postgres/contrib/tsearch2/ts_locale.c

#include "ts_locale.h"

#include "utils/builtins.h"
#include "utils/pg_locale.h"
#include "mb/pg_wchar.h"


#ifdef TS_USE_WIDE

#ifdef WIN32

size_t
wchar2char(char *to, const wchar_t *from, size_t len)
{
	if (GetDatabaseEncoding() == PG_UTF8)
	{
		int			r;

		if (len == 0)
			return 0;

		r = WideCharToMultiByte(CP_UTF8, 0, from, -1, to, len,
								NULL, NULL);

		if (r == 0)
			ereport(ERROR,
					(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
					 errmsg("UTF-16 to UTF-8 translation failed: %lu",
							GetLastError())));
		Assert(r <= len);

		return r;
	}

	return wcstombs(to, from, len);
}

size_t
char2wchar(wchar_t *to, const char *from, size_t len)
{
	if (GetDatabaseEncoding() == PG_UTF8)
	{
		int			r;

		if (len == 0)
			return 0;

		r = MultiByteToWideChar(CP_UTF8, 0, from, len, to, len);

		if (!r)
		{
			pg_verifymbstr(from, strlen(from), false);
			ereport(ERROR,
					(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
					 errmsg("invalid multibyte character for locale"),
					 errhint("The server's LC_CTYPE locale is probably incompatible with the database encoding.")));
		}

		Assert(r <= len);

		return r;
	}

	return mbstowcs(to, from, len);
}
#endif   /* WIN32 */

int
_t_isalpha(const char *ptr)
{
	wchar_t		character;

	char2wchar(&character, ptr, 1);

	return iswalpha((wint_t) character);
}

int
_t_isprint(const char *ptr)
{
	wchar_t		character;

	char2wchar(&character, ptr, 1);

	return iswprint((wint_t) character);
}
#endif   /* TS_USE_WIDE */

char *
lowerstr(char *str)
{
	char	   *ptr = str;
	char	   *out;
	int			len = strlen(str);

	if ( len == 0 )
		return pstrdup("");

#ifdef TS_USE_WIDE

	/*
	 * Use wide char code only when max encoding length > 1 and ctype != C.
	 * Some operating systems fail with multi-byte encodings and a C locale.
	 * Also, for a C locale there is no need to process as multibyte. From
	 * backend/utils/adt/oracle_compat.c Teodor
	 */
	if (pg_database_encoding_max_length() > 1 && !lc_ctype_is_c())
	{
		wchar_t    *wstr,
				   *wptr;
		int		    wlen;

		/* 
		 *alloc number of wchar_t for worst case, len contains
		 * number of bytes <= number of characters and
		 * alloc 1 wchar_t for 0, because wchar2char(wcstombs in really)
		 * wants zero-terminated string
		 */
		wptr = wstr = (wchar_t *) palloc(sizeof(wchar_t) * (len+1));

		/*
		 * str SHOULD be cstring, so wlen contains number
		 * of converted character
		 */
		wlen = char2wchar(wstr, str, len);
		if ( wlen < 0 )
			ereport(ERROR,
					(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
					 errmsg("transalation failed from server encoding to wchar_t")));

		Assert(wlen<=len);
		wstr[wlen] = 0;

		while (*wptr)
		{
			*wptr = towlower((wint_t) *wptr);
			wptr++;
		}

		/*
		 * Alloc result string for worst case + '\0'
		 */
		len = sizeof(char)*pg_database_encoding_max_length()*(wlen+1);
		out = (char*)palloc(len);

		/*
		 * wlen now is number of bytes which is always >= number of characters
		 */
		wlen = wchar2char(out, wstr, len);
		pfree(wstr);

		if ( wlen < 0 )
			ereport(ERROR,
					(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
					 errmsg("transalation failed from wchar_t to server encoding %d", errno)));
		Assert(wlen<=len);
		out[wlen]='\0';
	}
	else
#endif
	{
		char *outptr;

		outptr = out = (char*)palloc( sizeof(char) * (len+1) );
		while (*ptr)
		{
			*outptr++ = tolower(*(unsigned char *) ptr);
			ptr++;
		}
		*outptr = '\0';
	}

	return out;
}