cloudstack/services/console-proxy-rdp/rdpconsole/src/main/java/streamer/InputStreamSource.java

// 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 streamer;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Source element, which reads data from InputStream.
 */
public class InputStreamSource extends BaseElement {

  protected InputStream is;
  protected SocketWrapper socketWrapper;

  public InputStreamSource(String id) {
    super(id);
  }

  public InputStreamSource(String id, InputStream is) {
    super(id);
    this.is = is;
  }

  public InputStreamSource(String id, SocketWrapper socketWrapper) {
    super(id);
    this.socketWrapper = socketWrapper;
  }

  @Override
  public void handleEvent(Event event, Direction direction) {
    switch (event) {
    case SOCKET_UPGRADE_TO_SSL:
      socketWrapper.upgradeToSsl();
      break;
    default:
      super.handleEvent(event, direction);
    }
  }

  @Override
  public void setLink(String padName, Link link, Direction direction) {
    switch (direction) {
    case OUT:
      super.setLink(padName, link, direction);

      if (is == null) {
        // Pause links until data stream will be ready
        link.pause();
      }
      break;
    case IN:
      throw new RuntimeException("Cannot assign link to input pad in source element. Element: " + this + ", pad: " + padName + ", link: " + link + ".");
    }
  }

  public void setInputStream(InputStream is) {
    this.is = is;

    // Resume links
    resumeLinks();
  }

  private void resumeLinks() {
    for (DataSink sink : outputPads.values())
      ((Link) sink).resume();
  }

  /**
   * Read data from input stream.
   */
  @Override
  public void poll(boolean block) {
    try {
      if (!block && is.available() == 0) {

        if (verbose)
          System.out.println("[" + this + "] INFO: No data in stream is available now, returning.");

        return;
      }

      // Create buffer of recommended size and with default offset
      ByteBuffer buf = new ByteBuffer(incommingBufLength);

      if (verbose)
        System.out.println("[" + this + "] INFO: Reading data from stream.");

      int actualLength = is.read(buf.data, buf.offset, buf.data.length - buf.offset);

      if (actualLength < 0) {
        if (verbose)
          System.out.println("[" + this + "] INFO: End of stream.");

        buf.unref();
        closeStream();
        sendEventToAllPads(Event.STREAM_CLOSE, Direction.OUT);
        return;
      }

      if (actualLength == 0) {
        if (verbose)
          System.out.println("[" + this + "] INFO: Empty buffer is read from stream.");

        buf.unref();
        return;
      }

      buf.length = actualLength;

      if (verbose)
        System.out.println("[" + this + "] INFO: Data read from stream: " + buf + ".");

      pushDataToAllOuts(buf);

    } catch (IOException e) {
      System.err.println("[" + this + "] ERROR: " + e.getMessage());
      closeStream();
    }
  }

  @Override
  protected void onClose() {
    closeStream();
  }

  private void closeStream() {
    if (verbose)
      System.out.println("[" + this + "] INFO: Closing stream.");

    try {
      is.close();
    } catch (IOException e) {
    }
    try {
      sendEventToAllPads(Event.STREAM_CLOSE, Direction.OUT);
    } catch (Exception e) {
    }
  }

  @Override
  public String toString() {
    return "InputStreamSource(" + id + ")";
  }

  /**
   * Example.
   */
  public static void main(String args[]) {
    InputStream is = new ByteArrayInputStream(new byte[] { 1, 2, 3 });

    InputStreamSource source = new InputStreamSource("source") {
      {
        verbose = true;
      }
    };
    Element fakeSink = new FakeSink("sink") {
      {
        verbose = true;
      }
    };

    Link link = new SyncLink() {
      {
        verbose = true;
      }
    };

    source.setLink(STDOUT, link, Direction.OUT);
    fakeSink.setLink(STDIN, link, Direction.IN);

    source.setInputStream(is);

    link.sendEvent(Event.STREAM_START, Direction.OUT);
    link.run();

  }

}