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A fork of the Apache Cassandra Project ready to embed Elasticsearch.
/*
* 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 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;
import java.nio.ByteBuffer;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
public class ToJsonFct extends NativeScalarFunction implements IGenericFunction
{
public static final FunctionName NAME = FunctionName.nativeFunction("tojson");
private static final Map, ToJsonFct> instances = new ConcurrentHashMap<>();
public static ToJsonFct getInstance(List> argTypes) throws InvalidRequestException
{
if (argTypes.size() != 1)
throw new InvalidRequestException(String.format("toJson() only accepts one argument (got %d)", argTypes.size()));
AbstractType fromType = argTypes.get(0);
ToJsonFct func = instances.get(fromType);
if (func == null)
{
func = new ToJsonFct(fromType);
instances.put(fromType, func);
}
return func;
}
private ToJsonFct(AbstractType argType)
{
super("tojson", UTF8Type.instance, argType);
}
public ByteBuffer execute(int protocolVersion, List parameters) throws InvalidRequestException
{
assert parameters.size() == 1 : "Expected 1 argument for toJson(), but got " + parameters.size();
ByteBuffer parameter = parameters.get(0);
if (parameter == null)
return ByteBufferUtil.bytes("null");
return ByteBufferUtil.bytes(argTypes.get(0).toJSONString(parameter, protocolVersion));
}
}