unicode.c

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/*
 * Copyright (c) 2014-2017 Pavel Kalvoda <me@pavelkalvoda.com>
 *
 * libcbor is free software; you can redistribute it and/or modify
 * it under the terms of the MIT license. See LICENSE for details.
 */

#include "unicode.h"

#define UTF8_ACCEPT 0
#define UTF8_REJECT 1

static const uint8_t utf8d[] = {
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 00..1f */
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 20..3f */
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 40..5f */
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 60..7f */
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, /* 80..9f */
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, /* a0..bf */
    8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, /* c0..df */
    0xa,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x4,0x3,0x3, /* e0..ef */
    0xb,0x6,0x6,0x6,0x5,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8, /* f0..ff */
    0x0,0x1,0x2,0x3,0x5,0x8,0x7,0x1,0x1,0x1,0x4,0x6,0x1,0x1,0x1,0x1, /* s0..s0 */
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,1,1,1, /* s1..s2 */
    1,2,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1, /* s3..s4 */
    1,2,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,3,1,3,1,1,1,1,1,1, /* s5..s6 */
    1,3,1,1,1,1,1,3,1,3,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* s7..s8 */
};

/* Copyright of this function: (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de> */
/* See http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details. */
uint32_t _cbor_unicode_decode(uint32_t* state, uint32_t* codep, uint32_t byte) {
    uint32_t type = utf8d[byte];

    *codep = (*state != UTF8_ACCEPT) ?
             (byte & 0x3fu) | (*codep << 6) :
             (0xff >> type) & (byte);

    *state = utf8d[256 + *state * 16 + type];
    return *state;
}

size_t _cbor_unicode_codepoint_count(cbor_data source, size_t source_length, struct _cbor_unicode_status * status)
{
    *status = (struct _cbor_unicode_status) { .location = 0, .status = _CBOR_UNICODE_OK };
    uint32_t codepoint, state = UTF8_ACCEPT, res;
    size_t pos = 0, count = 0;

    for (; pos < source_length; pos++)
    {
        res = _cbor_unicode_decode(&state, &codepoint, source[pos]);

        if (res == UTF8_ACCEPT) {
            count++;
        } else if (res == UTF8_REJECT) {
            goto error;
        }
    }

    /* Unfinished multibyte codepoint */
    if (state != UTF8_ACCEPT)
        goto error;

    return count;

    error:
    *status = (struct _cbor_unicode_status) { .location = pos, .status = _CBOR_UNICODE_BADCP };
    return -1;
}