py/runtime: Optimise case of identity iterator so it doesn't alloc RAM.

This commit is contained in:
Damien George 2017-01-17 15:38:32 +11:00
parent 30b42dd72d
commit cb6300697c
1 changed files with 7 additions and 1 deletions

View File

@ -1103,6 +1103,13 @@ void mp_store_attr(mp_obj_t base, qstr attr, mp_obj_t value) {
mp_obj_t mp_getiter(mp_obj_t o_in, mp_obj_iter_buf_t *iter_buf) {
assert(o_in);
mp_obj_type_t *type = mp_obj_get_type(o_in);
// Check for native getiter which is the identity. We handle this case explicitly
// so we don't unnecessarily allocate any RAM for the iter_buf, which won't be used.
if (type->getiter == mp_identity_getiter) {
return o_in;
}
// if caller did not provide a buffer then allocate one on the heap
if (iter_buf == NULL) {
@ -1110,7 +1117,6 @@ mp_obj_t mp_getiter(mp_obj_t o_in, mp_obj_iter_buf_t *iter_buf) {
}
// check for native getiter (corresponds to __iter__)
mp_obj_type_t *type = mp_obj_get_type(o_in);
if (type->getiter != NULL) {
mp_obj_t iter = type->getiter(o_in, iter_buf);
if (iter != MP_OBJ_NULL) {