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.distributedlog.zk;
  
  import com.google.common.collect.Lists;
  import java.util.Collections;
  import java.util.List;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.atomic.AtomicBoolean;
  import org.apache.bookkeeper.common.concurrent.FutureUtils;
  import org.apache.distributedlog.ZooKeeperClient;
  import org.apache.distributedlog.util.Transaction;
  import org.apache.distributedlog.util.Utils;
  import org.apache.zookeeper.AsyncCallback;
  import org.apache.zookeeper.KeeperException;
  import org.apache.zookeeper.OpResult;
  
  /**
   * ZooKeeper Transaction.
   */
  public class ZKTransaction implements Transaction<Object>, AsyncCallback.MultiCallback {
  
      private final ZooKeeperClient zkc;
      private final List<ZKOp> ops;
      private final List<org.apache.zookeeper.Op> zkOps;
      private final CompletableFuture<Void> result;
      private final AtomicBoolean done = new AtomicBoolean(false);
  
      public ZKTransaction(ZooKeeperClient zkc) {
          this.zkc = zkc;
          this.ops = Lists.newArrayList();
          this.zkOps = Lists.newArrayList();
          this.result = new CompletableFuture<>();
      }
  
      @Override
      public void addOp(Op<Object> operation) {
          if (done.get()) {
              throw new IllegalStateException("Add an operation to a finished transaction");
          }
          assert(operation instanceof ZKOp);
          ZKOp zkOp = (ZKOp) operation;
          this.ops.add(zkOp);
          this.zkOps.add(zkOp.getOp());
      }
  
      @Override
      public CompletableFuture<Void> execute() {
          if (!done.compareAndSet(false, true)) {
              return result;
          }
          if (zkOps.isEmpty()) {
              this.processResult(KeeperException.Code.OK.intValue(), null, null, Collections.emptyList());
          } else {
              try {
                  zkc.get().multi(zkOps, this, result);
              } catch (ZooKeeperClient.ZooKeeperConnectionException e) {
                  result.completeExceptionally(Utils.zkException(e, ""));
              } catch (InterruptedException e) {
                  Thread.currentThread().interrupt();
                  result.completeExceptionally(Utils.zkException(e, ""));
              }
          }
          return result;
      }
  
      @Override
      public void abort(Throwable cause) {
          if (!done.compareAndSet(false, true)) {
              return;
          }
          for (int i = 0; i < ops.size(); i++) {
              ops.get(i).abortOpResult(cause, null);
          }
          FutureUtils.completeExceptionally(result, cause);
      }
  
      @Override
      public void processResult(int rc, String path, Object ctx, List<OpResult> results) {
          if (KeeperException.Code.OK.intValue() == rc) { // transaction succeed
              for (int i = 0; i < ops.size(); i++) {
                  ops.get(i).commitOpResult(results.get(i));
              }
              FutureUtils.complete(result, null);
          } else {
              KeeperException ke = KeeperException.create(KeeperException.Code.get(rc));
              for (int i = 0; i < ops.size(); i++) {
                  ops.get(i).abortOpResult(ke, null != results ? results.get(i) : null);
              }
              FutureUtils.completeExceptionally(result, ke);
          }
      }
  }
  