Modified selective sync to propagate the creation of new local directories and their...
[pithos-ms-client] / trunk / Pithos.Core / Agents / NetworkAgent.cs
index 36e2a63..6431ffe 100644 (file)
  */
 #endregion
 
-//TODO: Now there is a UUID tag. This can be used for renames/moves
-
-
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.ComponentModel.Composition;
 using System.Diagnostics;
@@ -52,9 +48,9 @@ using System.Diagnostics.Contracts;
 using System.IO;
 using System.Linq;
 using System.Net;
+using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Threading.Tasks.Dataflow;
 using Castle.ActiveRecord;
 using Pithos.Interfaces;
 using Pithos.Network;
@@ -62,46 +58,117 @@ using log4net;
 
 namespace Pithos.Core.Agents
 {
-    //TODO: Ensure all network operations use exact casing. Pithos is case sensitive
     [Export]
     public class NetworkAgent
     {
+        private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
         private Agent<CloudAction> _agent;
 
         [System.ComponentModel.Composition.Import]
-        private DeleteAgent _deleteAgent=new DeleteAgent();
+        private DeleteAgent DeleteAgent { get; set; }
 
         [System.ComponentModel.Composition.Import]
         public IStatusKeeper StatusKeeper { get; set; }
-        
-        public IStatusNotification StatusNotification { get; set; }
 
-        private static readonly ILog Log = LogManager.GetLogger("NetworkAgent");
+        private IStatusNotification _statusNotification;
+        public IStatusNotification StatusNotification
+        {
+            get { return _statusNotification; }
+            set
+            {
+                _statusNotification = value;
+                DeleteAgent.StatusNotification = value;
+                Uploader.StatusNotification = value;
+                Downloader.StatusNotification = value;
+            }
+        }
 
-        private readonly ConcurrentBag<AccountInfo> _accounts = new ConcurrentBag<AccountInfo>();
 
         [System.ComponentModel.Composition.Import]
         public IPithosSettings Settings { get; set; }
 
+        private Uploader _uploader;
+
+        [System.ComponentModel.Composition.Import]
+        public Uploader Uploader
+        {
+            get { return _uploader; }
+            set
+            {
+                _uploader = value;
+                _uploader.UnpauseEvent = _unPauseEvent;                
+            }
+        }
+
+        private Downloader _downloader;
+
+        [System.ComponentModel.Composition.Import]
+        public Downloader Downloader
+        {
+            get { return _downloader; }
+            set
+            {
+                _downloader = value;
+                _downloader.UnpauseEvent = _unPauseEvent;
+            }
+        }
+
+        [System.ComponentModel.Composition.Import]
+        public Selectives Selectives { get; set; }
+        
         //The Proceed signals the poll agent that it can proceed with polling. 
         //Essentially it stops the poll agent to give priority to the network agent
         //Initially the event is signalled because we don't need to pause
         private readonly AsyncManualResetEvent _proceedEvent = new AsyncManualResetEvent(true);
+        private Agents.Selectives _selectives;
+        private bool _pause;
 
         public AsyncManualResetEvent ProceedEvent
         {
             get { return _proceedEvent; }
         }
 
+        private readonly AsyncManualResetEvent _unPauseEvent = new AsyncManualResetEvent(true);
+
+        private CancellationTokenSource _currentOperationCancellation=new CancellationTokenSource();
+
+        public void CancelCurrentOperation()
+        {
+            //What does it mean to cancel the current upload/download?
+            //Obviously, the current operation will be cancelled by throwing
+            //a cancellation exception.
+            //
+            //The default behavior is to retry any operations that throw.
+            //Obviously this is not what we want in this situation.
+            //The cancelled operation should NOT bea retried. 
+            //
+            //This can be done by catching the cancellation exception
+            //and avoiding the retry.
+            //
+
+            //Have to reset the cancellation source - it is not possible to reset the source
+            //Have to prevent a case where an operation requests a token from the old source
+            var oldSource = Interlocked.Exchange(ref _currentOperationCancellation, new CancellationTokenSource());
+            oldSource.Cancel();
+            
+        }
 
         public void Start()
         {
+            if (_agent != null)
+                return;
+
+            if (Log.IsDebugEnabled)
+                Log.Debug("Starting Network Agent");
+
             _agent = Agent<CloudAction>.Start(inbox =>
             {
                 Action loop = null;
                 loop = () =>
                 {
-                    _deleteAgent.ProceedEvent.Wait();
+                    DeleteAgent.ProceedEvent.Wait();
+                    _unPauseEvent.Wait();
                     var message = inbox.Receive();
                     var process=message.Then(Process,inbox.CancellationToken);
                     inbox.LoopAsync(process, loop);
@@ -122,29 +189,29 @@ namespace Pithos.Core.Agents
 
 
 
-            using (log4net.ThreadContext.Stacks["NETWORK"].Push("PROCESS"))
+            using (ThreadContext.Stacks["Operation"].Push(action.ToString()))
             {                
-                Log.InfoFormat("[ACTION] Start Processing {0}", action);
 
                 var cloudFile = action.CloudFile;
                 var downloadPath = action.GetDownloadPath();
 
                 try
                 {
+                    StatusNotification.SetPithosStatus(PithosStatus.LocalSyncing,"Processing");
                     _proceedEvent.Reset();
-                    UpdateStatus(PithosStatus.Syncing);
+                    
                     var accountInfo = action.AccountInfo;
 
                     if (action.Action == CloudActionType.DeleteCloud)
                     {                        
                         //Redirect deletes to the delete agent 
-                        _deleteAgent.Post((CloudDeleteAction)action);
+                        DeleteAgent.Post((CloudDeleteAction)action);
                     }
-                    if (_deleteAgent.IsDeletedFile(action))
+                    if (DeleteAgent.IsDeletedFile(action))
                     {
                         //Clear the status of already deleted files to avoid reprocessing
                         if (action.LocalFile != null)
-                            this.StatusKeeper.ClearFileStatus(action.LocalFile.FullName);
+                            StatusKeeper.ClearFileStatus(action.LocalFile.FullName);
                     }
                     else
                     {
@@ -152,19 +219,24 @@ namespace Pithos.Core.Agents
                         {
                             case CloudActionType.UploadUnconditional:
                                 //Abort if the file was deleted before we reached this point
-                                await UploadCloudFile(action);
+                                var uploadAction = (CloudUploadAction) action;
+                                ProcessChildUploads(uploadAction);
+                                await Uploader.UploadCloudFile(uploadAction ,CurrentOperationCancelToken);
                                 break;
                             case CloudActionType.DownloadUnconditional:
-                                await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
+                                await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
                                 break;
                             case CloudActionType.RenameCloud:
                                 var moveAction = (CloudMoveAction)action;
                                 RenameCloudFile(accountInfo, moveAction);
                                 break;
+                            case CloudActionType.RenameLocal:
+                                RenameLocalFile(accountInfo, action);
+                                break;
                             case CloudActionType.MustSynch:
                                 if (!File.Exists(downloadPath) && !Directory.Exists(downloadPath))
                                 {
-                                    await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
+                                    await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
                                 }
                                 else
                                 {
@@ -173,16 +245,27 @@ namespace Pithos.Core.Agents
                                 break;
                         }
                     }
-                    Log.InfoFormat("[ACTION] End Processing {0}:{1}->{2}", action.Action, action.LocalFile,
+                    Log.InfoFormat("End Processing {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);
+                    
+                    
+                    //Actions that resulted in server errors should be retried                    
+                    var response = exc.Response as HttpWebResponse;
+                    if (response != null && response.StatusCode >= HttpStatusCode.InternalServerError)
+                    {
+                        _agent.Post(action);
+                        Log.WarnFormat("[REQUEUE] {0} : {1} -> {2}", action.Action, action.LocalFile, action.CloudFile);
+                    }
                 }
-                catch (OperationCanceledException)
-                {
-                    throw;
+*/
+                catch (OperationCanceledException ex)
+                {                    
+                    Log.WarnFormat("Cancelling [{0}]",ex);
                 }
                 catch (DirectoryNotFoundException)
                 {
@@ -209,18 +292,110 @@ namespace Pithos.Core.Agents
                 {
                     if (_agent.IsEmpty)
                         _proceedEvent.Set();
-                    UpdateStatus(PithosStatus.InSynch);                                        
+                    UpdateStatus(PithosStatus.LocalComplete);                                        
                 }
             }
         }
 
+        private void ProcessChildUploads(CloudUploadAction uploadAction)
+        {
+            if (!uploadAction.IsCreation || !(uploadAction.LocalFile is DirectoryInfo)) 
+                return;
+
+            var dirInfo = uploadAction.LocalFile as DirectoryInfo;
+
+            var account = uploadAction.AccountInfo;
+            var actions = from file in dirInfo.EnumerateFiles("*", SearchOption.AllDirectories)
+                          select
+                              new CloudUploadAction(account, file, null, account.BlockSize, account.BlockHash,
+                                                    uploadAction, true);
+            foreach (var action in actions)
+            {
+                var state=StatusKeeper.GetStateByFilePath(action.LocalFile.FullName);
+                if (state!=null)
+                    state.Delete();
+                //StatusKeeper.SetFileState(action.LocalFile.FullName,FileStatus.Created,FileOverlayStatus.Normal,String.Empty);
+                state=FileState.CreateFor(action.LocalFile);
+                //StatusKeeper.SetFileStatus();
+                state.FileStatus = FileStatus.Created;
+                state.OverlayStatus=FileOverlayStatus.Normal;
+                state.Create();
+                action.FileState = state;
+                Post(action);
+            }
+        }
+
+        private CancellationToken CurrentOperationCancelToken
+        {
+            get { return _currentOperationCancellation.Token; }
+        }
+
+
         private void UpdateStatus(PithosStatus status)
         {
-            StatusKeeper.SetPithosStatus(status);
-            StatusNotification.Notify(new Notification());
+            StatusNotification.SetPithosStatus(status);
+            //StatusNotification.Notify(new Notification());
+        }
+
+        private void RenameLocalFile(AccountInfo accountInfo, CloudAction action)
+        {
+            if (accountInfo == null)
+                throw new ArgumentNullException("accountInfo");
+            if (action == null)
+                throw new ArgumentNullException("action");
+            if (action.LocalFile == null)
+                throw new ArgumentException("The action's local file is not specified", "action");
+            if (!Path.IsPathRooted(action.LocalFile.FullName))
+                throw new ArgumentException("The action's local file path must be absolute", "action");
+            if (action.CloudFile == null)
+                throw new ArgumentException("The action's cloud file is not specified", "action");
+            Contract.EndContractBlock();
+            using (ThreadContext.Stacks["Operation"].Push("RenameLocalFile"))
+            {
+
+                //We assume that the local file already exists, otherwise the poll agent
+                //would have issued a download request
+
+                var currentInfo = action.CloudFile;
+                var previousInfo = action.CloudFile.Previous;
+                var fileAgent = FileAgent.GetFileAgent(accountInfo);
+
+                var previousRelativepath = previousInfo.RelativeUrlToFilePath(accountInfo.UserName);
+                var previousFile = fileAgent.GetFileSystemInfo(previousRelativepath);
+
+                //In every case we need to move the local file first
+                MoveLocalFile(accountInfo, previousFile, fileAgent, currentInfo);
+            }
+        }
+
+        private void MoveLocalFile(AccountInfo accountInfo, FileSystemInfo previousFile, FileAgent fileAgent,
+                                   ObjectInfo currentInfo)
+        {
+            var currentRelativepath = currentInfo.RelativeUrlToFilePath(accountInfo.UserName);
+            var newPath = Path.Combine(fileAgent.RootPath, currentRelativepath);
+
+            var isFile= (previousFile is FileInfo);
+            var previousFullPath = isFile? 
+                FileInfoExtensions.GetProperFilePathCapitalization(previousFile.FullName):
+                FileInfoExtensions.GetProperDirectoryCapitalization(previousFile.FullName);                
+            
+            using (NetworkGate.Acquire(previousFullPath, NetworkOperation.Renaming))
+            using (NetworkGate.Acquire(newPath,NetworkOperation.Renaming)) 
+            using (new SessionScope(FlushAction.Auto))
+            {
+                if (isFile)
+                    (previousFile as FileInfo).MoveTo(newPath);
+                else
+                {
+                    (previousFile as DirectoryInfo).MoveTo(newPath);
+                }
+                var state = StatusKeeper.GetStateByFilePath(previousFullPath);
+                state.FilePath = newPath;
+                state.SaveCopy();
+                StatusKeeper.SetFileState(previousFullPath,FileStatus.Deleted,FileOverlayStatus.Deleted, "Deleted");
+            }            
         }
 
-        
         private async Task SyncFiles(AccountInfo accountInfo,CloudAction action)
         {
             if (accountInfo == null)
@@ -234,51 +409,66 @@ namespace Pithos.Core.Agents
             if (action.CloudFile== null)
                 throw new ArgumentException("The action's cloud file is not specified", "action");
             Contract.EndContractBlock();
+            using (ThreadContext.Stacks["Operation"].Push("SyncFiles"))
+            {
 
-            var localFile = action.LocalFile;
-            var cloudFile = action.CloudFile;
-            var downloadPath=action.LocalFile.GetProperCapitalization();
+                //var localFile = action.LocalFile;
+                var cloudFile = action.CloudFile;
+                var downloadPath = action.LocalFile.GetProperCapitalization();
 
-            var cloudHash = cloudFile.Hash.ToLower();
-            string previousCloudHash = cloudFile.PreviousHash.ToLower();
-            var localHash = action.LocalHash.Value.ToLower();
-            var topHash = action.TopHash.Value.ToLower();
+                var cloudHash = cloudFile.Hash.ToLower();
+                var previousCloudHash = cloudFile.PreviousHash == null?null: cloudFile.PreviousHash.ToLower();
+                var localHash = action.TreeHash.Value.TopHash.ToHashString();// LocalHash.Value.ToLower();
+                //var topHash = action.TopHash.Value.ToLower();
 
-            //At this point we know that an object has changed on the server and that a local
-            //file already exists. We need to decide whether the file has only changed on 
-            //the server or there is a conflicting change on the client.
-            //
-            
-            //Not enough to compare only the local hashes (MD5), also have to compare the tophashes            
-            //If any of the hashes match, we are done
-            if ((cloudHash == localHash || cloudHash == topHash))
-            {
-                Log.InfoFormat("Skipping {0}, hashes match",downloadPath);
-                return;
-            }
+                if(cloudFile.IsDirectory && action.LocalFile is DirectoryInfo)
+                {
+                    Log.InfoFormat("Skipping folder {0} , exists in server", downloadPath);
+                    return;
+                }
 
-            //The hashes DON'T match. We need to sync
+                //At this point we know that an object has changed on the server and that a local
+                //file already exists. We need to decide whether the file has only changed on 
+                //the server or there is a conflicting change on the client.
+                //
 
-            // If the previous tophash matches the local tophash, the file was only changed on the server. 
-            if (localHash == previousCloudHash)
-            {
-                await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
-            }
-            else
-            {
-                //If the previous and local hash don't match, there was a local conflict
-                //that was not uploaded to the server. We have a conflict
-                ReportConflict(downloadPath);
+                //If the hashes match, we are done
+                if (cloudFile != ObjectInfo.Empty && cloudHash == localHash)
+                {
+                    Log.InfoFormat("Skipping {0}, hashes match", downloadPath);
+                    return;
+                }
+
+                //If the local and remote files have 0 length their hashes will not match
+                if (!cloudFile.IsDirectory && cloudFile.Bytes==0 && action.LocalFile is FileInfo && (action.LocalFile as FileInfo).Length==0 )
+                {
+                    Log.InfoFormat("Skipping {0}, files are empty", downloadPath);
+                    return;
+                }
+
+                //The hashes DON'T match. We need to sync
+
+                // If the previous tophash matches the local tophash, the file was only changed on the server. 
+                if (localHash == previousCloudHash)
+                {
+                    await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
+                }
+                else
+                {
+                    //If the previous and local hash don't match, there was a local conflict
+                    //that was not uploaded to the server. We have a conflict
+                    ReportConflictForMismatch(downloadPath);
+                }
             }
         }
 
-        private void ReportConflict(string downloadPath)
+        private void ReportConflictForMismatch(string downloadPath)
         {
             if (String.IsNullOrWhiteSpace(downloadPath))
                 throw new ArgumentNullException("downloadPath");
             Contract.EndContractBlock();
 
-            StatusKeeper.SetFileOverlayStatus(downloadPath, FileOverlayStatus.Conflict);
+            StatusKeeper.SetFileState(downloadPath,FileStatus.Conflict, FileOverlayStatus.Conflict,"File changed at the server");
             UpdateStatus(PithosStatus.HasConflicts);
             var message = String.Format("Conflict detected for file {0}", downloadPath);
             Log.Warn(message);
@@ -293,32 +483,10 @@ namespace Pithos.Core.Agents
                 throw new ArgumentException("The CloudAction.AccountInfo is empty","cloudAction");
             Contract.EndContractBlock();
 
-            _deleteAgent.ProceedEvent.Wait();
-
-            //If the action targets a local file, add a treehash calculation
-            if (!(cloudAction is CloudDeleteAction) && cloudAction.LocalFile as FileInfo != null)
-            {
-                var accountInfo = cloudAction.AccountInfo;
-                var localFile = (FileInfo) cloudAction.LocalFile;
-                if (localFile.Length > accountInfo.BlockSize)
-                    cloudAction.TopHash =
-                        new Lazy<string>(() => Signature.CalculateTreeHashAsync(localFile,
-                                                                                accountInfo.BlockSize,
-                                                                                accountInfo.BlockHash, Settings.HashingParallelism).Result
-                                                    .TopHash.ToHashString());
-                else
-                {
-                    cloudAction.TopHash = new Lazy<string>(() => cloudAction.LocalHash.Value);
-                }
-            }
-            else
-            {
-                //The hash for a directory is the empty string
-                cloudAction.TopHash = new Lazy<string>(() => String.Empty);
-            }
+            DeleteAgent.ProceedEvent.Wait();
             
             if (cloudAction is CloudDeleteAction)
-                _deleteAgent.Post((CloudDeleteAction)cloudAction);
+                DeleteAgent.Post((CloudDeleteAction)cloudAction);
             else
                 _agent.Post(cloudAction);
         }
@@ -331,20 +499,30 @@ namespace Pithos.Core.Agents
 
         public Task GetDeleteAwaiter()
         {
-            return _deleteAgent.ProceedEvent.WaitAsync();
+            return DeleteAgent.ProceedEvent.WaitAsync();
         }
         public CancellationToken CancellationToken
         {
             get { return _agent.CancellationToken; }
         }
 
-        private static FileAgent GetFileAgent(AccountInfo accountInfo)
+        public bool Pause
         {
-            return AgentLocator<FileAgent>.Get(accountInfo.AccountPath);
+            get {
+                return _pause;
+            }
+            set {
+                _pause = value;
+                if (_pause)
+                    _unPauseEvent.Reset();
+                else
+                {
+                    _unPauseEvent.Set();
+                }
+            }
         }
 
 
-
         private void RenameCloudFile(AccountInfo accountInfo,CloudMoveAction action)
         {
             if (accountInfo==null)
@@ -360,443 +538,44 @@ namespace Pithos.Core.Agents
             if (action.OldCloudFile==null)
                 throw new ArgumentException("OldCloudFile","action");
             Contract.EndContractBlock();
-            
-            
-            var newFilePath = action.LocalFile.FullName;
-            
-            //How do we handle concurrent renames and deletes/uploads/downloads?
-            //* A conflicting upload means that a file was renamed before it had a chance to finish uploading
-            //  This should never happen as the network agent executes only one action at a time
-            //* A conflicting download means that the file was modified on the cloud. While we can go on and complete
-            //  the rename, there may be a problem if the file is downloaded in blocks, as subsequent block requests for the 
-            //  same name will fail.
-            //  This should never happen as the network agent executes only one action at a time.
-            //* A conflicting delete can happen if the rename was followed by a delete action that didn't have the chance
-            //  to remove the rename from the queue.
-            //  We can probably ignore this case. It will result in an error which should be ignored            
-
-            
-            //The local file is already renamed
-            StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Modified);
-
-
-            var account = action.CloudFile.Account ?? accountInfo.UserName;
-            var container = action.CloudFile.Container;
-            
-            var client = new CloudFilesClient(accountInfo);
-            //TODO: What code is returned when the source file doesn't exist?
-            client.MoveObject(account, container, action.OldCloudFile.Name, container, action.CloudFile.Name);
-
-            StatusKeeper.SetFileStatus(newFilePath, FileStatus.Unchanged);
-            StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Normal);
-            NativeMethods.RaiseChangeNotification(newFilePath);
-        }
-
-        //Download a file.
-        private async Task DownloadCloudFile(AccountInfo accountInfo, ObjectInfo cloudFile , string filePath)
-        {
-            if (accountInfo == null)
-                throw new ArgumentNullException("accountInfo");
-            if (cloudFile == null)
-                throw new ArgumentNullException("cloudFile");
-            if (String.IsNullOrWhiteSpace(cloudFile.Account))
-                throw new ArgumentNullException("cloudFile");
-            if (String.IsNullOrWhiteSpace(cloudFile.Container))
-                throw new ArgumentNullException("cloudFile");
-            if (String.IsNullOrWhiteSpace(filePath))
-                throw new ArgumentNullException("filePath");
-            if (!Path.IsPathRooted(filePath))
-                throw new ArgumentException("The filePath must be rooted", "filePath");
-            Contract.EndContractBlock();
-            
-
-            var localPath = Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
-            var relativeUrl = new Uri(cloudFile.Name, UriKind.Relative);
-
-            var url = relativeUrl.ToString();
-            if (cloudFile.Name.EndsWith(".ignore", StringComparison.InvariantCultureIgnoreCase))
-                return;
-
-
-            //Are we already downloading or uploading the file? 
-            using (var gate=NetworkGate.Acquire(localPath, NetworkOperation.Downloading))
-            {
-                if (gate.Failed)
-                    return;
-                
-                var client = new CloudFilesClient(accountInfo);
-                var account = cloudFile.Account;
-                var container = cloudFile.Container;
-
-                if (cloudFile.Content_Type == @"application/directory")
-                {
-                    if (!Directory.Exists(localPath))
-                        Directory.CreateDirectory(localPath);
-                }
-                else
-                {                    
-                    //Retrieve the hashmap from the server
-                    var serverHash = await client.GetHashMap(account, container, url);
-                    //If it's a small file
-                    if (serverHash.Hashes.Count == 1)
-                        //Download it in one go
-                        await
-                            DownloadEntireFileAsync(accountInfo, client, cloudFile, relativeUrl, localPath, serverHash);
-                        //Otherwise download it block by block
-                    else
-                        await DownloadWithBlocks(accountInfo, client, cloudFile, relativeUrl, localPath, serverHash);
-
-                    if (cloudFile.AllowedTo == "read")
-                    {
-                        var attributes = File.GetAttributes(localPath);
-                        File.SetAttributes(localPath, attributes | FileAttributes.ReadOnly);                        
-                    }
-                }
-
-                //Now we can store the object's metadata without worrying about ghost status entries
-                StatusKeeper.StoreInfo(localPath, cloudFile);
-                
-            }
-        }
-
-        //Download a small file with a single GET operation
-        private async Task DownloadEntireFileAsync(AccountInfo accountInfo, CloudFilesClient client, ObjectInfo cloudFile, Uri relativeUrl, string filePath,TreeHash serverHash)
-        {
-            if (client == null)
-                throw new ArgumentNullException("client");
-            if (cloudFile==null)
-                throw new ArgumentNullException("cloudFile");
-            if (relativeUrl == null)
-                throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(filePath))
-                throw new ArgumentNullException("filePath");
-            if (!Path.IsPathRooted(filePath))
-                throw new ArgumentException("The localPath must be rooted", "filePath");
-            Contract.EndContractBlock();
 
-            var localPath = Pithos.Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
-            //If the file already exists
-            if (File.Exists(localPath))
+            using (ThreadContext.Stacks["Operation"].Push("RenameCloudFile"))
             {
-                //First check with MD5 as this is a small file
-                var localMD5 = Signature.CalculateMD5(localPath);
-                var cloudHash=serverHash.TopHash.ToHashString();
-                if (localMD5==cloudHash)
-                    return;
-                //Then check with a treehash
-                var localTreeHash = Signature.CalculateTreeHash(localPath, serverHash.BlockSize, serverHash.BlockHash);
-                var localHash = localTreeHash.TopHash.ToHashString();
-                if (localHash==cloudHash)
-                    return;
-            }
-            StatusNotification.Notify(new CloudNotification { Data = cloudFile });
-
-            var fileAgent = GetFileAgent(accountInfo);
-            //Calculate the relative file path for the new file
-            var relativePath = relativeUrl.RelativeUriToFilePath();
-            //The file will be stored in a temporary location while downloading with an extension .download
-            var tempPath = Path.Combine(fileAgent.CachePath, relativePath + ".download");
-            //Make sure the target folder exists. DownloadFileTask will not create the folder
-            var tempFolder = Path.GetDirectoryName(tempPath);
-            if (!Directory.Exists(tempFolder))
-                Directory.CreateDirectory(tempFolder);
-
-            //Download the object to the temporary location
-            await client.GetObject(cloudFile.Account, cloudFile.Container, relativeUrl.ToString(), tempPath);
-
-            //Create the local folder if it doesn't exist (necessary for shared objects)
-            var localFolder = Path.GetDirectoryName(localPath);
-            if (!Directory.Exists(localFolder))
-                Directory.CreateDirectory(localFolder);            
-            //And move it to its actual location once downloading is finished
-            if (File.Exists(localPath))
-                File.Replace(tempPath,localPath,null,true);
-            else
-                File.Move(tempPath,localPath);
-            //Notify listeners that a local file has changed
-            StatusNotification.NotifyChangedFile(localPath);
 
-                       
-        }
+                var newFilePath = action.LocalFile.FullName;
 
-        //Download a file asynchronously using blocks
-        public async Task DownloadWithBlocks(AccountInfo accountInfo, CloudFilesClient client, ObjectInfo cloudFile, Uri relativeUrl, string filePath, TreeHash serverHash)
-        {
-            if (client == null)
-                throw new ArgumentNullException("client");
-            if (cloudFile == null)
-                throw new ArgumentNullException("cloudFile");
-            if (relativeUrl == null)
-                throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(filePath))
-                throw new ArgumentNullException("filePath");
-            if (!Path.IsPathRooted(filePath))
-                throw new ArgumentException("The filePath must be rooted", "filePath");
-            if (serverHash == null)
-                throw new ArgumentNullException("serverHash");
-            Contract.EndContractBlock();
-            
-           var fileAgent = GetFileAgent(accountInfo);
-            var localPath = Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
-            
-            //Calculate the relative file path for the new file
-            var relativePath = relativeUrl.RelativeUriToFilePath();
-            var blockUpdater = new BlockUpdater(fileAgent.CachePath, localPath, relativePath, serverHash);
+                //How do we handle concurrent renames and deletes/uploads/downloads?
+                //* A conflicting upload means that a file was renamed before it had a chance to finish uploading
+                //  This should never happen as the network agent executes only one action at a time
+                //* A conflicting download means that the file was modified on the cloud. While we can go on and complete
+                //  the rename, there may be a problem if the file is downloaded in blocks, as subsequent block requests for the 
+                //  same name will fail.
+                //  This should never happen as the network agent executes only one action at a time.
+                //* A conflicting delete can happen if the rename was followed by a delete action that didn't have the chance
+                //  to remove the rename from the queue.
+                //  We can probably ignore this case. It will result in an error which should be ignored            
 
-            
-                        
-            //Calculate the file's treehash
-            var treeHash = await Signature.CalculateTreeHashAsync(localPath, serverHash.BlockSize, serverHash.BlockHash, 2);
-                
-            //And compare it with the server's hash
-            var upHashes = serverHash.GetHashesAsStrings();
-            var localHashes = treeHash.HashDictionary;
-            for (int i = 0; i < upHashes.Length; i++)
-            {
-                //For every non-matching hash
-                var upHash = upHashes[i];
-                if (!localHashes.ContainsKey(upHash))
-                {
-                    StatusNotification.Notify(new CloudNotification { Data = cloudFile });
 
-                    if (blockUpdater.UseOrphan(i, upHash))
-                    {
-                        Log.InfoFormat("[BLOCK GET] ORPHAN FOUND for {0} of {1} for {2}", i, upHashes.Length, localPath);
-                        continue;
-                    }
-                    Log.InfoFormat("[BLOCK GET] START {0} of {1} for {2}", i, upHashes.Length, localPath);
-                    var start = i*serverHash.BlockSize;
-                    //To download the last block just pass a null for the end of the range
-                    long? end = null;
-                    if (i < upHashes.Length - 1 )
-                        end= ((i + 1)*serverHash.BlockSize) ;
-                            
-                    //Download the missing block
-                    var block = await client.GetBlock(cloudFile.Account, cloudFile.Container, relativeUrl, start, end);
+                //The local file is already renamed
+                StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Modified).Wait();
 
-                    //and store it
-                    blockUpdater.StoreBlock(i, block);
-
-
-                    Log.InfoFormat("[BLOCK GET] FINISH {0} of {1} for {2}", i, upHashes.Length, localPath);
-                }
-            }
-
-            //Want to avoid notifications if no changes were made
-            var hasChanges = blockUpdater.HasBlocks;
-            blockUpdater.Commit();
-            
-            if (hasChanges)
-                //Notify listeners that a local file has changed
-                StatusNotification.NotifyChangedFile(localPath);
-
-            Log.InfoFormat("[BLOCK GET] COMPLETE {0}", localPath);            
-        }
-
-
-        private async Task UploadCloudFile(CloudAction action)
-        {
-            if (action == null)
-                throw new ArgumentNullException("action");           
-            Contract.EndContractBlock();
-
-            try
-            {                
-                var accountInfo = action.AccountInfo;
-
-                var fileInfo = action.LocalFile;
-
-                if (fileInfo.Extension.Equals("ignore", StringComparison.InvariantCultureIgnoreCase))
-                    return;
-                
-                var relativePath = fileInfo.AsRelativeTo(accountInfo.AccountPath);
-                if (relativePath.StartsWith(FolderConstants.OthersFolder))
-                {
-                    var parts = relativePath.Split('\\');
-                    var accountName = parts[1];
-                    var oldName = accountInfo.UserName;
-                    var absoluteUri = accountInfo.StorageUri.AbsoluteUri;
-                    var nameIndex = absoluteUri.IndexOf(oldName);
-                    var root = absoluteUri.Substring(0, nameIndex);
-
-                    accountInfo = new AccountInfo
-                    {
-                        UserName = accountName,
-                        AccountPath = Path.Combine(accountInfo.AccountPath, parts[0], parts[1]),
-                        StorageUri = new Uri(root + accountName),
-                        BlockHash = accountInfo.BlockHash,
-                        BlockSize = accountInfo.BlockSize,
-                        Token = accountInfo.Token
-                    };
-                }
-
-
-                var fullFileName = fileInfo.GetProperCapitalization();
-                using (var gate = NetworkGate.Acquire(fullFileName, NetworkOperation.Uploading))
-                {
-                    //Abort if the file is already being uploaded or downloaded
-                    if (gate.Failed)
-                        return;
-
-                    var cloudFile = action.CloudFile;
-                    var account = cloudFile.Account ?? accountInfo.UserName;
-
-                    var client = new CloudFilesClient(accountInfo);                    
-                    //Even if GetObjectInfo times out, we can proceed with the upload            
-                    var info = client.GetObjectInfo(account, cloudFile.Container, cloudFile.Name);
-
-                    //If this is a read-only file, do not upload changes
-                    if (info.AllowedTo == "read")
-                        return;
-                    
-                    //TODO: Check how a directory hash is calculated -> All dirs seem to have the same hash
-                    if (fileInfo is DirectoryInfo)
-                    {
-                        //If the directory doesn't exist the Hash property will be empty
-                        if (String.IsNullOrWhiteSpace(info.Hash))
-                            //Go on and create the directory
-                            await client.PutObject(account, cloudFile.Container, cloudFile.Name, fullFileName, String.Empty, "application/directory");
-                    }
-                    else
-                    {
-
-                        var cloudHash = info.Hash.ToLower();
-
-                        var hash = action.LocalHash.Value;
-                        var topHash = action.TopHash.Value;
-
-                        //If the file hashes match, abort the upload
-                        if (hash == cloudHash || topHash == cloudHash)
-                        {
-                            //but store any metadata changes 
-                            StatusKeeper.StoreInfo(fullFileName, info);
-                            Log.InfoFormat("Skip upload of {0}, hashes match", fullFileName);
-                            return;
-                        }
-
-
-                        //Mark the file as modified while we upload it
-                        StatusKeeper.SetFileOverlayStatus(fullFileName, FileOverlayStatus.Modified);
-                        //And then upload it
-
-                        //Upload even small files using the Hashmap. The server may already contain
-                        //the relevant block
-
-                        //First, calculate the tree hash
-                        var treeHash = await Signature.CalculateTreeHashAsync(fullFileName, accountInfo.BlockSize,
-                                                                              accountInfo.BlockHash, 2);
-
-                        await UploadWithHashMap(accountInfo, cloudFile, fileInfo as FileInfo, cloudFile.Name, treeHash);
-                    }
-                    //If everything succeeds, change the file and overlay status to normal
-                    StatusKeeper.SetFileState(fullFileName, FileStatus.Unchanged, FileOverlayStatus.Normal);
-                }
-                //Notify the Shell to update the overlays
-                NativeMethods.RaiseChangeNotification(fullFileName);
-                StatusNotification.NotifyChangedFile(fullFileName);
-            }
-            catch (AggregateException ex)
-            {
-                var exc = ex.InnerException as WebException;
-                if (exc == null)
-                    throw ex.InnerException;
-                if (HandleUploadWebException(action, exc)) 
-                    return;
-                throw;
-            }
-            catch (WebException ex)
-            {
-                if (HandleUploadWebException(action, ex))
-                    return;
-                throw;
-            }
-            catch (Exception ex)
-            {
-                Log.Error("Unexpected error while uploading file", ex);
-                throw;
-            }
-
-        }
 
+                var account = action.CloudFile.Account ?? accountInfo.UserName;
+                var container = action.CloudFile.Container;
 
+                var client = new CloudFilesClient(accountInfo);
+                //TODO: What code is returned when the source file doesn't exist?
+                client.MoveObject(account, container, action.OldCloudFile.Name, container, action.CloudFile.Name);
 
-        private bool HandleUploadWebException(CloudAction action, WebException exc)
-        {
-            var response = exc.Response as HttpWebResponse;
-            if (response == null)
-                throw exc;
-            if (response.StatusCode == HttpStatusCode.Unauthorized)
-            {
-                Log.Error("Not allowed to upload file", exc);
-                var message = String.Format("Not allowed to uplad file {0}", action.LocalFile.FullName);
-                StatusKeeper.SetFileState(action.LocalFile.FullName, FileStatus.Unchanged, FileOverlayStatus.Normal);
-                StatusNotification.NotifyChange(message, TraceLevel.Warning);
-                return true;
+                StatusKeeper.SetFileStatus(newFilePath, FileStatus.Unchanged);
+                StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Normal).Wait();
+                NativeMethods.RaiseChangeNotification(newFilePath);
             }
-            return false;
         }
 
-        public async Task UploadWithHashMap(AccountInfo accountInfo,ObjectInfo cloudFile,FileInfo fileInfo,string url,TreeHash treeHash)
-        {
-            if (accountInfo == null)
-                throw new ArgumentNullException("accountInfo");
-            if (cloudFile==null)
-                throw new ArgumentNullException("cloudFile");
-            if (fileInfo == null)
-                throw new ArgumentNullException("fileInfo");
-            if (String.IsNullOrWhiteSpace(url))
-                throw new ArgumentNullException(url);
-            if (treeHash==null)
-                throw new ArgumentNullException("treeHash");
-            if (String.IsNullOrWhiteSpace(cloudFile.Container) )
-                throw new ArgumentException("Invalid container","cloudFile");
-            Contract.EndContractBlock();
-
-            var fullFileName = fileInfo.GetProperCapitalization();
-
-            var account = cloudFile.Account ?? accountInfo.UserName;
-            var container = cloudFile.Container ;
-
-            var client = new CloudFilesClient(accountInfo);
-            //Send the hashmap to the server            
-            var missingHashes =  await client.PutHashMap(account, container, url, treeHash);
-            //If the server returns no missing hashes, we are done
-            while (missingHashes.Count > 0)
-            {
-
-                var buffer = new byte[accountInfo.BlockSize];
-                foreach (var missingHash in missingHashes)
-                {
-                    //Find the proper block
-                    var blockIndex = treeHash.HashDictionary[missingHash];
-                    var offset = blockIndex*accountInfo.BlockSize;
-
-                    var read = fileInfo.Read(buffer, offset, accountInfo.BlockSize);
-
-                    try
-                    {
-                        //And upload the block                
-                        await client.PostBlock(account, container, buffer, 0, read);
-                        Log.InfoFormat("[BLOCK] Block {0} of {1} uploaded", blockIndex, fullFileName);
-                    }
-                    catch (Exception exc)
-                    {
-                        Log.ErrorFormat("[ERROR] uploading block {0} of {1}\n{2}", blockIndex, fullFileName, exc);
-                    }
-
-                }
-
-                //Repeat until there are no more missing hashes                
-                missingHashes = await client.PutHashMap(account, container, url, treeHash);
-            }
-        }
 
+        
 
-        public void AddAccount(AccountInfo accountInfo)
-        {            
-            if (!_accounts.Contains(accountInfo))
-                _accounts.Add(accountInfo);
-        }
     }