modstruct.c 4.53 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * 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.
 */

27
28
29
30
31
32
33
34
#include <assert.h>
#include <string.h>
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "builtin.h"
#include "objtuple.h"
35
#include "objstr.h"
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
#include "binary.h"

#if MICROPY_ENABLE_MOD_STRUCT

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 uint calcsize_items(const char *fmt) {
    // TODO
    return strlen(fmt);
}

STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
    const char *fmt = mp_obj_str_get_str(fmt_in);
    char fmt_type = get_fmt_type(&fmt);
67
    machine_uint_t size;
68
    for (size = 0; *fmt; fmt++) {
69
70
        uint align;
        int sz = mp_binary_get_size(fmt_type, *fmt, &align);
71
72
        // TODO
        assert(sz != -1);
73
74
        // Apply alignment
        size = (size + align - 1) & ~(align - 1);
75
76
77
78
79
80
81
82
83
84
85
86
        size += sz;
    }
    return MP_OBJ_NEW_SMALL_INT(size);
}
MP_DEFINE_CONST_FUN_OBJ_1(struct_calcsize_obj, struct_calcsize);

STATIC mp_obj_t struct_unpack(mp_obj_t fmt_in, mp_obj_t data_in) {
    // TODO: "The buffer must contain exactly the amount of data required by the format (len(bytes) must equal calcsize(fmt))."
    const char *fmt = mp_obj_str_get_str(fmt_in);
    char fmt_type = get_fmt_type(&fmt);
    uint size = calcsize_items(fmt);
    mp_obj_tuple_t *res = mp_obj_new_tuple(size, NULL);
87
    mp_buffer_info_t bufinfo;
88
    mp_get_buffer_raise(data_in, &bufinfo, MP_BUFFER_READ);
89
90
91
    byte *p = bufinfo.buf;

    for (uint i = 0; i < size; i++) {
92
        mp_obj_t item = mp_binary_get_val(fmt_type, *fmt++, &p);
93
94
95
96
97
98
        res->items[i] = item;
    }
    return res;
}
MP_DEFINE_CONST_FUN_OBJ_2(struct_unpack_obj, struct_unpack);

99
100
101
102
103
104
105
106
107
108
109
110
111
112
STATIC mp_obj_t struct_pack(uint n_args, mp_obj_t *args) {
    // TODO: "The arguments must match the values required by the format exactly."
    const char *fmt = mp_obj_str_get_str(args[0]);
    char fmt_type = get_fmt_type(&fmt);
    int size = MP_OBJ_SMALL_INT_VALUE(struct_calcsize(args[0]));
    byte *p;
    mp_obj_t res = mp_obj_str_builder_start(&mp_type_bytes, size, &p);
    memset(p, 0, size);

    for (uint i = 1; i < n_args; i++) {
        mp_binary_set_val(fmt_type, *fmt++, args[i], &p);
    }
    return res;
}
113
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(struct_pack_obj, 1, MP_OBJ_FUN_ARGS_MAX, struct_pack);
114

115
116
117
STATIC const mp_map_elem_t mp_module_struct_globals_table[] = {
    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_struct) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_calcsize), (mp_obj_t)&struct_calcsize_obj },
118
    { MP_OBJ_NEW_QSTR(MP_QSTR_pack), (mp_obj_t)&struct_pack_obj },
119
120
121
122
123
124
125
126
    { MP_OBJ_NEW_QSTR(MP_QSTR_unpack), (mp_obj_t)&struct_unpack_obj },
};

STATIC const mp_obj_dict_t mp_module_struct_globals = {
    .base = {&mp_type_dict},
    .map = {
        .all_keys_are_qstrs = 1,
        .table_is_fixed_array = 1,
127
128
        .used = ARRAY_SIZE(mp_module_struct_globals_table),
        .alloc = ARRAY_SIZE(mp_module_struct_globals_table),
129
130
131
132
133
134
135
136
137
138
139
        .table = (mp_map_elem_t*)mp_module_struct_globals_table,
    },
};

const mp_obj_module_t mp_module_struct = {
    .base = { &mp_type_module },
    .name = MP_QSTR_struct,
    .globals = (mp_obj_dict_t*)&mp_module_struct_globals,
};

#endif