/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.phoenix.expression.function;
import java.sql.SQLException;
import java.util.List;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.phoenix.compile.KeyPart;
import org.apache.phoenix.expression.Expression;
import org.apache.phoenix.parse.FunctionParseNode.Argument;
import org.apache.phoenix.parse.FunctionParseNode.BuiltInFunction;
import org.apache.phoenix.query.KeyRange;
import org.apache.phoenix.schema.PColumn;
import org.apache.phoenix.schema.PDataType;
import org.apache.phoenix.schema.SortOrder;
import org.apache.phoenix.schema.tuple.Tuple;
@BuiltInFunction(name = InvertFunction.NAME, args = { @Argument() })
public class InvertFunction extends ScalarFunction {
public static final String NAME = "INVERT";
public InvertFunction() throws SQLException {}
public InvertFunction(List<Expression> children) throws SQLException {
super(children);
}
@Override
public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
if (!getChildExpression().evaluate(tuple, ptr)) { return false; }
if (ptr.getLength() == 0) { return true; }
byte[] buf = new byte[ptr.getLength()];
SortOrder.invert(ptr.get(), ptr.getOffset(), buf, 0, ptr.getLength());
ptr.set(buf);
return true;
}
@Override
public SortOrder getSortOrder() {
return getChildExpression().getSortOrder() == SortOrder.ASC ? SortOrder.DESC : SortOrder.ASC;
}
@Override
public PDataType getDataType() {
return getChildExpression().getDataType();
}
@Override
public Integer getMaxLength() {
return getChildExpression().getMaxLength();
}
@Override
public boolean isNullable() {
return getChildExpression().isNullable();
}
@Override
public String getName() {
return NAME;
}
/**
* INVERT may be optimized through
*/
@Override
public int getKeyFormationTraversalIndex() {
return 0;
}
/**
* Invert the childPart key range
*/
@Override
public KeyPart newKeyPart(final KeyPart childPart) {
return new KeyPart() {
@Override
public KeyRange getKeyRange(CompareOp op, Expression rhs) {
KeyRange range = childPart.getKeyRange(op, rhs);
return range.invert();
}
@Override
public List<Expression> getExtractNodes() {
return childPart.getExtractNodes();
}
@Override
public PColumn getColumn() {
return childPart.getColumn();
}
};
}
@Override
public OrderPreserving preservesOrder() {
return OrderPreserving.YES;
}
private Expression getChildExpression() {
return children.get(0);
}
}