conv.c

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/*-------------------------------------------------------------------------
 *
 *    Utility functions for conversion procs.
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *    src/backend/utils/mb/conv.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
#include "mb/pg_wchar.h"


/*
 * LATINn ---> MIC when the charset's local codes map directly to MIC
 *
 * l points to the source string of length len
 * p is the output area (must be large enough!)
 * lc is the mule character set id for the local encoding
 * encoding is the PG identifier for the local encoding
 */
void
latin2mic(const unsigned char *l, unsigned char *p, int len,
          int lc, int encoding)
{
    int         c1;

    while (len > 0)
    {
        c1 = *l;
        if (c1 == 0)
            report_invalid_encoding(encoding, (const char *) l, len);
        if (IS_HIGHBIT_SET(c1))
            *p++ = lc;
        *p++ = c1;
        l++;
        len--;
    }
    *p = '\0';
}

/*
 * MIC ---> LATINn when the charset's local codes map directly to MIC
 *
 * mic points to the source string of length len
 * p is the output area (must be large enough!)
 * lc is the mule character set id for the local encoding
 * encoding is the PG identifier for the local encoding
 */
void
mic2latin(const unsigned char *mic, unsigned char *p, int len,
          int lc, int encoding)
{
    int         c1;

    while (len > 0)
    {
        c1 = *mic;
        if (c1 == 0)
            report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic, len);
        if (!IS_HIGHBIT_SET(c1))
        {
            /* easy for ASCII */
            *p++ = c1;
            mic++;
            len--;
        }
        else
        {
            int         l = pg_mic_mblen(mic);

            if (len < l)
                report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic,
                                        len);
            if (l != 2 || c1 != lc || !IS_HIGHBIT_SET(mic[1]))
                report_untranslatable_char(PG_MULE_INTERNAL, encoding,
                                           (const char *) mic, len);
            *p++ = mic[1];
            mic += 2;
            len -= 2;
        }
    }
    *p = '\0';
}


/*
 * ASCII ---> MIC
 *
 * While ordinarily SQL_ASCII encoding is forgiving of high-bit-set
 * characters, here we must take a hard line because we don't know
 * the appropriate MIC equivalent.
 */
void
pg_ascii2mic(const unsigned char *l, unsigned char *p, int len)
{
    int         c1;

    while (len > 0)
    {
        c1 = *l;
        if (c1 == 0 || IS_HIGHBIT_SET(c1))
            report_invalid_encoding(PG_SQL_ASCII, (const char *) l, len);
        *p++ = c1;
        l++;
        len--;
    }
    *p = '\0';
}

/*
 * MIC ---> ASCII
 */
void
pg_mic2ascii(const unsigned char *mic, unsigned char *p, int len)
{
    int         c1;

    while (len > 0)
    {
        c1 = *mic;
        if (c1 == 0 || IS_HIGHBIT_SET(c1))
            report_untranslatable_char(PG_MULE_INTERNAL, PG_SQL_ASCII,
                                       (const char *) mic, len);
        *p++ = c1;
        mic++;
        len--;
    }
    *p = '\0';
}

/*
 * latin2mic_with_table: a generic single byte charset encoding
 * conversion from a local charset to the mule internal code.
 *
 * l points to the source string of length len
 * p is the output area (must be large enough!)
 * lc is the mule character set id for the local encoding
 * encoding is the PG identifier for the local encoding
 * tab holds conversion entries for the local charset
 * starting from 128 (0x80). each entry in the table
 * holds the corresponding code point for the mule internal code.
 */
void
latin2mic_with_table(const unsigned char *l,
                     unsigned char *p,
                     int len,
                     int lc,
                     int encoding,
                     const unsigned char *tab)
{
    unsigned char c1,
                c2;

    while (len > 0)
    {
        c1 = *l;
        if (c1 == 0)
            report_invalid_encoding(encoding, (const char *) l, len);
        if (!IS_HIGHBIT_SET(c1))
            *p++ = c1;
        else
        {
            c2 = tab[c1 - HIGHBIT];
            if (c2)
            {
                *p++ = lc;
                *p++ = c2;
            }
            else
                report_untranslatable_char(encoding, PG_MULE_INTERNAL,
                                           (const char *) l, len);
        }
        l++;
        len--;
    }
    *p = '\0';
}

/*
 * mic2latin_with_table: a generic single byte charset encoding
 * conversion from the mule internal code to a local charset.
 *
 * mic points to the source string of length len
 * p is the output area (must be large enough!)
 * lc is the mule character set id for the local encoding
 * encoding is the PG identifier for the local encoding
 * tab holds conversion entries for the mule internal code's
 * second byte, starting from 128 (0x80). each entry in the table
 * holds the corresponding code point for the local charset.
 */
void
mic2latin_with_table(const unsigned char *mic,
                     unsigned char *p,
                     int len,
                     int lc,
                     int encoding,
                     const unsigned char *tab)
{
    unsigned char c1,
                c2;

    while (len > 0)
    {
        c1 = *mic;
        if (c1 == 0)
            report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic, len);
        if (!IS_HIGHBIT_SET(c1))
        {
            /* easy for ASCII */
            *p++ = c1;
            mic++;
            len--;
        }
        else
        {
            int         l = pg_mic_mblen(mic);

            if (len < l)
                report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic,
                                        len);
            if (l != 2 || c1 != lc || !IS_HIGHBIT_SET(mic[1]) ||
                (c2 = tab[mic[1] - HIGHBIT]) == 0)
            {
                report_untranslatable_char(PG_MULE_INTERNAL, encoding,
                                           (const char *) mic, len);
                break;          /* keep compiler quiet */
            }
            *p++ = c2;
            mic += 2;
            len -= 2;
        }
    }
    *p = '\0';
}

/*
 * comparison routine for bsearch()
 * this routine is intended for UTF8 -> local code
 */
static int
compare1(const void *p1, const void *p2)
{
    uint32      v1,
                v2;

    v1 = *(const uint32 *) p1;
    v2 = ((const pg_utf_to_local *) p2)->utf;
    return (v1 > v2) ? 1 : ((v1 == v2) ? 0 : -1);
}

/*
 * comparison routine for bsearch()
 * this routine is intended for local code -> UTF8
 */
static int
compare2(const void *p1, const void *p2)
{
    uint32      v1,
                v2;

    v1 = *(const uint32 *) p1;
    v2 = ((const pg_local_to_utf *) p2)->code;
    return (v1 > v2) ? 1 : ((v1 == v2) ? 0 : -1);
}

/*
 * comparison routine for bsearch()
 * this routine is intended for combined UTF8 -> local code
 */
static int
compare3(const void *p1, const void *p2)
{
    uint32      s1,
                s2,
                d1,
                d2;

    s1 = *(const uint32 *) p1;
    s2 = *((const uint32 *) p1 + 1);
    d1 = ((const pg_utf_to_local_combined *) p2)->utf1;
    d2 = ((const pg_utf_to_local_combined *) p2)->utf2;
    return (s1 > d1 || (s1 == d1 && s2 > d2)) ? 1 : ((s1 == d1 && s2 == d2) ? 0 : -1);
}

/*
 * comparison routine for bsearch()
 * this routine is intended for local code -> combined UTF8
 */
static int
compare4(const void *p1, const void *p2)
{
    uint32      v1,
                v2;

    v1 = *(const uint32 *) p1;
    v2 = ((const pg_local_to_utf_combined *) p2)->code;
    return (v1 > v2) ? 1 : ((v1 == v2) ? 0 : -1);
}

/*
 * convert 32bit wide character to mutibye stream pointed to by iso
 */
static unsigned char *
set_iso_code(unsigned char *iso, uint32 code)
{
    if (code & 0xff000000)
        *iso++ = code >> 24;
    if (code & 0x00ff0000)
        *iso++ = (code & 0x00ff0000) >> 16;
    if (code & 0x0000ff00)
        *iso++ = (code & 0x0000ff00) >> 8;
    if (code & 0x000000ff)
        *iso++ = code & 0x000000ff;
    return iso;
}

/*
 * UTF8 ---> local code
 *
 * utf: input UTF8 string (need not be null-terminated).
 * iso: pointer to the output area (must be large enough!)
 * map: the conversion map.
 * cmap: the conversion map for combined characters.
 *        (optional)
 * size1: the size of the conversion map.
 * size2: the size of the conversion map for combined characters
 *        (optional)
 * encoding: the PG identifier for the local encoding.
 * len: length of input string.
 */
void
UtfToLocal(const unsigned char *utf, unsigned char *iso,
           const pg_utf_to_local *map, const pg_utf_to_local_combined *cmap,
           int size1, int size2, int encoding, int len)
{
    uint32      iutf;
    uint32      cutf[2];
    uint32      code;
    pg_utf_to_local *p;
    pg_utf_to_local_combined *cp;
    int         l;

    for (; len > 0; len -= l)
    {
        /* "break" cases all represent errors */
        if (*utf == '\0')
            break;

        l = pg_utf_mblen(utf);

        if (len < l)
            break;

        if (!pg_utf8_islegal(utf, l))
            break;

        if (l == 1)
        {
            /* ASCII case is easy */
            *iso++ = *utf++;
            continue;
        }
        else if (l == 2)
        {
            iutf = *utf++ << 8;
            iutf |= *utf++;
        }
        else if (l == 3)
        {
            iutf = *utf++ << 16;
            iutf |= *utf++ << 8;
            iutf |= *utf++;
        }
        else if (l == 4)
        {
            iutf = *utf++ << 24;
            iutf |= *utf++ << 16;
            iutf |= *utf++ << 8;
            iutf |= *utf++;
        }

        /*
         * first, try with combined map if possible
         */
        if (cmap && len > l)
        {
            const unsigned char *utf_save = utf;
            int         len_save = len;
            int         l_save = l;

            len -= l;

            l = pg_utf_mblen(utf);
            if (len < l)
                break;

            if (!pg_utf8_islegal(utf, l))
                break;

            cutf[0] = iutf;

            if (l == 1)
            {
                if (len_save > 1)
                {
                    p = bsearch(&cutf[0], map, size1,
                                sizeof(pg_utf_to_local), compare1);
                    if (p == NULL)
                        report_untranslatable_char(PG_UTF8, encoding,
                               (const char *) (utf_save - l_save), len_save);
                    iso = set_iso_code(iso, p->code);
                }

                /* ASCII case is easy */
                *iso++ = *utf++;
                continue;
            }
            else if (l == 2)
            {
                iutf = *utf++ << 8;
                iutf |= *utf++;
            }
            else if (l == 3)
            {
                iutf = *utf++ << 16;
                iutf |= *utf++ << 8;
                iutf |= *utf++;
            }
            else if (l == 4)
            {
                iutf = *utf++ << 24;
                iutf |= *utf++ << 16;
                iutf |= *utf++ << 8;
                iutf |= *utf++;
            }

            cutf[1] = iutf;
            cp = bsearch(cutf, cmap, size2,
                         sizeof(pg_utf_to_local_combined), compare3);
            if (cp)
                code = cp->code;
            else
            {
                /* not found in combined map. try with ordinary map */
                p = bsearch(&cutf[0], map, size1,
                            sizeof(pg_utf_to_local), compare1);
                if (p == NULL)
                    report_untranslatable_char(PG_UTF8, encoding,
                               (const char *) (utf_save - l_save), len_save);
                iso = set_iso_code(iso, p->code);

                p = bsearch(&cutf[1], map, size1,
                            sizeof(pg_utf_to_local), compare1);
                if (p == NULL)
                    report_untranslatable_char(PG_UTF8, encoding,
                                               (const char *) (utf - l), len);
                code = p->code;
            }
        }
        else    /* no cmap or no remaining data */
        {
            p = bsearch(&iutf, map, size1,
                        sizeof(pg_utf_to_local), compare1);
            if (p == NULL)
                report_untranslatable_char(PG_UTF8, encoding,
                                           (const char *) (utf - l), len);
            code = p->code;
        }
        iso = set_iso_code(iso, code);
    }

    if (len > 0)
        report_invalid_encoding(PG_UTF8, (const char *) utf, len);

    *iso = '\0';
}

/*
 * local code ---> UTF8
 *
 * iso: input local string (need not be null-terminated).
 * utf: pointer to the output area (must be large enough!)
 * map: the conversion map.
 * cmap: the conversion map for combined characters.
 *        (optional)
 * size1: the size of the conversion map.
 * size2: the size of the conversion map for combined characters
 *        (optional)
 * encoding: the PG identifier for the local encoding.
 * len: length of input string.
 */
void
LocalToUtf(const unsigned char *iso, unsigned char *utf,
           const pg_local_to_utf *map, const pg_local_to_utf_combined *cmap,
           int size1, int size2, int encoding, int len)
{
    unsigned int iiso;
    int         l;
    pg_local_to_utf *p;
    pg_local_to_utf_combined *cp;

    if (!PG_VALID_ENCODING(encoding))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid encoding number: %d", encoding)));

    for (; len > 0; len -= l)
    {
        /* "break" cases all represent errors */
        if (*iso == '\0')
            break;

        if (!IS_HIGHBIT_SET(*iso))
        {
            /* ASCII case is easy */
            *utf++ = *iso++;
            l = 1;
            continue;
        }

        l = pg_encoding_verifymb(encoding, (const char *) iso, len);
        if (l < 0)
            break;

        if (l == 1)
            iiso = *iso++;
        else if (l == 2)
        {
            iiso = *iso++ << 8;
            iiso |= *iso++;
        }
        else if (l == 3)
        {
            iiso = *iso++ << 16;
            iiso |= *iso++ << 8;
            iiso |= *iso++;
        }
        else if (l == 4)
        {
            iiso = *iso++ << 24;
            iiso |= *iso++ << 16;
            iiso |= *iso++ << 8;
            iiso |= *iso++;
        }

        p = bsearch(&iiso, map, size1,
                    sizeof(pg_local_to_utf), compare2);

        if (p == NULL)
        {
            /*
             * not found in the ordinary map. if there's a combined character
             * map, try with it
             */
            if (cmap)
            {
                cp = bsearch(&iiso, cmap, size2,
                             sizeof(pg_local_to_utf_combined), compare4);

                if (cp)
                {
                    if (cp->utf1 & 0xff000000)
                        *utf++ = cp->utf1 >> 24;
                    if (cp->utf1 & 0x00ff0000)
                        *utf++ = (cp->utf1 & 0x00ff0000) >> 16;
                    if (cp->utf1 & 0x0000ff00)
                        *utf++ = (cp->utf1 & 0x0000ff00) >> 8;
                    if (cp->utf1 & 0x000000ff)
                        *utf++ = cp->utf1 & 0x000000ff;

                    if (cp->utf2 & 0xff000000)
                        *utf++ = cp->utf2 >> 24;
                    if (cp->utf2 & 0x00ff0000)
                        *utf++ = (cp->utf2 & 0x00ff0000) >> 16;
                    if (cp->utf2 & 0x0000ff00)
                        *utf++ = (cp->utf2 & 0x0000ff00) >> 8;
                    if (cp->utf2 & 0x000000ff)
                        *utf++ = cp->utf2 & 0x000000ff;

                    continue;
                }
            }

            report_untranslatable_char(encoding, PG_UTF8,
                                       (const char *) (iso - l), len);

        }
        else
        {
            if (p->utf & 0xff000000)
                *utf++ = p->utf >> 24;
            if (p->utf & 0x00ff0000)
                *utf++ = (p->utf & 0x00ff0000) >> 16;
            if (p->utf & 0x0000ff00)
                *utf++ = (p->utf & 0x0000ff00) >> 8;
            if (p->utf & 0x000000ff)
                *utf++ = p->utf & 0x000000ff;
        }
    }

    if (len > 0)
        report_invalid_encoding(encoding, (const char *) iso, len);

    *utf = '\0';
}