diff options
Diffstat (limited to 'object.c')
| -rw-r--r-- | object.c | 59 |
1 files changed, 51 insertions, 8 deletions
@@ -43,14 +43,32 @@ int type_from_string(const char *str) die("invalid object type \"%s\"", str); } +/* + * Return a numerical hash value between 0 and n-1 for the object with + * the specified sha1. n must be a power of 2. Please note that the + * return value is *not* consistent across computer architectures. + */ static unsigned int hash_obj(const unsigned char *sha1, unsigned int n) { unsigned int hash; + + /* + * Since the sha1 is essentially random, we just take the + * required number of bits directly from the first + * sizeof(unsigned int) bytes of sha1. First we have to copy + * the bytes into a properly aligned integer. If we cared + * about getting consistent results across architectures, we + * would have to call ntohl() here, too. + */ memcpy(&hash, sha1, sizeof(unsigned int)); - /* Assumes power-of-2 hash sizes in grow_object_hash */ return hash & (n - 1); } +/* + * Insert obj into the hash table hash, which has length size (which + * must be a power of 2). On collisions, simply overflow to the next + * empty bucket. + */ static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size) { unsigned int j = hash_obj(obj->sha1, size); @@ -63,6 +81,10 @@ static void insert_obj_hash(struct object *obj, struct object **hash, unsigned i hash[j] = obj; } +/* + * Look up the record for the given sha1 in the hash map stored in + * obj_hash. Return NULL if it was not found. + */ struct object *lookup_object(const unsigned char *sha1) { unsigned int i, first; @@ -92,6 +114,11 @@ struct object *lookup_object(const unsigned char *sha1) return obj; } +/* + * Increase the size of the hash map stored in obj_hash to the next + * power of 2 (but at least 32). Copy the existing values to the new + * hash map. + */ static void grow_object_hash(void) { int i; @@ -114,13 +141,12 @@ static void grow_object_hash(void) obj_hash_size = new_hash_size; } -void *create_object(const unsigned char *sha1, int type, void *o) +void *create_object(const unsigned char *sha1, void *o) { struct object *obj = o; obj->parsed = 0; obj->used = 0; - obj->type = type; obj->flags = 0; hashcpy(obj->sha1, sha1); @@ -132,11 +158,30 @@ void *create_object(const unsigned char *sha1, int type, void *o) return obj; } +void *object_as_type(struct object *obj, enum object_type type, int quiet) +{ + if (obj->type == type) + return obj; + else if (obj->type == OBJ_NONE) { + if (type == OBJ_COMMIT) + ((struct commit *)obj)->index = alloc_commit_index(); + obj->type = type; + return obj; + } + else { + if (!quiet) + error("object %s is a %s, not a %s", + sha1_to_hex(obj->sha1), + typename(obj->type), typename(type)); + return NULL; + } +} + struct object *lookup_unknown_object(const unsigned char *sha1) { struct object *obj = lookup_object(sha1); if (!obj) - obj = create_object(sha1, OBJ_NONE, alloc_object_node()); + obj = create_object(sha1, alloc_object_node()); return obj; } @@ -170,8 +215,8 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t if (commit) { if (parse_commit_buffer(commit, buffer, size)) return NULL; - if (!commit->buffer) { - commit->buffer = buffer; + if (!get_cached_commit_buffer(commit, NULL)) { + set_commit_buffer(commit, buffer, size); *eaten_p = 1; } obj = &commit->object; @@ -187,8 +232,6 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t warning("object %s has unknown type id %d", sha1_to_hex(sha1), type); obj = NULL; } - if (obj && obj->type == OBJ_NONE) - obj->type = type; return obj; } |