/*
* Copyright (c) 2003 The Visigoth Software Society. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowledgement:
* "This product includes software developed by the
* Visigoth Software Society (http://www.visigoths.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
* project contributors may be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
* nor may "FreeMarker" or "Visigoth" appear in their names
* without prior written permission of the Visigoth Software Society.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Visigoth Software Society. For more
* information on the Visigoth Software Society, please see
* http://www.visigoths.org/
*/
package freemarker.core;
import java.math.*;
import java.util.HashMap;
import java.util.Map;
import freemarker.template.*;
import freemarker.template.utility.OptimizerUtil;
/**
* Class to perform arithmetic operations.
* @author <a href="mailto:[email protected]">Jonathan Revusky</a>
* @author Attila Szegedi
*/
public abstract class ArithmeticEngine {
/**
* Arithmetic engine that converts all numbers to {@link BigDecimal} and
* then operates on them. This is FreeMarker's default arithmetic engine.
*/
public static final BigDecimalEngine BIGDECIMAL_ENGINE = new BigDecimalEngine();
/**
* Arithmetic engine that uses (more-or-less) the widening conversions of
* Java language to determine the type of result of operation, instead of
* converting everything to BigDecimal up front.
*/
public static final ConservativeEngine CONSERVATIVE_ENGINE = new ConservativeEngine();
public abstract int compareNumbers(Number first, Number second) throws TemplateException;
public abstract Number add(Number first, Number second) throws TemplateException;
public abstract Number subtract(Number first, Number second) throws TemplateException;
public abstract Number multiply(Number first, Number second) throws TemplateException;
public abstract Number divide(Number first, Number second) throws TemplateException;
public abstract Number modulus(Number first, Number second) throws TemplateException;
public abstract Number toNumber(String s);
protected int minScale = 12;
protected int maxScale = 12;
protected int roundingPolicy = BigDecimal.ROUND_HALF_UP;
/**
* Sets the minimal scale to use when dividing BigDecimal numbers. Default
* value is 12.
*/
public void setMinScale(int minScale) {
if(minScale < 0) {
throw new IllegalArgumentException("minScale < 0");
}
this.minScale = minScale;
}
/**
* Sets the maximal scale to use when multiplying BigDecimal numbers.
* Default value is 100.
*/
public void setMaxScale(int maxScale) {
if(maxScale < minScale) {
throw new IllegalArgumentException("maxScale < minScale");
}
this.maxScale = maxScale;
}
public void setRoundingPolicy(int roundingPolicy) {
if (roundingPolicy != BigDecimal.ROUND_CEILING
&& roundingPolicy != BigDecimal.ROUND_DOWN
&& roundingPolicy != BigDecimal.ROUND_FLOOR
&& roundingPolicy != BigDecimal.ROUND_HALF_DOWN
&& roundingPolicy != BigDecimal.ROUND_HALF_EVEN
&& roundingPolicy != BigDecimal.ROUND_HALF_UP
&& roundingPolicy != BigDecimal.ROUND_UNNECESSARY
&& roundingPolicy != BigDecimal.ROUND_UP)
{
throw new IllegalArgumentException("invalid rounding policy");
}
this.roundingPolicy = roundingPolicy;
}
/**
* This is the default arithmetic engine in FreeMarker. It converts every
* number it receives into {@link BigDecimal}, then operates on these
* converted {@link BigDecimal}s.
*/
public static class BigDecimalEngine
extends
ArithmeticEngine
{
public int compareNumbers(Number first, Number second) {
BigDecimal left = toBigDecimal(first);
BigDecimal right = toBigDecimal(second);
return left.compareTo(right);
}
public Number add(Number first, Number second) {
BigDecimal left = toBigDecimal(first);
BigDecimal right = toBigDecimal(second);
return left.add(right);
}
public Number subtract(Number first, Number second) {
BigDecimal left = toBigDecimal(first);
BigDecimal right = toBigDecimal(second);
return left.subtract(right);
}
public Number multiply(Number first, Number second) {
BigDecimal left = toBigDecimal(first);
BigDecimal right = toBigDecimal(second);
BigDecimal result = left.multiply(right);
if (result.scale() > maxScale) {
result = result.setScale(maxScale, roundingPolicy);
}
return result;
}
public Number divide(Number first, Number second) {
BigDecimal left = toBigDecimal(first);
BigDecimal right = toBigDecimal(second);
return divide(left, right);
}
public Number modulus(Number first, Number second) {
long left = first.longValue();
long right = second.longValue();
return new Long(left % right);
}
public Number toNumber(String s) {
return new BigDecimal(s);
}
private BigDecimal divide(BigDecimal left, BigDecimal right) {
int scale1 = left.scale();
int scale2 = right.scale();
int scale = Math.max(scale1, scale2);
scale = Math.max(minScale, scale);
return left.divide(right, scale, roundingPolicy);
}
}
/**
* An arithmetic engine that conservatively widens the operation arguments
* to extent that they can hold the result of the operation. Widening
* conversions occur in following situations:
* <ul>
* <li>byte and short are always widened to int (alike to Java language).</li>
* <li>To preserve magnitude: when operands are of different types, the
* result type is the type of the wider operand.</li>
* <li>to avoid overflows: if add, subtract, or multiply would overflow on
* integer types, the result is widened from int to long, or from long to
* BigInteger.</li>
* <li>to preserve fractional part: if a division of integer types would
* have a fractional part, int and long are converted to double, and
* BigInteger is converted to BigDecimal. An operation on a float and a
* long results in a double. An operation on a float or double and a
* BigInteger results in a BigDecimal.</li>
* </ul>
*/
public static class ConservativeEngine extends ArithmeticEngine {
private static final int INTEGER = 0;
private static final int LONG = 1;
private static final int FLOAT = 2;
private static final int DOUBLE = 3;
private static final int BIGINTEGER = 4;
private static final int BIGDECIMAL = 5;
private static final Map classCodes = createClassCodesMap();
public int compareNumbers(Number first, Number second) throws TemplateException {
switch(getCommonClassCode(first, second)) {
case INTEGER: {
int n1 = first.intValue();
int n2 = second.intValue();
return n1 < n2 ? -1 : (n1 == n2 ? 0 : 1);
}
case LONG: {
long n1 = first.longValue();
long n2 = second.longValue();
return n1 < n2 ? -1 : (n1 == n2 ? 0 : 1);
}
case FLOAT: {
float n1 = first.floatValue();
float n2 = second.floatValue();
return n1 < n2 ? -1 : (n1 == n2 ? 0 : 1);
}
case DOUBLE: {
double n1 = first.doubleValue();
double n2 = second.doubleValue();
return n1 < n2 ? -1 : (n1 == n2 ? 0 : 1);
}
case BIGINTEGER: {
BigInteger n1 = toBigInteger(first);
BigInteger n2 = toBigInteger(second);
return n1.compareTo(n2);
}
case BIGDECIMAL: {
BigDecimal n1 = toBigDecimal(first);
BigDecimal n2 = toBigDecimal(second);
return n1.compareTo(n2);
}
}
// Make the compiler happy. getCommonClassCode() is guaranteed to
// return only above codes, or throw an exception.
throw new Error();
}
public Number add(Number first, Number second) throws TemplateException {
switch(getCommonClassCode(first, second)) {
case INTEGER: {
int n1 = first.intValue();
int n2 = second.intValue();
int n = n1 + n2;
return
((n ^ n1) < 0 && (n ^ n2) < 0) // overflow check
? (Number)new Long(((long)n1) + n2)
: (Number)new Integer(n);
}
case LONG: {
long n1 = first.longValue();
long n2 = second.longValue();
long n = n1 + n2;
return
((n ^ n1) < 0 && (n ^ n2) < 0) // overflow check
? (Number)toBigInteger(first).add(toBigInteger(second))
: (Number)new Long(n);
}
case FLOAT: {
return new Float(first.floatValue() + second.floatValue());
}
case DOUBLE: {
return new Double(first.doubleValue() + second.doubleValue());
}
case BIGINTEGER: {
BigInteger n1 = toBigInteger(first);
BigInteger n2 = toBigInteger(second);
return n1.add(n2);
}
case BIGDECIMAL: {
BigDecimal n1 = toBigDecimal(first);
BigDecimal n2 = toBigDecimal(second);
return n1.add(n2);
}
}
// Make the compiler happy. getCommonClassCode() is guaranteed to
// return only above codes, or throw an exception.
throw new Error();
}
public Number subtract(Number first, Number second) throws TemplateException {
switch(getCommonClassCode(first, second)) {
case INTEGER: {
int n1 = first.intValue();
int n2 = second.intValue();
int n = n1 - n2;
return
((n ^ n1) < 0 && (n ^ ~n2) < 0) // overflow check
? (Number)new Long(((long)n1) - n2)
: (Number)new Integer(n);
}
case LONG: {
long n1 = first.longValue();
long n2 = second.longValue();
long n = n1 - n2;
return
((n ^ n1) < 0 && (n ^ ~n2) < 0) // overflow check
? (Number)toBigInteger(first).subtract(toBigInteger(second))
: (Number)new Long(n);
}
case FLOAT: {
return new Float(first.floatValue() - second.floatValue());
}
case DOUBLE: {
return new Double(first.doubleValue() - second.doubleValue());
}
case BIGINTEGER: {
BigInteger n1 = toBigInteger(first);
BigInteger n2 = toBigInteger(second);
return n1.subtract(n2);
}
case BIGDECIMAL: {
BigDecimal n1 = toBigDecimal(first);
BigDecimal n2 = toBigDecimal(second);
return n1.subtract(n2);
}
}
// Make the compiler happy. getCommonClassCode() is guaranteed to
// return only above codes, or throw an exception.
throw new Error();
}
public Number multiply(Number first, Number second) throws TemplateException {
switch(getCommonClassCode(first, second)) {
case INTEGER: {
int n1 = first.intValue();
int n2 = second.intValue();
int n = n1 * n2;
return
n1== 0 || n/n1 == n2 // overflow check
? (Number)new Integer(n)
: (Number)new Long(((long)n1) * n2);
}
case LONG: {
long n1 = first.longValue();
long n2 = second.longValue();
long n = n1 * n2;
return
n1==0L || n / n1 == n2 // overflow check
? (Number)new Long(n)
: (Number)toBigInteger(first).multiply(toBigInteger(second));
}
case FLOAT: {
return new Float(first.floatValue() * second.floatValue());
}
case DOUBLE: {
return new Double(first.doubleValue() * second.doubleValue());
}
case BIGINTEGER: {
BigInteger n1 = toBigInteger(first);
BigInteger n2 = toBigInteger(second);
return n1.multiply(n2);
}
case BIGDECIMAL: {
BigDecimal n1 = toBigDecimal(first);
BigDecimal n2 = toBigDecimal(second);
BigDecimal r = n1.multiply(n2);
return r.scale() > maxScale ? r.setScale(maxScale, roundingPolicy) : r;
}
}
// Make the compiler happy. getCommonClassCode() is guaranteed to
// return only above codes, or throw an exception.
throw new Error();
}
public Number divide(Number first, Number second) throws TemplateException {
switch(getCommonClassCode(first, second)) {
case INTEGER: {
int n1 = first.intValue();
int n2 = second.intValue();
if (n1 % n2 == 0) {
return new Integer(n1/n2);
}
return new Double(((double)n1)/n2);
}
case LONG: {
long n1 = first.longValue();
long n2 = second.longValue();
if (n1 % n2 == 0) {
return new Long(n1/n2);
}
return new Double(((double)n1)/n2);
}
case FLOAT: {
return new Float(first.floatValue() / second.floatValue());
}
case DOUBLE: {
return new Double(first.doubleValue() / second.doubleValue());
}
case BIGINTEGER: {
BigInteger n1 = toBigInteger(first);
BigInteger n2 = toBigInteger(second);
BigInteger[] divmod = n1.divideAndRemainder(n2);
if(divmod[1].equals(BigInteger.ZERO)) {
return divmod[0];
}
else {
BigDecimal bd1 = new BigDecimal(n1);
BigDecimal bd2 = new BigDecimal(n2);
return bd1.divide(bd2, minScale, roundingPolicy);
}
}
case BIGDECIMAL: {
BigDecimal n1 = toBigDecimal(first);
BigDecimal n2 = toBigDecimal(second);
int scale1 = n1.scale();
int scale2 = n2.scale();
int scale = Math.max(scale1, scale2);
scale = Math.max(minScale, scale);
return n1.divide(n2, scale, roundingPolicy);
}
}
// Make the compiler happy. getCommonClassCode() is guaranteed to
// return only above codes, or throw an exception.
throw new Error();
}
public Number modulus(Number first, Number second) throws TemplateException {
switch(getCommonClassCode(first, second)) {
case INTEGER: {
return new Integer(first.intValue() % second.intValue());
}
case LONG: {
return new Long(first.longValue() % second.longValue());
}
case FLOAT: {
return new Float(first.floatValue() % second.floatValue());
}
case DOUBLE: {
return new Double(first.doubleValue() % second.doubleValue());
}
case BIGINTEGER: {
BigInteger n1 = toBigInteger(first);
BigInteger n2 = toBigInteger(second);
return n1.mod(n2);
}
case BIGDECIMAL: {
throw new TemplateException("Can't calculate remainder on BigDecimals", Environment.getCurrentEnvironment());
}
}
// Make the compiler happy. getCommonClassCode() is guaranteed to
// return only above codes, or throw an exception.
throw new Error();
}
public Number toNumber(String s) {
return OptimizerUtil.optimizeNumberRepresentation(new BigDecimal(s));
}
private static Map createClassCodesMap() {
Map map = new HashMap(17);
Integer intcode = new Integer(INTEGER);
map.put(Byte.class, intcode);
map.put(Short.class, intcode);
map.put(Integer.class, intcode);
map.put(Long.class, new Integer(LONG));
map.put(Float.class, new Integer(FLOAT));
map.put(Double.class, new Integer(DOUBLE));
map.put(BigInteger.class, new Integer(BIGINTEGER));
map.put(BigDecimal.class, new Integer(BIGDECIMAL));
return map;
}
private static int getClassCode(Number num) throws TemplateException {
try {
return ((Integer)classCodes.get(num.getClass())).intValue();
}
catch(NullPointerException e) {
if(num == null) {
throw new TemplateException("Unknown number type null", Environment.getCurrentEnvironment());
}
throw new TemplateException("Unknown number type " + num.getClass().getName(), Environment.getCurrentEnvironment());
}
}
private static int getCommonClassCode(Number num1, Number num2) throws TemplateException {
int c1 = getClassCode(num1);
int c2 = getClassCode(num2);
int c = c1 > c2 ? c1 : c2;
// If BigInteger is combined with a Float or Double, the result is a
// BigDecimal instead of BigInteger in order not to lose the
// fractional parts. If Float is combined with Long, the result is a
// Double instead of Float to preserve the bigger bit width.
switch(c) {
case FLOAT: {
if((c1 < c2 ? c1 : c2) == LONG) {
return DOUBLE;
}
break;
}
case BIGINTEGER: {
int min = c1 < c2 ? c1 : c2;
if(min == DOUBLE || min == FLOAT) {
return BIGDECIMAL;
}
break;
}
}
return c;
}
private static BigInteger toBigInteger(Number num) {
return num instanceof BigInteger ? (BigInteger) num : new BigInteger(num.toString());
}
}
private static BigDecimal toBigDecimal(Number num) {
return num instanceof BigDecimal ? (BigDecimal) num : new BigDecimal(num.toString());
}
}
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