/**
* Given a file and a source this will start a worker-less file downloading.
*
* @param nF
* @param bestSource
*/
private void startFileDownloading(DownloadFile nF, DownloadSource bestSource) {
// first ensure that the file is not already complete on disk:
if (downloadFileCompleteOnDisk(nF)) {
Logger.warn("Complete download: " + nF + " was in the queue. Issueing completion.");
nF.downloadComplete(); // issue completion
wereCompleteItemsInQueue = true;
return;
}
// Create a new info container for the file (if it has never been started before, or if for some
// reason there are no chunks in it (corrupt for some reason? broken code in the past probably))
if (nF.active == null) {
if (nF.getSize() == 0) {
// zero byte files do not need downloading. (and indeed they will fail to dispatch correctly
// as they will never have any incomplete chunks)
try {
nF.getFile().createNewFile();
nF.downloadComplete();
wereCompleteItemsInQueue = true;
return;
} catch (IOException e) {
Logger.severe(
"Empty file: " + nF.getFile().getPath() + " couldn't be created on disk: " + e);
}
}
nF.active = new DownloadInfo(nF);
} else {
if (nF.active.isComplete()) {
Logger.warn("Complete download: " + nF + " was in the queue. Issueing completion.");
nF.downloadComplete();
wereCompleteItemsInQueue = true;
return;
} else if (nF.active.chunks.size() == 0) {
Logger.warn(
"Active download '"
+ nF
+ "' in queue with no chunks. Restarting download from the beginning.");
nF.active = new DownloadInfo(nF);
}
}
try {
// Create the new worker:
DownloadWorker w = DownloadWorker.getDownloadWorker(this, nF.active);
nF.active.worker = w;
workers.add(w);
// Start one of the download chunks present in the info:
for (DownloadChunk c : w.getIncompleteInactiveChunks()) {
w.downloadChunk(c, bestSource, downloadThreadPool);
break;
}
} catch (IOException e) {
Logger.severe("Unable to dispatch a download: " + e);
Logger.log(e);
}
}
/**
* Finds a file that is not being serviced by a download worker and starts to download it.
*
* @return true iff there was a file in the queue to consider, false otherwise.
*/
private synchronized boolean dispatchFile() {
// 1) establish the active directory:
DownloadFile nF = controller.q.getInactiveDownloadFile();
if (nF != null) {
// Logger.log("attempting to dispatch: "+nF);
// start it downloading...
// 1) find a source for the download:
Map<String, DownloadSource> sources =
controller.ssvr.getIndexNodeCommunicator().getSourcesForFile(nF.hash);
if (sources.isEmpty()) {
nF.notifyNoSources();
} else {
startFileDownloading(nF, controller.peerstats.getBestSource(sources));
}
return true;
} else {
// Logger.log("Nothing to dispatch.");
return false;
}
}
/**
* Checks if the downloadFile specified has been completed already. This returns true iff: ) file
* exists ) is expected size ) hashes to the same fs2 hash.
*
* @param f
* @return
*/
private boolean downloadFileCompleteOnDisk(DownloadFile f) {
try {
File onDisk = f.getFile();
if (!onDisk.isFile()) return false;
if (onDisk.length() != f.size) return false;
if (!ThrottledFileDigester.fs2DigestFile(onDisk, null).equals(f.hash)) return false;
} catch (Exception e) {
Logger.warn("Couldn't test for file completion on disk: " + e);
Logger.log(e);
return false;
}
return true; // it's already complete!
}