forked from xuos/xiuos
270 lines
9.1 KiB
C
270 lines
9.1 KiB
C
/*
|
|
* 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
|
|
*
|
|
* 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"
|
|
|
|
#if MICROPY_PY_STRUCT
|
|
|
|
/*
|
|
This module implements most of character typecodes from CPython, with
|
|
some extensions:
|
|
|
|
O - (Pointer to) an arbitrary Python object. This is useful for callback
|
|
data, etc. Note that you must keep reference to passed object in
|
|
your Python application, otherwise it may be garbage-collected,
|
|
and then when you get back this value from callback it may be
|
|
invalid (and lead to crash).
|
|
S - Pointer to a string (returned as a Python string). Note the
|
|
difference from "Ns", - the latter says "in this place of structure
|
|
is character data of up to N bytes length", while "S" means
|
|
"in this place of a structure is a pointer to zero-terminated
|
|
character data".
|
|
*/
|
|
|
|
STATIC char get_fmt_type(const char **fmt) {
|
|
char t = **fmt;
|
|
switch (t) {
|
|
case '!':
|
|
t = '>';
|
|
break;
|
|
case '@':
|
|
case '=':
|
|
case '<':
|
|
case '>':
|
|
break;
|
|
default:
|
|
return '@';
|
|
}
|
|
// Skip type char
|
|
(*fmt)++;
|
|
return t;
|
|
}
|
|
|
|
STATIC mp_uint_t get_fmt_num(const char **p) {
|
|
const char *num = *p;
|
|
uint len = 1;
|
|
while (unichar_isdigit(*++num)) {
|
|
len++;
|
|
}
|
|
mp_uint_t val = (mp_uint_t)MP_OBJ_SMALL_INT_VALUE(mp_parse_num_integer(*p, len, 10, NULL));
|
|
*p = num;
|
|
return val;
|
|
}
|
|
|
|
STATIC size_t calc_size_items(const char *fmt, size_t *total_sz) {
|
|
char fmt_type = get_fmt_type(&fmt);
|
|
size_t total_cnt = 0;
|
|
size_t size;
|
|
for (size = 0; *fmt; fmt++) {
|
|
mp_uint_t cnt = 1;
|
|
if (unichar_isdigit(*fmt)) {
|
|
cnt = get_fmt_num(&fmt);
|
|
}
|
|
|
|
if (*fmt == 's') {
|
|
total_cnt += 1;
|
|
size += cnt;
|
|
} else {
|
|
total_cnt += cnt;
|
|
size_t align;
|
|
size_t sz = mp_binary_get_size(fmt_type, *fmt, &align);
|
|
while (cnt--) {
|
|
// Apply alignment
|
|
size = (size + align - 1) & ~(align - 1);
|
|
size += sz;
|
|
}
|
|
}
|
|
}
|
|
*total_sz = size;
|
|
return total_cnt;
|
|
}
|
|
|
|
STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
|
|
const char *fmt = mp_obj_str_get_str(fmt_in);
|
|
size_t size;
|
|
calc_size_items(fmt, &size);
|
|
return MP_OBJ_NEW_SMALL_INT(size);
|
|
}
|
|
MP_DEFINE_CONST_FUN_OBJ_1(struct_calcsize_obj, struct_calcsize);
|
|
|
|
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".
|
|
const char *fmt = mp_obj_str_get_str(args[0]);
|
|
size_t total_sz;
|
|
size_t num_items = calc_size_items(fmt, &total_sz);
|
|
char fmt_type = get_fmt_type(&fmt);
|
|
mp_obj_tuple_t *res = MP_OBJ_TO_PTR(mp_obj_new_tuple(num_items, NULL));
|
|
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];
|
|
mp_int_t offset = 0;
|
|
|
|
if (n_args > 2) {
|
|
// offset arg provided
|
|
offset = mp_obj_get_int(args[2]);
|
|
if (offset < 0) {
|
|
// negative offsets are relative to the end of the buffer
|
|
offset = bufinfo.len + offset;
|
|
if (offset < 0) {
|
|
mp_raise_ValueError(MP_ERROR_TEXT("buffer too small"));
|
|
}
|
|
}
|
|
p += offset;
|
|
}
|
|
byte *p_base = p;
|
|
|
|
// Check that the input buffer is big enough to unpack all the values
|
|
if (p + total_sz > end_p) {
|
|
mp_raise_ValueError(MP_ERROR_TEXT("buffer too small"));
|
|
}
|
|
|
|
for (size_t i = 0; i < num_items;) {
|
|
mp_uint_t cnt = 1;
|
|
if (unichar_isdigit(*fmt)) {
|
|
cnt = get_fmt_num(&fmt);
|
|
}
|
|
mp_obj_t item;
|
|
if (*fmt == 's') {
|
|
item = mp_obj_new_bytes(p, cnt);
|
|
p += cnt;
|
|
res->items[i++] = item;
|
|
} else {
|
|
while (cnt--) {
|
|
item = mp_binary_get_val(fmt_type, *fmt, p_base, &p);
|
|
res->items[i++] = item;
|
|
}
|
|
}
|
|
fmt++;
|
|
}
|
|
return MP_OBJ_FROM_PTR(res);
|
|
}
|
|
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(struct_unpack_from_obj, 2, 3, struct_unpack_from);
|
|
|
|
// This function assumes there is enough room in p to store all the values
|
|
STATIC void struct_pack_into_internal(mp_obj_t fmt_in, byte *p, size_t n_args, const mp_obj_t *args) {
|
|
const char *fmt = mp_obj_str_get_str(fmt_in);
|
|
char fmt_type = get_fmt_type(&fmt);
|
|
|
|
byte *p_base = p;
|
|
size_t i;
|
|
for (i = 0; i < n_args;) {
|
|
mp_uint_t cnt = 1;
|
|
if (*fmt == '\0') {
|
|
// more arguments given than used by format string; CPython raises struct.error here
|
|
break;
|
|
}
|
|
if (unichar_isdigit(*fmt)) {
|
|
cnt = get_fmt_num(&fmt);
|
|
}
|
|
|
|
if (*fmt == 's') {
|
|
mp_buffer_info_t bufinfo;
|
|
mp_get_buffer_raise(args[i++], &bufinfo, MP_BUFFER_READ);
|
|
mp_uint_t to_copy = cnt;
|
|
if (bufinfo.len < to_copy) {
|
|
to_copy = bufinfo.len;
|
|
}
|
|
memcpy(p, bufinfo.buf, to_copy);
|
|
memset(p + to_copy, 0, cnt - to_copy);
|
|
p += cnt;
|
|
} else {
|
|
// If we run out of args then we just finish; CPython would raise struct.error
|
|
while (cnt-- && i < n_args) {
|
|
mp_binary_set_val(fmt_type, *fmt, args[i++], p_base, &p);
|
|
}
|
|
}
|
|
fmt++;
|
|
}
|
|
}
|
|
|
|
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);
|
|
struct_pack_into_internal(args[0], 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);
|
|
|
|
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_ValueError(MP_ERROR_TEXT("buffer too small"));
|
|
}
|
|
}
|
|
byte *p = (byte *)bufinfo.buf;
|
|
byte *end_p = &p[bufinfo.len];
|
|
p += offset;
|
|
|
|
// Check that the output buffer is big enough to hold all the values
|
|
mp_int_t sz = MP_OBJ_SMALL_INT_VALUE(struct_calcsize(args[0]));
|
|
if (p + sz > end_p) {
|
|
mp_raise_ValueError(MP_ERROR_TEXT("buffer too small"));
|
|
}
|
|
|
|
struct_pack_into_internal(args[0], 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);
|
|
|
|
STATIC const mp_rom_map_elem_t mp_module_struct_globals_table[] = {
|
|
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_ustruct) },
|
|
{ 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 mp_module_ustruct = {
|
|
.base = { &mp_type_module },
|
|
.globals = (mp_obj_dict_t *)&mp_module_struct_globals,
|
|
};
|
|
|
|
#endif
|