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
9static 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
35void prepare_replace_object(struct repository *r)
36{
37 if (r->objects->replace_map)
38 return;
39
40 r->objects->replace_map =
41 xmalloc(sizeof(*r->objects->replace_map));
42 oidmap_init(r->objects->replace_map, 0);
43
44 for_each_replace_ref(r, register_replace_ref, NULL);
45}
46
47/* We allow "recursive" replacement. Only within reason, though */
48#define MAXREPLACEDEPTH 5
49
50/*
51 * If a replacement for object oid has been set up, return the
52 * replacement object's name (replaced recursively, if necessary).
53 * The return value is either oid or a pointer to a
54 * permanently-allocated value. This function always respects replace
55 * references, regardless of the value of read_replace_refs.
56 */
57const struct object_id *do_lookup_replace_object(struct repository *r,
58 const struct object_id *oid)
59{
60 int depth = MAXREPLACEDEPTH;
61 const struct object_id *cur = oid;
62
63 prepare_replace_object(r);
64
65 /* Try to recursively replace the object */
66 while (depth-- > 0) {
67 struct replace_object *repl_obj =
68 oidmap_get(r->objects->replace_map, cur);
69 if (!repl_obj)
70 return cur;
71 cur = &repl_obj->replacement;
72 }
73 die(_("replace depth too high for object %s"), oid_to_hex(oid));
74}