objarray.c

/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 * Copyright (c) 2014 Paul Sokolovsky
 *
 * 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 <string.h>
#include <assert.h>
#include <stdint.h>

#include "py/nlr.h"
#include "py/runtime0.h"
#include "py/runtime.h"
#include "py/binary.h"

#if MICROPY_PY_ARRAY || MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_BUILTINS_MEMORYVIEW

// About memoryview object: We want to reuse as much code as possible from
// array, and keep the memoryview object 4 words in size so it fits in 1 GC
// block.  Also, memoryview must keep a pointer to the base of the buffer so
// that the buffer is not GC'd if the original parent object is no longer
// around (we are assuming that all memoryview'able objects return a pointer
// which points to the start of a GC chunk).  Given the above constraints we
// do the following:
//  - typecode high bit is set if the buffer is read-write (else read-only)
//  - free is the offset in elements to the first item in the memoryview
//  - len is the length in elements
//  - items points to the start of the original buffer
// Note that we don't handle the case where the original buffer might change
// size due to a resize of the original parent object.

// make (& TYPECODE_MASK) a null operation if memorview not enabled
#if MICROPY_PY_BUILTINS_MEMORYVIEW
#define TYPECODE_MASK (0x7f)
#else
#define TYPECODE_MASK (~(mp_uint_t)1)
#endif

typedef struct _mp_obj_array_t {
    mp_obj_base_t base;
    mp_uint_t typecode : 8;
    // free is number of unused elements after len used elements
    // alloc size = len + free
    mp_uint_t free : (8 * sizeof(mp_uint_t) - 8);
    mp_uint_t len; // in elements
    void *items;
} mp_obj_array_t;

STATIC mp_obj_t array_iterator_new(mp_obj_t array_in);