/*
* Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed 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://aws.amazon.com/apache2.0
*
* This file 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 com.amazonaws.mobileconnectors.s3.transfermanager.internal;
import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.event.ProgressEvent;
import com.amazonaws.event.ProgressListener;
import com.amazonaws.event.ProgressListenerCallbackExecutor;
import com.amazonaws.event.ProgressListenerChain;
import com.amazonaws.mobileconnectors.s3.transfermanager.Transfer;
import com.amazonaws.mobileconnectors.s3.transfermanager.TransferProgress;
import com.amazonaws.services.s3.model.LegacyS3ProgressListener;
import java.util.Collection;
import java.util.LinkedList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
/**
* Abstract transfer implementation.
*/
public abstract class AbstractTransfer implements Transfer {
/** The current state of this transfer. */
protected volatile TransferState state = TransferState.Waiting;
protected TransferMonitor monitor;
/** The progress of this transfer. */
private final TransferProgress transferProgress;
private final String description;
/** Hook for adding/removing more progress listeners. */
protected final ProgressListenerChain progressListenerChain;
/**
* Collection of listeners to be notified for changes to the state of this
* transfer via setState()
*/
protected final Collection<TransferStateChangeListener> stateChangeListeners = new LinkedList<TransferStateChangeListener>();
AbstractTransfer(String description, TransferProgress transferProgress,
ProgressListenerChain progressListenerChain) {
this(description, transferProgress, progressListenerChain, null);
}
AbstractTransfer(String description, TransferProgress transferProgress,
ProgressListenerChain progressListenerChain,
TransferStateChangeListener stateChangeListener) {
this.description = description;
this.progressListenerChain = progressListenerChain;
this.transferProgress = transferProgress;
addStateChangeListener(stateChangeListener);
}
/**
* Returns whether or not the transfer is finished (i.e. completed
* successfully, failed, or was canceled).
*
* @return Returns <code>true</code> if this transfer is finished (i.e.
* completed successfully, failed, or was canceled). Returns
* <code>false</code> if otherwise.
*/
@Override
public synchronized boolean isDone() {
return (state == TransferState.Failed ||
state == TransferState.Completed || state == TransferState.Canceled);
}
/**
* Waits for this transfer to complete. This is a blocking call; the current
* thread is suspended until this transfer completes.
*
* @throws AmazonClientException If any errors were encountered in the
* client while making the request or handling the response.
* @throws AmazonServiceException If any errors occurred in Amazon S3 while
* processing the request.
* @throws InterruptedException If this thread is interrupted while waiting
* for the transfer to complete.
*/
@Override
public void waitForCompletion()
throws AmazonClientException, AmazonServiceException, InterruptedException {
try {
Object result = null;
while (!monitor.isDone() || result == null) {
Future<?> f = monitor.getFuture();
result = f.get();
}
} catch (ExecutionException e) {
rethrowExecutionException(e);
}
}
/**
* Waits for this transfer to finish and returns any error that occurred, or
* returns <code>null</code> if no errors occurred. This is a blocking call;
* the current thread will be suspended until this transfer either fails or
* completes successfully.
*
* @return Any error that occurred while processing this transfer. Otherwise
* returns <code>null</code> if no errors occurred.
* @throws InterruptedException If this thread is interrupted while waiting
* for the transfer to complete.
*/
@Override
public AmazonClientException waitForException() throws InterruptedException {
try {
while (!monitor.isDone()) {
monitor.getFuture().get();
}
monitor.getFuture().get();
return null;
} catch (ExecutionException e) {
return unwrapExecutionException(e);
}
}
/**
* Returns a human-readable description of this transfer.
*
* @return A human-readable description of this transfer.
*/
@Override
public String getDescription() {
return description;
}
/**
* Returns the current state of this transfer.
*
* @return The current state of this transfer.
*/
@Override
public synchronized TransferState getState() {
return state;
}
/**
* Sets the current state of this transfer.
*/
public void setState(TransferState state) {
synchronized (this) {
this.state = state;
}
for (TransferStateChangeListener listener : stateChangeListeners) {
listener.transferStateChanged(this, state);
}
}
/**
* Notifies all the registered state change listeners of the state update.
*/
public void notifyStateChangeListeners(TransferState state) {
for (TransferStateChangeListener listener : stateChangeListeners) {
listener.transferStateChanged(this, state);
}
}
/**
* Adds the specified progress listener to the list of listeners receiving
* updates about this transfer's progress.
*
* @param listener The progress listener to add.
*/
@Override
public synchronized void addProgressListener(ProgressListener listener) {
progressListenerChain.addProgressListener(listener);
}
/**
* Removes the specified progress listener from the list of progress
* listeners receiving updates about this transfer's progress.
*
* @param listener The progress listener to remove.
*/
@Override
public synchronized void removeProgressListener(ProgressListener listener) {
progressListenerChain.removeProgressListener(listener);
}
/**
* @deprecated Replaced by {@link #addProgressListener(ProgressListener)}
*/
@Override
@Deprecated
public synchronized void addProgressListener(
com.amazonaws.services.s3.model.ProgressListener listener) {
progressListenerChain.addProgressListener(new LegacyS3ProgressListener(listener));
}
/**
* @deprecated Replaced by {@link #removeProgressListener(ProgressListener)}
*/
@Override
@Deprecated
public synchronized void removeProgressListener(
com.amazonaws.services.s3.model.ProgressListener listener) {
progressListenerChain.removeProgressListener(new LegacyS3ProgressListener(listener));
}
/**
* Adds the given state change listener to the collection of listeners.
*/
public synchronized void addStateChangeListener(TransferStateChangeListener listener) {
if (listener != null)
stateChangeListeners.add(listener);
}
/**
* Removes the given state change listener from the collection of listeners.
*/
public synchronized void removeStateChangeListener(TransferStateChangeListener listener) {
if (listener != null)
stateChangeListeners.remove(listener);
}
/**
* Returns progress information about this transfer.
*
* @return The progress information about this transfer.
*/
@Override
public TransferProgress getProgress() {
return transferProgress;
}
/**
* Sets the monitor used to poll for transfer completion.
*/
public void setMonitor(TransferMonitor monitor) {
this.monitor = monitor;
}
public TransferMonitor getMonitor() {
return monitor;
}
protected void fireProgressEvent(final int eventType) {
ProgressListenerCallbackExecutor.progressChanged(
this.progressListenerChain, new ProgressEvent(eventType, 0));
}
/**
* Examines the cause of the specified ExecutionException and either
* rethrows it directly (if it's a type of AmazonClientException) or wraps
* it in an AmazonClientException and rethrows it.
*
* @param e The execution exception to examine.
*/
protected void rethrowExecutionException(ExecutionException e) {
throw unwrapExecutionException(e);
}
/**
* Unwraps the root exception that caused the specified ExecutionException
* and returns it. If it was not an instance of AmazonClientException, it is
* wrapped as an AmazonClientException.
*
* @param e The ExecutionException to unwrap.
* @return The root exception that caused the specified ExecutionException.
*/
protected AmazonClientException unwrapExecutionException(ExecutionException e) {
Throwable t = e.getCause();
if (t instanceof AmazonClientException)
return (AmazonClientException) t;
return new AmazonClientException("Unable to complete transfer: " + t.getMessage(), t);
}
}