content: /*
   * 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.bookkeeper.statelib.impl.kv;
  
  import static org.apache.bookkeeper.statelib.impl.kv.KVUtils.newCommand;
  
  import com.google.protobuf.InvalidProtocolBufferException;
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufUtil;
  import lombok.AccessLevel;
  import lombok.Cleanup;
  import lombok.NoArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.bookkeeper.proto.statestore.kv.Command;
  import org.apache.bookkeeper.proto.statestore.kv.DeleteRequest;
  import org.apache.bookkeeper.proto.statestore.kv.PutRequest;
  import org.apache.bookkeeper.statelib.impl.journal.CommandProcessor;
  
  /**
   * A command processor to apply commands happened to the kv state store.
   */
  @Slf4j
  @NoArgsConstructor(access = AccessLevel.PRIVATE)
  class KVCommandProcessor implements CommandProcessor<RocksdbKVStore<byte[], byte[]>> {
  
      public static KVCommandProcessor of() {
          return new KVCommandProcessor();
      }
  
      @Override
      public void applyCommand(long revision, ByteBuf cmdBuf, RocksdbKVStore<byte[], byte[]> store) {
          Command command;
          try {
              command = newCommand(cmdBuf);
          } catch (InvalidProtocolBufferException e) {
              log.error("Invalid kv command found : buffer = {}, txid = {}", cmdBuf, revision);
              // TODO: better to handle this
              return;
          }
  
          switch (command.getReqCase()) {
              case NOP_REQ:
                  break;
              case PUT_IF_ABSENT_REQ:
                  applyPutIfAbsentCommand(revision, command, store);
                  return;
              case PUT_REQ:
                  applyPutCommand(revision, command, store);
                  return;
              case DEL_REQ:
                  applyDeleteCommand(revision, command, store);
                  return;
              default:
                  return;
          }
      }
  
      private void applyPutCommand(long revision, Command command, RocksdbKVStore<byte[], byte[]> store) {
          PutRequest putReq = command.getPutReq();
          byte[] keyBytes = putReq.getKey().toByteArray();
          byte[] valBytes = putReq.getValue().toByteArray();
          @Cleanup("release") ByteBuf serializedValBuf = KVUtils.serialize(valBytes, revision);
          byte[] serializedValBytes = ByteBufUtil.getBytes(serializedValBuf);
          store.put(keyBytes, serializedValBytes, revision);
      }
  
      private void applyPutIfAbsentCommand(long revision, Command command, RocksdbKVStore<byte[], byte[]> store) {
          PutRequest putReq = command.getPutReq();
          byte[] keyBytes = putReq.getKey().toByteArray();
          byte[] valBytes = putReq.getValue().toByteArray();
          @Cleanup("release") ByteBuf serializedValBuf = KVUtils.serialize(valBytes, revision);
          byte[] serializedValBytes = ByteBufUtil.getBytes(serializedValBuf);
          store.putIfAbsent(keyBytes, serializedValBytes, revision);
      }
  
      private void applyDeleteCommand(long revision, Command command, RocksdbKVStore<byte[], byte[]> store) {
          DeleteRequest delReq = command.getDelReq();
          byte[] keyBytes = delReq.getKey().toByteArray();
          store.delete(keyBytes, revision);
      }
  }
  