shell/src/main/scala/org/apache/clerezza/shell/InterruptibleInputStream.scala

/*
 * 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.clerezza.shell

import java.io.InputStream
import java.nio.channels.ClosedByInterruptException
import scala.actors.Actor
import scala.actors.Actor._

class InterruptibleInputStream(base: InputStream) extends InputStream {
  private case object Stop
  private case object Read

  private var readingThread: Thread = null

  val readerActor = new Actor() {
    def act() {
      loop {
        react {
          case Stop => exit()
          case Read => {
              readingThread = Thread.currentThread
              val ch = try {
                 base.read()
              } catch {
                case e: ClosedByInterruptException => {
                    -1
                }
              }
              readingThread = null
              sender ! ch
          }
        }
      }
    }
  }
  readerActor.start()

  def read() = {
    readerActor ! Read
    self.receive {
      case x: Int => x
    }
  }

  def terminate() {
    readerActor ! Stop
    val currentReadingThread = readingThread
    if (currentReadingThread != null) {
      currentReadingThread.interrupt()
    }
  }

}