/*******************************************************************************
* Copyright (c) 2013, Salesforce.com, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 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.
* Neither the name of Salesforce.com nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS 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 COPYRIGHT HOLDER OR 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.
******************************************************************************/
package com.salesforce.phoenix.expression;
import java.math.BigDecimal;
import java.util.List;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import com.salesforce.phoenix.exception.ValueTypeIncompatibleException;
import com.salesforce.phoenix.schema.ColumnModifier;
import com.salesforce.phoenix.schema.PDataType;
import com.salesforce.phoenix.schema.tuple.Tuple;
import com.salesforce.phoenix.util.NumberUtil;
/**
*
* Subtract expression implementation
*
* @author kmahadik
* @since 0.1
*/
public class DecimalSubtractExpression extends SubtractExpression {
private Integer maxLength;
private Integer scale;
public DecimalSubtractExpression() {
}
public DecimalSubtractExpression(List<Expression> children) {
super(children);
for (int i=0; i<children.size(); i++) {
Expression childExpr = children.get(i);
if (i == 0) {
maxLength = childExpr.getMaxLength();
scale = childExpr.getScale();
} else {
maxLength = getPrecision(maxLength, childExpr.getMaxLength(), scale, childExpr.getScale());
scale = getScale(maxLength, childExpr.getMaxLength(), scale, childExpr.getScale());
}
}
}
@Override
public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
BigDecimal result = null;
for (int i=0; i<children.size(); i++) {
Expression childExpr = children.get(i);
if (!childExpr.evaluate(tuple, ptr)) {
return false;
}
if (ptr.getLength() == 0) {
return true;
}
PDataType childType = childExpr.getDataType();
boolean isDate = childType.isCoercibleTo(PDataType.DATE);
ColumnModifier childColumnModifier = childExpr.getColumnModifier();
BigDecimal bd = isDate ?
BigDecimal.valueOf(childType.getCodec().decodeLong(ptr, childColumnModifier)) :
(BigDecimal)PDataType.DECIMAL.toObject(ptr, childType, childColumnModifier);
if (result == null) {
result = bd;
} else {
result = result.subtract(bd);
/*
* Special case for date subtraction - note that only first two expression may be dates.
* We need to convert the date to a unit of "days" because that's what sql expects.
*/
if (isDate) {
result = result.divide(BD_MILLIS_IN_DAY, PDataType.DEFAULT_MATH_CONTEXT);
}
}
}
if (maxLength != null && scale != null) {
result = NumberUtil.setDecimalWidthAndScale(result, maxLength, scale);
}
if (result == null) {
throw new ValueTypeIncompatibleException(PDataType.DECIMAL, maxLength, scale);
}
ptr.set(PDataType.DECIMAL.toBytes(result));
return true;
}
@Override
public PDataType getDataType() {
return PDataType.DECIMAL;
}
@Override
public Integer getScale() {
return scale;
}
@Override
public Integer getMaxLength() {
return maxLength;
}
}