251 lines
6.7 KiB
C++

/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is TransforMiiX XSLT processor.
*
* The Initial Developer of the Original Code is The MITRE Corporation.
* Portions created by MITRE are Copyright (C) 1999 The MITRE Corporation.
*
* Portions created by Keith Visco as a Non MITRE employee,
* (C) 1999 Keith Visco. All Rights Reserved.
*
* Contributor(s):
*
* Keith Visco, kvisco@ziplink.net
* -- original author.
*
* Larry Fitzpatrick, lef@opentext.com
*
* Eric Du, duxy@leyou.com.cn
* -- added fix for FreeBSD
*
* NaN/Infinity code copied from the JS-library with permission from
* Netscape Communications Corporation: http://www.mozilla.org/js
* http://lxr.mozilla.org/seamonkey/source/js/src/jsnum.h
*
*/
#include "primitives.h"
#include <math.h>
#ifdef WIN32
#include <float.h>
#endif
//A trick to handle IEEE floating point exceptions on FreeBSD - E.D.
#ifdef __FreeBSD__
#include <floatingpoint.h>
#endif
//----------------------------/
//- Implementation of Double -/
//----------------------------/
/**
* A wrapper for the primitive double type, and provides some simple
* floating point related routines
**/
//A trick to handle IEEE floating point exceptions on FreeBSD - E.D.
#ifdef __FreeBSD__
fp_except_t allmask = FP_X_INV|FP_X_OFL|FP_X_UFL|FP_X_DZ|FP_X_IMP|FP_X_DNML;
fp_except_t oldmask = fpsetmask(~allmask);
#endif
/**
* Macros to workaround math-bugs bugs in various platforms
**/
#ifdef IS_BIG_ENDIAN
#define TX_DOUBLE_HI32(x) (((PRUint32 *)&(x))[0])
#define TX_DOUBLE_LO32(x) (((PRUint32 *)&(x))[1])
#else
#define TX_DOUBLE_HI32(x) (((PRUint32 *)&(x))[1])
#define TX_DOUBLE_LO32(x) (((PRUint32 *)&(x))[0])
#endif
#define TX_DOUBLE_HI32_SIGNBIT 0x80000000
#define TX_DOUBLE_HI32_EXPMASK 0x7ff00000
#define TX_DOUBLE_HI32_MANTMASK 0x000fffff
//-- Initialize Double related constants
#ifdef IS_BIG_ENDIAN
const PRUint32 nanMask[2] = {TX_DOUBLE_HI32_EXPMASK | TX_DOUBLE_HI32_MANTMASK,
0xffffffff};
const PRUint32 infMask[2] = {TX_DOUBLE_HI32_EXPMASK, 0};
const PRUint32 negInfMask[2] = {TX_DOUBLE_HI32_EXPMASK | TX_DOUBLE_HI32_SIGNBIT, 0};
#else
const PRUint32 nanMask[2] = {0xffffffff,
TX_DOUBLE_HI32_EXPMASK | TX_DOUBLE_HI32_MANTMASK};
const PRUint32 infMask[2] = {0, TX_DOUBLE_HI32_EXPMASK};
const PRUint32 negInfMask[2] = {0, TX_DOUBLE_HI32_EXPMASK | TX_DOUBLE_HI32_SIGNBIT};
#endif
const double Double::NaN = *((double*)nanMask);
const double Double::POSITIVE_INFINITY = *((double*)infMask);
const double Double::NEGATIVE_INFINITY = *((double*)negInfMask);
/**
* Creates a new Double with it's value initialized from the given String.
* The String will be converted to a double. If the String does not
* represent an IEEE 754 double, the value will be initialized to NaN
**/
Double::Double(const String& string) {
this->value = toDouble(string);
} //-- Double
/**
* Returns the value of this Double as a double
**/
double Double::doubleValue() {
return this->value;
} //-- doubleValue
/**
* Returns the value of this Double as an int
**/
int Double::intValue() {
return (int)value;
} //-- intValue
/**
* Determines whether the given double represents positive or negative
* inifinity
**/
MBool Double::isInfinite(double dbl) {
return ((TX_DOUBLE_HI32(dbl) & ~TX_DOUBLE_HI32_SIGNBIT) == TX_DOUBLE_HI32_EXPMASK &&
!TX_DOUBLE_LO32(dbl));
} //-- isInfinite
/**
* Determines whether the given double is NaN
**/
MBool Double::isNaN(double dbl) {
return ((TX_DOUBLE_HI32(dbl) & TX_DOUBLE_HI32_EXPMASK) == TX_DOUBLE_HI32_EXPMASK &&
(TX_DOUBLE_LO32(dbl) || (TX_DOUBLE_HI32(dbl) & TX_DOUBLE_HI32_MANTMASK)));
} //-- isNaN
/**
* Determines whether the given double is negative
**/
MBool Double::isNeg(double dbl) {
return (TX_DOUBLE_HI32(dbl) & TX_DOUBLE_HI32_SIGNBIT) != 0;
} //-- isNeg
/**
* Converts the given String to a double, if the String value does not
* represent a double, NaN will be returned
**/
double Double::toDouble(const String& src) {
double dbl = 0.0;
double multiplier = 10.0;
PRInt32 idx = 0;
double sign = 1.0;
//-- trim leading whitespace
for ( ; idx < src.length(); idx++ )
if ( src.charAt(idx) != ' ' ) break;
//-- check first character for sign
if ( idx < src.length() ) {
PRInt32 ch = src.charAt(idx);
if ( ch == '-' ) {
sign = -1.0;
++idx;
}
}
else {
return Double::NaN;
}
//-- convert remaining to number
for ( ; idx < src.length(); idx++ ) {
PRInt32 ch = src.charAt(idx);
if (( ch >= '0') && (ch <= '9')) {
if ( multiplier > 1.0 ) {
dbl = dbl*multiplier;
dbl += (double) (ch-48);
}
else {
dbl += multiplier * (ch-48);
multiplier = multiplier * 0.1;
}
}
else if ( ch == '.') {
if ( multiplier < 1.0 ) return Double::NaN;
multiplier = 0.1;
}
else return Double::NaN;
}
dbl = dbl*sign;
return dbl;
} //-- toDouble
/**
* Converts the value of the given double to a String, and places
* The result into the destination String.
* @return the given dest string
**/
String& Double::toString(double value, String& dest) {
//-- check for special cases
if ( isNaN(value) ) {
dest.append("NaN");
return dest;
}
if ( isInfinite(value) ) {
if (value < 0) dest.append('-');
dest.append("Infinity");
return dest;
}
MBool isNegative = (MBool)(value<0.0);
double val = value;
if ( isNegative ) val = val * -1.0;
double ival = 0;
double fval = modf(val, &ival);
String iStr;
int temp = (int)ival;
if ( temp > 0.0 ) {
while ( temp > 0.0 ) {
iStr.append( (char) ((temp % 10)+48) );
temp = temp / 10;
}
if ( isNegative ) iStr.append('-');
iStr.reverse();
}
else iStr.append('0');
iStr.append('.');
if ( fval > 0.0 ) {
while ( fval > 0.0000001 ) {
fval = fval*10.0;
fval = modf(fval, &ival);
iStr.append( (char) (ival+48) );
}
}
else iStr.append('0');
dest.append(iStr);
return dest;
} //-- toString