| /* |
| * 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.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.*; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.cassandra.cql3.CQL3Type; |
| |
| import org.apache.cassandra.cql3.QueryOptions; |
| import org.apache.cassandra.db.marshal.*; |
| import org.apache.cassandra.exceptions.FunctionExecutionException; |
| import org.apache.cassandra.exceptions.InvalidRequestException; |
| import org.apache.cassandra.serializers.MarshalException; |
| import org.apache.cassandra.transport.ProtocolVersion; |
| import org.apache.cassandra.utils.JsonUtils; |
| |
| import static java.lang.String.format; |
| |
| public class FromJsonFct extends NativeScalarFunction |
| { |
| private static final Map<AbstractType<?>, FromJsonFct> instances = new ConcurrentHashMap<>(); |
| |
| public static FromJsonFct getInstance(FunctionName name, AbstractType<?> returnType) |
| { |
| FromJsonFct func = instances.get(returnType); |
| if (func == null) |
| { |
| func = new FromJsonFct(name, returnType); |
| instances.put(returnType, func); |
| } |
| return func; |
| } |
| |
| private FromJsonFct(FunctionName name, AbstractType<?> returnType) |
| { |
| super(name.name, returnType, UTF8Type.instance); |
| } |
| |
| public ByteBuffer execute(ProtocolVersion protocolVersion, List<ByteBuffer> parameters) |
| { |
| assert parameters.size() == 1 : format("Unexpectedly got %d arguments for %s()", parameters.size(), name.name); |
| ByteBuffer argument = parameters.get(0); |
| if (argument == null) |
| return null; |
| |
| String jsonArg = UTF8Type.instance.getSerializer().deserialize(argument); |
| try |
| { |
| Object object = JsonUtils.JSON_OBJECT_MAPPER.readValue(jsonArg, Object.class); |
| if (object == null) |
| return null; |
| return returnType.fromJSONObject(object).bindAndGet(QueryOptions.forProtocolVersion(protocolVersion)); |
| } |
| catch (IOException exc) |
| { |
| throw FunctionExecutionException.create(name(), |
| Collections.singletonList("text"), |
| format("Could not decode JSON string '%s': %s", jsonArg, exc)); |
| } |
| catch (MarshalException exc) |
| { |
| throw FunctionExecutionException.create(this, exc); |
| } |
| } |
| |
| public static void addFunctionsTo(NativeFunctions functions) |
| { |
| functions.add(new Factory("from_json")); |
| functions.add(new Factory("fromjson")); |
| } |
| |
| private static class Factory extends FunctionFactory |
| { |
| private Factory(String name) |
| { |
| super(name, FunctionParameter.fixed(CQL3Type.Native.TEXT)); |
| } |
| |
| @Override |
| protected NativeFunction doGetOrCreateFunction(List<AbstractType<?>> argTypes, AbstractType<?> receiverType) |
| { |
| if (receiverType == null) |
| throw new InvalidRequestException(format("%s() cannot be used in the selection clause of a SELECT statement", name.name)); |
| |
| return FromJsonFct.getInstance(name, receiverType); |
| } |
| } |
| } |