Changes to delete check order
[pithos-ms-client] / trunk / Pithos.Core / Agents / NetworkAgent.cs
index 7643c45..584532c 100644 (file)
@@ -1,4 +1,42 @@
-using System;
+// -----------------------------------------------------------------------
+// <copyright file="NetworkAgent.cs" company="GRNET">
+// Copyright 2011 GRNET S.A. All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or
+// without modification, are permitted provided that the following
+// conditions are met:
+// 
+//   1. Redistributions of source code must retain the above
+//      copyright notice, this list of conditions and the following
+//      disclaimer.
+// 
+//   2. Redistributions in binary form must reproduce the above
+//      copyright notice, this list of conditions and the following
+//      disclaimer in the documentation and/or other materials
+//      provided with the distribution.
+// 
+// THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+// OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+// 
+// The views and conclusions contained in the software and
+// documentation are those of the authors and should not be
+// interpreted as representing official policies, either expressed
+// or implied, of GRNET S.A.
+// </copyright>
+// -----------------------------------------------------------------------
+
+using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.ComponentModel.Composition;
 using System.Diagnostics;
@@ -6,59 +44,35 @@ using System.Diagnostics.Contracts;
 using System.IO;
 using System.Linq;
 using System.Net;
-using System.Text;
-using System.Threading;
 using System.Threading.Tasks;
+using Castle.ActiveRecord;
 using Pithos.Interfaces;
 using Pithos.Network;
 using log4net;
 
 namespace Pithos.Core.Agents
 {
+    //TODO: Ensure all network operations use exact casing. Pithos is case sensitive
     [Export]
     public class NetworkAgent
     {
         private Agent<CloudAction> _agent;
 
-        [Import]
+        //A separate agent is used to execute delete actions immediatelly;
+        private Agent<CloudDeleteAction> _deleteAgent;
+        readonly ConcurrentDictionary<string,DateTime> _deletedFiles=new ConcurrentDictionary<string, DateTime>();
+
+        [System.ComponentModel.Composition.Import]
         public IStatusKeeper StatusKeeper { get; set; }
         
         public IStatusNotification StatusNotification { get; set; }
-        [Import]
-        public ICloudClient CloudClient { get; set; }
-
-        [Import]
-        public FileAgent FileAgent {get;set;}
-
-        /*
-        [Import]
-        public IPithosWorkflow Workflow { get; set; }
-*/
-
-
-        public string PithosContainer { get; set; }
-        public string TrashContainer { get; private set; }
-        public IList<string> Containers { get; private set; }
 
-        public int BlockSize { get; set; }
-        public string BlockHash { get; set; }
+        private static readonly ILog Log = LogManager.GetLogger("NetworkAgent");
 
-        private static readonly ILog Log = LogManager.GetLogger(typeof(NetworkAgent));
+        private readonly ConcurrentBag<AccountInfo> _accounts = new ConcurrentBag<AccountInfo>();
 
-
-        public void Start(string pithosContainer, string trashContainer, int blockSize, string blockHash)
+        public void Start()
         {
-            if (String.IsNullOrWhiteSpace(pithosContainer))
-                throw new ArgumentNullException("pithosContainer");
-            if (String.IsNullOrWhiteSpace(trashContainer))
-                throw new ArgumentNullException("trashContainer");
-            Contract.EndContractBlock();
-
-            PithosContainer = pithosContainer;
-            TrashContainer = trashContainer;
-            BlockSize = blockSize;
-            BlockHash = blockHash;
-
 
             _agent = Agent<CloudAction>.Start(inbox =>
             {
@@ -71,73 +85,102 @@ namespace Pithos.Core.Agents
                 };
                 loop();
             });
+
+            _deleteAgent = Agent<CloudDeleteAction>.Start(inbox =>
+            {
+                Action loop = null;
+                loop = () =>
+                            {
+                                var message = inbox.Receive();
+                                var process = message.Then(ProcessDelete,inbox.CancellationToken);
+                                inbox.LoopAsync(process, loop);
+                            };
+                loop();
+
+            });
         }
 
-        private Task<object> Process(CloudAction action)
+        private async Task Process(CloudAction action)
         {
             if (action == null)
                 throw new ArgumentNullException("action");
+            if (action.AccountInfo==null)
+                throw new ArgumentException("The action.AccountInfo is empty","action");
             Contract.EndContractBlock();
 
-            using (log4net.LogicalThreadContext.Stacks["NETWORK"].Push("PROCESS"))
+            var accountInfo = action.AccountInfo;
+
+            using (log4net.ThreadContext.Stacks["NETWORK"].Push("PROCESS"))
             {                
-                Log.InfoFormat("[ACTION] Start Processing {0}:{1}->{2}", action.Action, action.LocalFile,
-                               action.CloudFile.Name);
+                Log.InfoFormat("[ACTION] Start Processing {0}", action);
 
-                var localFile = action.LocalFile;
                 var cloudFile = action.CloudFile;
-                var downloadPath = (cloudFile == null)
-                                       ? String.Empty
-                                       : Path.Combine(FileAgent.RootPath, cloudFile.RelativeUrlToFilePath(CloudClient.UserName));
+                var downloadPath = action.GetDownloadPath();
 
                 try
                 {
-                    var account = action.CloudFile.Account ?? CloudClient.UserName;
-                    var container = action.CloudFile.Container ?? PithosContainer;
 
-                    switch (action.Action)
+                    if (action.Action == CloudActionType.DeleteCloud)
                     {
-                        case CloudActionType.UploadUnconditional:
-                            UploadCloudFile(account, container, localFile, action.LocalHash.Value, action.TopHash.Value);
-                            break;
-                        case CloudActionType.DownloadUnconditional:
-
-                            DownloadCloudFile(account, container, new Uri(cloudFile.Name, UriKind.Relative),
-                                              downloadPath);
-                            break;
-                        case CloudActionType.DeleteCloud:
-                            DeleteCloudFile(account, container, cloudFile.Name);
-                            break;
-                        case CloudActionType.RenameCloud:
-                            var moveAction = (CloudMoveAction)action;
-                            RenameCloudFile(account, container, moveAction.OldFileName, moveAction.NewPath,
-                                            moveAction.NewFileName);
-                            break;
-                        case CloudActionType.MustSynch:
-
-                            if (!File.Exists(downloadPath))
-                            {
-                                var cloudUri = new Uri(action.CloudFile.Name, UriKind.Relative);
-                                DownloadCloudFile(account, container, cloudUri, downloadPath);
-                            }
-                            else
-                            {
-                                SyncFiles(action);
-                            }
-                            break;
+                        //Redirect deletes to the delete agent 
+                        _deleteAgent.Post((CloudDeleteAction)action);                        
+                    }
+                    if (IsDeletedFile(action))
+                    {
+                        //Clear the status of already deleted files to avoid reprocessing
+                        this.StatusKeeper.ClearFileStatus(action.LocalFile.FullName);
+                    }
+                    else
+                    {
+                        switch (action.Action)
+                        {
+                            case CloudActionType.UploadUnconditional:
+                                //Abort if the file was deleted before we reached this point
+                                await UploadCloudFile(action);
+                                break;
+                            case CloudActionType.DownloadUnconditional:
+                                await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
+                                break;
+                            case CloudActionType.RenameCloud:
+                                var moveAction = (CloudMoveAction) action;
+                                RenameCloudFile(accountInfo, moveAction);
+                                break;
+                            case CloudActionType.MustSynch:
+                                if (!File.Exists(downloadPath) && !Directory.Exists(downloadPath))
+                                {
+                                    await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
+                                }
+                                else
+                                {
+                                    await SyncFiles(accountInfo, action);
+                                }
+                                break;
+                        }
                     }
                     Log.InfoFormat("[ACTION] 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);
+                }
                 catch (OperationCanceledException)
                 {
                     throw;
                 }
-                catch (System.IO.FileNotFoundException exc)
+                catch (DirectoryNotFoundException)
+                {
+                    Log.ErrorFormat("{0} : {1} -> {2}  failed because the directory was not found.\n Rescheduling a delete",
+                        action.Action, action.LocalFile, action.CloudFile);
+                    //Post a delete action for the missing file
+                    Post(new CloudDeleteAction(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, exc);
-                    Post(new CloudAction(CloudActionType.DeleteCloud,action.CloudFile));
+                        action.Action, action.LocalFile, action.CloudFile);
+                    //Post a delete action for the missing file
+                    Post(new CloudDeleteAction(action));
                 }
                 catch (Exception exc)
                 {
@@ -145,13 +188,97 @@ namespace Pithos.Core.Agents
                                      action.Action, action.LocalFile, action.CloudFile, exc);
 
                     _agent.Post(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 async Task 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;
+
+                        // 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);                    
                 }
-                return CompletedTask<object>.Default;
+                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);
+                }                
             }
         }
 
-        private void SyncFiles(CloudAction action)
+        private static string GetFileKey(ObjectInfo info)
         {
+            var key = String.Format("{0}/{1}/{2}", info.Account, info.Container,info.Name);
+            return key;
+        }
+
+        private async Task SyncFiles(AccountInfo accountInfo,CloudAction action)
+        {
+            if (accountInfo == null)
+                throw new ArgumentNullException("accountInfo");
             if (action==null)
                 throw new ArgumentNullException("action");
             if (action.LocalFile==null)
@@ -164,13 +291,8 @@ namespace Pithos.Core.Agents
 
             var localFile = action.LocalFile;
             var cloudFile = action.CloudFile;
-            var downloadPath=action.LocalFile.FullName.ToLower();
-
-            var account = cloudFile.Account;
-            //Use "pithos" by default if no container is specified
-            var container = cloudFile.Container ?? PithosContainer;
+            var downloadPath=action.LocalFile.GetProperCapitalization();
 
-            var cloudUri = new Uri(cloudFile.Name, UriKind.Relative);
             var cloudHash = cloudFile.Hash.ToLower();
             var localHash = action.LocalHash.Value.ToLower();
             var topHash = action.TopHash.Value.ToLower();
@@ -192,8 +314,7 @@ namespace Pithos.Core.Agents
             if (lastUpTime <= lastLocalTime)
             {
                 //It probably means it was changed while the app was down                        
-                UploadCloudFile(account, container, localFile, action.LocalHash.Value,
-                                action.TopHash.Value);
+                UploadCloudFile(action);
             }
             else
             {
@@ -204,7 +325,7 @@ namespace Pithos.Core.Agents
                 {
                     case FileStatus.Unchanged:                        
                         //If the local file's status is Unchanged, we can go on and download the newer cloud file
-                        DownloadCloudFile(account, container,cloudUri,downloadPath);
+                        await DownloadCloudFile(accountInfo,cloudFile,downloadPath);
                         break;
                     case FileStatus.Modified:
                         //If the local file is Modified, we may have a conflict. In this case we should mark the file as Conflict
@@ -239,60 +360,43 @@ namespace Pithos.Core.Agents
             StatusNotification.NotifyChange(message, TraceLevel.Warning);
         }
 
-/*
-        private Task<object> Process(CloudMoveAction action)
-        {
-            if (action == null)
-                throw new ArgumentNullException("action");
-            Contract.EndContractBlock();
-
-            Trace.TraceInformation("[ACTION] Start Processing {0}:{1}->{2}", action.Action, action.LocalFile, action.CloudFile.Name);
-
-            try
-            {
-                RenameCloudFile(action.OldFileName, action.NewPath, action.NewFileName);
-                Trace.TraceInformation("[ACTION] End Processing {0}:{1}->{2}", action.Action, action.LocalFile, action.CloudFile.Name);
-            }
-            catch (OperationCanceledException)
-            {
-                throw;
-            }
-            catch (Exception exc)
-            {
-                Trace.TraceError("[REQUEUE] {0} : {1} -> {2} due to exception\r\n{3}",
-                                action.Action, action.OldFileName, action.NewFileName, exc);
-
-                _agent.Post(action);
-            }
-            return CompletedTask<object>.Default;
-        }
-*/
-
-
         public void Post(CloudAction cloudAction)
         {
             if (cloudAction == null)
                 throw new ArgumentNullException("cloudAction");
+            if (cloudAction.AccountInfo==null)
+                throw new ArgumentException("The CloudAction.AccountInfo is empty","cloudAction");
             Contract.EndContractBlock();
-            
+
             //If the action targets a local file, add a treehash calculation
-            if (cloudAction.LocalFile != null)
+            if (!(cloudAction is CloudDeleteAction) && cloudAction.LocalFile as FileInfo != null)
             {
-
-                if (cloudAction.LocalFile.Length>BlockSize)
-                    cloudAction.TopHash = new Lazy<string>(() => Signature.CalculateTreeHashAsync(cloudAction.LocalFile, 
-                                    BlockSize, BlockHash).Result
-                                     .TopHash.ToHashString());
+                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).Result
+                                                    .TopHash.ToHashString());
                 else
                 {
-                    cloudAction.TopHash=new Lazy<string>(()=> cloudAction.LocalHash.Value);
+                    cloudAction.TopHash = new Lazy<string>(() => cloudAction.LocalHash.Value);
                 }
-
             }
-            _agent.Post(cloudAction);
+            else
+            {
+                //The hash for a directory is the empty string
+                cloudAction.TopHash = new Lazy<string>(() => String.Empty);
+            }
+            
+            if (cloudAction is CloudDeleteAction)
+                _deleteAgent.Post((CloudDeleteAction)cloudAction);
+            else
+                _agent.Post(cloudAction);
         }
 
-        class ObjectInfoByNameComparer:IEqualityComparer<ObjectInfo>
+       /* class ObjectInfoByNameComparer:IEqualityComparer<ObjectInfo>
         {
             public bool Equals(ObjectInfo x, ObjectInfo y)
             {
@@ -303,71 +407,105 @@ namespace Pithos.Core.Agents
             {
                 return obj.Name.ToLower().GetHashCode();
             }
-        }
+        }*/
+
+        
 
         //Remote files are polled periodically. Any changes are processed
-        public Task ProcessRemoteFiles(string accountPath,DateTime? since=null)
-        {   
-            if (String.IsNullOrWhiteSpace(accountPath))
-                throw new ArgumentNullException(accountPath);
-            Contract.EndContractBlock();
+        public async Task ProcessRemoteFiles(DateTime? since = null)
+        {            
+            await TaskEx.Delay(TimeSpan.FromSeconds(10),_agent.CancellationToken);
 
-            using (log4net.LogicalThreadContext.Stacks["SCHEDULE"].Push("Retrieve Remote"))
+            using (log4net.ThreadContext.Stacks["Retrieve Remote"].Push("All accounts"))
             {
-                Log.Info("[LISTENER] Scheduled");
 
-                //Get the list of server objects changed since the last check
-                var listObjects = Task<IList<ObjectInfo>>.Factory.StartNewDelayed(10000, () =>
-                                CloudClient.ListObjects(CloudClient.UserName, PithosContainer, since));
-                //Get the list of deleted objects since the last check
-                var listTrash = Task<IList<ObjectInfo>>.Factory.StartNewDelayed(10000, () =>
-                                CloudClient.ListObjects(CloudClient.UserName, TrashContainer, since));                
+                try
+                {
+                    //Next time we will check for all changes since the current check minus 1 second
+                    //This is done to ensure there are no discrepancies due to clock differences
+                    DateTime nextSince = DateTime.Now.AddSeconds(-1);
+
+                    var tasks = from accountInfo in _accounts
+                                select ProcessAccountFiles(accountInfo, since);
 
-                var listShared = Task<IList<ObjectInfo>>.Factory.StartNewDelayed(10000, () =>
-                                CloudClient.ListSharedObjects(since));
+                    await TaskEx.WhenAll(tasks.ToList());
 
-                var listAll = Task.Factory.TrackedSequence(
-                    () => listObjects,
-                    () => listTrash,
-                    () => listShared);
+                    ProcessRemoteFiles(nextSince);
+                }
+                catch (Exception ex)
+                {
+                    Log.ErrorFormat("Error while processing accounts\r\n{0}",ex);
+                    //In case of failure retry with the same parameter
+                    ProcessRemoteFiles(since);
+                }
+                
 
-                //Next time we will check for all changes since the current check minus 1 second
-                //This is done to ensure there are no discrepancies due to clock differences
-                DateTime nextSince = DateTime.Now.AddSeconds(-1);
+            }
+        }
 
+        public async Task ProcessAccountFiles(AccountInfo accountInfo,DateTime? since=null)
+        {   
+            if (accountInfo==null)
+                throw new ArgumentNullException("accountInfo");
+            if (String.IsNullOrWhiteSpace(accountInfo.AccountPath))
+                throw new ArgumentException("The AccountInfo.AccountPath is empty","accountInfo");
+            Contract.EndContractBlock();
 
-                var enqueueFiles = listAll.ContinueWith(task =>
+            using (log4net.ThreadContext.Stacks["Retrieve Remote"].Push(accountInfo.UserName))
+            {
+                Log.Info("Scheduled");
+                var client=new CloudFilesClient(accountInfo);
+
+                var containers = client.ListContainers(accountInfo.UserName);
+                
+                CreateContainerFolders(accountInfo, containers);
+
+                try
                 {
-                    if (task.IsFaulted)
-                    {
-                        //ListObjects failed at this point, need to reschedule
-                        Log.ErrorFormat("[FAIL] ListObjects in ProcessRemoteFiles with {0}", task.Exception);
-                        ProcessRemoteFiles(accountPath, since);
-                        return;
-                    }
-                    using (log4net.LogicalThreadContext.Stacks["SCHEDULE"].Push("Process Results"))
+                    
+                    //Get the list of server objects changed since the last check
+                    //The name of the container is passed as state in order to create a dictionary of tasks in a subsequent step
+                    var listObjects = from container in containers
+                                      select  Task<IList<ObjectInfo>>.Factory.StartNew(_ =>
+                                            client.ListObjects(accountInfo.UserName,container.Name, since),container.Name);
+
+
+                    var listTasks = await Task.Factory.WhenAll(listObjects.ToArray());
+
+                    using (log4net.ThreadContext.Stacks["SCHEDULE"].Push("Process Results"))
                     {
-                        var remoteObjects = ((Task<IList<ObjectInfo>>) task.Result[0]).Result;
-                        var trashObjects = ((Task<IList<ObjectInfo>>) task.Result[1]).Result;
-                        var sharedObjects = ((Task<IList<ObjectInfo>>) task.Result[2]).Result;
+                        var dict = listTasks.ToDictionary(t => t.AsyncState);
+
+                        //Get all non-trash objects. Remember, the container name is stored in AsyncState
+                        var remoteObjects = from objectList in listTasks
+                                            where (string) objectList.AsyncState != "trash"
+                                            from obj in objectList.Result
+                                            select obj;
+
+                        var trashObjects = dict["trash"].Result;
+                        //var sharedObjects = ((Task<IList<ObjectInfo>>) task.Result[2]).Result;
 
                         //Items with the same name, hash may be both in the container and the trash
                         //Don't delete items that exist in the container
                         var realTrash = from trash in trashObjects
-                                        where !remoteObjects.Any(info => info.Hash == trash.Hash)
+                                        where
+                                            !remoteObjects.Any(
+                                                info => info.Name == trash.Name && info.Hash == trash.Hash)
                                         select trash;
-                        ProcessDeletedFiles(realTrash);                        
+                        ProcessDeletedFiles(accountInfo, realTrash);
 
 
-                        var remote = from info in remoteObjects.Union(sharedObjects)
+                        var remote = from info in remoteObjects
+                                     //.Union(sharedObjects)
                                      let name = info.Name
                                      where !name.EndsWith(".ignore", StringComparison.InvariantCultureIgnoreCase) &&
-                                           !name.StartsWith("fragments/", StringComparison.InvariantCultureIgnoreCase)
+                                           !name.StartsWith(FolderConstants.CacheFolder + "/",
+                                                            StringComparison.InvariantCultureIgnoreCase)
                                      select info;
 
                         //Create a list of actions from the remote files
-                        var allActions = ObjectsToActions(remote);
-                       
+                        var allActions = ObjectsToActions(accountInfo, remote);
+
                         //And remove those that are already being processed by the agent
                         var distinctActions = allActions
                             .Except(_agent.GetEnumerable(), new PithosMonitor.LocalFileComparer())
@@ -379,286 +517,332 @@ namespace Pithos.Core.Agents
                             Post(message);
                         }
 
-                        //Report the number of new files
-                        var remoteCount = distinctActions.Count(action=>
-                            action.Action==CloudActionType.DownloadUnconditional);
-                        if ( remoteCount > 0)
-                            StatusNotification.NotifyChange(String.Format("Processing {0} new files", remoteCount));
-
-                        Log.Info("[LISTENER] End Processing");                        
+                        Log.Info("[LISTENER] End Processing");
                     }
-                });
+                }
+                catch (Exception ex)
+                {
+                    Log.ErrorFormat("[FAIL] ListObjects for{0} in ProcessRemoteFiles with {1}", accountInfo.UserName, ex);
+                    return;
+                }
 
-                var loop = enqueueFiles.ContinueWith(t =>
-                {                    
-                    if (t.IsFaulted)
-                    {
-                        Log.Error("[LISTENER] Exception", t.Exception);
-                    }
-                    else
-                    {
-                        Log.Info("[LISTENER] Finished");
-                    }
-                    ProcessRemoteFiles(accountPath, nextSince);
+                Log.Info("[LISTENER] Finished");
 
-                });
-                return loop;
+            }
+        }
+
+        private static void CreateContainerFolders(AccountInfo accountInfo, IEnumerable<ContainerInfo> containers)
+        {
+            var containerPaths = from container in containers
+                                 let containerPath = Path.Combine(accountInfo.AccountPath, container.Name)
+                                 where container.Name != FolderConstants.TrashContainer && !Directory.Exists(containerPath)
+                                 select containerPath;
+
+            foreach (var path in containerPaths)
+            {
+                Directory.CreateDirectory(path);
             }
         }
 
         //Creates an appropriate action for each server file
-        private IEnumerable<CloudAction> ObjectsToActions(IEnumerable<ObjectInfo> remote)
+        private IEnumerable<CloudAction> ObjectsToActions(AccountInfo accountInfo,IEnumerable<ObjectInfo> remote)
         {
             if (remote==null)
                 throw new ArgumentNullException();
             Contract.EndContractBlock();
+            var fileAgent = GetFileAgent(accountInfo);
 
             //In order to avoid multiple iterations over the files, we iterate only once
             //over the remote files
             foreach (var objectInfo in remote)
             {
-                var relativePath = objectInfo.RelativeUrlToFilePath(CloudClient.UserName);
+                var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
                 //and remove any matching objects from the list, adding them to the commonObjects list
-                if (FileAgent.Exists(relativePath))
+                
+                if (fileAgent.Exists(relativePath))
                 {
-                    var localFile = FileAgent.GetFileInfo(relativePath);
-                    var state = FileState.FindByFilePath(localFile.FullName);
-                    //Common files should be checked on a per-case basis to detect differences, which is newer
+                    //If a directory object already exists, we don't need to perform any other action                    
+                    var localFile = fileAgent.GetFileSystemInfo(relativePath);
+                    if (objectInfo.Content_Type == @"application/directory" && localFile is DirectoryInfo)
+                        continue;
+                    using (new SessionScope(FlushAction.Never))
+                    {
+                        var state =  StatusKeeper.GetStateByFilePath(localFile.FullName);
+                        //FileState.FindByFilePath(localFile.FullName);
+                        //Common files should be checked on a per-case basis to detect differences, which is newer
 
-                    yield return new CloudAction(CloudActionType.MustSynch,
-                                                   localFile, objectInfo, state, BlockSize, BlockHash);
+                        yield return new CloudAction(accountInfo, CloudActionType.MustSynch,
+                                                     localFile, objectInfo, state, accountInfo.BlockSize,
+                                                     accountInfo.BlockHash);
+                    }
                 }
                 else
                 {
                     //If there is no match we add them to the localFiles list
                     //but only if the file is not marked for deletion
-                    var targetFile = Path.Combine(FileAgent.RootPath, relativePath);
+                    var targetFile = Path.Combine(accountInfo.AccountPath, relativePath);
                     var fileStatus = StatusKeeper.GetFileStatus(targetFile);
                     if (fileStatus != FileStatus.Deleted)
                     {
                         //Remote files should be downloaded
-                        yield return new CloudAction(CloudActionType.DownloadUnconditional, objectInfo);
+                        yield return new CloudDownloadAction(accountInfo,objectInfo);
                     }
                 }
             }            
         }
 
-        private void ProcessDeletedFiles(IEnumerable<ObjectInfo> trashObjects)
+        private static FileAgent GetFileAgent(AccountInfo accountInfo)
+        {
+            return AgentLocator<FileAgent>.Get(accountInfo.AccountPath);
+        }
+
+        private void ProcessDeletedFiles(AccountInfo accountInfo,IEnumerable<ObjectInfo> trashObjects)
         {
+            var fileAgent = GetFileAgent(accountInfo);
             foreach (var trashObject in trashObjects)
             {
-                var relativePath = trashObject.RelativeUrlToFilePath(CloudClient.UserName);
-                //and remove any matching objects from the list, adding them to the commonObjects list
-                FileAgent.Delete(relativePath);                                
+                var barePath = trashObject.RelativeUrlToFilePath(accountInfo.UserName);
+                //HACK: Assume only the "pithos" container is used. Must find out what happens when
+                //deleting a file from a different container
+                var relativePath = Path.Combine("pithos", barePath);
+                fileAgent.Delete(relativePath);                                
             }
         }
 
 
-        private void RenameCloudFile(string account, string container,string oldFileName, string newPath, string newFileName)
+        private void RenameCloudFile(AccountInfo accountInfo,CloudMoveAction action)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (String.IsNullOrWhiteSpace(oldFileName))
-                throw new ArgumentNullException("oldFileName");
-            if (String.IsNullOrWhiteSpace(oldFileName))
-                throw new ArgumentNullException("newPath");
-            if (String.IsNullOrWhiteSpace(oldFileName))
-                throw new ArgumentNullException("newFileName");
+            if (accountInfo==null)
+                throw new ArgumentNullException("accountInfo");
+            if (action==null)
+                throw new ArgumentNullException("action");
+            if (action.CloudFile==null)
+                throw new ArgumentException("CloudFile","action");
+            if (action.LocalFile==null)
+                throw new ArgumentException("LocalFile","action");
+            if (action.OldLocalFile==null)
+                throw new ArgumentException("OldLocalFile","action");
+            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
-            this.StatusKeeper.SetFileOverlayStatus(newPath, FileOverlayStatus.Modified);
+            StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Modified);
 
-            CloudClient.MoveObject(account, container, oldFileName, container, newFileName);
 
-            this.StatusKeeper.SetFileStatus(newPath, FileStatus.Unchanged);
-            this.StatusKeeper.SetFileOverlayStatus(newPath, FileOverlayStatus.Normal);
-            NativeMethods.RaiseChangeNotification(newPath);
+            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);
         }
 
-        private void DeleteCloudFile(string account,string container, string fileName)
+        private void DeleteCloudFile(AccountInfo accountInfo, ObjectInfo cloudFile)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-
-            if (String.IsNullOrWhiteSpace(fileName))
-                throw new ArgumentNullException("fileName");
-            if (Path.IsPathRooted(fileName))
-                throw new ArgumentException("The fileName should not be rooted","fileName");
+            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.LogicalThreadContext.Stacks["DeleteCloudFile"].Push("Delete"))
+            using ( log4net.ThreadContext.Stacks["DeleteCloudFile"].Push("Delete"))
             {
-                var info = FileAgent.GetFileInfo(fileName);
-                var path = info.FullName.ToLower();
-                this.StatusKeeper.SetFileOverlayStatus(path, FileOverlayStatus.Modified);
+                var fileName= cloudFile.RelativeUrlToFilePath(accountInfo.UserName);
+                var info = fileAgent.GetFileSystemInfo(fileName);                
+                var fullPath = info.FullName.ToLower();
 
-                CloudClient.DeleteObject(account, container, fileName, TrashContainer);
+                StatusKeeper.SetFileOverlayStatus(fullPath, FileOverlayStatus.Modified);
 
-                this.StatusKeeper.ClearFileStatus(path);
+                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);
             }
         }
 
         //Download a file.
-        private void DownloadCloudFile(string account,string container, Uri relativeUrl, string localPath)
+        private async Task DownloadCloudFile(AccountInfo accountInfo, ObjectInfo cloudFile , string filePath)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (relativeUrl == null)
-                throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(localPath))
-                throw new ArgumentNullException("localPath");
-            if (!Path.IsPathRooted(localPath))
-                throw new ArgumentException("The localPath must be rooted", "localPath");
+            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 download=Task.Factory.Iterate(DownloadIterator(account,container, relativeUrl, localPath));
-            download.Wait();
-        }
 
-        private IEnumerable<Task> DownloadIterator(string account,string container, Uri relativeUrl, string localPath)
-        {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (relativeUrl==null)
-                throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(localPath))
-                throw new ArgumentNullException("localPath");
-            if (!Path.IsPathRooted(localPath))
-                throw new ArgumentException("The localPath must be rooted", "localPath");
-            Contract.EndContractBlock();
+            var localPath = Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
+            var relativeUrl = new Uri(cloudFile.Name, UriKind.Relative);
 
             var url = relativeUrl.ToString();
-            if (url.EndsWith(".ignore",StringComparison.InvariantCultureIgnoreCase))
-                yield break;
+            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)
-                    yield break;
+                    return;
                 //The file's hashmap will be stored in the same location with the extension .hashmap
-                //var hashPath = Path.Combine(FileAgent.FragmentsPath, relativePath + ".hashmap");
+                //var hashPath = Path.Combine(FileAgent.CachePath, relativePath + ".hashmap");
                 
-                //Retrieve the hashmap from the server
-                var getHashMap = CloudClient.GetHashMap(account, container, url);
-                yield return getHashMap;
-                
-                var serverHash=getHashMap.Result;
-                //If it's a small file
-                var downloadTask=(serverHash.Hashes.Count == 1 )
-                    //Download it in one go
-                    ? DownloadEntireFile(account,container, relativeUrl, localPath) 
-                    //Otherwise download it block by block
-                    : DownloadWithBlocks(account,container, relativeUrl, localPath, serverHash);
+                var client = new CloudFilesClient(accountInfo);
+                var account = cloudFile.Account;
+                var container = cloudFile.Container;
 
-                yield return downloadTask;
+                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);                        
+                    }
+                }
 
-                //Retrieve the object's metadata
-                var info=CloudClient.GetObjectInfo(account, container, url);
-                //And store it
-                StatusKeeper.StoreInfo(localPath, info);
+                //Now we can store the object's metadata without worrying about ghost status entries
+                StatusKeeper.StoreInfo(localPath, cloudFile);
                 
-                //Notify listeners that a local file has changed
-                StatusNotification.NotifyChangedFile(localPath);
-
             }
         }
 
         //Download a small file with a single GET operation
-        private Task DownloadEntireFile(string account,string container, Uri relativeUrl, string localPath)
+        private async Task DownloadEntireFileAsync(AccountInfo accountInfo, CloudFilesClient client, ObjectInfo cloudFile, Uri relativeUrl, string filePath,TreeHash serverHash)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
+            if (client == null)
+                throw new ArgumentNullException("client");
+            if (cloudFile==null)
+                throw new ArgumentNullException("cloudFile");
             if (relativeUrl == null)
                 throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(localPath))
-                throw new ArgumentNullException("localPath");
-            if (!Path.IsPathRooted(localPath))
-                throw new ArgumentException("The localPath must be rooted", "localPath");
+            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))
+            {
+                //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;
+            }
+
+            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.FragmentsPath, relativePath + ".download");
+            var tempPath = Path.Combine(fileAgent.CachePath, relativePath + ".download");
             //Make sure the target folder exists. DownloadFileTask will not create the folder
-            var directoryPath = Path.GetDirectoryName(tempPath);
-            if (!Directory.Exists(directoryPath))
-                Directory.CreateDirectory(directoryPath);
+            var tempFolder = Path.GetDirectoryName(tempPath);
+            if (!Directory.Exists(tempFolder))
+                Directory.CreateDirectory(tempFolder);
 
             //Download the object to the temporary location
-            var getObject = CloudClient.GetObject(account, container, relativeUrl.ToString(), tempPath).ContinueWith(t =>
-            {
-                t.PropagateExceptions();
-                //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);
-            });
-            return getObject;
+            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);
+
+                       
         }
 
         //Download a file asynchronously using blocks
-        public Task DownloadWithBlocks(string account,string container, Uri relativeUrl, string localPath, TreeHash serverHash)
+        public async Task DownloadWithBlocks(AccountInfo accountInfo, CloudFilesClient client, ObjectInfo cloudFile, Uri relativeUrl, string filePath, TreeHash serverHash)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
+            if (client == null)
+                throw new ArgumentNullException("client");
+            if (cloudFile == null)
+                throw new ArgumentNullException("cloudFile");
             if (relativeUrl == null)
                 throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(localPath))
-                throw new ArgumentNullException("localPath");
-            if (!Path.IsPathRooted(localPath))
-                throw new ArgumentException("The localPath must be rooted", "localPath");
+            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();
             
-            return Task.Factory.Iterate(BlockDownloadIterator(account,container, relativeUrl, localPath, serverHash));
-        }
-        
-        private IEnumerable<Task> BlockDownloadIterator(string account,string container,Uri relativeUrl, string localPath,TreeHash serverHash)
-        {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (relativeUrl == null)
-                throw new ArgumentNullException("relativeUrl");
-            if (String.IsNullOrWhiteSpace(localPath))
-                throw new ArgumentNullException("localPath");
-            if (!Path.IsPathRooted(localPath))
-                throw new ArgumentException("The localPath must be rooted", "localPath");
-            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.FragmentsPath, localPath, relativePath, serverHash);
+            var blockUpdater = new BlockUpdater(fileAgent.CachePath, localPath, relativePath, serverHash);
 
             
                         
             //Calculate the file's treehash
-            var calcHash = Signature.CalculateTreeHashAsync(localPath, this.BlockSize,BlockHash);
-            yield return calcHash;                        
-            var treeHash = calcHash.Result;
+            var treeHash = await Signature.CalculateTreeHashAsync(localPath, serverHash.BlockSize, serverHash.BlockHash);
                 
             //And compare it with the server's hash
             var upHashes = serverHash.GetHashesAsStrings();
@@ -675,169 +859,251 @@ namespace Pithos.Core.Agents
                         continue;
                     }
                     Log.InfoFormat("[BLOCK GET] START {0} of {1} for {2}", i, upHashes.Length, localPath);
-                    var start = i*BlockSize;
+                    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)*BlockSize) ;
+                        end= ((i + 1)*serverHash.BlockSize) ;
                             
                     //Download the missing block
-                    var getBlock = CloudClient.GetBlock(account, container, relativeUrl, start, end);
-                    yield return getBlock;
-                    var block = getBlock.Result;
+                    var block = await client.GetBlock(cloudFile.Account, cloudFile.Container, relativeUrl, start, end);
 
                     //and store it
-                    yield return blockUpdater.StoreBlock(i, block);
+                    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 void UploadCloudFile(string account,string container,FileInfo fileInfo, string hash,string topHash)
-        {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (fileInfo == null)
-                throw new ArgumentNullException("fileInfo");
-            if (String.IsNullOrWhiteSpace(hash))
-                throw new ArgumentNullException("hash");
-            if (topHash == null)
-                throw new ArgumentNullException("topHash");
-            Contract.EndContractBlock();
-
-            var upload = Task.Factory.Iterate(UploadIterator(account,container,fileInfo, hash, topHash));
-            upload.Wait();
-        }
-
-        private IEnumerable<Task> UploadIterator(string account,string container,FileInfo fileInfo, string hash,string topHash)
+        private async Task UploadCloudFile(CloudAction action)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
-            if (fileInfo == null)
-                throw new ArgumentNullException("fileInfo");
-            if (String.IsNullOrWhiteSpace(hash))
-                throw new ArgumentNullException("hash");
-            if (topHash == null)
-                throw new ArgumentNullException("topHash");
+            if (action == null)
+                throw new ArgumentNullException("action");           
             Contract.EndContractBlock();
 
-            if (fileInfo.Extension.Equals("ignore", StringComparison.InvariantCultureIgnoreCase))
-                yield break;
-            
-            var url = fileInfo.AsRelativeUrlTo(FileAgent.RootPath);
-
-            var fullFileName = fileInfo.FullName;
-            using(var gate=NetworkGate.Acquire(fullFileName,NetworkOperation.Uploading))
+            try
             {
-                //Abort if the file is already being uploaded or downloaded
-                if (gate.Failed)
-                    yield break; 
-
+                var accountInfo = action.AccountInfo;
 
-                //Even if GetObjectInfo times out, we can proceed with the upload            
-                var info = CloudClient.GetObjectInfo(account, container, url);
+                var fileInfo = action.LocalFile;
 
-                //If the file hashes match, abort the upload
-                if (hash.Equals(info.Hash, StringComparison.InvariantCultureIgnoreCase) ||
-                    topHash.Equals(info.Hash, StringComparison.InvariantCultureIgnoreCase))
+                if (fileInfo.Extension.Equals("ignore", StringComparison.InvariantCultureIgnoreCase))
+                    return;
+                
+                var relativePath = fileInfo.AsRelativeTo(accountInfo.AccountPath);
+                if (relativePath.StartsWith(FolderConstants.OthersFolder))
                 {
-                    //but store any metadata changes 
-                    this.StatusKeeper.StoreInfo(fullFileName, info);
-                    Log.InfoFormat("Skip upload of {0}, hashes match", fullFileName);
-                    yield break;
+                    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
+                    };
                 }
 
-                //Mark the file as modified while we upload it
-                StatusKeeper.SetFileOverlayStatus(fullFileName, FileOverlayStatus.Modified);
-                //And then upload it
 
-                //If the file is larger than the block size, try a hashmap PUT
-                if (fileInfo.Length > BlockSize )
+                var fullFileName = fileInfo.GetProperCapitalization();
+                using (var gate = NetworkGate.Acquire(fullFileName, NetworkOperation.Uploading))
                 {
-                    //To upload using a hashmap
-                    //First, calculate the tree hash
-                    var treeHash = Signature.CalculateTreeHashAsync(fileInfo.FullName, BlockSize, BlockHash);
-                    yield return treeHash;
+                    //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;
                     
-                    yield return Task.Factory.Iterate(UploadWithHashMap(account,container,fileInfo,url,treeHash));
-                                        
-                }
-                else
-                {
-                    //Otherwise do a regular PUT
-                    yield return CloudClient.PutObject(account, container, url, fullFileName, hash);                    
+                    //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
+                            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);
+
+                        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);
                 }
-                //If everything succeeds, change the file and overlay status to normal
-                this.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;
             }
-            //Notify the Shell to update the overlays
-            NativeMethods.RaiseChangeNotification(fullFileName);
-            StatusNotification.NotifyChangedFile(fullFileName);
+
+        }
+
+        private bool IsDeletedFile(CloudAction action)
+        {            
+            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;
         }
 
-        public IEnumerable<Task> UploadWithHashMap(string account,string container,FileInfo fileInfo,string url,Task<TreeHash> treeHash)
+        private bool HandleUploadWebException(CloudAction action, WebException exc)
         {
-            if (String.IsNullOrWhiteSpace(account))
-                throw new ArgumentNullException("account");
-            if (String.IsNullOrWhiteSpace(container))
-                throw new ArgumentNullException("container");
+            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;
+            }
+            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.FullName;
+            var fullFileName = fileInfo.GetProperCapitalization();
 
-            //Send the hashmap to the server            
-            var hashPut = CloudClient.PutHashMap(account, container, url, treeHash.Result);
-            yield return hashPut;
+            var account = cloudFile.Account ?? accountInfo.UserName;
+            var container = cloudFile.Container ;
 
-            var missingHashes = hashPut.Result;
+            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[BlockSize];
+                var buffer = new byte[accountInfo.BlockSize];
                 foreach (var missingHash in missingHashes)
                 {
                     //Find the proper block
-                    var blockIndex = treeHash.Result.HashDictionary[missingHash];
-                    var offset = blockIndex*BlockSize;
+                    var blockIndex = treeHash.HashDictionary[missingHash];
+                    var offset = blockIndex*accountInfo.BlockSize;
 
-                    var read = fileInfo.Read(buffer, offset, BlockSize);
+                    var read = fileInfo.Read(buffer, offset, accountInfo.BlockSize);
 
-                    //And upload the block                
-                    var postBlock = CloudClient.PostBlock(account, container, buffer, 0, read);
+                    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);
+                    }
 
-                    //We have to handle possible exceptions in a continuation because
-                    //*yield return* can't appear inside a try block
-                    yield return postBlock.ContinueWith(t => 
-                        t.ReportExceptions(
-                            exc => Log.ErrorFormat("[ERROR] uploading block {0} of {1}\n{2}", blockIndex, fullFileName, exc),
-                            ()=>Log.InfoFormat("[BLOCK] Block {0} of {1} uploaded", blockIndex,fullFileName)));
                 }
 
-                //Repeat until there are no more missing hashes
-                hashPut = CloudClient.PutHashMap(account, container, url, treeHash.Result);
-                yield return hashPut;
-                missingHashes = hashPut.Result;
+                //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);
+        }
     }