public void run() {
// Create a file channel for the file
try {
_parent.addToActive(this);
file = new RandomAccessFile(Globals.ourHome + outFile, "rwd");
channel = file.getChannel();
// Create a segment downloader for each segment and run them simultaneously
for (int i = 0; i < nSeg; i++) {
segDownloads.add(new SegDownloader(this, peers.get(i % peers.size()) + "/" + path, i));
(new Thread(segDownloads.get(segDownloads.size() - 1))).start();
}
// Wait for a download thread to either finish or fail, and update our bookkeeping
try {
while (!done) {
// Get a new segment downloader off the stopped list.
SegDownloader s = bstopped.take();
// Give a new path to every download thread that failed.
if (s.status() == Dstatus.FAILED) {
synchronized (s) {
s.dlPath = getNewPath();
removeStopped(s);
s.notify();
}
}
// Check if that segment finishes off the download.
else if (s.status() == Dstatus.FINISHED) {
if (nSeg == doneSegs) {
done = true;
percentDone = 100;
System.out.println("Download " + Globals.ourHome + outFile + " Finished!");
// "Notify" the waiters that we're done.
while (waiters > 0 && waitToken.take()) {
waiters--;
}
}
} else throw new RuntimeException("Impossible");
}
} catch (InterruptedException e) {
status = Dstatus.FAILED;
}
} catch (IOException e) {
Log.info("Could not open file for download!");
status = Dstatus.FAILED;
} catch (InterruptedException e) {
// TODO Auto-generated catch block
status = Dstatus.FAILED;
}
}
public void removeActive(SegDownloader s) {
try {
if (doneSegs < nSeg) active.take();
} catch (InterruptedException e) {
// Nothing
}
}
// Only call this from a downloader thread.
// If the active queue is full, the downloader will
// block until a spot frees up.
public void addActive(SegDownloader s) {
try {
active.put(s);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public synchronized void addStopped(SegDownloader s) {
try {
bstopped.put(s);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// Wait on this download to finish. Implemented by trying to push something to the
// blocking queue. Since the pusher waits until the queue has space, only empty
// the queue if the download is finished.
public void waitForMe() {
waiters++;
try {
waitToken.put(true);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
ChunkDownload(
String dpath, String output, List<String> recentPeers, int segments, Download parent) {
done = false;
path = dpath;
nSeg = segments;
peers = recentPeers;
segFin = new boolean[nSeg];
doneSegs = 0;
status = Dstatus.DOWNLOADING;
outFile = output;
_parent = parent;
segDownloads = new ArrayList<SegDownloader>(segments);
bstopped = new ArrayBlockingQueue<SegDownloader>(segments);
active = new ArrayBlockingQueue<SegDownloader>(maxThreads);
// Helping variables to allow a thread to blocking wait on this download.
waitToken = new ArrayBlockingQueue<Boolean>(1);
waitToken.add(true);
waiters = 0;
percentDone = 0;
}
public synchronized void removeStopped(SegDownloader s) {
bstopped.remove(s);
}
