| /* |
| * 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.serializers; |
| |
| import java.nio.ByteBuffer; |
| import java.util.Collection; |
| import java.util.List; |
| |
| import org.apache.cassandra.transport.ProtocolVersion; |
| import org.apache.cassandra.utils.ByteBufferUtil; |
| |
| public abstract class CollectionSerializer<T> implements TypeSerializer<T> |
| { |
| protected abstract List<ByteBuffer> serializeValues(T value); |
| protected abstract int getElementCount(T value); |
| |
| public abstract T deserializeForNativeProtocol(ByteBuffer buffer, ProtocolVersion version); |
| public abstract void validateForNativeProtocol(ByteBuffer buffer, ProtocolVersion version); |
| |
| public ByteBuffer serialize(T value) |
| { |
| List<ByteBuffer> values = serializeValues(value); |
| // See deserialize() for why using the protocol v3 variant is the right thing to do. |
| return pack(values, getElementCount(value), ProtocolVersion.V3); |
| } |
| |
| public T deserialize(ByteBuffer bytes) |
| { |
| // The only cases we serialize/deserialize collections internally (i.e. not for the protocol sake), |
| // is: |
| // 1) when collections are frozen |
| // 2) for internal calls. |
| // In both case, using the protocol 3 version variant is the right thing to do. |
| return deserializeForNativeProtocol(bytes, ProtocolVersion.V3); |
| } |
| |
| public void validate(ByteBuffer bytes) throws MarshalException |
| { |
| // Same thing as above |
| validateForNativeProtocol(bytes, ProtocolVersion.V3); |
| } |
| |
| public static ByteBuffer pack(Collection<ByteBuffer> buffers, int elements, ProtocolVersion version) |
| { |
| int size = 0; |
| for (ByteBuffer bb : buffers) |
| size += sizeOfValue(bb, version); |
| |
| ByteBuffer result = ByteBuffer.allocate(sizeOfCollectionSize(elements, version) + size); |
| writeCollectionSize(result, elements, version); |
| for (ByteBuffer bb : buffers) |
| writeValue(result, bb, version); |
| return (ByteBuffer)result.flip(); |
| } |
| |
| protected static void writeCollectionSize(ByteBuffer output, int elements, ProtocolVersion version) |
| { |
| output.putInt(elements); |
| } |
| |
| public static int readCollectionSize(ByteBuffer input, ProtocolVersion version) |
| { |
| return input.getInt(); |
| } |
| |
| protected static int sizeOfCollectionSize(int elements, ProtocolVersion version) |
| { |
| return 4; |
| } |
| |
| public static void writeValue(ByteBuffer output, ByteBuffer value, ProtocolVersion version) |
| { |
| if (value == null) |
| { |
| output.putInt(-1); |
| return; |
| } |
| |
| output.putInt(value.remaining()); |
| output.put(value.duplicate()); |
| } |
| |
| public static ByteBuffer readValue(ByteBuffer input, ProtocolVersion version) |
| { |
| int size = input.getInt(); |
| if (size < 0) |
| return null; |
| |
| return ByteBufferUtil.readBytes(input, size); |
| } |
| |
| public static int sizeOfValue(ByteBuffer value, ProtocolVersion version) |
| { |
| return value == null ? 4 : 4 + value.remaining(); |
| } |
| } |