SynchChannelInputStream xref

View Javadoc

    1   /***
    2   *
    3   * Copyright 2004 Hiram Chirino
    4   *
    5   *  Licensed under the Apache License, Version 2.0 (the "License");
    6   *  you may not use this file except in compliance with the License.
    7   *  You may obtain a copy of the License at
    8   *
    9   *     http://www.apache.org/licenses/LICENSE-2.0
    10  *
    11  *  Unless required by applicable law or agreed to in writing, software
    12  *  distributed under the License is distributed on an "AS IS" BASIS,
    13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  *  See the License for the specific language governing permissions and
    15  *  limitations under the License.
    16  */
    17  package org.activeio.adapter;
    18
    19  import java.io.IOException;
    20  import java.io.InputStream;
    21
    22  import org.activeio.Channel;
    23  import org.activeio.Packet;
    24  import org.activeio.SynchChannel;
    25  import org.activeio.packet.EOSPacket;
    26
    27  /***
    28   * Provides an InputStream for a given SynchChannel.
    29   *
    30   * @version $Revision$
    31   */
    32  public class SynchChannelInputStream extends InputStream {
    33
    34      private final SynchChannel channel;
    35      private Packet lastPacket;
    36      private boolean closed;
    37      private long timeout = Channel.WAIT_FOREVER_TIMEOUT;
    38
    39      /***
    40       * @param channel
    41       */
    42      public SynchChannelInputStream(final SynchChannel channel) {
    43          this.channel = channel;
    44      }
    45
    46      /***
    47       * @see java.io.InputStream#read()
    48       */
    49      public int read() throws IOException {
    50          while( true ) {
    51              if( lastPacket==null ) {
    52                  try {
    53                      lastPacket = channel.read(timeout);
    54                  } catch (IOException e) {
    55                      throw (IOException)new IOException("Channel failed: "+e.getMessage()).initCause(e);
    56                  }
    57              }
    58              if( lastPacket.hasRemaining() ) {
    59                  return lastPacket.read();
    60              }
    61          }
    62      }
    63
    64      /***
    65       * @see java.io.InputStream#read(byte[], int, int)
    66       */
    67      public int read(byte[] b, int off, int len) throws IOException {
    68          while( true ) {
    69              if( lastPacket==null || !lastPacket.hasRemaining() ) {
    70                  try {
    71                      lastPacket = channel.read(timeout);
    72                  } catch (IOException e) {
    73                      throw (IOException)new IOException("Channel failed: "+e.getMessage()).initCause(e);
    74                  }
    75              }
    76              if( lastPacket==EOSPacket.EOS_PACKET ) {
    77                  return -1;
    78              }
    79              if( lastPacket!=null && lastPacket.hasRemaining() ) {
    80                  return lastPacket.read(b, off, len);
    81              }
    82          }
    83      }
    84
    85      /***
    86       * @see java.io.InputStream#close()
    87       */
    88      public void close() throws IOException {
    89          closed=true;
    90          super.close();
    91      }
    92
    93      public boolean isClosed() {
    94          return closed;
    95      }
    96
    97      /***
    98       * @param timeout
    99       */
    100     public void setTimeout(long timeout) {
    101         if( timeout <= 0 )
    102             timeout = Channel.WAIT_FOREVER_TIMEOUT;
    103         this.timeout = timeout;
    104     }
    105
    106     /***
    107      * @return
    108      */
    109     public long getTimeout() {
    110         if( timeout == Channel.WAIT_FOREVER_TIMEOUT )
    111             return 0;
    112         return timeout;
    113     }
    114 }