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package com.salesforce.phoenix.expression;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.List;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.io.WritableUtils;
import com.salesforce.phoenix.expression.visitor.ExpressionVisitor;
import com.salesforce.phoenix.schema.ColumnModifier;
import com.salesforce.phoenix.schema.PDataType;
import com.salesforce.phoenix.schema.tuple.Tuple;
import com.salesforce.phoenix.util.ByteUtil;
import com.salesforce.phoenix.util.StringUtil;
/**
*
* Implementation for <,<=,>,>=,=,!= comparison expressions
* @author jtaylor
* @since 0.1
*/
public class ComparisonExpression extends BaseCompoundExpression {
private CompareOp op;
private static final String[] CompareOpString = new String[CompareOp.values().length];
static {
CompareOpString[CompareOp.EQUAL.ordinal()] = " = ";
CompareOpString[CompareOp.NOT_EQUAL.ordinal()] = " != ";
CompareOpString[CompareOp.GREATER.ordinal()] = " > ";
CompareOpString[CompareOp.LESS.ordinal()] = " < ";
CompareOpString[CompareOp.GREATER_OR_EQUAL.ordinal()] = " >= ";
CompareOpString[CompareOp.LESS_OR_EQUAL.ordinal()] = " <= ";
}
public ComparisonExpression() {
}
public ComparisonExpression(CompareOp op, List<Expression> children) {
super(children);
if (op == null) {
throw new NullPointerException();
}
this.op = op;
}
@Override
public int hashCode() {
final int prime = 31;
int result = super.hashCode();
result = prime * result + op.hashCode();
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (!super.equals(obj)) return false;
if (getClass() != obj.getClass()) return false;
ComparisonExpression other = (ComparisonExpression)obj;
if (op != other.op) return false;
return true;
}
@Override
public PDataType getDataType() {
return PDataType.BOOLEAN;
}
@Override
public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
if (!children.get(0).evaluate(tuple, ptr)) {
return false;
}
byte[] lhsBytes = ptr.get();
int lhsOffset = ptr.getOffset();
int lhsLength = ptr.getLength();
PDataType lhsDataType = children.get(0).getDataType();
ColumnModifier lhsColumnModifier = children.get(0).getColumnModifier();
if (!children.get(1).evaluate(tuple, ptr)) {
return false;
}
byte[] rhsBytes = ptr.get();
int rhsOffset = ptr.getOffset();
int rhsLength = ptr.getLength();
PDataType rhsDataType = children.get(1).getDataType();
ColumnModifier rhsColumnModifier = children.get(1).getColumnModifier();
if (rhsDataType == PDataType.CHAR) {
rhsLength = StringUtil.getUnpaddedCharLength(rhsBytes, rhsOffset, rhsLength, rhsColumnModifier);
}
if (lhsDataType == PDataType.CHAR) {
lhsLength = StringUtil.getUnpaddedCharLength(lhsBytes, lhsOffset, lhsLength, lhsColumnModifier);
}
int comparisonResult = lhsDataType.compareTo(lhsBytes, lhsOffset, lhsLength, lhsColumnModifier,
rhsBytes, rhsOffset, rhsLength, rhsColumnModifier, rhsDataType);
ptr.set(ByteUtil.compare(op, comparisonResult) ? PDataType.TRUE_BYTES : PDataType.FALSE_BYTES);
return true;
}
@Override
public void readFields(DataInput input) throws IOException {
op = CompareOp.values()[WritableUtils.readVInt(input)];
super.readFields(input);
}
@Override
public void write(DataOutput output) throws IOException {
WritableUtils.writeVInt(output, op.ordinal());
super.write(output);
}
@Override
public final <T> T accept(ExpressionVisitor<T> visitor) {
List<T> l = acceptChildren(visitor, visitor.visitEnter(this));
T t = visitor.visitLeave(this, l);
if (t == null) {
t = visitor.defaultReturn(this, l);
}
return t;
}
public CompareOp getFilterOp() {
return op;
}
public static String toString(CompareOp op, List<Expression> children) {
return (children.get(0) + CompareOpString[op.ordinal()] + children.get(1));
}
@Override
public String toString() {
return toString(getFilterOp(), children);
}
}