/*
* 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.cassandra.cql3.functions;
import java.nio.ByteBuffer;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.db.marshal.UTF8Type;
import org.apache.cassandra.exceptions.InvalidRequestException;
import org.apache.cassandra.utils.ByteBufferUtil;
/**
* CQL toString function.
*
*/
public class ToStringFct extends NativeScalarFunction implements IGenericFunction
{
public static final FunctionName NAME = FunctionName.nativeFunction("tostring");
private static final Map<AbstractType<?>, ToStringFct> instances = new ConcurrentHashMap<>();
public static ToStringFct getInstance(List<AbstractType<?>> argTypes) throws InvalidRequestException
{
assert argTypes.size() == 1 : "Expected 1 argument for toString(), but got " + argTypes.size();
AbstractType<?> argType = argTypes.get(0);
ToStringFct func = instances.get(argType);
if (func == null)
{
func = new ToStringFct(argType);
instances.put(argType, func);
}
return func;
}
private ToStringFct(AbstractType<?> argType)
{
super("tostring", UTF8Type.instance, argType);
}
public ByteBuffer execute(int protocolVersion, List<ByteBuffer> parameters) throws InvalidRequestException
{
ByteBuffer bb = parameters.get(0);
if (bb == null)
return ByteBufferUtil.bytes("null");
return ByteBufferUtil.bytes(argTypes.get(0).getSerializer().deserialize(bb).toString());
}
public static class Loader implements IGenericFunction.Loader
{
public Loader()
{
}
}
}