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;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.concurrent.CompletableFuture;
  import org.apache.bookkeeper.common.concurrent.FutureEventListener;
  import org.apache.bookkeeper.common.concurrent.FutureUtils;
  import org.apache.distributedlog.exceptions.UnexpectedException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * AppendOnlyStreamWriter.
   */
  public class AppendOnlyStreamWriter implements Closeable {
      static final Logger LOG = LoggerFactory.getLogger(AppendOnlyStreamWriter.class);
  
      // Use a 1-length array to satisfy Java's inner class reference rules. Use primitive
      // type because synchronized block is needed anyway.
      final long[] syncPos = new long[1];
      BKAsyncLogWriter logWriter;
      long requestPos = 0;
  
      public AppendOnlyStreamWriter(BKAsyncLogWriter logWriter, long pos) {
          if (LOG.isDebugEnabled()) {
              LOG.debug("initialize at position {}", pos);
          }
          this.logWriter = logWriter;
          this.syncPos[0] = pos;
          this.requestPos = pos;
      }
  
      public CompletableFuture<DLSN> write(byte[] data) {
          requestPos += data.length;
          CompletableFuture<DLSN> writeResult = logWriter.write(new LogRecord(requestPos, data));
          return writeResult.whenComplete(new WriteCompleteListener(requestPos));
      }
  
      public void force(boolean metadata) throws IOException {
          long pos = 0;
          try {
              pos = FutureUtils.result(logWriter.flushAndCommit());
          } catch (IOException ioe) {
              throw ioe;
          } catch (Exception ex) {
              LOG.error("unexpected exception in AppendOnlyStreamWriter.force ", ex);
              throw new UnexpectedException("unexpected exception in AppendOnlyStreamWriter.force", ex);
          }
          synchronized (syncPos) {
              syncPos[0] = pos;
          }
      }
  
      public long position() {
          synchronized (syncPos) {
              return syncPos[0];
          }
      }
  
      @Override
      public void close() throws IOException {
          logWriter.closeAndComplete();
      }
  
      public void markEndOfStream() throws IOException {
          try {
              FutureUtils.result(logWriter.markEndOfStream());
          } catch (IOException ioe) {
              throw ioe;
          } catch (Exception ex) {
              throw new UnexpectedException("Mark end of stream hit unexpected exception", ex);
          }
      }
  
      class WriteCompleteListener implements FutureEventListener<DLSN> {
          private final long position;
          public WriteCompleteListener(long position) {
              this.position = position;
          }
          @Override
          public void onSuccess(DLSN response) {
              synchronized (syncPos) {
                  if (position > syncPos[0]) {
                      syncPos[0] = position;
                  }
              }
          }
          @Override
          public void onFailure(Throwable cause) {
              // Handled at the layer above
          }
      }
  }
  