| #include "cache.h" |
| #include "sha1-lookup.h" |
| #include "refs.h" |
| #include "commit.h" |
| |
| /* |
| * An array of replacements. The array is kept sorted by the original |
| * sha1. |
| */ |
| static struct replace_object { |
| unsigned char original[20]; |
| unsigned char replacement[20]; |
| } **replace_object; |
| |
| static int replace_object_alloc, replace_object_nr; |
| |
| static const unsigned char *replace_sha1_access(size_t index, void *table) |
| { |
| struct replace_object **replace = table; |
| return replace[index]->original; |
| } |
| |
| static int replace_object_pos(const unsigned char *sha1) |
| { |
| return sha1_pos(sha1, replace_object, replace_object_nr, |
| replace_sha1_access); |
| } |
| |
| static int register_replace_object(struct replace_object *replace, |
| int ignore_dups) |
| { |
| int pos = replace_object_pos(replace->original); |
| |
| if (0 <= pos) { |
| if (ignore_dups) |
| free(replace); |
| else { |
| free(replace_object[pos]); |
| replace_object[pos] = replace; |
| } |
| return 1; |
| } |
| pos = -pos - 1; |
| ALLOC_GROW(replace_object, replace_object_nr + 1, replace_object_alloc); |
| replace_object_nr++; |
| if (pos < replace_object_nr) |
| memmove(replace_object + pos + 1, |
| replace_object + pos, |
| (replace_object_nr - pos - 1) * |
| sizeof(*replace_object)); |
| replace_object[pos] = replace; |
| return 0; |
| } |
| |
| static int register_replace_ref(const char *refname, |
| const struct object_id *oid, |
| int flag, void *cb_data) |
| { |
| /* Get sha1 from refname */ |
| const char *slash = strrchr(refname, '/'); |
| const char *hash = slash ? slash + 1 : refname; |
| struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj)); |
| |
| if (strlen(hash) != 40 || get_sha1_hex(hash, repl_obj->original)) { |
| free(repl_obj); |
| warning("bad replace ref name: %s", refname); |
| return 0; |
| } |
| |
| /* Copy sha1 from the read ref */ |
| hashcpy(repl_obj->replacement, oid->hash); |
| |
| /* Register new object */ |
| if (register_replace_object(repl_obj, 1)) |
| die("duplicate replace ref: %s", refname); |
| |
| return 0; |
| } |
| |
| static void prepare_replace_object(void) |
| { |
| static int replace_object_prepared; |
| |
| if (replace_object_prepared) |
| return; |
| |
| for_each_replace_ref(register_replace_ref, NULL); |
| replace_object_prepared = 1; |
| if (!replace_object_nr) |
| check_replace_refs = 0; |
| } |
| |
| /* We allow "recursive" replacement. Only within reason, though */ |
| #define MAXREPLACEDEPTH 5 |
| |
| /* |
| * If a replacement for object sha1 has been set up, return the |
| * replacement object's name (replaced recursively, if necessary). |
| * The return value is either sha1 or a pointer to a |
| * permanently-allocated value. This function always respects replace |
| * references, regardless of the value of check_replace_refs. |
| */ |
| const unsigned char *do_lookup_replace_object(const unsigned char *sha1) |
| { |
| int pos, depth = MAXREPLACEDEPTH; |
| const unsigned char *cur = sha1; |
| |
| prepare_replace_object(); |
| |
| /* Try to recursively replace the object */ |
| do { |
| if (--depth < 0) |
| die("replace depth too high for object %s", |
| sha1_to_hex(sha1)); |
| |
| pos = replace_object_pos(cur); |
| if (0 <= pos) |
| cur = replace_object[pos]->replacement; |
| } while (0 <= pos); |
| |
| return cur; |
| } |