diff options
Diffstat (limited to 'object.c')
| -rw-r--r-- | object.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/object.c b/object.c new file mode 100644 index 0000000..23d6c96 --- /dev/null +++ b/object.c @@ -0,0 +1,426 @@ +#include "cache.h" +#include "object.h" +#include "blob.h" +#include "tree.h" +#include "commit.h" +#include "tag.h" + +static struct object **obj_hash; +static int nr_objs, obj_hash_size; + +unsigned int get_max_object_index(void) +{ + return obj_hash_size; +} + +struct object *get_indexed_object(unsigned int idx) +{ + return obj_hash[idx]; +} + +static const char *object_type_strings[] = { + NULL, /* OBJ_NONE = 0 */ + "commit", /* OBJ_COMMIT = 1 */ + "tree", /* OBJ_TREE = 2 */ + "blob", /* OBJ_BLOB = 3 */ + "tag", /* OBJ_TAG = 4 */ +}; + +const char *typename(unsigned int type) +{ + if (type >= ARRAY_SIZE(object_type_strings)) + return NULL; + return object_type_strings[type]; +} + +int type_from_string_gently(const char *str, ssize_t len, int gentle) +{ + int i; + + if (len < 0) + len = strlen(str); + + for (i = 1; i < ARRAY_SIZE(object_type_strings); i++) + if (!strncmp(str, object_type_strings[i], len)) + return i; + + if (gentle) + return -1; + + 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) +{ + return sha1hash(sha1) & (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); + + while (hash[j]) { + j++; + if (j >= size) + j = 0; + } + 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; + struct object *obj; + + if (!obj_hash) + return NULL; + + first = i = hash_obj(sha1, obj_hash_size); + while ((obj = obj_hash[i]) != NULL) { + if (!hashcmp(sha1, obj->sha1)) + break; + i++; + if (i == obj_hash_size) + i = 0; + } + if (obj && i != first) { + /* + * Move object to where we started to look for it so + * that we do not need to walk the hash table the next + * time we look for it. + */ + struct object *tmp = obj_hash[i]; + obj_hash[i] = obj_hash[first]; + obj_hash[first] = tmp; + } + 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; + /* + * Note that this size must always be power-of-2 to match hash_obj + * above. + */ + int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size; + struct object **new_hash; + + new_hash = xcalloc(new_hash_size, sizeof(struct object *)); + for (i = 0; i < obj_hash_size; i++) { + struct object *obj = obj_hash[i]; + if (!obj) + continue; + insert_obj_hash(obj, new_hash, new_hash_size); + } + free(obj_hash); + obj_hash = new_hash; + obj_hash_size = new_hash_size; +} + +void *create_object(const unsigned char *sha1, void *o) +{ + struct object *obj = o; + + obj->parsed = 0; + obj->used = 0; + obj->flags = 0; + hashcpy(obj->sha1, sha1); + + if (obj_hash_size - 1 <= nr_objs * 2) + grow_object_hash(); + + insert_obj_hash(obj, obj_hash, obj_hash_size); + nr_objs++; + 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, alloc_object_node()); + return obj; +} + +struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p) +{ + struct object *obj; + *eaten_p = 0; + + obj = NULL; + if (type == OBJ_BLOB) { + struct blob *blob = lookup_blob(sha1); + if (blob) { + if (parse_blob_buffer(blob, buffer, size)) + return NULL; + obj = &blob->object; + } + } else if (type == OBJ_TREE) { + struct tree *tree = lookup_tree(sha1); + if (tree) { + obj = &tree->object; + if (!tree->buffer) + tree->object.parsed = 0; + if (!tree->object.parsed) { + if (parse_tree_buffer(tree, buffer, size)) + return NULL; + *eaten_p = 1; + } + } + } else if (type == OBJ_COMMIT) { + struct commit *commit = lookup_commit(sha1); + if (commit) { + if (parse_commit_buffer(commit, buffer, size)) + return NULL; + if (!get_cached_commit_buffer(commit, NULL)) { + set_commit_buffer(commit, buffer, size); + *eaten_p = 1; + } + obj = &commit->object; + } + } else if (type == OBJ_TAG) { + struct tag *tag = lookup_tag(sha1); + if (tag) { + if (parse_tag_buffer(tag, buffer, size)) + return NULL; + obj = &tag->object; + } + } else { + warning("object %s has unknown type id %d", sha1_to_hex(sha1), type); + obj = NULL; + } + return obj; +} + +struct object *parse_object_or_die(const unsigned char *sha1, + const char *name) +{ + struct object *o = parse_object(sha1); + if (o) + return o; + + die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1)); +} + +struct object *parse_object(const unsigned char *sha1) +{ + unsigned long size; + enum object_type type; + int eaten; + const unsigned char *repl = lookup_replace_object(sha1); + void *buffer; + struct object *obj; + + obj = lookup_object(sha1); + if (obj && obj->parsed) + return obj; + + if ((obj && obj->type == OBJ_BLOB) || + (!obj && has_sha1_file(sha1) && + sha1_object_info(sha1, NULL) == OBJ_BLOB)) { + if (check_sha1_signature(repl, NULL, 0, NULL) < 0) { + error("sha1 mismatch %s", sha1_to_hex(repl)); + return NULL; + } + parse_blob_buffer(lookup_blob(sha1), NULL, 0); + return lookup_object(sha1); + } + + buffer = read_sha1_file(sha1, &type, &size); + if (buffer) { + if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) { + free(buffer); + error("sha1 mismatch %s", sha1_to_hex(repl)); + return NULL; + } + + obj = parse_object_buffer(sha1, type, size, buffer, &eaten); + if (!eaten) + free(buffer); + return obj; + } + return NULL; +} + +struct object_list *object_list_insert(struct object *item, + struct object_list **list_p) +{ + struct object_list *new_list = xmalloc(sizeof(struct object_list)); + new_list->item = item; + new_list->next = *list_p; + *list_p = new_list; + return new_list; +} + +int object_list_contains(struct object_list *list, struct object *obj) +{ + while (list) { + if (list->item == obj) + return 1; + list = list->next; + } + return 0; +} + +/* + * A zero-length string to which object_array_entry::name can be + * initialized without requiring a malloc/free. + */ +static char object_array_slopbuf[1]; + +void add_object_array_with_path(struct object *obj, const char *name, + struct object_array *array, + unsigned mode, const char *path) +{ + unsigned nr = array->nr; + unsigned alloc = array->alloc; + struct object_array_entry *objects = array->objects; + struct object_array_entry *entry; + + if (nr >= alloc) { + alloc = (alloc + 32) * 2; + REALLOC_ARRAY(objects, alloc); + array->alloc = alloc; + array->objects = objects; + } + entry = &objects[nr]; + entry->item = obj; + if (!name) + entry->name = NULL; + else if (!*name) + /* Use our own empty string instead of allocating one: */ + entry->name = object_array_slopbuf; + else + entry->name = xstrdup(name); + entry->mode = mode; + if (path) + entry->path = xstrdup(path); + else + entry->path = NULL; + array->nr = ++nr; +} + +void add_object_array(struct object *obj, const char *name, struct object_array *array) +{ + add_object_array_with_path(obj, name, array, S_IFINVALID, NULL); +} + +/* + * Free all memory associated with an entry; the result is + * in an unspecified state and should not be examined. + */ +static void object_array_release_entry(struct object_array_entry *ent) +{ + if (ent->name != object_array_slopbuf) + free(ent->name); + free(ent->path); +} + +void object_array_filter(struct object_array *array, + object_array_each_func_t want, void *cb_data) +{ + unsigned nr = array->nr, src, dst; + struct object_array_entry *objects = array->objects; + + for (src = dst = 0; src < nr; src++) { + if (want(&objects[src], cb_data)) { + if (src != dst) + objects[dst] = objects[src]; + dst++; + } else { + object_array_release_entry(&objects[src]); + } + } + array->nr = dst; +} + +void object_array_clear(struct object_array *array) +{ + int i; + for (i = 0; i < array->nr; i++) + object_array_release_entry(&array->objects[i]); + free(array->objects); + array->objects = NULL; + array->nr = array->alloc = 0; +} + +/* + * Return true iff array already contains an entry with name. + */ +static int contains_name(struct object_array *array, const char *name) +{ + unsigned nr = array->nr, i; + struct object_array_entry *object = array->objects; + + for (i = 0; i < nr; i++, object++) + if (!strcmp(object->name, name)) + return 1; + return 0; +} + +void object_array_remove_duplicates(struct object_array *array) +{ + unsigned nr = array->nr, src; + struct object_array_entry *objects = array->objects; + + array->nr = 0; + for (src = 0; src < nr; src++) { + if (!contains_name(array, objects[src].name)) { + if (src != array->nr) + objects[array->nr] = objects[src]; + array->nr++; + } else { + object_array_release_entry(&objects[src]); + } + } +} + +void clear_object_flags(unsigned flags) +{ + int i; + + for (i=0; i < obj_hash_size; i++) { + struct object *obj = obj_hash[i]; + if (obj) + obj->flags &= ~flags; + } +} |