int git_odb_exists_prefix(
git_oid *out, git_odb *db, const git_oid *short_id, size_t len)
{
int error = GIT_ENOTFOUND, num_found = 0;
size_t i;
git_oid key = {{0}}, last_found = {{0}}, found;
assert(db && short_id);
if (len < GIT_OID_MINPREFIXLEN)
return git_odb__error_ambiguous("prefix length too short");
if (len > GIT_OID_HEXSZ)
len = GIT_OID_HEXSZ;
if (len == GIT_OID_HEXSZ) {
if (git_odb_exists(db, short_id)) {
if (out)
git_oid_cpy(out, short_id);
return 0;
} else {
return git_odb__error_notfound("no match for id prefix", short_id);
}
}
/* just copy valid part of short_id */
memcpy(&key.id, short_id->id, (len + 1) / 2);
if (len & 1)
key.id[len / 2] &= 0xF0;
for (i = 0; i < db->backends.length; ++i) {
backend_internal *internal = (backend_internal *) git_vector_get(&db->backends, i);
git_odb_backend *b = internal->backend;
if (!b->exists_prefix)
continue;
error = b->exists_prefix(&found, b, &key, len);
if (error == GIT_ENOTFOUND || error == GIT_PASSTHROUGH)
continue;
if (error)
return error;
/* make sure found item doesn't introduce ambiguity */
if (num_found) {
if (git_oid__cmp(&last_found, &found))
return git_odb__error_ambiguous("multiple matches for prefix");
} else {
git_oid_cpy(&last_found, &found);
num_found++;
}
}
if (!num_found)
return git_odb__error_notfound("no match for id prefix", &key);
if (out)
git_oid_cpy(out, &last_found);
return 0;
}
static int pack_entry_find_prefix(
struct git_pack_entry *e,
struct pack_backend *backend,
const git_oid *short_oid,
size_t len)
{
int error;
size_t i;
git_oid found_full_oid = {{0}};
bool found = false;
struct git_pack_file *last_found = backend->last_found;
if (last_found) {
error = git_pack_entry_find(e, last_found, short_oid, len);
if (error == GIT_EAMBIGUOUS)
return error;
if (!error) {
git_oid_cpy(&found_full_oid, &e->sha1);
found = true;
}
}
for (i = 0; i < backend->packs.length; ++i) {
struct git_pack_file *p;
p = (git_pack_file*) git_vector_get(&backend->packs, i);
if (p == last_found)
continue;
error = git_pack_entry_find(e, p, short_oid, len);
if (error == GIT_EAMBIGUOUS)
return error;
if (!error) {
if (found && git_oid_cmp(&e->sha1, &found_full_oid))
return git_odb__error_ambiguous("found multiple pack entries");
git_oid_cpy(&found_full_oid, &e->sha1);
found = true;
backend->last_found = p;
}
}
if (!found)
return git_odb__error_notfound("no matching pack entry for prefix", short_oid);
else
return 0;
}
static int pack_backend__read_prefix_internal(
git_oid *out_oid,
void **buffer_p,
size_t *len_p,
git_otype *type_p,
git_odb_backend *backend,
const git_oid *short_oid,
size_t len)
{
int error = 0;
if (len < GIT_OID_MINPREFIXLEN)
error = git_odb__error_ambiguous("prefix length too short");
else if (len >= GIT_OID_HEXSZ) {
/* We can fall back to regular read method */
error = pack_backend__read(buffer_p, len_p, type_p, backend, short_oid);
if (!error)
git_oid_cpy(out_oid, short_oid);
} else {
struct git_pack_entry e;
git_rawobj raw;
if ((error = pack_entry_find_prefix(
&e, (struct pack_backend *)backend, short_oid, len)) == 0 &&
(error = git_packfile_unpack(&raw, e.p, &e.offset)) == 0)
{
*buffer_p = raw.data;
*len_p = raw.len;
*type_p = raw.type;
git_oid_cpy(out_oid, &e.sha1);
}
}
return error;
}
/* Locate an object matching a given short oid */
static int locate_object_short_oid(
git_buf *object_location,
git_oid *res_oid,
loose_backend *backend,
const git_oid *short_oid,
size_t len)
{
char *objects_dir = backend->objects_dir;
size_t dir_len = strlen(objects_dir), alloc_len;
loose_locate_object_state state;
int error;
/* prealloc memory for OBJ_DIR/xx/xx..38x..xx */
GITERR_CHECK_ALLOC_ADD(&alloc_len, dir_len, GIT_OID_HEXSZ);
GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 3);
if (git_buf_grow(object_location, alloc_len) < 0)
return -1;
git_buf_set(object_location, objects_dir, dir_len);
git_path_to_dir(object_location);
/* save adjusted position at end of dir so it can be restored later */
dir_len = git_buf_len(object_location);
/* Convert raw oid to hex formatted oid */
git_oid_fmt((char *)state.short_oid, short_oid);
/* Explore OBJ_DIR/xx/ where xx is the beginning of hex formatted short oid */
if (git_buf_put(object_location, (char *)state.short_oid, 3) < 0)
return -1;
object_location->ptr[object_location->size - 1] = '/';
/* Check that directory exists */
if (git_path_isdir(object_location->ptr) == false)
return git_odb__error_notfound("no matching loose object for prefix",
short_oid, len);
state.dir_len = git_buf_len(object_location);
state.short_oid_len = len;
state.found = 0;
/* Explore directory to find a unique object matching short_oid */
error = git_path_direach(
object_location, 0, fn_locate_object_short_oid, &state);
if (error < 0 && error != GIT_EAMBIGUOUS)
return error;
if (!state.found)
return git_odb__error_notfound("no matching loose object for prefix",
short_oid, len);
if (state.found > 1)
return git_odb__error_ambiguous("multiple matches in loose objects");
/* Convert obtained hex formatted oid to raw */
error = git_oid_fromstr(res_oid, (char *)state.res_oid);
if (error)
return error;
/* Update the location according to the oid obtained */
GITERR_CHECK_ALLOC_ADD(&alloc_len, dir_len, GIT_OID_HEXSZ);
GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2);
git_buf_truncate(object_location, dir_len);
if (git_buf_grow(object_location, alloc_len) < 0)
return -1;
git_oid_pathfmt(object_location->ptr + dir_len, res_oid);
object_location->size += GIT_OID_HEXSZ + 1;
object_location->ptr[object_location->size] = '\0';
return 0;
}
int git_odb_read_prefix(
git_odb_object **out, git_odb *db, const git_oid *short_id, size_t len)
{
size_t i;
int error = GIT_ENOTFOUND;
git_oid key = {{0}}, found_full_oid = {{0}};
git_rawobj raw;
void *data = NULL;
bool found = false;
git_odb_object *object;
assert(out && db);
if (len < GIT_OID_MINPREFIXLEN)
return git_odb__error_ambiguous("prefix length too short");
if (len > GIT_OID_HEXSZ)
len = GIT_OID_HEXSZ;
if (len == GIT_OID_HEXSZ) {
*out = git_cache_get_raw(odb_cache(db), short_id);
if (*out != NULL)
return 0;
}
/* just copy valid part of short_id */
memcpy(&key.id, short_id->id, (len + 1) / 2);
if (len & 1)
key.id[len / 2] &= 0xF0;
for (i = 0; i < db->backends.length; ++i) {
backend_internal *internal = (backend_internal *) git_vector_get(&db->backends, i);
git_odb_backend *b = internal->backend;
if (b->read_prefix != NULL) {
git_oid full_oid;
error = b->read_prefix(&full_oid, &raw.data, &raw.len, &raw.type, b, &key, len);
if (error == GIT_ENOTFOUND || error == GIT_PASSTHROUGH)
continue;
if (error)
return error;
git__free(data);
data = raw.data;
if (found && git_oid__cmp(&full_oid, &found_full_oid)) {
git__free(raw.data);
return git_odb__error_ambiguous("multiple matches for prefix");
}
found_full_oid = full_oid;
found = true;
}
}
if (!found)
return git_odb__error_notfound("no match for prefix", &key);
if ((object = odb_object__alloc(&found_full_oid, &raw)) == NULL)
return -1;
*out = (git_odb_object*) git_cache_store_raw(odb_cache(db), object);
return 0;
}
