varchar.c

关系型数据库 Postgresql 6.5.2

	int			i;
	int			len;

	len = VARSIZE(arg) - VARHDRSZ;
	for (i = len - 1; i >= 0; i--)
	{
		if (s[i] != ' ')
			break;
	}
	return i + 1;
}

int32
bpcharlen(char *arg)
{
#ifdef MULTIBYTE
	unsigned char *s;
	int			len,
				l,
				wl;

#endif
	if (!PointerIsValid(arg))
		elog(ERROR, "Bad (null) char() external representation", NULL);
#ifdef MULTIBYTE
	l = bcTruelen(arg);
	len = 0;
	s = VARDATA(arg);
	while (l > 0)
	{
		wl = pg_mblen(s);
		l -= wl;
		s += wl;
		len++;
	}
	return (len);
#else
	return bcTruelen(arg);
#endif
}

int32
bpcharoctetlen(char *arg)
{
	if (!PointerIsValid(arg))
		elog(ERROR, "Bad (null) char() external representation", NULL);

	return bcTruelen(arg);
}

bool
bpchareq(char *arg1, char *arg2)
{
	int			len1,
				len2;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	if (len1 != len2)
		return 0;

	return strncmp(VARDATA(arg1), VARDATA(arg2), len1) == 0;
}

bool
bpcharne(char *arg1, char *arg2)
{
	int			len1,
				len2;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	if (len1 != len2)
		return 1;

	return strncmp(VARDATA(arg1), VARDATA(arg2), len1) != 0;
}

bool
bpcharlt(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (cmp == 0)
		return len1 < len2;
	else
		return cmp < 0;
}

bool
bpcharle(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (0 == cmp)
		return (bool) (len1 <= len2 ? 1 : 0);
	else
		return (bool) (cmp <= 0);
}

bool
bpchargt(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (cmp == 0)
		return len1 > len2;
	else
		return cmp > 0;
}

bool
bpcharge(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (0 == cmp)
		return (bool) (len1 >= len2 ? 1 : 0);
	else
		return (bool) (cmp >= 0);
}

int32
bpcharcmp(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	len1 = bcTruelen(arg1);
	len2 = bcTruelen(arg2);

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if ((0 == cmp) && (len1 != len2))
		return (int32) (len1 < len2 ? -1 : 1);
	else
		return cmp;
}

/*****************************************************************************
 *	Comparison Functions used for varchar
 *****************************************************************************/

int32
varcharlen(char *arg)
{
#ifdef MULTIBYTE
	unsigned char *s;
	int			len,
				l,
				wl;

#endif
	if (!PointerIsValid(arg))
		elog(ERROR, "Bad (null) varchar() external representation", NULL);

#ifdef MULTIBYTE
	len = 0;
	s = VARDATA(arg);
	l = VARSIZE(arg) - VARHDRSZ;
	while (l > 0)
	{
		wl = pg_mblen(s);
		l -= wl;
		s += wl;
		len++;
	}
	return (len);
#else
	return VARSIZE(arg) - VARHDRSZ;
#endif
}

int32
varcharoctetlen(char *arg)
{
	if (!PointerIsValid(arg))
		elog(ERROR, "Bad (null) varchar() external representation", NULL);
	return VARSIZE(arg) - VARHDRSZ;
}

bool
varchareq(char *arg1, char *arg2)
{
	int			len1,
				len2;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;

	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;

	if (len1 != len2)
		return 0;

	return strncmp(VARDATA(arg1), VARDATA(arg2), len1) == 0;
}

bool
varcharne(char *arg1, char *arg2)
{
	int			len1,
				len2;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;

	if (len1 != len2)
		return 1;

	return strncmp(VARDATA(arg1), VARDATA(arg2), len1) != 0;
}

bool
varcharlt(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (cmp == 0)
		return len1 < len2;
	else
		return cmp < 0;
}

bool
varcharle(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (0 == cmp)
		return (bool) (len1 <= len2 ? 1 : 0);
	else
		return (bool) (cmp <= 0);
}

bool
varchargt(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (cmp == 0)
		return len1 > len2;
	else
		return cmp > 0;
}

bool
varcharge(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	if (arg1 == NULL || arg2 == NULL)
		return (bool) 0;
	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;

	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if (0 == cmp)
		return (bool) (len1 >= len2 ? 1 : 0);
	else
		return (bool) (cmp >= 0);

}

int32
varcharcmp(char *arg1, char *arg2)
{
	int			len1,
				len2;
	int			cmp;

	len1 = VARSIZE(arg1) - VARHDRSZ;
	len2 = VARSIZE(arg2) - VARHDRSZ;
	cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
	if ((0 == cmp) && (len1 != len2))
		return (int32) (len1 < len2 ? -1 : 1);
	else
		return (int32) (cmp);
}

/*****************************************************************************
 * Hash functions (modified from hashtext in access/hash/hashfunc.c)
 *****************************************************************************/

uint32
hashbpchar(struct varlena * key)
{
	int			keylen;
	char	   *keydata;
	uint32		n;
	int			loop;

	keydata = VARDATA(key);
	keylen = bcTruelen((char *) key);

#define HASHC	n = *keydata++ + 65599 * n

	n = 0;
	if (keylen > 0)
	{
		loop = (keylen + 8 - 1) >> 3;

		switch (keylen & (8 - 1))
		{
			case 0:
				do
				{				/* All fall throughs */
					HASHC;
			case 7:
					HASHC;
			case 6:
					HASHC;
			case 5:
					HASHC;
			case 4:
					HASHC;
			case 3:
					HASHC;
			case 2:
					HASHC;
			case 1:
					HASHC;
				} while (--loop);
		}
	}
	return n;
}

uint32
hashvarchar(struct varlena * key)
{
	int			keylen;
	char	   *keydata;
	uint32		n;
	int			loop;

	keydata = VARDATA(key);
	keylen = VARSIZE(key) - VARHDRSZ;

#define HASHC	n = *keydata++ + 65599 * n

	n = 0;
	if (keylen > 0)
	{
		loop = (keylen + 8 - 1) >> 3;

		switch (keylen & (8 - 1))
		{
			case 0:
				do
				{				/* All fall throughs */
					HASHC;
			case 7:
					HASHC;
			case 6:
					HASHC;
			case 5:
					HASHC;
			case 4:
					HASHC;
			case 3:
					HASHC;
			case 2:
					HASHC;
			case 1:
					HASHC;
				} while (--loop);
		}
	}
	return n;
}