Synnefo » Pithos MS Client

        //A separate agent is used to execute delete actions immediatelly;

        private ActionBlock<CloudDeleteAction> _deleteAgent;

        //TODO: CHECK

        readonly ConcurrentDictionary<string,DateTime> _deletedFiles=new ConcurrentDictionary<string, DateTime>();

        //The Pause event stops the network agent to give priority to the deletion agent

        //Initially the event is signalled because we don't need to pause

        private readonly AsyncManualResetEvent _pauseEvent = new AsyncManualResetEvent(true);

                    _pauseEvent.Wait();

            _deleteAgent = new ActionBlock<CloudDeleteAction>(message =>ProcessDelete(message),new ExecutionDataflowBlockOptions{MaxDegreeOfParallelism=4});

                    if (IsDeletedFile(action))

        /// <summary>

        /// Processes cloud delete actions

        /// </summary>

        /// <param name="action">The delete action to execute</param>

        /// <returns></returns>

        /// <remarks>

        /// When a file/folder is deleted locally, we must delete it ASAP from the server and block any download

        /// operations that may be in progress.

        /// <para>

        /// A separate agent is used to process deletes because the main agent may be busy with a long operation.

        /// </para>

        /// </remarks>

        private void ProcessDelete(CloudDeleteAction action)

        {

            if (action == null)

                throw new ArgumentNullException("action");

            if (action.AccountInfo==null)

                throw new ArgumentException("The action.AccountInfo is empty","action");

            Contract.EndContractBlock();

            var accountInfo = action.AccountInfo;

            using (log4net.ThreadContext.Stacks["NETWORK"].Push("PROCESS"))

            {                

                Log.InfoFormat("[ACTION] Start Processing {0}", action);

                var cloudFile = action.CloudFile;

                try

                {

                    //Acquire a lock on the deleted file to prevent uploading/downloading operations from the normal

                    //agent

                    using (var gate = NetworkGate.Acquire(action.LocalFile.FullName, NetworkOperation.Deleting))

                    {

                        //Add the file URL to the deleted files list

                        var key = GetFileKey(action.CloudFile);

                        _deletedFiles[key] = DateTime.Now;

                        _pauseEvent.Reset();

                        // and then delete the file from the server

                                DeleteCloudFile(accountInfo, cloudFile);

                        Log.InfoFormat("[ACTION] End Delete {0}:{1}->{2}", action.Action, action.LocalFile,

                                       action.CloudFile.Name);

                    }

                }

                catch (WebException exc)

                {

                    Log.ErrorFormat("[WEB ERROR] {0} : {1} -> {2} due to exception\r\n{3}", action.Action, action.LocalFile, action.CloudFile, exc);

                }

                catch (OperationCanceledException)

                {

                    throw;

                }

                catch (DirectoryNotFoundException)

                {

                    Log.ErrorFormat("{0} : {1} -> {2}  failed because the directory was not found.\n Rescheduling a delete",

                        action.Action, action.LocalFile, action.CloudFile);

                    //Repost a delete action for the missing file

                    _deleteAgent.Post(action);

                }

                catch (FileNotFoundException)

                {

                    Log.ErrorFormat("{0} : {1} -> {2}  failed because the file was not found.\n Rescheduling a delete",

                        action.Action, action.LocalFile, action.CloudFile);

                    //Post a delete action for the missing file

                    _deleteAgent.Post(action);

                }

                catch (Exception exc)

                {

                    Log.ErrorFormat("[REQUEUE] {0} : {1} -> {2} due to exception\r\n{3}",

                                     action.Action, action.LocalFile, action.CloudFile, exc);

                    _deleteAgent.Post(action);

                }

                finally

                {

                    //Set the event when all delete actions are processed

                    if (_deleteAgent.InputCount == 0)

                        _pauseEvent.Set();

                }

            }

        }

        private static string GetFileKey(ObjectInfo info)

        {

            var key = String.Format("{0}/{1}/{2}", info.Account, info.Container,info.Name);

            return key;

        }

            _pauseEvent.Wait();

                await _pauseEvent.WaitAsync();

                    await _pauseEvent.WaitAsync();

        private void DeleteCloudFile(AccountInfo accountInfo, ObjectInfo cloudFile)

        {

            if (accountInfo == null)

                throw new ArgumentNullException("accountInfo");

            if (cloudFile==null)

                throw new ArgumentNullException("cloudFile");

            if (String.IsNullOrWhiteSpace(cloudFile.Container))

                throw new ArgumentException("Invalid container", "cloudFile");

            Contract.EndContractBlock();

            var fileAgent = GetFileAgent(accountInfo);

            using ( log4net.ThreadContext.Stacks["DeleteCloudFile"].Push("Delete"))

            {

                var fileName= cloudFile.RelativeUrlToFilePath(accountInfo.UserName);

                var info = fileAgent.GetFileSystemInfo(fileName);                

                var fullPath = info.FullName.ToLower();

                StatusKeeper.SetFileOverlayStatus(fullPath, FileOverlayStatus.Modified);

                var account = cloudFile.Account ?? accountInfo.UserName;

                var container = cloudFile.Container ;//?? FolderConstants.PithosContainer;

                var client = new CloudFilesClient(accountInfo);

                client.DeleteObject(account, container, cloudFile.Name);

                StatusKeeper.ClearFileStatus(fullPath);

            }

        }

        //Returns true if an action concerns a file that was deleted

        private bool IsDeletedFile(CloudAction action)

        {

            //Doesn't work for actions targeting shared files

            if (action.IsShared)

                return false;

            var key = GetFileKey(action.CloudFile);

            DateTime entryDate;

            if (_deletedFiles.TryGetValue(key, out entryDate))

            {

                //If the delete entry was created after this action, abort the action

                if (entryDate > action.Created)

                    return true;

                //Otherwise, remove the stale entry 

                _deletedFiles.TryRemove(key, out entryDate);

            }

            return false;

        }