diff options
author | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
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committer | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
commit | 4fd287655a72b9aea14cdac715ad5b90ed082ed2 (patch) | |
tree | 65d393bc0e699dd12d05b29ba568e04cea666207 /circuitpython/py/map.c | |
parent | 0150f70ce9c39e9e6dd878766c0620c85e47bed0 (diff) |
add circuitpython code
Diffstat (limited to 'circuitpython/py/map.c')
-rw-r--r-- | circuitpython/py/map.c | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/circuitpython/py/map.c b/circuitpython/py/map.c new file mode 100644 index 0000000..092adf9 --- /dev/null +++ b/circuitpython/py/map.c @@ -0,0 +1,462 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#include "py/mpconfig.h" +#include "py/misc.h" +#include "py/runtime.h" + +#include "supervisor/linker.h" + +#if MICROPY_DEBUG_VERBOSE // print debugging info +#define DEBUG_PRINT (1) +#else // don't print debugging info +#define DEBUG_PRINT (0) +#define DEBUG_printf(...) (void)0 +#endif + +#if MICROPY_OPT_MAP_LOOKUP_CACHE +// MP_STATE_VM(map_lookup_cache) provides a cache of index to the last known +// position of that index in any map. On a cache hit, this allows +// short-circuiting the full linear search in the case of an ordered map +// (i.e. all builtin modules and objects' locals dicts), and computation of +// the hash (and potentially some linear probing) in the case of a regular +// map. Note the same cache is shared across all maps. + +// Gets the index into the cache for this index. Shift down by two to remove +// mp_obj_t tag bits. +#define MAP_CACHE_OFFSET(index) ((((uintptr_t)(index)) >> 2) % MICROPY_OPT_MAP_LOOKUP_CACHE_SIZE) +// Gets the map cache entry for the corresponding index. +#define MAP_CACHE_ENTRY(index) (MP_STATE_VM(map_lookup_cache)[MAP_CACHE_OFFSET(index)]) +// Retrieve the mp_obj_t at the location suggested by the cache. +#define MAP_CACHE_GET(map, index) (&(map)->table[MAP_CACHE_ENTRY(index) % (map)->alloc]) +// Update the cache for this index. +#define MAP_CACHE_SET(index, pos) MAP_CACHE_ENTRY(index) = (pos) & 0xff; +#else +#define MAP_CACHE_SET(index, pos) +#endif + +// This table of sizes is used to control the growth of hash tables. +// The first set of sizes are chosen so the allocation fits exactly in a +// 4-word GC block, and it's not so important for these small values to be +// prime. The latter sizes are prime and increase at an increasing rate. +STATIC const uint16_t hash_allocation_sizes[] = { + 0, 2, 4, 6, 8, 10, 12, // +2 + 17, 23, 29, 37, 47, 59, 73, // *1.25 + 97, 127, 167, 223, 293, 389, 521, 691, 919, 1223, 1627, 2161, // *1.33 + 3229, 4831, 7243, 10861, 16273, 24407, 36607, 54907, // *1.5 +}; + +STATIC size_t get_hash_alloc_greater_or_equal_to(size_t x) { + for (size_t i = 0; i < MP_ARRAY_SIZE(hash_allocation_sizes); i++) { + if (hash_allocation_sizes[i] >= x) { + return hash_allocation_sizes[i]; + } + } + // ran out of primes in the table! + // return something sensible, at least make it odd + return (x + x / 2) | 1; +} + +/******************************************************************************/ +/* map */ + +void mp_map_init(mp_map_t *map, size_t n) { + if (n == 0) { + map->alloc = 0; + map->table = NULL; + } else { + map->alloc = n; + map->table = m_new0(mp_map_elem_t, map->alloc); + } + map->used = 0; + map->all_keys_are_qstrs = 1; + map->is_fixed = 0; + map->is_ordered = 0; +} + +void mp_map_init_fixed_table(mp_map_t *map, size_t n, const mp_obj_t *table) { + map->alloc = n; + map->used = n; + map->all_keys_are_qstrs = 1; + map->is_fixed = 1; + map->is_ordered = 1; + map->table = (mp_map_elem_t *)table; +} + +// Differentiate from mp_map_clear() - semantics is different +void mp_map_deinit(mp_map_t *map) { + if (!map->is_fixed) { + m_del(mp_map_elem_t, map->table, map->alloc); + } + map->used = map->alloc = 0; +} + +void mp_map_clear(mp_map_t *map) { + if (!map->is_fixed) { + m_del(mp_map_elem_t, map->table, map->alloc); + } + map->alloc = 0; + map->used = 0; + map->all_keys_are_qstrs = 1; + map->is_fixed = 0; + map->table = NULL; +} + +STATIC void mp_map_rehash(mp_map_t *map) { + size_t old_alloc = map->alloc; + size_t new_alloc = get_hash_alloc_greater_or_equal_to(map->alloc + 1); + DEBUG_printf("mp_map_rehash(%p): " UINT_FMT " -> " UINT_FMT "\n", map, old_alloc, new_alloc); + mp_map_elem_t *old_table = map->table; + mp_map_elem_t *new_table = m_new0(mp_map_elem_t, new_alloc); + // If we reach this point, table resizing succeeded, now we can edit the old map. + map->alloc = new_alloc; + map->used = 0; + map->all_keys_are_qstrs = 1; + map->table = new_table; + for (size_t i = 0; i < old_alloc; i++) { + if (old_table[i].key != MP_OBJ_NULL && old_table[i].key != MP_OBJ_SENTINEL) { + mp_map_lookup(map, old_table[i].key, MP_MAP_LOOKUP_ADD_IF_NOT_FOUND)->value = old_table[i].value; + } + } + 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 *MICROPY_WRAP_MP_MAP_LOOKUP(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 only be called for a lookup + assert(!map->is_fixed || lookup_kind == MP_MAP_LOOKUP); + + #if MICROPY_OPT_MAP_LOOKUP_CACHE + // Try the cache for lookup or add-if-not-found. + if (lookup_kind != MP_MAP_LOOKUP_REMOVE_IF_FOUND && map->alloc) { + mp_map_elem_t *slot = MAP_CACHE_GET(map, index); + // Note: Just comparing key for value equality will have false negatives, but + // these will be handled by the regular path below. + if (slot->key == index) { + return slot; + } + } + #endif + + // 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 MICROPY_PY_COLLECTIONS_ORDEREDDICT + 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 + // note: caller must NULL the value so the GC can clean up (e.g. see dict_get_helper). + elem = &map->table[map->used]; + elem->key = MP_OBJ_NULL; + elem->value = value; + } + #endif + MAP_CACHE_SET(index, elem - map->table); + return elem; + } + } + #if MICROPY_PY_COLLECTIONS_ORDEREDDICT + 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; + #else + return NULL; + #endif + } + + // 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 + } + MAP_CACHE_SET(index, pos); + 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; + } + } + } +} + +/******************************************************************************/ +/* set */ + +#if MICROPY_PY_BUILTINS_SET + +void mp_set_init(mp_set_t *set, size_t n) { + set->alloc = n; + set->used = 0; + set->table = m_new0(mp_obj_t, set->alloc); +} + +STATIC void mp_set_rehash(mp_set_t *set) { + size_t old_alloc = set->alloc; + mp_obj_t *old_table = set->table; + set->alloc = get_hash_alloc_greater_or_equal_to(set->alloc + 1); + set->used = 0; + set->table = m_new0(mp_obj_t, set->alloc); + for (size_t i = 0; i < old_alloc; i++) { + if (old_table[i] != MP_OBJ_NULL && old_table[i] != MP_OBJ_SENTINEL) { + mp_set_lookup(set, old_table[i], MP_MAP_LOOKUP_ADD_IF_NOT_FOUND); + } + } + m_del(mp_obj_t, old_table, old_alloc); +} + +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); + } else { + return MP_OBJ_NULL; + } + } + mp_uint_t hash = MP_OBJ_SMALL_INT_VALUE(mp_unary_op(MP_UNARY_OP_HASH, index)); + size_t pos = hash % set->alloc; + size_t start_pos = pos; + mp_obj_t *avail_slot = NULL; + for (;;) { + mp_obj_t elem = set->table[pos]; + if (elem == MP_OBJ_NULL) { + // found NULL slot, so index is not in table + if (lookup_kind & MP_MAP_LOOKUP_ADD_IF_NOT_FOUND) { + if (avail_slot == NULL) { + avail_slot = &set->table[pos]; + } + set->used++; + *avail_slot = index; + return index; + } else { + return MP_OBJ_NULL; + } + } else if (elem == MP_OBJ_SENTINEL) { + // found deleted slot, remember for later + if (avail_slot == NULL) { + avail_slot = &set->table[pos]; + } + } else if (mp_obj_equal(elem, index)) { + // found index + if (lookup_kind & MP_MAP_LOOKUP_REMOVE_IF_FOUND) { + // delete element + set->used--; + if (set->table[(pos + 1) % set->alloc] == MP_OBJ_NULL) { + // optimisation if next slot is empty + set->table[pos] = MP_OBJ_NULL; + } else { + set->table[pos] = MP_OBJ_SENTINEL; + } + } + return elem; + } + + // not yet found, keep searching in this table + pos = (pos + 1) % set->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 + set->used++; + *avail_slot = index; + return index; + } else { + // not enough room in table, rehash it + mp_set_rehash(set); + // restart the search for the new element + start_pos = pos = hash % set->alloc; + } + } else { + return MP_OBJ_NULL; + } + } + } +} + +mp_obj_t mp_set_remove_first(mp_set_t *set) { + for (size_t pos = 0; pos < set->alloc; pos++) { + if (mp_set_slot_is_filled(set, pos)) { + mp_obj_t elem = set->table[pos]; + // delete element + set->used--; + if (set->table[(pos + 1) % set->alloc] == MP_OBJ_NULL) { + // optimisation if next slot is empty + set->table[pos] = MP_OBJ_NULL; + } else { + set->table[pos] = MP_OBJ_SENTINEL; + } + return elem; + } + } + return MP_OBJ_NULL; +} + +void mp_set_clear(mp_set_t *set) { + m_del(mp_obj_t, set->table, set->alloc); + set->alloc = 0; + set->used = 0; + set->table = NULL; +} + +#endif // MICROPY_PY_BUILTINS_SET + +#if defined(DEBUG_PRINT) && DEBUG_PRINT +void mp_map_dump(mp_map_t *map) { + for (size_t i = 0; i < map->alloc; i++) { + if (map->table[i].key != MP_OBJ_NULL) { + mp_obj_print(map->table[i].key, PRINT_REPR); + } else { + DEBUG_printf("(nil)"); + } + DEBUG_printf(": %p\n", map->table[i].value); + } + DEBUG_printf("---\n"); +} +#endif |