
67                 return 0;
68         }
70         /* Copy sha1 from the read ref */
71         hashcpy(repl_obj->replacement, oid->hash);
73         /* Register new object */
74         if (register_replace_object(repl_obj, 1))
75                 die("duplicate replace ref: %s", refname);
77         return 0;
80 static void prepare_replace_object(void)
82         static int replace_object_prepared;
84         if (replace_object_prepared)
85                 return;
87         for_each_replace_ref(register_replace_ref, NULL);
88         replace_object_prepared = 1;
89         if (!replace_object_nr)
90                 check_replace_refs = 0;
93 /* We allow "recursive" replacement. Only within reason, though */
94 #define MAXREPLACEDEPTH 5
97  * If a replacement for object sha1 has been set up, return the
98  * replacement object's name (replaced recursively, if necessary).
99  * The return value is either sha1 or a pointer to a
100  * permanently-allocated value.  This function always respects replace
101  * references, regardless of the value of check_replace_refs.
102  */
103 const unsigned char *do_lookup_replace_object(const unsigned char *sha1)
105         int pos, depth = MAXREPLACEDEPTH;
106         const unsigned char *cur = sha1;
108         prepare_replace_object();
110         /* Try to recursively replace the object */
111         do {
112                 if (--depth < 0)
113                         die("replace depth too high for object %s",
114                             sha1_to_hex(sha1));
116                 pos = replace_object_pos(cur);
117                 if (0 <= pos)
118                         cur = replace_object[pos]->replacement;
119         } while (0 <= pos);
121         return cur;