// MP_MAP_LOOKUP behaviour:
// - returns NULL if not found, else the slot it was found in with key,value non-null
// MP_MAP_LOOKUP_ADD_IF_NOT_FOUND behaviour:
// - returns slot, with key non-null and value=MP_OBJ_NULL if it was added
// MP_MAP_LOOKUP_REMOVE_IF_FOUND behaviour:
// - returns NULL if not found, else the slot if was found in with key null and value non-null
mp_map_elem_t *mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t lookup_kind) {
if (map->is_fixed && lookup_kind != MP_MAP_LOOKUP) {
// can't add/remove from a fixed array
return NULL;
}
// Work out if we can compare just pointers
bool compare_only_ptrs = map->all_keys_are_qstrs;
if (compare_only_ptrs) {
if (MP_OBJ_IS_QSTR(index)) {
// Index is a qstr, so can just do ptr comparison.
} else if (MP_OBJ_IS_TYPE(index, &mp_type_str)) {
// Index is a non-interned string.
// We can either intern the string, or force a full equality comparison.
// We chose the latter, since interning costs time and potentially RAM,
// 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) {
// 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;
}
}
// if the map is an ordered array then we must do a brute force linear search
if (map->is_ordered) {
for (mp_map_elem_t *elem = &map->table[0], *top = &map->table[map->used]; elem < top; elem++) {
if (elem->key == index || (!compare_only_ptrs && mp_obj_equal(elem->key, index))) {
if (MP_UNLIKELY(lookup_kind == MP_MAP_LOOKUP_REMOVE_IF_FOUND)) {
// remove the found element by moving the rest of the array down
mp_obj_t value = elem->value;
--map->used;
memmove(elem, elem + 1, (top - elem - 1) * sizeof(*elem));
// put the found element after the end so the caller can access it if needed
elem = &map->table[map->used];
elem->key = MP_OBJ_NULL;
elem->value = value;
}
return elem;
}
}
if (MP_LIKELY(lookup_kind != MP_MAP_LOOKUP_ADD_IF_NOT_FOUND)) {
return NULL;
}
if (map->used == map->alloc) {
// TODO: Alloc policy
map->alloc += 4;
map->table = m_renew(mp_map_elem_t, map->table, map->used, map->alloc);
mp_seq_clear(map->table, map->used, map->alloc, sizeof(*map->table));
}
mp_map_elem_t *elem = map->table + map->used++;
elem->key = index;
if (!MP_OBJ_IS_QSTR(index)) {
map->all_keys_are_qstrs = 0;
}
return elem;
}
// 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) {
mp_map_rehash(map);
} else {
return NULL;
}
}
// get hash of index, with fast path for common case of qstr
mp_uint_t hash;
if (MP_OBJ_IS_QSTR(index)) {
hash = qstr_hash(MP_OBJ_QSTR_VALUE(index));
} else {
hash = MP_OBJ_SMALL_INT_VALUE(mp_unary_op(MP_UNARY_OP_HASH, index));
}
size_t pos = hash % map->alloc;
size_t start_pos = pos;
mp_map_elem_t *avail_slot = NULL;
for (;;) {
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) {
map->used += 1;
if (avail_slot == NULL) {
avail_slot = slot;
}
avail_slot->key = index;
avail_slot->value = MP_OBJ_NULL;
if (!MP_OBJ_IS_QSTR(index)) {
map->all_keys_are_qstrs = 0;
}
return avail_slot;
} else {
return NULL;
}
} else if (slot->key == MP_OBJ_SENTINEL) {
// found deleted slot, remember for later
if (avail_slot == NULL) {
avail_slot = slot;
}
} 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) {
// delete element in this slot
map->used--;
if (map->table[(pos + 1) % map->alloc].key == MP_OBJ_NULL) {
// optimisation if next slot is empty
slot->key = MP_OBJ_NULL;
} else {
slot->key = MP_OBJ_SENTINEL;
}
// keep slot->value so that caller can access it if needed
}
return slot;
}
// not yet found, keep searching in this table
pos = (pos + 1) % map->alloc;
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 (avail_slot != NULL) {
// there was an available slot, so use that
map->used++;
avail_slot->key = index;
avail_slot->value = MP_OBJ_NULL;
if (!MP_OBJ_IS_QSTR(index)) {
map->all_keys_are_qstrs = 0;
}
return avail_slot;
} else {
// not enough room in table, rehash it
mp_map_rehash(map);
// restart the search for the new element
start_pos = pos = hash % map->alloc;
}
} else {
return NULL;
}
}
}
}
mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t lookup_kind) {
// if the map is a fixed array then we must do a brute force linear search
if (map->table_is_fixed_array) {
if (lookup_kind != MP_MAP_LOOKUP) {
return NULL;
}
for (mp_map_elem_t *elem = &map->table[0], *top = &map->table[map->used]; elem < top; elem++) {
if (elem->key == index || (!map->all_keys_are_qstrs && mp_obj_equal(elem->key, index))) {
return elem;
}
}
return NULL;
}
// map is a hash table (not a fixed array), so do a hash lookup
machine_uint_t hash;
hash = mp_obj_hash(index);
if (map->alloc == 0) {
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
mp_map_rehash(map);
} else {
return NULL;
}
}
uint pos = hash % map->alloc;
for (;;) {
mp_map_elem_t *elem = &map->table[pos];
if (elem->key == NULL) {
// not in table
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
if (map->used + 1 >= map->alloc) {
// not enough room in table, rehash it
mp_map_rehash(map);
// restart the search for the new element
pos = hash % map->alloc;
} else {
map->used += 1;
elem->key = index;
if (!MP_OBJ_IS_QSTR(index)) {
map->all_keys_are_qstrs = 0;
}
return elem;
}
} else {
return NULL;
}
} else if (elem->key == index || (!map->all_keys_are_qstrs && mp_obj_equal(elem->key, index))) {
// found it
/* it seems CPython does not replace the index; try x={True:'true'};x[1]='one';x
if (add_if_not_found) {
elem->key = index;
}
*/
if (lookup_kind & MP_MAP_LOOKUP_REMOVE_IF_FOUND) {
map->used--;
// this leaks this memory (but see dict_get_helper)
mp_map_elem_t *retval = m_new(mp_map_elem_t, 1);
retval->key = elem->key;
retval->value = elem->value;
elem->key = NULL;
elem->value = NULL;
return retval;
}
return elem;
} else {
// not yet found, keep searching in this table
pos = (pos + 1) % map->alloc;
}
}
}
// MP_MAP_LOOKUP behaviour:
// - returns NULL if not found, else the slot it was found in with key,value non-null
// MP_MAP_LOOKUP_ADD_IF_NOT_FOUND behaviour:
// - returns slot, with key non-null and value=MP_OBJ_NULL if it was added
// MP_MAP_LOOKUP_REMOVE_IF_FOUND behaviour:
// - returns NULL if not found, else the slot if was found in with key null and value non-null
mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t lookup_kind) {
// Work out if we can compare just pointers
bool compare_only_ptrs = map->all_keys_are_qstrs;
if (compare_only_ptrs) {
if (MP_OBJ_IS_QSTR(index)) {
// Index is a qstr, so can just do ptr comparison.
} else if (MP_OBJ_IS_TYPE(index, &mp_type_str)) {
// Index is a non-interned string.
// We can either intern the string, or force a full equality comparison.
// We chose the latter, since interning costs time and potentially RAM,
// 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)) {
// 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;
}
}
// if the map is a fixed array then we must do a brute force linear search
if (map->table_is_fixed_array) {
if (lookup_kind != MP_MAP_LOOKUP) {
return NULL;
}
for (mp_map_elem_t *elem = &map->table[0], *top = &map->table[map->used]; elem < top; elem++) {
if (elem->key == index || (!compare_only_ptrs && mp_obj_equal(elem->key, index))) {
return elem;
}
}
return NULL;
}
// map is a hash table (not a fixed array), so do a hash lookup
if (map->alloc == 0) {
if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
mp_map_rehash(map);
} else {
return NULL;
}
}
mp_uint_t hash = mp_obj_hash(index);
mp_uint_t pos = hash % map->alloc;
mp_uint_t start_pos = pos;
mp_map_elem_t *avail_slot = NULL;
for (;;) {
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) {
map->used += 1;
if (avail_slot == NULL) {
avail_slot = slot;
}
slot->key = index;
slot->value = MP_OBJ_NULL;
if (!MP_OBJ_IS_QSTR(index)) {
map->all_keys_are_qstrs = 0;
}
return slot;
} else {
return NULL;
}
} else if (slot->key == MP_OBJ_SENTINEL) {
// found deleted slot, remember for later
if (avail_slot == NULL) {
avail_slot = slot;
}
} 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) {
// delete element in this slot
map->used--;
if (map->table[(pos + 1) % map->alloc].key == MP_OBJ_NULL) {
// optimisation if next slot is empty
slot->key = MP_OBJ_NULL;
} else {
slot->key = MP_OBJ_SENTINEL;
}
// keep slot->value so that caller can access it if needed
}
return slot;
}
// not yet found, keep searching in this table
pos = (pos + 1) % map->alloc;
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 (avail_slot != NULL) {
// there was an available slot, so use that
map->used++;
avail_slot->key = index;
avail_slot->value = MP_OBJ_NULL;
if (!MP_OBJ_IS_QSTR(index)) {
map->all_keys_are_qstrs = 0;
}
return avail_slot;
} else {
// not enough room in table, rehash it
mp_map_rehash(map);
// restart the search for the new element
start_pos = pos = hash % map->alloc;
}
} else {
return NULL;
}
}
}
}
