1 #include "cache.h"
2 #include "oidmap.h"
3 #include "object-store.h"
4 #include "replace-object.h"
5 #include "refs.h"
6 #include "repository.h"
7 #include "commit.h"
8
register_replace_ref(struct repository * r,const char * refname,const struct object_id * oid,int flag,void * cb_data)9 static int register_replace_ref(struct repository *r,
10 const char *refname,
11 const struct object_id *oid,
12 int flag, void *cb_data)
13 {
14 /* Get sha1 from refname */
15 const char *slash = strrchr(refname, '/');
16 const char *hash = slash ? slash + 1 : refname;
17 struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
18
19 if (get_oid_hex(hash, &repl_obj->original.oid)) {
20 free(repl_obj);
21 warning(_("bad replace ref name: %s"), refname);
22 return 0;
23 }
24
25 /* Copy sha1 from the read ref */
26 oidcpy(&repl_obj->replacement, oid);
27
28 /* Register new object */
29 if (oidmap_put(r->objects->replace_map, repl_obj))
30 die(_("duplicate replace ref: %s"), refname);
31
32 return 0;
33 }
34
prepare_replace_object(struct repository * r)35 void prepare_replace_object(struct repository *r)
36 {
37 if (r->objects->replace_map_initialized)
38 return;
39
40 pthread_mutex_lock(&r->objects->replace_mutex);
41 if (r->objects->replace_map_initialized) {
42 pthread_mutex_unlock(&r->objects->replace_mutex);
43 return;
44 }
45
46 r->objects->replace_map =
47 xmalloc(sizeof(*r->objects->replace_map));
48 oidmap_init(r->objects->replace_map, 0);
49
50 for_each_replace_ref(r, register_replace_ref, NULL);
51 r->objects->replace_map_initialized = 1;
52
53 pthread_mutex_unlock(&r->objects->replace_mutex);
54 }
55
56 /* We allow "recursive" replacement. Only within reason, though */
57 #define MAXREPLACEDEPTH 5
58
59 /*
60 * If a replacement for object oid has been set up, return the
61 * replacement object's name (replaced recursively, if necessary).
62 * The return value is either oid or a pointer to a
63 * permanently-allocated value. This function always respects replace
64 * references, regardless of the value of read_replace_refs.
65 */
do_lookup_replace_object(struct repository * r,const struct object_id * oid)66 const struct object_id *do_lookup_replace_object(struct repository *r,
67 const struct object_id *oid)
68 {
69 int depth = MAXREPLACEDEPTH;
70 const struct object_id *cur = oid;
71
72 prepare_replace_object(r);
73
74 /* Try to recursively replace the object */
75 while (depth-- > 0) {
76 struct replace_object *repl_obj =
77 oidmap_get(r->objects->replace_map, cur);
78 if (!repl_obj)
79 return cur;
80 cur = &repl_obj->replacement;
81 }
82 die(_("replace depth too high for object %s"), oid_to_hex(oid));
83 }
84