float.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("integer out of range")));

	result = (int32) rint(num);
	PG_RETURN_INT32(result);
}


/*
 *		ftoi2			- converts a float4 number to an int2 number
 */
Datum
ftoi2(PG_FUNCTION_ARGS)
{
	float4		num = PG_GETARG_FLOAT4(0);
	int16		result;

	if ((num < SHRT_MIN) || (num > SHRT_MAX))
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("smallint out of range")));

	result = (int16) rint(num);
	PG_RETURN_INT16(result);
}


/*
 *		i4tof			- converts an int4 number to a float8 number
 */
Datum
i4tof(PG_FUNCTION_ARGS)
{
	int32		num = PG_GETARG_INT32(0);
	float4		result;

	result = num;
	PG_RETURN_FLOAT4(result);
}


/*
 *		i2tof			- converts an int2 number to a float4 number
 */
Datum
i2tof(PG_FUNCTION_ARGS)
{
	int16		num = PG_GETARG_INT16(0);
	float4		result;

	result = num;
	PG_RETURN_FLOAT4(result);
}


/*
 *		float8_text		- converts a float8 number to a text string
 */
Datum
float8_text(PG_FUNCTION_ARGS)
{
	float8		num = PG_GETARG_FLOAT8(0);
	text	   *result;
	int			len;
	char	   *str;

	str = DatumGetCString(DirectFunctionCall1(float8out,
											  Float8GetDatum(num)));

	len = strlen(str) + VARHDRSZ;

	result = (text *) palloc(len);

	VARATT_SIZEP(result) = len;
	memcpy(VARDATA(result), str, (len - VARHDRSZ));

	pfree(str);

	PG_RETURN_TEXT_P(result);
}


/*
 *		text_float8		- converts a text string to a float8 number
 */
Datum
text_float8(PG_FUNCTION_ARGS)
{
	text	   *string = PG_GETARG_TEXT_P(0);
	Datum		result;
	int			len;
	char	   *str;

	len = (VARSIZE(string) - VARHDRSZ);
	str = palloc(len + 1);
	memcpy(str, VARDATA(string), len);
	*(str + len) = '\0';

	result = DirectFunctionCall1(float8in, CStringGetDatum(str));

	pfree(str);

	PG_RETURN_DATUM(result);
}


/*
 *		float4_text		- converts a float4 number to a text string
 */
Datum
float4_text(PG_FUNCTION_ARGS)
{
	float4		num = PG_GETARG_FLOAT4(0);
	text	   *result;
	int			len;
	char	   *str;

	str = DatumGetCString(DirectFunctionCall1(float4out,
											  Float4GetDatum(num)));

	len = strlen(str) + VARHDRSZ;

	result = (text *) palloc(len);

	VARATT_SIZEP(result) = len;
	memcpy(VARDATA(result), str, (len - VARHDRSZ));

	pfree(str);

	PG_RETURN_TEXT_P(result);
}


/*
 *		text_float4		- converts a text string to a float4 number
 */
Datum
text_float4(PG_FUNCTION_ARGS)
{
	text	   *string = PG_GETARG_TEXT_P(0);
	Datum		result;
	int			len;
	char	   *str;

	len = (VARSIZE(string) - VARHDRSZ);
	str = palloc(len + 1);
	memcpy(str, VARDATA(string), len);
	*(str + len) = '\0';

	result = DirectFunctionCall1(float4in, CStringGetDatum(str));

	pfree(str);

	PG_RETURN_DATUM(result);
}


/*
 *		=======================
 *		RANDOM FLOAT8 OPERATORS
 *		=======================
 */

/*
 *		dround			- returns	ROUND(arg1)
 */
Datum
dround(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	result = rint(arg1);

	PG_RETURN_FLOAT8(result);
}

/*
 *		dceil			- returns the smallest integer greater than or
 *						  equal to the specified float
 */
Datum
dceil(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);

	PG_RETURN_FLOAT8(ceil(arg1));
}

/*
 *		dfloor			- returns the largest integer lesser than or
 *						  equal to the specified float
 */
Datum
dfloor(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);

	PG_RETURN_FLOAT8(floor(arg1));
}

/*
 *		dsign			- returns -1 if the argument is less than 0, 0
 *						  if the argument is equal to 0, and 1 if the
 *						  argument is greater than zero.
 */
Datum
dsign(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	if (arg1 > 0)
		result = 1.0;
	else if (arg1 < 0)
		result = -1.0;
	else
		result = 0.0;

	PG_RETURN_FLOAT8(result);
}

/*
 *		dtrunc			- returns truncation-towards-zero of arg1,
 *						  arg1 >= 0 ... the greatest integer less
 *										than or equal to arg1
 *						  arg1 < 0	... the least integer greater
 *										than or equal to arg1
 */
Datum
dtrunc(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	if (arg1 >= 0)
		result = floor(arg1);
	else
		result = -floor(-arg1);

	PG_RETURN_FLOAT8(result);
}


/*
 *		dsqrt			- returns square root of arg1
 */
Datum
dsqrt(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	if (arg1 < 0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
				 errmsg("cannot take square root of a negative number")));

	result = sqrt(arg1);

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dcbrt			- returns cube root of arg1
 */
Datum
dcbrt(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	result = cbrt(arg1);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dpow			- returns pow(arg1,arg2)
 */
Datum
dpow(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);
	float8		result;

	/*
	 * The SQL spec requires that we emit a particular SQLSTATE error code for
	 * certain error conditions.
	 */
	if ((arg1 == 0 && arg2 < 0) ||
		(arg1 < 0 && floor(arg2) != arg2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
				 errmsg("invalid argument for power function")));

	/*
	 * We must check both for errno getting set and for a NaN result, in order
	 * to deal with the vagaries of different platforms...
	 */
	errno = 0;
	result = pow(arg1, arg2);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("result is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dexp			- returns the exponential function of arg1
 */
Datum
dexp(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	/*
	 * We must check both for errno getting set and for a NaN result, in order
	 * to deal with the vagaries of different platforms. Also, a zero result
	 * implies unreported underflow.
	 */
	errno = 0;
	result = exp(arg1);
	if (errno != 0 || result == 0.0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("result is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dlog1			- returns the natural logarithm of arg1
 */
Datum
dlog1(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	/*
	 * Emit particular SQLSTATE error codes for ln(). This is required by the
	 * SQL standard.
	 */
	if (arg1 == 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
				 errmsg("cannot take logarithm of zero")));
	if (arg1 < 0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
				 errmsg("cannot take logarithm of a negative number")));

	result = log(arg1);

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dlog10			- returns the base 10 logarithm of arg1
 */
Datum
dlog10(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	/*
	 * Emit particular SQLSTATE error codes for log(). The SQL spec doesn't
	 * define log(), but it does define ln(), so it makes sense to emit the
	 * same error code for an analogous error condition.
	 */
	if (arg1 == 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
				 errmsg("cannot take logarithm of zero")));
	if (arg1 < 0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
				 errmsg("cannot take logarithm of a negative number")));

	result = log10(arg1);

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dacos			- returns the arccos of arg1 (radians)
 */
Datum
dacos(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	errno = 0;
	result = acos(arg1);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dasin			- returns the arcsin of arg1 (radians)
 */
Datum
dasin(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	errno = 0;
	result = asin(arg1);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		datan			- returns the arctan of arg1 (radians)
 */
Datum
datan(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	errno = 0;
	result = atan(arg1);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		atan2			- returns the arctan2 of arg1 (radians)
 */
Datum
datan2(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);
	float8		result;

	errno = 0;
	result = atan2(arg1, arg2);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dcos			- returns the cosine of arg1 (radians)
 */
Datum
dcos(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	errno = 0;
	result = cos(arg1);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dcot			- returns the cotangent of arg1 (radians)
 */
Datum
dcot(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	errno = 0;
	result = tan(arg1);
	if (errno != 0 || result == 0.0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	result = 1.0 / result;
	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*
 *		dsin			- returns the sine of arg1 (radians)
 */
Datum
dsin(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float8		result;

	errno = 0;
	result = sin(arg1);
	if (errno != 0
#ifdef HAVE_FINITE
		|| !finite(result)
#endif
		)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("input is out of range")));

	CheckFloat8Val(result);
	PG_RETURN_FLOAT8(result);
}


/*