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.streaming;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.nio.ByteBuffer;
  import org.apache.bookkeeper.client.BKException;
  import org.apache.bookkeeper.client.LedgerHandle;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * this class provides a streaming api to get an output stream from a ledger
   * handle and write to it as a stream of bytes. This is built on top of
   * ledgerhandle api and uses a buffer to cache the data written to it and writes
   * out the entry to the ledger.
   */
  public class LedgerOutputStream extends OutputStream {
  
      private static final Logger LOG = LoggerFactory.getLogger(LedgerOutputStream.class);
  
      private final LedgerHandle lh;
      private ByteBuffer bytebuff;
      byte[] bbytes;
      int defaultSize = 1024 * 1024; // 1MB default size
  
      /**
       * construct a outputstream from a ledger handle.
       *
       * @param lh
       *            ledger handle
       */
      public LedgerOutputStream(LedgerHandle lh) {
          this.lh = lh;
          bbytes = new byte[defaultSize];
          this.bytebuff = ByteBuffer.wrap(bbytes);
      }
  
      /**
       * construct a outputstream from a ledger handle.
       *
       * @param lh
       *            the ledger handle
       * @param size
       *            the size of the buffer
       */
      public LedgerOutputStream(LedgerHandle lh, int size) {
          this.lh = lh;
          bbytes = new byte[size];
          this.bytebuff = ByteBuffer.wrap(bbytes);
      }
  
      @Override
      public void close() {
          // flush everything
          // we have
          flush();
      }
  
      @Override
      public synchronized void flush() {
          // lets flush all the data
          // into the ledger entry
          if (bytebuff.position() > 0) {
              // copy the bytes into
              // a new byte buffer and send it out
              byte[] b = new byte[bytebuff.position()];
              LOG.info("Comment: flushing with params " + " " + bytebuff.position());
              System.arraycopy(bbytes, 0, b, 0, bytebuff.position());
              try {
                  lh.addEntry(b);
              } catch (InterruptedException ie) {
                  LOG.warn("Interrupted while flushing " + ie);
                  Thread.currentThread().interrupt();
              } catch (BKException bke) {
                  LOG.warn("BookKeeper exception ", bke);
              }
          }
      }
  
      /**
       * make space for len bytes to be written to the buffer.
       *
       * @param len
       * @return if true then we can make space for len if false we cannot
       */
      private boolean makeSpace(int len) {
          if (bytebuff.remaining() < len) {
              flush();
              bytebuff.clear();
              return bytebuff.capacity() >= len;
          }
          return true;
      }
  
      @Override
      public synchronized void write(byte[] b) {
          if (makeSpace(b.length)) {
              bytebuff.put(b);
          } else {
              try {
                  lh.addEntry(b);
              } catch (InterruptedException ie) {
                  LOG.warn("Interrupted while writing", ie);
                  Thread.currentThread().interrupt();
              } catch (BKException bke) {
                  LOG.warn("BookKeeper exception", bke);
              }
          }
      }
  
      @Override
      public synchronized void write(byte[] b, int off, int len) {
          if (!makeSpace(len)) {
              // lets try making the buffer bigger
              bbytes = new byte[len];
              bytebuff = ByteBuffer.wrap(bbytes);
          }
          bytebuff.put(b, off, len);
      }
  
      @Override
      public synchronized void write(int b) throws IOException {
          makeSpace(1);
          byte oneB = (byte) (b & 0xFF);
          bytebuff.put(oneB);
      }
  }
  