예제 #1
0
Datum
utf8_to_iso8859_1(PG_FUNCTION_ARGS)
{
	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
	int			len = PG_GETARG_INT32(4);
	unsigned short c,
				c1;

	Assert(PG_GETARG_INT32(0) == PG_UTF8);
	Assert(PG_GETARG_INT32(1) == PG_LATIN1);
	Assert(len >= 0);

	while (len > 0)
	{
		c = *src;
		if (c == 0)
			report_invalid_encoding(PG_UTF8, (const char *) src, len);
		/* fast path for ASCII-subset characters */
		if (!IS_HIGHBIT_SET(c))
		{
			*dest++ = c;
			src++;
			len--;
		}
		else
		{
			int			l = pg_utf_mblen(src);

			if (l > len || !pg_utf8_islegal(src, l))
				report_invalid_encoding(PG_UTF8, (const char *) src, len);
			if (l != 2)
				report_untranslatable_char(PG_UTF8, PG_LATIN1,
										   (const char *) src, len);
			c1 = src[1] & 0x3f;
			c = ((c & 0x1f) << 6) | c1;
			if (c >= 0x80 && c <= 0xff)
			{
				*dest++ = (unsigned char) c;
				src += 2;
				len -= 2;
			}
			else
				report_untranslatable_char(PG_UTF8, PG_LATIN1,
										   (const char *) src, len);
		}
	}
	*dest = '\0';

	PG_RETURN_VOID();
}
예제 #2
0
/*
 * MIC ---> EUC_CN
 */
static void
mic2euc_cn(const unsigned char *mic, unsigned char *p, int len)
{
	int			c1;

	while (len > 0)
	{
		c1 = *mic;
		if (IS_HIGHBIT_SET(c1))
		{
			if (c1 != LC_GB2312_80)
				report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_CN,
										   (const char *) mic, len);
			if (len < 3 || !IS_HIGHBIT_SET(mic[1]) || !IS_HIGHBIT_SET(mic[2]))
				report_invalid_encoding(PG_MULE_INTERNAL,
										(const char *) mic, len);
			mic++;
			*p++ = *mic++;
			*p++ = *mic++;
			len -= 3;
		}
		else
		{						/* should be ASCII */
			if (c1 == 0)
				report_invalid_encoding(PG_MULE_INTERNAL,
										(const char *) mic, len);
			*p++ = c1;
			mic++;
			len--;
		}
	}
	*p = '\0';
}
예제 #3
0
파일: conv.c 프로젝트: markwkm/postgres
/*
 * 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';
}
예제 #4
0
파일: conv.c 프로젝트: markwkm/postgres
/*
 * 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';
}
예제 #5
0
/*
 * local2local: a generic single byte charset encoding
 * conversion between two ASCII-superset encodings.
 *
 * l points to the source string of length len
 * p is the output area (must be large enough!)
 * src_encoding is the PG identifier for the source encoding
 * dest_encoding is the PG identifier for the target encoding
 * tab holds conversion entries for the source charset
 * starting from 128 (0x80). each entry in the table holds the corresponding
 * code point for the target charset, or 0 if there is no equivalent code.
 */
void
local2local(const unsigned char *l,
			unsigned char *p,
			int len,
			int src_encoding,
			int dest_encoding,
			const unsigned char *tab)
{
	unsigned char c1,
				c2;

	while (len > 0)
	{
		c1 = *l;
		if (c1 == 0)
			report_invalid_encoding(src_encoding, (const char *) l, len);
		if (!IS_HIGHBIT_SET(c1))
			*p++ = c1;
		else
		{
			c2 = tab[c1 - HIGHBIT];
			if (c2)
				*p++ = c2;
			else
				report_untranslatable_char(src_encoding, dest_encoding,
										   (const char *) l, len);
		}
		l++;
		len--;
	}
	*p = '\0';
}
예제 #6
0
파일: euc_tw_and_big5.c 프로젝트: 50wu/gpdb
/*
 * MIC ---> EUC_TW
 */
static void
mic2euc_tw(const unsigned char *mic, unsigned char *p, int len)
{
	int			c1;
	int			l;

	while (len > 0)
	{
		c1 = *mic;
		if (!IS_HIGHBIT_SET(c1))
		{
			/* ASCII */
			if (c1 == 0)
				report_invalid_encoding(PG_MULE_INTERNAL,
										(const char *) mic, len);
			*p++ = c1;
			mic++;
			len--;
			continue;
		}
		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
		if (l < 0)
			report_invalid_encoding(PG_MULE_INTERNAL,
									(const char *) mic, len);
		if (c1 == LC_CNS11643_1)
		{
			*p++ = mic[1];
			*p++ = mic[2];
		}
		else if (c1 == LC_CNS11643_2)
		{
			*p++ = SS2;
			*p++ = 0xa2;
			*p++ = mic[1];
			*p++ = mic[2];
		}
		else if (c1 == 0x9d &&
				 mic[1] >= LC_CNS11643_3 && mic[1] <= LC_CNS11643_7)
		{						/* LCPRV2? */
			*p++ = SS2;
			*p++ = mic[1] - LC_CNS11643_3 + 0xa3;
			*p++ = mic[2];
			*p++ = mic[3];
		}
		else
			report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_TW,
									   (const char *) mic, len);
		mic += l;
		len -= l;
	}
	*p = '\0';
}
예제 #7
0
파일: conv.c 프로젝트: markwkm/postgres
/*
 * 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';
}
예제 #8
0
파일: euc_tw_and_big5.c 프로젝트: 50wu/gpdb
/*
 * Big5 ---> MIC
 */
static void
big52mic(const unsigned char *big5, unsigned char *p, int len)
{
	unsigned short c1;
	unsigned short big5buf,
				cnsBuf;
	unsigned char lc;
	int			l;

	while (len > 0)
	{
		c1 = *big5;
		if (!IS_HIGHBIT_SET(c1))
		{
			/* ASCII */
			if (c1 == 0)
				report_invalid_encoding(PG_BIG5,
										(const char *) big5, len);
			*p++ = c1;
			big5++;
			len--;
			continue;
		}
		l = pg_encoding_verifymb(PG_BIG5, (const char *) big5, len);
		if (l < 0)
			report_invalid_encoding(PG_BIG5,
									(const char *) big5, len);
		big5buf = (c1 << 8) | big5[1];
		cnsBuf = BIG5toCNS(big5buf, &lc);
		if (lc != 0)
		{
			if (lc == LC_CNS11643_3 || lc == LC_CNS11643_4)
			{
				*p++ = 0x9d;	/* LCPRV2 */
			}
			*p++ = lc;			/* Plane No. */
			*p++ = (cnsBuf >> 8) & 0x00ff;
			*p++ = cnsBuf & 0x00ff;
		}
		else
			report_untranslatable_char(PG_BIG5, PG_MULE_INTERNAL,
									   (const char *) big5, len);
		big5 += l;
		len -= l;
	}
예제 #9
0
파일: conv.c 프로젝트: markwkm/postgres
/*
 * 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';
}
예제 #10
0
파일: euc_kr_and_mic.c 프로젝트: 50wu/gpdb
/*
 * MIC ---> EUC_KR
 */
static void
mic2euc_kr(const unsigned char *mic, unsigned char *p, int len)
{
	int			c1;
	int			l;

	while (len > 0)
	{
		c1 = *mic;
		if (!IS_HIGHBIT_SET(c1))
		{
			/* ASCII */
			if (c1 == 0)
				report_invalid_encoding(PG_MULE_INTERNAL,
										(const char *) mic, len);
			*p++ = c1;
			mic++;
			len--;
			continue;
		}
		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
		if (l < 0)
			report_invalid_encoding(PG_MULE_INTERNAL,
									(const char *) mic, len);
		if (c1 == LC_KS5601)
		{
			*p++ = mic[1];
			*p++ = mic[2];
		}
		else
			report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_KR,
									   (const char *) mic, len);
		mic += l;
		len -= l;
	}
	*p = '\0';
}
예제 #11
0
파일: conv.c 프로젝트: markwkm/postgres
/*
 * 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;
		}
	}
예제 #12
0
파일: conv.c 프로젝트: markwkm/postgres
/*
 * 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';
}
예제 #13
0
/*
 * local code ---> UTF8
 *
 * iso: input string in local encoding (need not be null-terminated)
 * len: length of input string (in bytes)
 * utf: pointer to the output area (must be large enough!)
		  (output string will be null-terminated)
 * map: conversion map for single characters
 * mapsize: number of entries in the conversion map
 * cmap: conversion map for combined characters
 *		  (optional, pass NULL if none)
 * cmapsize: number of entries in the conversion map for combined characters
 *		  (optional, pass 0 if none)
 * conv_func: algorithmic encoding conversion function
 *		  (optional, pass NULL if none)
 * encoding: PG identifier for the local encoding
 *
 * For each character, the map is consulted first; if no match, the cmap
 * (if provided) is consulted next; if still no match, the conv_func
 * (if provided) is applied.  An error is raised if no match is found.
 *
 * See pg_wchar.h for more details about the data structures used here.
 */
void
LocalToUtf(const unsigned char *iso, int len,
		   unsigned char *utf,
		   const pg_local_to_utf *map, int mapsize,
		   const pg_local_to_utf_combined *cmap, int cmapsize,
		   utf_local_conversion_func conv_func,
		   int encoding)
{
	uint32		iiso;
	int			l;
	const pg_local_to_utf *p;
	const 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, assume it's one-to-one conversion */
			*utf++ = *iso++;
			l = 1;
			continue;
		}

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

		/* collect coded char of length l */
		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++;
		}
		else
		{
			elog(ERROR, "unsupported character length %d", l);
			iiso = 0;			/* keep compiler quiet */
		}

		/* First check ordinary map */
		p = bsearch(&iiso, map, mapsize,
					sizeof(pg_local_to_utf), compare2);

		if (p)
		{
			utf = store_coded_char(utf, p->utf);
			continue;
		}

		/* If there's a combined character map, try that */
		if (cmap)
		{
			cp = bsearch(&iiso, cmap, cmapsize,
						 sizeof(pg_local_to_utf_combined), compare4);

			if (cp)
			{
				utf = store_coded_char(utf, cp->utf1);
				utf = store_coded_char(utf, cp->utf2);
				continue;
			}
		}

		/* if there's a conversion function, try that */
		if (conv_func)
		{
			uint32		converted = (*conv_func) (iiso);

			if (converted)
			{
				utf = store_coded_char(utf, converted);
				continue;
			}
		}

		/* failed to translate this character */
		report_untranslatable_char(encoding, PG_UTF8,
								   (const char *) (iso - l), len);
	}

	/* if we broke out of loop early, must be invalid input */
	if (len > 0)
		report_invalid_encoding(encoding, (const char *) iso, len);

	*utf = '\0';
}
예제 #14
0
/*
 * UTF8 ---> local code
 *
 * utf: input string in UTF8 encoding (need not be null-terminated)
 * len: length of input string (in bytes)
 * iso: pointer to the output area (must be large enough!)
		  (output string will be null-terminated)
 * map: conversion map for single characters
 * mapsize: number of entries in the conversion map
 * cmap: conversion map for combined characters
 *		  (optional, pass NULL if none)
 * cmapsize: number of entries in the conversion map for combined characters
 *		  (optional, pass 0 if none)
 * conv_func: algorithmic encoding conversion function
 *		  (optional, pass NULL if none)
 * encoding: PG identifier for the local encoding
 *
 * For each character, the cmap (if provided) is consulted first; if no match,
 * the map is consulted next; if still no match, the conv_func (if provided)
 * is applied.  An error is raised if no match is found.
 *
 * See pg_wchar.h for more details about the data structures used here.
 */
void
UtfToLocal(const unsigned char *utf, int len,
		   unsigned char *iso,
		   const pg_utf_to_local *map, int mapsize,
		   const pg_utf_to_local_combined *cmap, int cmapsize,
		   utf_local_conversion_func conv_func,
		   int encoding)
{
	uint32		iutf;
	int			l;
	const pg_utf_to_local *p;
	const pg_utf_to_local_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 (*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, assume it's one-to-one conversion */
			*iso++ = *utf++;
			continue;
		}

		/* collect coded char of length l */
		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++;
		}
		else
		{
			elog(ERROR, "unsupported character length %d", l);
			iutf = 0;			/* keep compiler quiet */
		}

		/* 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;

			/* collect next character, same as above */
			len -= l;

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

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

			/* We assume ASCII character cannot be in combined map */
			if (l > 1)
			{
				uint32		iutf2;
				uint32		cutf[2];

				if (l == 2)
				{
					iutf2 = *utf++ << 8;
					iutf2 |= *utf++;
				}
				else if (l == 3)
				{
					iutf2 = *utf++ << 16;
					iutf2 |= *utf++ << 8;
					iutf2 |= *utf++;
				}
				else if (l == 4)
				{
					iutf2 = *utf++ << 24;
					iutf2 |= *utf++ << 16;
					iutf2 |= *utf++ << 8;
					iutf2 |= *utf++;
				}
				else
				{
					elog(ERROR, "unsupported character length %d", l);
					iutf2 = 0;	/* keep compiler quiet */
				}

				cutf[0] = iutf;
				cutf[1] = iutf2;

				cp = bsearch(cutf, cmap, cmapsize,
							 sizeof(pg_utf_to_local_combined), compare3);

				if (cp)
				{
					iso = store_coded_char(iso, cp->code);
					continue;
				}
			}

			/* fail, so back up to reprocess second character next time */
			utf = utf_save;
			len = len_save;
			l = l_save;
		}

		/* Now check ordinary map */
		p = bsearch(&iutf, map, mapsize,
					sizeof(pg_utf_to_local), compare1);

		if (p)
		{
			iso = store_coded_char(iso, p->code);
			continue;
		}

		/* if there's a conversion function, try that */
		if (conv_func)
		{
			uint32		converted = (*conv_func) (iutf);

			if (converted)
			{
				iso = store_coded_char(iso, converted);
				continue;
			}
		}

		/* failed to translate this character */
		report_untranslatable_char(PG_UTF8, encoding,
								   (const char *) (utf - l), len);
	}

	/* if we broke out of loop early, must be invalid input */
	if (len > 0)
		report_invalid_encoding(PG_UTF8, (const char *) utf, len);

	*iso = '\0';
}