/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * 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 #include #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" //| :mod:`struct` --- manipulation of c-style data //| ======================================================== //| //| .. module:: struct //| :synopsis: byte data control //| :platform: SAMD21 //| //| 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*, *h*, *H*, *i*, *I*, *l*, *L*, *q*, *Q*, //| *s*, *P*, *f*, *d* (the latter 2 depending on the floating-point support). //| //| .. function:: calcsize(fmt) //| //| 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); //| .. function:: pack(fmt, v1, v2, ...) //| //| Pack the values v1, v2, ... 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) { // TODO: "The arguments must match the values required by the format exactly." 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); //| .. function:: pack_into(fmt, buffer, offset, v1, v2, ...) //| //| Pack the values v1, v2, ... 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("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); //| .. function:: unpack(fmt, data) //| //| Unpack from the data according to the format string fmt. The return value //| is a tuple of the unpacked values. //| //| .. function:: unpack_from(fmt, data, offset) //| //| 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. //| STATIC mp_obj_t struct_unpack_from(size_t n_args, const mp_obj_t *args) { // unpack requires that the buffer be exactly the right size. // unpack_from requires that the buffer be "big enough". // Since we implement unpack and unpack_from using the same function // we relax the "exact" requirement, and only implement "big enough". 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]; if (n_args > 2) { mp_int_t offset = mp_obj_get_int(args[2]); // offset arg provided if (offset < 0) { // negative offsets are relative to the end of the buffer offset = bufinfo.len + offset; if (offset < 0) { mp_raise_RuntimeError("buffer too small"); } } p += offset; } return MP_OBJ_FROM_PTR(shared_modules_struct_unpack_from(args[0] , p, end_p)); } MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(struct_unpack_from_obj, 2, 3, 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_from_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, };