public void EnqueueSynchronization(string destination, SynchronizationWorkItem workItem)
{
pendingRemoveLocks.GetOrAdd(destination, new ReaderWriterLockSlim()).EnterUpgradeableReadLock();
try
{
var pendingForDestination = pendingSynchronizations.GetOrAdd(destination,
new ConcurrentQueue<SynchronizationWorkItem>());
// if delete work is enqueued and there are other synchronization works for a given file then remove them from a queue
if (workItem.SynchronizationType == SynchronizationType.Delete &&
pendingForDestination.Any(
x => x.FileName == workItem.FileName && x.SynchronizationType != SynchronizationType.Delete))
{
pendingRemoveLocks.GetOrAdd(destination, new ReaderWriterLockSlim()).EnterWriteLock();
try
{
var modifiedQueue = new ConcurrentQueue<SynchronizationWorkItem>();
foreach (var pendingWork in pendingForDestination)
{
if (pendingWork.FileName != workItem.FileName)
modifiedQueue.Enqueue(pendingWork);
}
modifiedQueue.Enqueue(workItem);
pendingForDestination = pendingSynchronizations.AddOrUpdate(destination, modifiedQueue,
(key, value) => modifiedQueue);
}
finally
{
pendingRemoveLocks.GetOrAdd(destination, new ReaderWriterLockSlim()).ExitWriteLock();
}
}
foreach (var pendingWork in pendingForDestination)
{
// if there is a file in pending synchronizations do not add it again
if (pendingWork.Equals(workItem))
{
Log.Debug("{0} for a file {1} and a destination {2} was already existed in a pending queue",
workItem.GetType().Name, workItem.FileName, destination);
return;
}
// if there is a work for a file of the same type but with lower file ETag just refresh existing work metadata and do not enqueue again
if (pendingWork.FileName == workItem.FileName &&
pendingWork.SynchronizationType == workItem.SynchronizationType &&
Buffers.Compare(workItem.FileETag.ToByteArray(), pendingWork.FileETag.ToByteArray()) > 0)
{
pendingWork.RefreshMetadata();
Log.Debug(
"{0} for a file {1} and a destination {2} was already existed in a pending queue but with older ETag, it's metadata has been refreshed",
workItem.GetType().Name, workItem.FileName, destination);
return;
}
}
var activeForDestination = activeSynchronizations.GetOrAdd(destination,
new ConcurrentDictionary<string, SynchronizationWorkItem>
());
// if there is a work in an active synchronizations do not add it again
if (activeForDestination.ContainsKey(workItem.FileName) && activeForDestination[workItem.FileName].Equals(workItem))
{
Log.Debug("{0} for a file {1} and a destination {2} was already existed in an active queue",
workItem.GetType().Name, workItem.FileName, destination);
return;
}
pendingForDestination.Enqueue(workItem);
Log.Debug("{0} for a file {1} and a destination {2} was enqueued", workItem.GetType().Name, workItem.FileName,
destination);
}
finally
{
pendingRemoveLocks.GetOrAdd(destination, new ReaderWriterLockSlim()).ExitUpgradeableReadLock();
}
}
private async Task<SynchronizationReport> PerformSynchronizationAsync(string destinationUrl,
SynchronizationWorkItem work)
{
Log.Debug("Starting to perform {0} for a file '{1}' and a destination server {2}", work.GetType().Name, work.FileName,
destinationUrl);
if (!CanSynchronizeTo(destinationUrl))
{
Log.Debug("The limit of active synchronizations to {0} server has been achieved. Cannot process a file '{1}'.",
destinationUrl, work.FileName);
synchronizationQueue.EnqueueSynchronization(destinationUrl, work);
return new SynchronizationReport(work.FileName, work.FileETag, work.SynchronizationType)
{
Exception = new SynchronizationException(string.Format(
"The limit of active synchronizations to {0} server has been achieved. Cannot process a file '{1}'.",
destinationUrl, work.FileName))
};
}
string fileName = work.FileName;
synchronizationQueue.SynchronizationStarted(work, destinationUrl);
publisher.Publish(new SynchronizationUpdate
{
FileName = work.FileName,
DestinationServer = destinationUrl,
SourceServerId = storage.Id,
SourceServerUrl = ServerUrl,
Type = work.SynchronizationType,
Action = SynchronizationAction.Start,
SynchronizationDirection = SynchronizationDirection.Outgoing
});
SynchronizationReport report;
try
{
report = await work.PerformAsync(destinationUrl);
}
catch (Exception ex)
{
report = new SynchronizationReport(work.FileName, work.FileETag, work.SynchronizationType)
{
Exception = ex,
};
}
var synchronizationCancelled = false;
if (report.Exception == null)
{
var moreDetails = string.Empty;
if (work.SynchronizationType == SynchronizationType.ContentUpdate)
{
moreDetails = string.Format(". {0} bytes were transfered and {1} bytes copied. Need list length was {2}",
report.BytesTransfered, report.BytesCopied, report.NeedListLength);
}
Log.Debug("{0} to {1} has finished successfully{2}", work.ToString(), destinationUrl, moreDetails);
}
else
{
if (work.IsCancelled || report.Exception is TaskCanceledException)
{
synchronizationCancelled = true;
Log.DebugException(string.Format("{0} to {1} was cancelled", work, destinationUrl), report.Exception);
}
else
{
Log.WarnException(string.Format("{0} to {1} has finished with the exception", work, destinationUrl),
report.Exception);
}
}
Queue.SynchronizationFinished(work, destinationUrl);
if (!synchronizationCancelled)
CreateSyncingConfiguration(fileName, work.FileETag, destinationUrl, work.SynchronizationType);
publisher.Publish(new SynchronizationUpdate
{
FileName = work.FileName,
DestinationServer = destinationUrl,
SourceServerId = storage.Id,
SourceServerUrl = ServerUrl,
Type = work.SynchronizationType,
Action = SynchronizationAction.Finish,
SynchronizationDirection = SynchronizationDirection.Outgoing
});
return report;
}