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py: Make mp_map_lookup not allocate memory on removal.

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This commit is contained in:
Damien George 2014-04-05 23:33:12 +01:00
parent 09af5364d4
commit d0e824387e
2 changed files with 9 additions and 11 deletions
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16
py/map.c
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@ -91,6 +91,12 @@ STATIC void mp_map_rehash(mp_map_t *map) {
m_del(mp_map_elem_t, old_table, old_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) {
// if the map is a fixed array then we must do a brute force linear search
if (map->table_is_fixed_array) {
@ -135,7 +141,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
}
return slot;
} else {
return MP_OBJ_NULL;
return NULL;
}
} else if (slot->key == MP_OBJ_SENTINEL) {
// found deleted slot, remember for later
@ -146,10 +152,6 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
// 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) {
// this leaks this memory (but see dict_get_helper)
mp_map_elem_t *retval = m_new(mp_map_elem_t, 1);
retval->key = slot->key;
retval->value = slot->value;
// delete element in this slot
map->used--;
if (map->table[(pos + 1) % map->alloc].key == MP_OBJ_NULL) {
@ -158,7 +160,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
} else {
slot->key = MP_OBJ_SENTINEL;
}
return retval;
// keep slot->value so that caller can access it if needed
}
return slot;
}
@ -185,7 +187,7 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
start_pos = pos = hash % map->alloc;
}
} else {
return MP_OBJ_NULL;
return NULL;
}
}
}

4
py/objdict.c
View File

@ -208,10 +208,6 @@ STATIC mp_obj_t dict_get_helper(mp_map_t *self, mp_obj_t key, mp_obj_t deflt, mp
}
} else {
value = elem->value;
if (lookup_kind == MP_MAP_LOOKUP_REMOVE_IF_FOUND) {
// catch the leak (from mp_map_lookup)
m_free(elem, sizeof(mp_map_elem_t));
}
}
if (lookup_kind == MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) {
elem->value = value;