circuitpython/shared-bindings/struct/__init__.c

182 lines
7.1 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2014 Paul Sokolovsky
* Copyright (c) 2017 Michael McWethy
*
* 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 <assert.h>
#include <string.h>
#include "py/runtime.h"
#include "py/builtin.h"
#include "py/objtuple.h"
#include "py/binary.h"
#include "py/parsenum.h"
#include "shared-bindings/struct/__init__.h"
#include "shared-module/struct/__init__.h"
#include "supervisor/shared/translate.h"
//| """Manipulation of c-style data
//|
//| This module implements a subset of the corresponding CPython module,
//| as described below. For more information, refer to the original CPython
//| documentation: struct.
//|
//| Supported size/byte order prefixes: *@*, *<*, *>*, *!*.
//|
//| Supported format codes: *b*, *B*, *x*, *h*, *H*, *i*, *I*, *l*, *L*, *q*, *Q*,
//| *s*, *P*, *f*, *d* (the latter 2 depending on the floating-point support)."""
//|
//| def calcsize(fmt: str) -> int:
//| """Return the number of bytes needed to store the given fmt."""
//| ...
//|
STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
return MP_OBJ_NEW_SMALL_INT(shared_modules_struct_calcsize(fmt_in));
}
MP_DEFINE_CONST_FUN_OBJ_1(struct_calcsize_obj, struct_calcsize);
//| def pack(fmt: str, *values: Any) -> bytes:
//| """Pack the values according to the format string fmt.
//| The return value is a bytes object encoding the values."""
//| ...
//|
STATIC mp_obj_t struct_pack(size_t n_args, const mp_obj_t *args) {
mp_int_t size = MP_OBJ_SMALL_INT_VALUE(struct_calcsize(args[0]));
vstr_t vstr;
vstr_init_len(&vstr, size);
byte *p = (byte*)vstr.buf;
memset(p, 0, size);
byte *end_p = &p[size];
shared_modules_struct_pack_into(args[0], p, end_p, n_args - 1, &args[1]);
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(struct_pack_obj, 1, MP_OBJ_FUN_ARGS_MAX, struct_pack);
//| def pack_into(fmt: str, buffer: WriteableBuffer, offset: int, *values: Any) -> None:
//| """Pack the values according to the format string fmt into a buffer
//| starting at offset. offset may be negative to count from the end of buffer."""
//| ...
//|
STATIC mp_obj_t struct_pack_into(size_t n_args, const mp_obj_t *args) {
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
mp_int_t offset = mp_obj_get_int(args[2]);
if (offset < 0) {
// negative offsets are relative to the end of the buffer
offset = (mp_int_t)bufinfo.len + offset;
if (offset < 0) {
mp_raise_RuntimeError(translate("buffer too small"));
}
}
byte *p = (byte *)bufinfo.buf;
byte *end_p = &p[bufinfo.len];
p += offset;
shared_modules_struct_pack_into(args[0], p, end_p, n_args - 3, &args[3]);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(struct_pack_into_obj, 3, MP_OBJ_FUN_ARGS_MAX, struct_pack_into);
//| def unpack(fmt: str, data: ReadableBuffer) -> Tuple[Any, ...]:
//| """Unpack from the data according to the format string fmt. The return value
//| is a tuple of the unpacked values. The buffer size must match the size
//| required by the format."""
//| ...
//|
STATIC mp_obj_t struct_unpack(size_t n_args, const mp_obj_t *args) {
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_READ);
byte *p = bufinfo.buf;
byte *end_p = &p[bufinfo.len];
// true means check the size must be exactly right.
return MP_OBJ_FROM_PTR(shared_modules_struct_unpack_from(args[0] , p, end_p, true));
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(struct_unpack_obj, 2, 3, struct_unpack);
//| def unpack_from(fmt: str, data: ReadableBuffer, offset: int = 0) -> Tuple[Any, ...]:
//| """Unpack from the data starting at offset according to the format string fmt.
//| offset may be negative to count from the end of buffer. The return value is
//| a tuple of the unpacked values. The buffer size must be at least as big
//| as the size required by the form."""
//| ...
//|
STATIC mp_obj_t struct_unpack_from(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_format, ARG_buffer, ARG_offset };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_format, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_offset, MP_ARG_INT, {.u_int = 0} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ);
byte *p = bufinfo.buf;
byte *end_p = &p[bufinfo.len];
mp_int_t offset = args[ARG_offset].u_int;
if (offset < 0) {
// negative offsets are relative to the end of the buffer
offset = bufinfo.len + offset;
if (offset < 0) {
mp_raise_RuntimeError(translate("buffer too small"));
}
}
p += offset;
// false means the size doesn't have to be exact. struct.unpack_from() only requires
// that be buffer be big enough.
return MP_OBJ_FROM_PTR(shared_modules_struct_unpack_from(args[ARG_format].u_obj, p, end_p, false));
}
MP_DEFINE_CONST_FUN_OBJ_KW(struct_unpack_from_obj, 0, struct_unpack_from);
STATIC const mp_rom_map_elem_t mp_module_struct_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_struct) },
{ MP_ROM_QSTR(MP_QSTR_calcsize), MP_ROM_PTR(&struct_calcsize_obj) },
{ MP_ROM_QSTR(MP_QSTR_pack), MP_ROM_PTR(&struct_pack_obj) },
{ MP_ROM_QSTR(MP_QSTR_pack_into), MP_ROM_PTR(&struct_pack_into_obj) },
{ MP_ROM_QSTR(MP_QSTR_unpack), MP_ROM_PTR(&struct_unpack_obj) },
{ MP_ROM_QSTR(MP_QSTR_unpack_from), MP_ROM_PTR(&struct_unpack_from_obj) },
};
STATIC MP_DEFINE_CONST_DICT(mp_module_struct_globals, mp_module_struct_globals_table);
const mp_obj_module_t struct_module = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t*)&mp_module_struct_globals,
};