py: Clarify API for map/set lookup when removing&adding at once.

Addresses issue #1160.
This commit is contained in:
Damien George 2015-03-20 17:41:37 +00:00
parent d48035b06b
commit d1cee02783
3 changed files with 14 additions and 10 deletions

View File

@ -150,7 +150,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
// and it won't necessarily benefit subsequent calls because these calls
// most likely won't pass the newly-interned string.
compare_only_ptrs = false;
} else if (!(lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND)) {
} else if (lookup_kind != MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
// If we are not adding, then we can return straight away a failed
// lookup because we know that the index will never be found.
return NULL;
@ -193,7 +193,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
// map is a hash table (not an ordered array), so do a hash lookup
if (map->alloc == 0) {
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
if (lookup_kind == MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
mp_map_rehash(map);
} else {
return NULL;
@ -208,7 +208,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
mp_map_elem_t *slot = &map->table[pos];
if (slot->key == MP_OBJ_NULL) {
// found NULL slot, so index is not in table
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
if (lookup_kind == MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
map->used += 1;
if (avail_slot == NULL) {
avail_slot = slot;
@ -230,7 +230,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
} else if (slot->key == index || (!compare_only_ptrs && mp_obj_equal(slot->key, index))) {
// found index
// Note: CPython does not replace the index; try x={True:'true'};x[1]='one';x
if (lookup_kind & MP_MAP_LOOKUP_REMOVE_IF_FOUND) {
if (lookup_kind == MP_MAP_LOOKUP_REMOVE_IF_FOUND) {
// delete element in this slot
map->used--;
if (map->table[(pos + 1) % map->alloc].key == MP_OBJ_NULL) {
@ -249,7 +249,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
if (pos == start_pos) {
// search got back to starting position, so index is not in table
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
if (lookup_kind == MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
if (avail_slot != NULL) {
// there was an available slot, so use that
map->used++;
@ -298,6 +298,9 @@ STATIC void mp_set_rehash(mp_set_t *set) {
}
mp_obj_t mp_set_lookup(mp_set_t *set, mp_obj_t index, mp_map_lookup_kind_t lookup_kind) {
// Note: lookup_kind can be MP_MAP_LOOKUP_ADD_IF_NOT_FOUND_OR_REMOVE_IF_FOUND which
// is handled by using bitwise operations.
if (set->alloc == 0) {
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
mp_set_rehash(set);

View File

@ -159,11 +159,12 @@ typedef struct _mp_map_t {
mp_map_elem_t *table;
} mp_map_t;
// These can be or'd together
// mp_set_lookup requires these constants to have the values they do
typedef enum _mp_map_lookup_kind_t {
MP_MAP_LOOKUP, // 0
MP_MAP_LOOKUP_ADD_IF_NOT_FOUND, // 1
MP_MAP_LOOKUP_REMOVE_IF_FOUND, // 2
MP_MAP_LOOKUP = 0,
MP_MAP_LOOKUP_ADD_IF_NOT_FOUND = 1,
MP_MAP_LOOKUP_REMOVE_IF_FOUND = 2,
MP_MAP_LOOKUP_ADD_IF_NOT_FOUND_OR_REMOVE_IF_FOUND = 3, // only valid for mp_set_lookup
} mp_map_lookup_kind_t;
extern const mp_map_t mp_const_empty_map;

View File

@ -427,7 +427,7 @@ STATIC mp_obj_t set_symmetric_difference_update(mp_obj_t self_in, mp_obj_t other
mp_obj_t iter = mp_getiter(other_in);
mp_obj_t next;
while ((next = mp_iternext(iter)) != MP_OBJ_STOP_ITERATION) {
mp_set_lookup(&self->set, next, MP_MAP_LOOKUP_REMOVE_IF_FOUND | MP_MAP_LOOKUP_ADD_IF_NOT_FOUND);
mp_set_lookup(&self->set, next, MP_MAP_LOOKUP_ADD_IF_NOT_FOUND_OR_REMOVE_IF_FOUND);
}
return mp_const_none;
}