split.c

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/*
 * qrencode - QR Code encoder
 *
 * Input data splitter.
 * Copyright (C) 2006-2017 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * The following data / specifications are taken from
 * "Two dimensional symbol -- QR-code -- Basic Specification" (JIS X0510:2004)
 *  or
 * "Automatic identification and data capture techniques --
 *  QR Code 2005 bar code symbology specification" (ISO/IEC 18004:2006)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "qrencode.h"
#include "qrinput.h"
#include "qrspec.h"
#include "split.h"

#define isdigit(__c__) ((unsigned char)((signed char)(__c__) - '0') < 10)
#define isalnum(__c__) (QRinput_lookAnTable(__c__) >= 0)

#if !HAVE_STRDUP
#undef strdup
char *strdup(const char *s)
{
    size_t len = strlen(s) + 1;
    void *newstring = malloc(len);
    if(newstring == NULL) return NULL;
    return (char *)memcpy(newstring, s, len);
}
#endif

static QRencodeMode Split_identifyMode(const char *string, QRencodeMode hint)
{
    unsigned char c, d;
    unsigned int word;

    c = (unsigned char)string[0];

    if(c == '\0') return QR_MODE_NUL;
    if(isdigit(c)) {
        return QR_MODE_NUM;
    } else if(isalnum(c)) {
        return QR_MODE_AN;
    } else if(hint == QR_MODE_KANJI) {
        d = (unsigned char)string[1];
        if(d != '\0') {
            word = ((unsigned int)c << 8) | d;
            if((word >= 0x8140 && word <= 0x9ffc) || (word >= 0xe040 && word <= 0xebbf)) {
                return QR_MODE_KANJI;
            }
        }
    }

    return QR_MODE_8;
}

static int Split_eatAn(const char *string, QRinput *input, QRencodeMode hint);
static int Split_eat8(const char *string, QRinput *input, QRencodeMode hint);

static int Split_eatNum(const char *string, QRinput *input,QRencodeMode hint)
{
    const char *p;
    int ret;
    int run;
    int dif;
    int ln;
    QRencodeMode mode;

    ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

    p = string;
    while(isdigit(*p)) {
        p++;
    }
    run = (int)(p - string);
    mode = Split_identifyMode(p, hint);
    if(mode == QR_MODE_8) {
        dif = QRinput_estimateBitsModeNum(run) + 4 + ln
            + QRinput_estimateBitsMode8(1) /* + 4 + l8 */
            - QRinput_estimateBitsMode8(run + 1) /* - 4 - l8 */;
        if(dif > 0) {
            return Split_eat8(string, input, hint);
        }
    }
    if(mode == QR_MODE_AN) {
        dif = QRinput_estimateBitsModeNum(run) + 4 + ln
            + QRinput_estimateBitsModeAn(1) /* + 4 + la */
            - QRinput_estimateBitsModeAn(run + 1) /* - 4 - la */;
        if(dif > 0) {
            return Split_eatAn(string, input, hint);
        }
    }

    ret = QRinput_append(input, QR_MODE_NUM, run, (unsigned char *)string);
    if(ret < 0) return -1;

    return run;
}

static int Split_eatAn(const char *string, QRinput *input, QRencodeMode hint)
{
    const char *p, *q;
    int ret;
    int run;
    int dif;
    int la, ln;

    la = QRspec_lengthIndicator(QR_MODE_AN, input->version);
    ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

    p = string;
    while(isalnum(*p)) {
        if(isdigit(*p)) {
            q = p;
            while(isdigit(*q)) {
                q++;
            }
            dif = QRinput_estimateBitsModeAn((int)(p - string)) /* + 4 + la */
                + QRinput_estimateBitsModeNum((int)(q - p)) + 4 + ln
                + (isalnum(*q)?(4 + ln):0)
                - QRinput_estimateBitsModeAn((int)(q - string)) /* - 4 - la */;
            if(dif < 0) {
                break;
            }
            p = q;
        } else {
            p++;
        }
    }

    run = (int)(p - string);

    if(*p && !isalnum(*p)) {
        dif = QRinput_estimateBitsModeAn(run) + 4 + la
            + QRinput_estimateBitsMode8(1) /* + 4 + l8 */
            - QRinput_estimateBitsMode8(run + 1) /* - 4 - l8 */;
        if(dif > 0) {
            return Split_eat8(string, input, hint);
        }
    }

    ret = QRinput_append(input, QR_MODE_AN, run, (unsigned char *)string);
    if(ret < 0) return -1;

    return run;
}

static int Split_eatKanji(const char *string, QRinput *input, QRencodeMode hint)
{
    const char *p;
    int ret;
    int run;

    p = string;
    while(Split_identifyMode(p, hint) == QR_MODE_KANJI) {
        p += 2;
    }
    run = (int)(p - string);
    ret = QRinput_append(input, QR_MODE_KANJI, run, (unsigned char *)string);
    if(ret < 0) return -1;

    return run;
}

static int Split_eat8(const char *string, QRinput *input, QRencodeMode hint)
{
    const char *p, *q;
    QRencodeMode mode;
    int ret;
    int run;
    int dif;
    int la, ln, l8;
    int swcost;

    la = QRspec_lengthIndicator(QR_MODE_AN, input->version);
    ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);
    l8 = QRspec_lengthIndicator(QR_MODE_8, input->version);

    p = string + 1;
    while(*p != '\0') {
        mode = Split_identifyMode(p, hint);
        if(mode == QR_MODE_KANJI) {
            break;
        }
        if(mode == QR_MODE_NUM) {
            q = p;
            while(isdigit(*q)) {
                q++;
            }
            if(Split_identifyMode(q, hint) == QR_MODE_8) {
                swcost = 4 + l8;
            } else {
                swcost = 0;
            }
            dif = QRinput_estimateBitsMode8((int)(p - string)) /* + 4 + l8 */
                + QRinput_estimateBitsModeNum((int)(q - p)) + 4 + ln
                + swcost
                - QRinput_estimateBitsMode8((int)(q - string)) /* - 4 - l8 */;
            if(dif < 0) {
                break;
            }
            p = q;
        } else if(mode == QR_MODE_AN) {
            q = p;
            while(isalnum(*q)) {
                q++;
            }
            if(Split_identifyMode(q, hint) == QR_MODE_8) {
                swcost = 4 + l8;
            } else {
                swcost = 0;
            }
            dif = QRinput_estimateBitsMode8((int)(p - string)) /* + 4 + l8 */
                + QRinput_estimateBitsModeAn((int)(q - p)) + 4 + la
                + swcost
                - QRinput_estimateBitsMode8((int)(q - string)) /* - 4 - l8 */;
            if(dif < 0) {
                break;
            }
            p = q;
        } else {
            p++;
        }
    }

    run = (int)(p - string);
    ret = QRinput_append(input, QR_MODE_8, run, (unsigned char *)string);
    if(ret < 0) return -1;

    return run;
}

static int Split_splitString(const char *string, QRinput *input,
        QRencodeMode hint)
{
    int length;
    QRencodeMode mode;

    while(*string != '\0') {
        mode = Split_identifyMode(string, hint);
        if(mode == QR_MODE_NUM) {
            length = Split_eatNum(string, input, hint);
        } else if(mode == QR_MODE_AN) {
            length = Split_eatAn(string, input, hint);
        } else if(mode == QR_MODE_KANJI && hint == QR_MODE_KANJI) {
            length = Split_eatKanji(string, input, hint);
        } else {
            length = Split_eat8(string, input, hint);
        }
        if(length == 0) break;
        if(length < 0) return -1;
        string += length;
    }

    return 0;
}

static char *dupAndToUpper(const char *str, QRencodeMode hint)
{
    char *newstr, *p;
    QRencodeMode mode;

    newstr = strdup(str);
    if(newstr == NULL) return NULL;

    p = newstr;
    while(*p != '\0') {
        mode = Split_identifyMode(p, hint);
        if(mode == QR_MODE_KANJI) {
            p += 2;
        } else {
            if (*p >= 'a' && *p <= 'z') {
                *p = (char)((int)*p - 32);
            }
            p++;
        }
    }

    return newstr;
}

int Split_splitStringToQRinput(const char *string, QRinput *input,
        QRencodeMode hint, int casesensitive)
{
    char *newstr;
    int ret;

    if(string == NULL || *string == '\0') {
        errno = EINVAL;
        return -1;
    }
    if(!casesensitive) {
        newstr = dupAndToUpper(string, hint);
        if(newstr == NULL) return -1;
        ret = Split_splitString(newstr, input, hint);
        free(newstr);
    } else {
        ret = Split_splitString(string, input, hint);
    }

    return ret;
}