encnames.c

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/*-------------------------------------------------------------------------
 *
 * encnames.c
 *    Encoding names and routines for working with them.
 *
 * Portions Copyright (c) 2001-2026, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *    src/common/encnames.c
 *
 *-------------------------------------------------------------------------
 */
#include "c.h"
 
#include <ctype.h>
#include <unistd.h>
 
#include "mb/pg_wchar.h"
 
 
/* ----------
 * All encoding names, sorted:       *** A L P H A B E T I C ***
 *
 * All names must be without irrelevant chars, search routines use
 * isalnum() chars only. It means ISO-8859-1, iso_8859-1 and Iso8859_1
 * are always converted to 'iso88591'. All must be lower case.
 *
 * The table doesn't contain 'cs' aliases (like csISOLatin1). It's needed?
 *
 * Karel Zak, Aug 2001
 * ----------
 */
typedef struct pg_encname
{
    const char *name;
    pg_enc      encoding;
} pg_encname;
 
static const pg_encname pg_encname_tbl[] =
{
    {
        "abc", PG_WIN1258
    },                          /* alias for WIN1258 */
    {
        "alt", PG_WIN866
    },                          /* IBM866 */
    {
        "big5", PG_BIG5
    },                          /* Big5; Chinese for Taiwan multibyte set */
    {
        "euccn", PG_EUC_CN
    },                          /* EUC-CN; Extended Unix Code for simplified
                                 * Chinese */
    {
        "eucjis2004", PG_EUC_JIS_2004
    },                          /* EUC-JIS-2004; Extended UNIX Code fixed
                                 * Width for Japanese, standard JIS X 0213 */
    {
        "eucjp", PG_EUC_JP
    },                          /* EUC-JP; Extended UNIX Code fixed Width for
                                 * Japanese, standard OSF */
    {
        "euckr", PG_EUC_KR
    },                          /* EUC-KR; Extended Unix Code for Korean
                                 * precomposed (Wansung) encoding, standard KS
                                 * X 1001 */
    {
        "euctw", PG_EUC_TW
    },                          /* EUC-TW; Extended Unix Code for
                                 *
                                 * traditional Chinese */
    {
        "gb18030", PG_GB18030
    },                          /* GB18030;GB18030 */
    {
        "gbk", PG_GBK
    },                          /* GBK; Chinese Windows CodePage 936
                                 * simplified Chinese */
    {
        "iso88591", PG_LATIN1
    },                          /* ISO-8859-1; RFC1345,KXS2 */
    {
        "iso885910", PG_LATIN6
    },                          /* ISO-8859-10; RFC1345,KXS2 */
    {
        "iso885913", PG_LATIN7
    },                          /* ISO-8859-13; RFC1345,KXS2 */
    {
        "iso885914", PG_LATIN8
    },                          /* ISO-8859-14; RFC1345,KXS2 */
    {
        "iso885915", PG_LATIN9
    },                          /* ISO-8859-15; RFC1345,KXS2 */
    {
        "iso885916", PG_LATIN10
    },                          /* ISO-8859-16; RFC1345,KXS2 */
    {
        "iso88592", PG_LATIN2
    },                          /* ISO-8859-2; RFC1345,KXS2 */
    {
        "iso88593", PG_LATIN3
    },                          /* ISO-8859-3; RFC1345,KXS2 */
    {
        "iso88594", PG_LATIN4
    },                          /* ISO-8859-4; RFC1345,KXS2 */
    {
        "iso88595", PG_ISO_8859_5
    },                          /* ISO-8859-5; RFC1345,KXS2 */
    {
        "iso88596", PG_ISO_8859_6
    },                          /* ISO-8859-6; RFC1345,KXS2 */
    {
        "iso88597", PG_ISO_8859_7
    },                          /* ISO-8859-7; RFC1345,KXS2 */
    {
        "iso88598", PG_ISO_8859_8
    },                          /* ISO-8859-8; RFC1345,KXS2 */
    {
        "iso88599", PG_LATIN5
    },                          /* ISO-8859-9; RFC1345,KXS2 */
    {
        "johab", PG_JOHAB
    },                          /* JOHAB; Korean combining (Johab) encoding,
                                 * standard KS X 1001 annex 3 */
    {
        "koi8", PG_KOI8R
    },                          /* _dirty_ alias for KOI8-R (backward
                                 * compatibility) */
    {
        "koi8r", PG_KOI8R
    },                          /* KOI8-R; RFC1489 */
    {
        "koi8u", PG_KOI8U
    },                          /* KOI8-U; RFC2319 */
    {
        "latin1", PG_LATIN1
    },                          /* alias for ISO-8859-1 */
    {
        "latin10", PG_LATIN10
    },                          /* alias for ISO-8859-16 */
    {
        "latin2", PG_LATIN2
    },                          /* alias for ISO-8859-2 */
    {
        "latin3", PG_LATIN3
    },                          /* alias for ISO-8859-3 */
    {
        "latin4", PG_LATIN4
    },                          /* alias for ISO-8859-4 */
    {
        "latin5", PG_LATIN5
    },                          /* alias for ISO-8859-9 */
    {
        "latin6", PG_LATIN6
    },                          /* alias for ISO-8859-10 */
    {
        "latin7", PG_LATIN7
    },                          /* alias for ISO-8859-13 */
    {
        "latin8", PG_LATIN8
    },                          /* alias for ISO-8859-14 */
    {
        "latin9", PG_LATIN9
    },                          /* alias for ISO-8859-15 */
    {
        "mskanji", PG_SJIS
    },                          /* alias for Shift_JIS */
    {
        "shiftjis", PG_SJIS
    },                          /* Shift_JIS; JIS X 0202-1991 */
 
    {
        "shiftjis2004", PG_SHIFT_JIS_2004
    },                          /* SHIFT-JIS-2004; Shift JIS for Japanese,
                                 * standard JIS X 0213 */
    {
        "sjis", PG_SJIS
    },                          /* alias for Shift_JIS */
    {
        "sqlascii", PG_SQL_ASCII
    },
    {
        "tcvn", PG_WIN1258
    },                          /* alias for WIN1258 */
    {
        "tcvn5712", PG_WIN1258
    },                          /* alias for WIN1258 */
    {
        "uhc", PG_UHC
    },                          /* UHC; Unified Hangul Code, Microsoft Windows
                                 * CodePage 949; superset of EUC-KR covering
                                 * all 11,172 precomposed Hangul syllables */
    {
        "unicode", PG_UTF8
    },                          /* alias for UTF8 */
    {
        "utf8", PG_UTF8
    },                          /* alias for UTF8 */
    {
        "vscii", PG_WIN1258
    },                          /* alias for WIN1258 */
    {
        "win", PG_WIN1251
    },                          /* _dirty_ alias for windows-1251 (backward
                                 * compatibility) */
    {
        "win1250", PG_WIN1250
    },                          /* alias for Windows-1250 */
    {
        "win1251", PG_WIN1251
    },                          /* alias for Windows-1251 */
    {
        "win1252", PG_WIN1252
    },                          /* alias for Windows-1252 */
    {
        "win1253", PG_WIN1253
    },                          /* alias for Windows-1253 */
    {
        "win1254", PG_WIN1254
    },                          /* alias for Windows-1254 */
    {
        "win1255", PG_WIN1255
    },                          /* alias for Windows-1255 */
    {
        "win1256", PG_WIN1256
    },                          /* alias for Windows-1256 */
    {
        "win1257", PG_WIN1257
    },                          /* alias for Windows-1257 */
    {
        "win1258", PG_WIN1258
    },                          /* alias for Windows-1258 */
    {
        "win866", PG_WIN866
    },                          /* IBM866 */
    {
        "win874", PG_WIN874
    },                          /* alias for Windows-874 */
    {
        "win932", PG_SJIS
    },                          /* alias for Shift_JIS */
    {
        "win936", PG_GBK
    },                          /* alias for GBK */
    {
        "win949", PG_UHC
    },                          /* alias for UHC */
    {
        "win950", PG_BIG5
    },                          /* alias for BIG5 */
    {
        "windows1250", PG_WIN1250
    },                          /* Windows-1251; Microsoft */
    {
        "windows1251", PG_WIN1251
    },                          /* Windows-1251; Microsoft */
    {
        "windows1252", PG_WIN1252
    },                          /* Windows-1252; Microsoft */
    {
        "windows1253", PG_WIN1253
    },                          /* Windows-1253; Microsoft */
    {
        "windows1254", PG_WIN1254
    },                          /* Windows-1254; Microsoft */
    {
        "windows1255", PG_WIN1255
    },                          /* Windows-1255; Microsoft */
    {
        "windows1256", PG_WIN1256
    },                          /* Windows-1256; Microsoft */
    {
        "windows1257", PG_WIN1257
    },                          /* Windows-1257; Microsoft */
    {
        "windows1258", PG_WIN1258
    },                          /* Windows-1258; Microsoft */
    {
        "windows866", PG_WIN866
    },                          /* IBM866 */
    {
        "windows874", PG_WIN874
    },                          /* Windows-874; Microsoft */
    {
        "windows932", PG_SJIS
    },                          /* alias for Shift_JIS */
    {
        "windows936", PG_GBK
    },                          /* alias for GBK */
    {
        "windows949", PG_UHC
    },                          /* alias for UHC */
    {
        "windows950", PG_BIG5
    }                           /* alias for BIG5 */
};
 
/* ----------
 * These are "official" encoding names.
 * ----------
 */
#ifndef WIN32
#define DEF_ENC2NAME(name, codepage) { #name, PG_##name }
#else
#define DEF_ENC2NAME(name, codepage) { #name, PG_##name, codepage }
#endif
 
const pg_enc2name pg_enc2name_tbl[] =
{
    [PG_SQL_ASCII] = DEF_ENC2NAME(SQL_ASCII, 0),
    [PG_EUC_JP] = DEF_ENC2NAME(EUC_JP, 20932),
    [PG_EUC_CN] = DEF_ENC2NAME(EUC_CN, 20936),
    [PG_EUC_KR] = DEF_ENC2NAME(EUC_KR, 51949),
    [PG_EUC_TW] = DEF_ENC2NAME(EUC_TW, 0),
    [PG_EUC_JIS_2004] = DEF_ENC2NAME(EUC_JIS_2004, 20932),
    [PG_UTF8] = DEF_ENC2NAME(UTF8, 65001),
    [PG_LATIN1] = DEF_ENC2NAME(LATIN1, 28591),
    [PG_LATIN2] = DEF_ENC2NAME(LATIN2, 28592),
    [PG_LATIN3] = DEF_ENC2NAME(LATIN3, 28593),
    [PG_LATIN4] = DEF_ENC2NAME(LATIN4, 28594),
    [PG_LATIN5] = DEF_ENC2NAME(LATIN5, 28599),
    [PG_LATIN6] = DEF_ENC2NAME(LATIN6, 0),
    [PG_LATIN7] = DEF_ENC2NAME(LATIN7, 0),
    [PG_LATIN8] = DEF_ENC2NAME(LATIN8, 0),
    [PG_LATIN9] = DEF_ENC2NAME(LATIN9, 28605),
    [PG_LATIN10] = DEF_ENC2NAME(LATIN10, 0),
    [PG_WIN1256] = DEF_ENC2NAME(WIN1256, 1256),
    [PG_WIN1258] = DEF_ENC2NAME(WIN1258, 1258),
    [PG_WIN866] = DEF_ENC2NAME(WIN866, 866),
    [PG_WIN874] = DEF_ENC2NAME(WIN874, 874),
    [PG_KOI8R] = DEF_ENC2NAME(KOI8R, 20866),
    [PG_WIN1251] = DEF_ENC2NAME(WIN1251, 1251),
    [PG_WIN1252] = DEF_ENC2NAME(WIN1252, 1252),
    [PG_ISO_8859_5] = DEF_ENC2NAME(ISO_8859_5, 28595),
    [PG_ISO_8859_6] = DEF_ENC2NAME(ISO_8859_6, 28596),
    [PG_ISO_8859_7] = DEF_ENC2NAME(ISO_8859_7, 28597),
    [PG_ISO_8859_8] = DEF_ENC2NAME(ISO_8859_8, 28598),
    [PG_WIN1250] = DEF_ENC2NAME(WIN1250, 1250),
    [PG_WIN1253] = DEF_ENC2NAME(WIN1253, 1253),
    [PG_WIN1254] = DEF_ENC2NAME(WIN1254, 1254),
    [PG_WIN1255] = DEF_ENC2NAME(WIN1255, 1255),
    [PG_WIN1257] = DEF_ENC2NAME(WIN1257, 1257),
    [PG_KOI8U] = DEF_ENC2NAME(KOI8U, 21866),
    [PG_SJIS] = DEF_ENC2NAME(SJIS, 932),
    [PG_BIG5] = DEF_ENC2NAME(BIG5, 950),
    [PG_GBK] = DEF_ENC2NAME(GBK, 936),
    [PG_UHC] = DEF_ENC2NAME(UHC, 949),
    [PG_GB18030] = DEF_ENC2NAME(GB18030, 54936),
    [PG_JOHAB] = DEF_ENC2NAME(JOHAB, 0),
    [PG_SHIFT_JIS_2004] = DEF_ENC2NAME(SHIFT_JIS_2004, 932),
};
 
/* ----------
 * These are encoding names for gettext.
 * ----------
 */
const char *pg_enc2gettext_tbl[] =
{
    [PG_SQL_ASCII] = "US-ASCII",
    [PG_UTF8] = "UTF-8",
    [PG_LATIN1] = "LATIN1",
    [PG_LATIN2] = "LATIN2",
    [PG_LATIN3] = "LATIN3",
    [PG_LATIN4] = "LATIN4",
    [PG_ISO_8859_5] = "ISO-8859-5",
    [PG_ISO_8859_6] = "ISO_8859-6",
    [PG_ISO_8859_7] = "ISO-8859-7",
    [PG_ISO_8859_8] = "ISO-8859-8",
    [PG_LATIN5] = "LATIN5",
    [PG_LATIN6] = "LATIN6",
    [PG_LATIN7] = "LATIN7",
    [PG_LATIN8] = "LATIN8",
    [PG_LATIN9] = "LATIN-9",
    [PG_LATIN10] = "LATIN10",
    [PG_KOI8R] = "KOI8-R",
    [PG_KOI8U] = "KOI8-U",
    [PG_WIN1250] = "CP1250",
    [PG_WIN1251] = "CP1251",
    [PG_WIN1252] = "CP1252",
    [PG_WIN1253] = "CP1253",
    [PG_WIN1254] = "CP1254",
    [PG_WIN1255] = "CP1255",
    [PG_WIN1256] = "CP1256",
    [PG_WIN1257] = "CP1257",
    [PG_WIN1258] = "CP1258",
    [PG_WIN866] = "CP866",
    [PG_WIN874] = "CP874",
    [PG_EUC_CN] = "EUC-CN",
    [PG_EUC_JP] = "EUC-JP",
    [PG_EUC_KR] = "EUC-KR",
    [PG_EUC_TW] = "EUC-TW",
    [PG_EUC_JIS_2004] = "EUC-JP",
    [PG_SJIS] = "SHIFT-JIS",
    [PG_BIG5] = "BIG5",
    [PG_GBK] = "GBK",
    [PG_UHC] = "UHC",
    [PG_GB18030] = "GB18030",
    [PG_JOHAB] = "JOHAB",
    [PG_SHIFT_JIS_2004] = "SHIFT_JISX0213",
};
 
 
/*
 * Table of encoding names for ICU (currently covers backend encodings only)
 *
 * Reference: <https://ssl.icu-project.org/icu-bin/convexp>
 *
 * NULL entries are not supported by ICU, or their mapping is unclear.
 */
static const char *const pg_enc2icu_tbl[] =
{
    [PG_SQL_ASCII] = NULL,
    [PG_EUC_JP] = "EUC-JP",
    [PG_EUC_CN] = "EUC-CN",
    [PG_EUC_KR] = "EUC-KR",
    [PG_EUC_TW] = "EUC-TW",
    [PG_EUC_JIS_2004] = NULL,
    [PG_UTF8] = "UTF-8",
    [PG_LATIN1] = "ISO-8859-1",
    [PG_LATIN2] = "ISO-8859-2",
    [PG_LATIN3] = "ISO-8859-3",
    [PG_LATIN4] = "ISO-8859-4",
    [PG_LATIN5] = "ISO-8859-9",
    [PG_LATIN6] = "ISO-8859-10",
    [PG_LATIN7] = "ISO-8859-13",
    [PG_LATIN8] = "ISO-8859-14",
    [PG_LATIN9] = "ISO-8859-15",
    [PG_LATIN10] = NULL,
    [PG_WIN1256] = "CP1256",
    [PG_WIN1258] = "CP1258",
    [PG_WIN866] = "CP866",
    [PG_WIN874] = NULL,
    [PG_KOI8R] = "KOI8-R",
    [PG_WIN1251] = "CP1251",
    [PG_WIN1252] = "CP1252",
    [PG_ISO_8859_5] = "ISO-8859-5",
    [PG_ISO_8859_6] = "ISO-8859-6",
    [PG_ISO_8859_7] = "ISO-8859-7",
    [PG_ISO_8859_8] = "ISO-8859-8",
    [PG_WIN1250] = "CP1250",
    [PG_WIN1253] = "CP1253",
    [PG_WIN1254] = "CP1254",
    [PG_WIN1255] = "CP1255",
    [PG_WIN1257] = "CP1257",
    [PG_KOI8U] = "KOI8-U",
};
 
StaticAssertDecl(lengthof(pg_enc2icu_tbl) == PG_ENCODING_BE_LAST + 1,
                 "pg_enc2icu_tbl incomplete");
 
 
/*
 * Is this encoding supported by ICU?
 */
bool
is_encoding_supported_by_icu(int encoding)
{
    if (!PG_VALID_BE_ENCODING(encoding))
        return false;
    return (pg_enc2icu_tbl[encoding] != NULL);
}
 
/*
 * Returns ICU's name for encoding, or NULL if not supported
 */
const char *
get_encoding_name_for_icu(int encoding)
{
    if (!PG_VALID_BE_ENCODING(encoding))
        return NULL;
    return pg_enc2icu_tbl[encoding];
}
 
 
/* ----------
 * Encoding checks, for error returns -1 else encoding id
 * ----------
 */
int
pg_valid_client_encoding(const char *name)
{
    int         enc;
 
    if ((enc = pg_char_to_encoding(name)) < 0)
        return -1;
 
    if (!PG_VALID_FE_ENCODING(enc))
        return -1;
 
    return enc;
}
 
int
pg_valid_server_encoding(const char *name)
{
    int         enc;
 
    if ((enc = pg_char_to_encoding(name)) < 0)
        return -1;
 
    if (!PG_VALID_BE_ENCODING(enc))
        return -1;
 
    return enc;
}
 
int
pg_valid_server_encoding_id(int encoding)
{
    return PG_VALID_BE_ENCODING(encoding);
}
 
/*
 * Remove irrelevant chars from encoding name, store at *newkey
 *
 * (Caller's responsibility to provide a large enough buffer)
 */
static char *
clean_encoding_name(const char *key, char *newkey)
{
    const char *p;
    char       *np;
 
    for (p = key, np = newkey; *p != '\0'; p++)
    {
        if (isalnum((unsigned char) *p))
        {
            if (*p >= 'A' && *p <= 'Z')
                *np++ = *p + 'a' - 'A';
            else
                *np++ = *p;
        }
    }
    *np = '\0';
    return newkey;
}
 
/*
 * Search encoding by encoding name
 *
 * Returns encoding ID, or -1 if not recognized
 */
int
pg_char_to_encoding(const char *name)
{
    unsigned int nel = lengthof(pg_encname_tbl);
    const pg_encname *base = pg_encname_tbl,
               *last = base + nel - 1,
               *position;
    int         result;
    char        buff[NAMEDATALEN],
               *key;
 
    if (name == NULL || *name == '\0')
        return -1;
 
    if (strlen(name) >= NAMEDATALEN)
        return -1;              /* it's certainly not in the table */
 
    key = clean_encoding_name(name, buff);
 
    while (last >= base)
    {
        position = base + ((last - base) >> 1);
        result = key[0] - position->name[0];
 
        if (result == 0)
        {
            result = strcmp(key, position->name);
            if (result == 0)
                return position->encoding;
        }
        if (result < 0)
            last = position - 1;
        else
            base = position + 1;
    }
    return -1;
}
 
const char *
pg_encoding_to_char(int encoding)
{
    if (PG_VALID_ENCODING(encoding))
    {
        const pg_enc2name *p = &pg_enc2name_tbl[encoding];
 
        Assert(encoding == p->encoding);
        return p->name;
    }
    return "";
}