oid.c

关系型数据库 Postgresql 6.5.2

/*-------------------------------------------------------------------------
 *
 * oid.c
 *	  Functions for the built-in type Oid.
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /usr/local/cvsroot/pgsql/src/backend/utils/adt/oid.c,v 1.23.2.1 1999/08/02 05:24:56 scrappy Exp $
 *
 *-------------------------------------------------------------------------
 */


#include "postgres.h"
#include "utils/builtins.h"

/*****************************************************************************
 *	 USER I/O ROUTINES														 *
 *****************************************************************************/

/*
 *		oid8in			- converts "num num ..." to internal form
 *
 *		Note:
 *				Fills any nonexistent digits with NULL oids.
 */
Oid *
oid8in(char *oidString)
{
	Oid		   *result;
	int			nums;

	if (oidString == NULL)
		return NULL;

	result = (Oid *) palloc(sizeof(Oid[8]));
	if ((nums = sscanf(oidString, "%u%u%u%u%u%u%u%u",
					   &result[0],
					   &result[1],
					   &result[2],
					   &result[3],
					   &result[4],
					   &result[5],
					   &result[6],
					   &result[7])) != 8)
	{
		do
			result[nums++] = 0;
		while (nums < 8);
	}
	return result;
}

/*
 *		oid8out - converts internal form to "num num ..."
 */
char *
oid8out(Oid *oidArray)
{
	int			num;
	Oid		   *sp;
	char	   *rp;
	char	   *result;

	if (oidArray == NULL)
	{
		result = (char *) palloc(2);
		result[0] = '-';
		result[1] = '\0';
		return result;
	}

	/* assumes sign, 10 digits, ' ' */
	rp = result = (char *) palloc(8 * 12);
	sp = oidArray;
	for (num = 8; num != 0; num--)
	{
		ltoa(*sp++, rp);
		while (*++rp != '\0')
			;
		*rp++ = ' ';
	}
	*--rp = '\0';
	return result;
}

Oid
oidin(char *s)
{
	return int4in(s);
}

char *
oidout(Oid o)
{
	return int4out(o);
}

/*****************************************************************************
 *	 PUBLIC ROUTINES														 *
 *****************************************************************************/

/*
 * If you change this function, change heap_keytest()
 * because we have hardcoded this in there as an optimization
 */
bool
oideq(Oid arg1, Oid arg2)
{
	return arg1 == arg2;
}

bool
oidne(Oid arg1, Oid arg2)
{
	return arg1 != arg2;
}

bool
oid8eq(Oid *arg1, Oid *arg2)
{
	return (bool) (memcmp(arg1, arg2, 8 * sizeof(Oid)) == 0);
}

bool
oid8ne(Oid *arg1, Oid *arg2)
{
	return (bool) (memcmp(arg1, arg2, 8 * sizeof(Oid)) != 0);
}

bool
oid8lt(Oid *arg1, Oid *arg2)
{
	int			i;

	for (i = 0; i < 8; i++)
		if (!int4eq(arg1[i], arg2[i]))
			return int4lt(arg1[i], arg2[i]);
	return false;
}

bool
oid8le(Oid *arg1, Oid *arg2)
{
	int			i;

	for (i = 0; i < 8; i++)
		if (!int4eq(arg1[i], arg2[i]))
			return int4le(arg1[i], arg2[i]);
	return true;
}

bool
oid8ge(Oid *arg1, Oid *arg2)
{
	int			i;

	for (i = 0; i < 8; i++)
		if (!int4eq(arg1[i], arg2[i]))
			return int4ge(arg1[i], arg2[i]);
	return true;
}

bool
oid8gt(Oid *arg1, Oid *arg2)
{
	int			i;

	for (i = 0; i < 8; i++)
		if (!int4eq(arg1[i], arg2[i]))
			return int4gt(arg1[i], arg2[i]);
	return false;
}

bool
oideqint4(Oid arg1, int32 arg2)
{
/* oid is unsigned, but int4 is signed */
	return arg2 >= 0 && arg1 == arg2;
}

bool
int4eqoid(int32 arg1, Oid arg2)
{
/* oid is unsigned, but int4 is signed */
	return arg1 >= 0 && arg1 == arg2;
}

text *
oid_text(Oid oid)
{
	text	   *result;

	int			len;
	char	   *str;

	str = oidout(oid);
	len = (strlen(str) + VARHDRSZ);

	result = palloc(len);

	VARSIZE(result) = len;
	memmove(VARDATA(result), str, (len - VARHDRSZ));
	pfree(str);

	return result;
}	/* oid_text() */

Oid
text_oid(text *string)
{
	Oid			result;

	int			len;
	char	   *str;

	len = (VARSIZE(string) - VARHDRSZ);

	str = palloc(len + 1);
	memmove(str, VARDATA(string), len);
	*(str + len) = '\0';

	result = oidin(str);
	pfree(str);

	return result;
}	/* oid_text() */