| /* |
| * 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.transport; |
| |
| import java.lang.reflect.Array; |
| import java.util.EnumMap; |
| import java.util.Map; |
| |
| import io.netty.buffer.ByteBuf; |
| |
| import io.netty.buffer.Unpooled; |
| import org.apache.cassandra.utils.Pair; |
| |
| public class OptionCodec<T extends Enum<T> & OptionCodec.Codecable<T>> |
| { |
| public interface Codecable<T extends Enum<T>> |
| { |
| public int getId(int version); |
| |
| public Object readValue(ByteBuf cb, int version); |
| public void writeValue(Object value, ByteBuf cb, int version); |
| public int serializedValueSize(Object obj, int version); |
| } |
| |
| private final Class<T> klass; |
| private final T[] ids; |
| |
| @SuppressWarnings({"unchecked"}) |
| public OptionCodec(Class<T> klass) |
| { |
| this.klass = klass; |
| |
| T[] values = klass.getEnumConstants(); |
| int maxId = -1; |
| for (T opt : values) |
| maxId = Math.max(maxId, opt.getId(Server.CURRENT_VERSION)); |
| ids = (T[])Array.newInstance(klass, maxId + 1); |
| for (T opt : values) |
| { |
| if (ids[opt.getId(Server.CURRENT_VERSION)] != null) |
| throw new IllegalStateException(String.format("Duplicate option id %d", opt.getId(Server.CURRENT_VERSION))); |
| ids[opt.getId(Server.CURRENT_VERSION)] = opt; |
| } |
| } |
| |
| private T fromId(int id) |
| { |
| T opt = ids[id]; |
| if (opt == null) |
| throw new ProtocolException(String.format("Unknown option id %d", id)); |
| return opt; |
| } |
| |
| public Map<T, Object> decode(ByteBuf body, int version) |
| { |
| EnumMap<T, Object> options = new EnumMap<T, Object>(klass); |
| int n = body.readUnsignedShort(); |
| for (int i = 0; i < n; i++) |
| { |
| T opt = fromId(body.readUnsignedShort()); |
| Object value = opt.readValue(body, version); |
| if (options.containsKey(opt)) |
| throw new ProtocolException(String.format("Duplicate option %s in message", opt.name())); |
| options.put(opt, value); |
| } |
| return options; |
| } |
| |
| public ByteBuf encode(Map<T, Object> options, int version) |
| { |
| int optLength = 2; |
| for (Map.Entry<T, Object> entry : options.entrySet()) |
| optLength += 2 + entry.getKey().serializedValueSize(entry.getValue(), version); |
| ByteBuf cb = Unpooled.buffer(optLength); |
| cb.writeShort(options.size()); |
| for (Map.Entry<T, Object> entry : options.entrySet()) |
| { |
| T opt = entry.getKey(); |
| cb.writeShort(opt.getId(version)); |
| opt.writeValue(entry.getValue(), cb, version); |
| } |
| return cb; |
| } |
| |
| public Pair<T, Object> decodeOne(ByteBuf body, int version) |
| { |
| T opt = fromId(body.readUnsignedShort()); |
| Object value = opt.readValue(body, version); |
| return Pair.create(opt, value); |
| } |
| |
| public void writeOne(Pair<T, Object> option, ByteBuf dest, int version) |
| { |
| T opt = option.left; |
| Object obj = option.right; |
| dest.writeShort(opt.getId(version)); |
| opt.writeValue(obj, dest, version); |
| } |
| |
| public int oneSerializedSize(Pair<T, Object> option, int version) |
| { |
| T opt = option.left; |
| Object obj = option.right; |
| return 2 + opt.serializedValueSize(obj, version); |
| } |
| } |