code.grnet.gr Git - pithos-ms-client/blob - trunk/Pithos.Core/Agents/NetworkAgent.cs

   1 // -----------------------------------------------------------------------
   2 // <copyright file="NetworkAgent.cs" company="GRNET">
   3 // Copyright 2011-2012 GRNET S.A. All rights reserved.
   4 //
   5 // Redistribution and use in source and binary forms, with or
   6 // without modification, are permitted provided that the following
   7 // conditions are met:
   8 //
   9 //   1. Redistributions of source code must retain the above
  10 //      copyright notice, this list of conditions and the following
  11 //      disclaimer.
  12 //
  13 //   2. Redistributions in binary form must reproduce the above
  14 //      copyright notice, this list of conditions and the following
  15 //      disclaimer in the documentation and/or other materials
  16 //      provided with the distribution.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
  19 // OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  21 // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
  22 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  25 // USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26 // AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  28 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29 // POSSIBILITY OF SUCH DAMAGE.
  30 //
  31 // The views and conclusions contained in the software and
  32 // documentation are those of the authors and should not be
  33 // interpreted as representing official policies, either expressed
  34 // or implied, of GRNET S.A.
  35 // </copyright>
  36 // -----------------------------------------------------------------------
  37
  38 using System;
  39 using System.Collections.Concurrent;
  40 using System.Collections.Generic;
  41 using System.ComponentModel.Composition;
  42 using System.Diagnostics;
  43 using System.Diagnostics.Contracts;
  44 using System.IO;
  45 using System.Linq;
  46 using System.Net;
  47 using System.Threading;
  48 using System.Threading.Tasks;
  49 using System.Threading.Tasks.Dataflow;
  50 using Castle.ActiveRecord;
  51 using Pithos.Interfaces;
  52 using Pithos.Network;
  53 using log4net;
  54
  55 namespace Pithos.Core.Agents
  56 {
  57     //TODO: Ensure all network operations use exact casing. Pithos is case sensitive
  58     [Export]
  59     public class NetworkAgent
  60     {
  61         private Agent<CloudAction> _agent;
  62
  63         [System.ComponentModel.Composition.Import]
  64         private DeleteAgent _deleteAgent=new DeleteAgent();
  65
  66         [System.ComponentModel.Composition.Import]
  67         public IStatusKeeper StatusKeeper { get; set; }
  68
  69         public IStatusNotification StatusNotification { get; set; }
  70
  71         private static readonly ILog Log = LogManager.GetLogger("NetworkAgent");
  72
  73         private readonly ConcurrentBag<AccountInfo> _accounts = new ConcurrentBag<AccountInfo>();
  74
  75         [System.ComponentModel.Composition.Import]
  76         public IPithosSettings Settings { get; set; }
  77
  78         private bool _firstPoll = true;
  79
  80         //The Sync Event signals a manual synchronisation
  81         private readonly AsyncManualResetEvent _syncEvent=new AsyncManualResetEvent();
  82
  83         private ConcurrentDictionary<string, DateTime> _lastSeen = new ConcurrentDictionary<string, DateTime>();
  84
  85         public void Start()
  86         {
  87             _firstPoll = true;
  88             _agent = Agent<CloudAction>.Start(inbox =>
  89             {
  90                 Action loop = null;
  91                 loop = () =>
  92                 {
  93                     _deleteAgent.PauseEvent.Wait();
  94                     var message = inbox.Receive();
  95                     var process=message.Then(Process,inbox.CancellationToken);
  96                     inbox.LoopAsync(process, loop);
  97                 };
  98                 loop();
  99             });
 100
 101         }
 102
 103         private async Task Process(CloudAction action)
 104         {
 105             if (action == null)
 106                 throw new ArgumentNullException("action");
 107             if (action.AccountInfo==null)
 108                 throw new ArgumentException("The action.AccountInfo is empty","action");
 109             Contract.EndContractBlock();
 110
 111             UpdateStatus(PithosStatus.Syncing);
 112             var accountInfo = action.AccountInfo;
 113
 114             using (log4net.ThreadContext.Stacks["NETWORK"].Push("PROCESS"))
 115             {
 116                 Log.InfoFormat("[ACTION] Start Processing {0}", action);
 117
 118                 var cloudFile = action.CloudFile;
 119                 var downloadPath = action.GetDownloadPath();
 120
 121                 try
 122                 {
 123                     if (action.Action == CloudActionType.DeleteCloud)
 124                     {
 125                         //Redirect deletes to the delete agent
 126                         _deleteAgent.Post((CloudDeleteAction)action);
 127                     }
 128                     if (_deleteAgent.IsDeletedFile(action))
 129                     {
 130                         //Clear the status of already deleted files to avoid reprocessing
 131                         if (action.LocalFile != null)
 132                             this.StatusKeeper.ClearFileStatus(action.LocalFile.FullName);
 133                     }
 134                     else
 135                     {
 136                         switch (action.Action)
 137                         {
 138                             case CloudActionType.UploadUnconditional:
 139                                 //Abort if the file was deleted before we reached this point
 140                                 await UploadCloudFile(action);
 141                                 break;
 142                             case CloudActionType.DownloadUnconditional:
 143                                 await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
 144                                 break;
 145                             case CloudActionType.RenameCloud:
 146                                 var moveAction = (CloudMoveAction)action;
 147                                 RenameCloudFile(accountInfo, moveAction);
 148                                 break;
 149                             case CloudActionType.MustSynch:
 150                                 if (!File.Exists(downloadPath) && !Directory.Exists(downloadPath))
 151                                 {
 152                                     await DownloadCloudFile(accountInfo, cloudFile, downloadPath);
 153                                 }
 154                                 else
 155                                 {
 156                                     await SyncFiles(accountInfo, action);
 157                                 }
 158                                 break;
 159                         }
 160                     }
 161                     Log.InfoFormat("[ACTION] End Processing {0}:{1}->{2}", action.Action, action.LocalFile,
 162                                            action.CloudFile.Name);
 163                 }
 164                 catch (WebException exc)
 165                 {
 166                     Log.ErrorFormat("[WEB ERROR] {0} : {1} -> {2} due to exception\r\n{3}", action.Action, action.LocalFile, action.CloudFile, exc);
 167                 }
 168                 catch (OperationCanceledException)
 169                 {
 170                     throw;
 171                 }
 172                 catch (DirectoryNotFoundException)
 173                 {
 174                     Log.ErrorFormat("{0} : {1} -> {2}  failed because the directory was not found.\n Rescheduling a delete",
 175                         action.Action, action.LocalFile, action.CloudFile);
 176                     //Post a delete action for the missing file
 177                     Post(new CloudDeleteAction(action));
 178                 }
 179                 catch (FileNotFoundException)
 180                 {
 181                     Log.ErrorFormat("{0} : {1} -> {2}  failed because the file was not found.\n Rescheduling a delete",
 182                         action.Action, action.LocalFile, action.CloudFile);
 183                     //Post a delete action for the missing file
 184                     Post(new CloudDeleteAction(action));
 185                 }
 186                 catch (Exception exc)
 187                 {
 188                     Log.ErrorFormat("[REQUEUE] {0} : {1} -> {2} due to exception\r\n{3}",
 189                                      action.Action, action.LocalFile, action.CloudFile, exc);
 190
 191                     _agent.Post(action);
 192                 }
 193                 finally
 194                 {
 195                     UpdateStatus(PithosStatus.InSynch);
 196                 }
 197             }
 198         }
 199
 200         private void UpdateStatus(PithosStatus status)
 201         {
 202             StatusKeeper.SetPithosStatus(status);
 203             StatusNotification.Notify(new Notification());
 204         }
 205
 206
 207         private async Task SyncFiles(AccountInfo accountInfo,CloudAction action)
 208         {
 209             if (accountInfo == null)
 210                 throw new ArgumentNullException("accountInfo");
 211             if (action==null)
 212                 throw new ArgumentNullException("action");
 213             if (action.LocalFile==null)
 214                 throw new ArgumentException("The action's local file is not specified","action");
 215             if (!Path.IsPathRooted(action.LocalFile.FullName))
 216                 throw new ArgumentException("The action's local file path must be absolute","action");
 217             if (action.CloudFile== null)
 218                 throw new ArgumentException("The action's cloud file is not specified", "action");
 219             Contract.EndContractBlock();
 220
 221             var localFile = action.LocalFile;
 222             var cloudFile = action.CloudFile;
 223             var downloadPath=action.LocalFile.GetProperCapitalization();
 224
 225             var cloudHash = cloudFile.Hash.ToLower();
 226             var localHash = action.LocalHash.Value.ToLower();
 227             var topHash = action.TopHash.Value.ToLower();
 228
 229             //Not enough to compare only the local hashes, also have to compare the tophashes
 230
 231             //If any of the hashes match, we are done
 232             if ((cloudHash == localHash || cloudHash == topHash))
 233             {
 234                 Log.InfoFormat("Skipping {0}, hashes match",downloadPath);
 235                 return;
 236             }
 237
 238             //The hashes DON'T match. We need to sync
 239             var lastLocalTime = localFile.LastWriteTime;
 240             var lastUpTime = cloudFile.Last_Modified;
 241
 242             //If the local file is newer upload it
 243             if (lastUpTime <= lastLocalTime)
 244             {
 245                 //It probably means it was changed while the app was down
 246                 UploadCloudFile(action);
 247             }
 248             else
 249             {
 250                 //It the cloud file has a later date, it was modified by another user or computer.
 251                 //We need to check the local file's status
 252                 var status = StatusKeeper.GetFileStatus(downloadPath);
 253                 switch (status)
 254                 {
 255                     case FileStatus.Unchanged:
 256                         //If the local file's status is Unchanged, we can go on and download the newer cloud file
 257                         await DownloadCloudFile(accountInfo,cloudFile,downloadPath);
 258                         break;
 259                     case FileStatus.Modified:
 260                         //If the local file is Modified, we may have a conflict. In this case we should mark the file as Conflict
 261                         //We can't ensure that a file modified online since the last time will appear as Modified, unless we
 262                         //index all files before we start listening.
 263                     case FileStatus.Created:
 264                         //If the local file is Created, it means that the local and cloud files aren't related,
 265                         // yet they have the same name.
 266
 267                         //In both cases we must mark the file as in conflict
 268                         ReportConflict(downloadPath);
 269                         break;
 270                     default:
 271                         //Other cases should never occur. Mark them as Conflict as well but log a warning
 272                         ReportConflict(downloadPath);
 273                         Log.WarnFormat("Unexcepted status {0} for file {1}->{2}", status,
 274                                        downloadPath, action.CloudFile.Name);
 275                         break;
 276                 }
 277             }
 278         }
 279
 280         private void ReportConflict(string downloadPath)
 281         {
 282             if (String.IsNullOrWhiteSpace(downloadPath))
 283                 throw new ArgumentNullException("downloadPath");
 284             Contract.EndContractBlock();
 285
 286             StatusKeeper.SetFileOverlayStatus(downloadPath, FileOverlayStatus.Conflict);
 287             UpdateStatus(PithosStatus.HasConflicts);
 288             var message = String.Format("Conflict detected for file {0}", downloadPath);
 289             Log.Warn(message);
 290             StatusNotification.NotifyChange(message, TraceLevel.Warning);
 291         }
 292
 293         public void Post(CloudAction cloudAction)
 294         {
 295             if (cloudAction == null)
 296                 throw new ArgumentNullException("cloudAction");
 297             if (cloudAction.AccountInfo==null)
 298                 throw new ArgumentException("The CloudAction.AccountInfo is empty","cloudAction");
 299             Contract.EndContractBlock();
 300
 301             _deleteAgent.PauseEvent.Wait();
 302
 303             //If the action targets a local file, add a treehash calculation
 304             if (!(cloudAction is CloudDeleteAction) && cloudAction.LocalFile as FileInfo != null)
 305             {
 306                 var accountInfo = cloudAction.AccountInfo;
 307                 var localFile = (FileInfo) cloudAction.LocalFile;
 308                 if (localFile.Length > accountInfo.BlockSize)
 309                     cloudAction.TopHash =
 310                         new Lazy<string>(() => Signature.CalculateTreeHashAsync(localFile,
 311                                                                                 accountInfo.BlockSize,
 312                                                                                 accountInfo.BlockHash, Settings.HashingParallelism).Result
 313                                                     .TopHash.ToHashString());
 314                 else
 315                 {
 316                     cloudAction.TopHash = new Lazy<string>(() => cloudAction.LocalHash.Value);
 317                 }
 318             }
 319             else
 320             {
 321                 //The hash for a directory is the empty string
 322                 cloudAction.TopHash = new Lazy<string>(() => String.Empty);
 323             }
 324
 325             if (cloudAction is CloudDeleteAction)
 326                 _deleteAgent.Post((CloudDeleteAction)cloudAction);
 327             else
 328                 _agent.Post(cloudAction);
 329         }
 330
 331
 332         /// <summary>
 333         /// Start a manual synchronization
 334         /// </summary>
 335         public void SynchNow()
 336         {
 337             _syncEvent.Set();
 338         }
 339
 340         //Remote files are polled periodically. Any changes are processed
 341         public async Task PollRemoteFiles(DateTime? since = null)
 342         {
 343             UpdateStatus(PithosStatus.Syncing);
 344             StatusNotification.Notify(new PollNotification());
 345
 346             using (log4net.ThreadContext.Stacks["Retrieve Remote"].Push("All accounts"))
 347             {
 348                 //If this poll fails, we will retry with the same since value
 349                 var nextSince = since;
 350                 try
 351                 {
 352                     //Next time we will check for all changes since the current check minus 1 second
 353                     //This is done to ensure there are no discrepancies due to clock differences
 354                     var current = DateTime.Now.AddSeconds(-1);
 355
 356                     var tasks = from accountInfo in _accounts
 357                                 select ProcessAccountFiles(accountInfo, since);
 358
 359                     await TaskEx.WhenAll(tasks.ToList());
 360
 361                     _firstPoll = false;
 362                     //Reschedule the poll with the current timestamp as a "since" value
 363                     nextSince = current;
 364                 }
 365                 catch (Exception ex)
 366                 {
 367                     Log.ErrorFormat("Error while processing accounts\r\n{0}",ex);
 368                     //In case of failure retry with the same "since" value
 369                 }
 370
 371                 UpdateStatus(PithosStatus.InSynch);
 372                 //Wait for the polling interval to pass or the Sync event to be signalled
 373                 nextSince = await WaitForScheduledOrManualPoll(nextSince);
 374
 375                 PollRemoteFiles(nextSince);
 376
 377             }
 378         }
 379
 380         /// <summary>
 381         /// Wait for the polling period to expire or a manual sync request
 382         /// </summary>
 383         /// <param name="since"></param>
 384         /// <returns></returns>
 385         private async Task<DateTime?> WaitForScheduledOrManualPoll(DateTime? since)
 386         {
 387             var sync=_syncEvent.WaitAsync();
 388             var wait = TaskEx.Delay(TimeSpan.FromSeconds(Settings.PollingInterval), _agent.CancellationToken);
 389             var signaledTask = await TaskEx.WhenAny(sync, wait);
 390
 391             //If polling is signalled by SynchNow, ignore the since tag
 392             if (signaledTask is Task<bool>)
 393                 return null;
 394             return since;
 395         }
 396
 397         public async Task ProcessAccountFiles(AccountInfo accountInfo,DateTime? since=null)
 398         {
 399             if (accountInfo==null)
 400                 throw new ArgumentNullException("accountInfo");
 401             if (String.IsNullOrWhiteSpace(accountInfo.AccountPath))
 402                 throw new ArgumentException("The AccountInfo.AccountPath is empty","accountInfo");
 403             Contract.EndContractBlock();
 404
 405
 406             using (log4net.ThreadContext.Stacks["Retrieve Remote"].Push(accountInfo.UserName))
 407             {
 408                 await _deleteAgent.PauseEvent.WaitAsync();
 409
 410                 Log.Info("Scheduled");
 411                 var client = new CloudFilesClient(accountInfo)
 412                                  {
 413                                      Proxy = PithosMonitor.ProxyFromSettings(this.Settings)
 414                                  };
 415
 416                 var containers = client.ListContainers(accountInfo.UserName);
 417
 418
 419                 CreateContainerFolders(accountInfo, containers);
 420
 421                 try
 422                 {
 423                     await _deleteAgent.PauseEvent.WaitAsync();
 424                     //Get the poll time now. We may miss some deletions but it's better to keep a file that was deleted
 425                     //than delete a file that was created while we were executing the poll
 426                     var pollTime = DateTime.Now;
 427
 428                     //Get the list of server objects changed since the last check
 429                     //The name of the container is passed as state in order to create a dictionary of tasks in a subsequent step
 430                     var listObjects = (from container in containers
 431                                       select  Task<IList<ObjectInfo>>.Factory.StartNew(_ =>
 432                                             client.ListObjects(accountInfo.UserName,container.Name, since),container.Name)).ToList();
 433
 434                     var listShared = Task<IList<ObjectInfo>>.Factory.StartNew(_ => client.ListSharedObjects(since), "shared");
 435                     listObjects.Add(listShared);
 436                     var listTasks = await Task.Factory.WhenAll(listObjects.ToArray());
 437
 438                     using (log4net.ThreadContext.Stacks["SCHEDULE"].Push("Process Results"))
 439                     {
 440                         var dict = listTasks.ToDictionary(t => t.AsyncState);
 441
 442                         //Get all non-trash objects. Remember, the container name is stored in AsyncState
 443                         var remoteObjects = from objectList in listTasks
 444                                             where (string) objectList.AsyncState != "trash"
 445                                             from obj in objectList.Result
 446                                             select obj;
 447
 448                         var trashObjects = dict["trash"].Result;
 449                         var sharedObjects = dict["shared"].Result;
 450
 451                         //Items with the same name, hash may be both in the container and the trash
 452                         //Don't delete items that exist in the container
 453                         var realTrash = from trash in trashObjects
 454                                         where
 455                                             !remoteObjects.Any(
 456                                                 info => info.Name == trash.Name && info.Hash == trash.Hash)
 457                                         select trash;
 458                         ProcessTrashedFiles(accountInfo, realTrash);
 459
 460                         var cleanRemotes = (from info in remoteObjects.Union(sharedObjects)
 461                                      let name = info.Name
 462                                      where !name.EndsWith(".ignore", StringComparison.InvariantCultureIgnoreCase) &&
 463                                            !name.StartsWith(FolderConstants.CacheFolder + "/",
 464                                                             StringComparison.InvariantCultureIgnoreCase)
 465                                      select info).ToList();
 466
 467                         var differencer = _differencer.PostSnapshot(accountInfo, cleanRemotes);
 468
 469                         ProcessDeletedFiles(accountInfo, differencer.Deleted, pollTime);
 470
 471                         //Create a list of actions from the remote files
 472                         var allActions = ChangesToActions(accountInfo, differencer.Changed)
 473                                         .Union(
 474                                         CreatesToActions(accountInfo,differencer.Created));
 475
 476                         //And remove those that are already being processed by the agent
 477                         var distinctActions = allActions
 478                             .Except(_agent.GetEnumerable(), new PithosMonitor.LocalFileComparer())
 479                             .ToList();
 480
 481                         //Queue all the actions
 482                         foreach (var message in distinctActions)
 483                         {
 484                             Post(message);
 485                         }
 486
 487                         Log.Info("[LISTENER] End Processing");
 488                     }
 489                 }
 490                 catch (Exception ex)
 491                 {
 492                     Log.ErrorFormat("[FAIL] ListObjects for{0} in ProcessRemoteFiles with {1}", accountInfo.UserName, ex);
 493                     return;
 494                 }
 495
 496                 Log.Info("[LISTENER] Finished");
 497
 498             }
 499         }
 500
 501         AccountsDifferencer _differencer= new AccountsDifferencer();
 502
 503         /// <summary>
 504         /// Deletes local files that are not found in the list of cloud files
 505         /// </summary>
 506         /// <param name="accountInfo"></param>
 507         /// <param name="cloudFiles"></param>
 508         /// <param name="pollTime"></param>
 509         private void ProcessDeletedFiles(AccountInfo accountInfo, IEnumerable<ObjectInfo> cloudFiles, DateTime pollTime)
 510         {
 511             if (accountInfo == null)
 512                 throw new ArgumentNullException("accountInfo");
 513             if (String.IsNullOrWhiteSpace(accountInfo.AccountPath))
 514                 throw new ArgumentException("The AccountInfo.AccountPath is empty", "accountInfo");
 515             if (cloudFiles == null)
 516                 throw new ArgumentNullException("cloudFiles");
 517             Contract.EndContractBlock();
 518
 519             //On the first run
 520             if (_firstPoll)
 521             {
 522                 //Only consider files that are not being modified, ie they are in the Unchanged state
 523                 var deleteCandidates = FileState.Queryable.Where(state =>
 524                     state.FilePath.StartsWith(accountInfo.AccountPath)
 525                     && state.FileStatus == FileStatus.Unchanged).ToList();
 526
 527
 528                 //TODO: filesToDelete must take into account the Others container
 529                 var filesToDelete = (from deleteCandidate in deleteCandidates
 530                                          let localFile = FileInfoExtensions.FromPath(deleteCandidate.FilePath)
 531                                          let relativeFilePath = localFile.AsRelativeTo(accountInfo.AccountPath)
 532                                      where
 533                                          !cloudFiles.Any(r => r.RelativeUrlToFilePath(accountInfo.UserName) == relativeFilePath)
 534                                      select localFile).ToList();
 535
 536
 537
 538                 //Set the status of missing files to Conflict
 539                 foreach (var item in filesToDelete)
 540                 {
 541                     //Try to acquire a gate on the file, to take into account files that have been dequeued
 542                     //and are being processed
 543                     using (var gate = NetworkGate.Acquire(item.FullName, NetworkOperation.Deleting))
 544                     {
 545                         if (gate.Failed)
 546                             continue;
 547                         StatusKeeper.SetFileState(item.FullName, FileStatus.Conflict, FileOverlayStatus.Deleted);
 548                     }
 549                 }
 550                 UpdateStatus(PithosStatus.HasConflicts);
 551                 StatusNotification.NotifyConflicts(filesToDelete, String.Format("{0} local files are missing from Pithos, possibly because they were deleted",filesToDelete.Count));
 552                 StatusNotification.NotifyForFiles(filesToDelete, String.Format("{0} files were deleted", filesToDelete.Count), TraceLevel.Info);
 553             }
 554             else
 555             {
 556                 var deletedFiles = new List<FileSystemInfo>();
 557                 foreach (var objectInfo in cloudFiles)
 558                 {
 559                     var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
 560                     var item = GetFileAgent(accountInfo).GetFileSystemInfo(relativePath);
 561                     if (item.Exists)
 562                     {
 563                         if ((item.Attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)
 564                         {
 565                             item.Attributes = item.Attributes & ~FileAttributes.ReadOnly;
 566
 567                         }
 568                         item.Delete();
 569                         DateTime lastDate;
 570                         _lastSeen.TryRemove(item.FullName, out lastDate);
 571                         deletedFiles.Add(item);
 572                     }
 573                     StatusKeeper.SetFileState(item.FullName, FileStatus.Deleted, FileOverlayStatus.Deleted);
 574                 }
 575                 StatusNotification.NotifyForFiles(deletedFiles, String.Format("{0} files were deleted", deletedFiles.Count), TraceLevel.Info);
 576             }
 577
 578         }
 579
 580         private static void CreateContainerFolders(AccountInfo accountInfo, IEnumerable<ContainerInfo> containers)
 581         {
 582             var containerPaths = from container in containers
 583                                  let containerPath = Path.Combine(accountInfo.AccountPath, container.Name)
 584                                  where container.Name != FolderConstants.TrashContainer && !Directory.Exists(containerPath)
 585                                  select containerPath;
 586
 587             foreach (var path in containerPaths)
 588             {
 589                 Directory.CreateDirectory(path);
 590             }
 591         }
 592
 593         //Creates an appropriate action for each server file
 594         private IEnumerable<CloudAction> ChangesToActions(AccountInfo accountInfo,IEnumerable<ObjectInfo> changes)
 595         {
 596             if (changes==null)
 597                 throw new ArgumentNullException();
 598             Contract.EndContractBlock();
 599             var fileAgent = GetFileAgent(accountInfo);
 600
 601             //In order to avoid multiple iterations over the files, we iterate only once
 602             //over the remote files
 603             foreach (var objectInfo in changes)
 604             {
 605                 var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
 606                 //and remove any matching objects from the list, adding them to the commonObjects list
 607                 if (fileAgent.Exists(relativePath))
 608                 {
 609                     //If a directory object already exists, we don't need to perform any other action
 610                     var localFile = fileAgent.GetFileSystemInfo(relativePath);
 611                     if (objectInfo.Content_Type == @"application/directory" && localFile is DirectoryInfo)
 612                         continue;
 613                     using (new SessionScope(FlushAction.Never))
 614                     {
 615                         var state =  StatusKeeper.GetStateByFilePath(localFile.FullName);
 616                         _lastSeen[localFile.FullName] = DateTime.Now;
 617                         //Common files should be checked on a per-case basis to detect differences, which is newer
 618
 619                         yield return new CloudAction(accountInfo, CloudActionType.MustSynch,
 620                                                      localFile, objectInfo, state, accountInfo.BlockSize,
 621                                                      accountInfo.BlockHash);
 622                     }
 623                 }
 624                 else
 625                 {
 626                     //Remote files should be downloaded
 627                     yield return new CloudDownloadAction(accountInfo,objectInfo);
 628                 }
 629             }
 630         }
 631
 632         private IEnumerable<CloudAction> CreatesToActions(AccountInfo accountInfo,IEnumerable<ObjectInfo> creates)
 633         {
 634             if (creates==null)
 635                 throw new ArgumentNullException();
 636             Contract.EndContractBlock();
 637             var fileAgent = GetFileAgent(accountInfo);
 638
 639             //In order to avoid multiple iterations over the files, we iterate only once
 640             //over the remote files
 641             foreach (var objectInfo in creates)
 642             {
 643                 var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
 644                 //and remove any matching objects from the list, adding them to the commonObjects list
 645                 if (fileAgent.Exists(relativePath))
 646                 {
 647                     //If the object already exists, we probably have a conflict
 648                     //If a directory object already exists, we don't need to perform any other action
 649                     var localFile = fileAgent.GetFileSystemInfo(relativePath);
 650                     StatusKeeper.SetFileState(localFile.FullName,FileStatus.Conflict,FileOverlayStatus.Conflict);
 651                 }
 652                 else
 653                 {
 654                     //Remote files should be downloaded
 655                     yield return new CloudDownloadAction(accountInfo,objectInfo);
 656                 }
 657             }
 658         }
 659
 660
 661         private static FileAgent GetFileAgent(AccountInfo accountInfo)
 662         {
 663             return AgentLocator<FileAgent>.Get(accountInfo.AccountPath);
 664         }
 665
 666         private void ProcessTrashedFiles(AccountInfo accountInfo,IEnumerable<ObjectInfo> trashObjects)
 667         {
 668             var fileAgent = GetFileAgent(accountInfo);
 669             foreach (var trashObject in trashObjects)
 670             {
 671                 var barePath = trashObject.RelativeUrlToFilePath(accountInfo.UserName);
 672                 //HACK: Assume only the "pithos" container is used. Must find out what happens when
 673                 //deleting a file from a different container
 674                 var relativePath = Path.Combine("pithos", barePath);
 675                 fileAgent.Delete(relativePath);
 676             }
 677         }
 678
 679
 680         private void RenameCloudFile(AccountInfo accountInfo,CloudMoveAction action)
 681         {
 682             if (accountInfo==null)
 683                 throw new ArgumentNullException("accountInfo");
 684             if (action==null)
 685                 throw new ArgumentNullException("action");
 686             if (action.CloudFile==null)
 687                 throw new ArgumentException("CloudFile","action");
 688             if (action.LocalFile==null)
 689                 throw new ArgumentException("LocalFile","action");
 690             if (action.OldLocalFile==null)
 691                 throw new ArgumentException("OldLocalFile","action");
 692             if (action.OldCloudFile==null)
 693                 throw new ArgumentException("OldCloudFile","action");
 694             Contract.EndContractBlock();
 695
 696
 697             var newFilePath = action.LocalFile.FullName;
 698
 699             //How do we handle concurrent renames and deletes/uploads/downloads?
 700             //* A conflicting upload means that a file was renamed before it had a chance to finish uploading
 701             //  This should never happen as the network agent executes only one action at a time
 702             //* A conflicting download means that the file was modified on the cloud. While we can go on and complete
 703             //  the rename, there may be a problem if the file is downloaded in blocks, as subsequent block requests for the
 704             //  same name will fail.
 705             //  This should never happen as the network agent executes only one action at a time.
 706             //* A conflicting delete can happen if the rename was followed by a delete action that didn't have the chance
 707             //  to remove the rename from the queue.
 708             //  We can probably ignore this case. It will result in an error which should be ignored
 709
 710
 711             //The local file is already renamed
 712             StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Modified);
 713
 714
 715             var account = action.CloudFile.Account ?? accountInfo.UserName;
 716             var container = action.CloudFile.Container;
 717
 718             var client = new CloudFilesClient(accountInfo);
 719             //TODO: What code is returned when the source file doesn't exist?
 720             client.MoveObject(account, container, action.OldCloudFile.Name, container, action.CloudFile.Name);
 721
 722             StatusKeeper.SetFileStatus(newFilePath, FileStatus.Unchanged);
 723             StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Normal);
 724             NativeMethods.RaiseChangeNotification(newFilePath);
 725         }
 726
 727         //Download a file.
 728         private async Task DownloadCloudFile(AccountInfo accountInfo, ObjectInfo cloudFile , string filePath)
 729         {
 730             if (accountInfo == null)
 731                 throw new ArgumentNullException("accountInfo");
 732             if (cloudFile == null)
 733                 throw new ArgumentNullException("cloudFile");
 734             if (String.IsNullOrWhiteSpace(cloudFile.Account))
 735                 throw new ArgumentNullException("cloudFile");
 736             if (String.IsNullOrWhiteSpace(cloudFile.Container))
 737                 throw new ArgumentNullException("cloudFile");
 738             if (String.IsNullOrWhiteSpace(filePath))
 739                 throw new ArgumentNullException("filePath");
 740             if (!Path.IsPathRooted(filePath))
 741                 throw new ArgumentException("The filePath must be rooted", "filePath");
 742             Contract.EndContractBlock();
 743
 744
 745             var localPath = Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
 746             var relativeUrl = new Uri(cloudFile.Name, UriKind.Relative);
 747
 748             var url = relativeUrl.ToString();
 749             if (cloudFile.Name.EndsWith(".ignore", StringComparison.InvariantCultureIgnoreCase))
 750                 return;
 751
 752
 753             //Are we already downloading or uploading the file?
 754             using (var gate=NetworkGate.Acquire(localPath, NetworkOperation.Downloading))
 755             {
 756                 if (gate.Failed)
 757                     return;
 758
 759                 var client = new CloudFilesClient(accountInfo);
 760                 var account = cloudFile.Account;
 761                 var container = cloudFile.Container;
 762
 763                 if (cloudFile.Content_Type == @"application/directory")
 764                 {
 765                     if (!Directory.Exists(localPath))
 766                         Directory.CreateDirectory(localPath);
 767                 }
 768                 else
 769                 {
 770                     //Retrieve the hashmap from the server
 771                     var serverHash = await client.GetHashMap(account, container, url);
 772                     //If it's a small file
 773                     if (serverHash.Hashes.Count == 1)
 774                         //Download it in one go
 775                         await
 776                             DownloadEntireFileAsync(accountInfo, client, cloudFile, relativeUrl, localPath, serverHash);
 777                         //Otherwise download it block by block
 778                     else
 779                         await DownloadWithBlocks(accountInfo, client, cloudFile, relativeUrl, localPath, serverHash);
 780
 781                     if (cloudFile.AllowedTo == "read")
 782                     {
 783                         var attributes = File.GetAttributes(localPath);
 784                         File.SetAttributes(localPath, attributes | FileAttributes.ReadOnly);
 785                     }
 786                 }
 787
 788                 //Now we can store the object's metadata without worrying about ghost status entries
 789                 StatusKeeper.StoreInfo(localPath, cloudFile);
 790
 791             }
 792         }
 793
 794         //Download a small file with a single GET operation
 795         private async Task DownloadEntireFileAsync(AccountInfo accountInfo, CloudFilesClient client, ObjectInfo cloudFile, Uri relativeUrl, string filePath,TreeHash serverHash)
 796         {
 797             if (client == null)
 798                 throw new ArgumentNullException("client");
 799             if (cloudFile==null)
 800                 throw new ArgumentNullException("cloudFile");
 801             if (relativeUrl == null)
 802                 throw new ArgumentNullException("relativeUrl");
 803             if (String.IsNullOrWhiteSpace(filePath))
 804                 throw new ArgumentNullException("filePath");
 805             if (!Path.IsPathRooted(filePath))
 806                 throw new ArgumentException("The localPath must be rooted", "filePath");
 807             Contract.EndContractBlock();
 808
 809             var localPath = Pithos.Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
 810             //If the file already exists
 811             if (File.Exists(localPath))
 812             {
 813                 //First check with MD5 as this is a small file
 814                 var localMD5 = Signature.CalculateMD5(localPath);
 815                 var cloudHash=serverHash.TopHash.ToHashString();
 816                 if (localMD5==cloudHash)
 817                     return;
 818                 //Then check with a treehash
 819                 var localTreeHash = Signature.CalculateTreeHash(localPath, serverHash.BlockSize, serverHash.BlockHash);
 820                 var localHash = localTreeHash.TopHash.ToHashString();
 821                 if (localHash==cloudHash)
 822                     return;
 823             }
 824             StatusNotification.Notify(new CloudNotification { Data = cloudFile });
 825
 826             var fileAgent = GetFileAgent(accountInfo);
 827             //Calculate the relative file path for the new file
 828             var relativePath = relativeUrl.RelativeUriToFilePath();
 829             //The file will be stored in a temporary location while downloading with an extension .download
 830             var tempPath = Path.Combine(fileAgent.CachePath, relativePath + ".download");
 831             //Make sure the target folder exists. DownloadFileTask will not create the folder
 832             var tempFolder = Path.GetDirectoryName(tempPath);
 833             if (!Directory.Exists(tempFolder))
 834                 Directory.CreateDirectory(tempFolder);
 835
 836             //Download the object to the temporary location
 837             await client.GetObject(cloudFile.Account, cloudFile.Container, relativeUrl.ToString(), tempPath);
 838
 839             //Create the local folder if it doesn't exist (necessary for shared objects)
 840             var localFolder = Path.GetDirectoryName(localPath);
 841             if (!Directory.Exists(localFolder))
 842                 Directory.CreateDirectory(localFolder);
 843             //And move it to its actual location once downloading is finished
 844             if (File.Exists(localPath))
 845                 File.Replace(tempPath,localPath,null,true);
 846             else
 847                 File.Move(tempPath,localPath);
 848             //Notify listeners that a local file has changed
 849             StatusNotification.NotifyChangedFile(localPath);
 850
 851
 852         }
 853
 854         //Download a file asynchronously using blocks
 855         public async Task DownloadWithBlocks(AccountInfo accountInfo, CloudFilesClient client, ObjectInfo cloudFile, Uri relativeUrl, string filePath, TreeHash serverHash)
 856         {
 857             if (client == null)
 858                 throw new ArgumentNullException("client");
 859             if (cloudFile == null)
 860                 throw new ArgumentNullException("cloudFile");
 861             if (relativeUrl == null)
 862                 throw new ArgumentNullException("relativeUrl");
 863             if (String.IsNullOrWhiteSpace(filePath))
 864                 throw new ArgumentNullException("filePath");
 865             if (!Path.IsPathRooted(filePath))
 866                 throw new ArgumentException("The filePath must be rooted", "filePath");
 867             if (serverHash == null)
 868                 throw new ArgumentNullException("serverHash");
 869             Contract.EndContractBlock();
 870
 871            var fileAgent = GetFileAgent(accountInfo);
 872             var localPath = Interfaces.FileInfoExtensions.GetProperFilePathCapitalization(filePath);
 873
 874             //Calculate the relative file path for the new file
 875             var relativePath = relativeUrl.RelativeUriToFilePath();
 876             var blockUpdater = new BlockUpdater(fileAgent.CachePath, localPath, relativePath, serverHash);
 877
 878
 879
 880             //Calculate the file's treehash
 881             var treeHash = await Signature.CalculateTreeHashAsync(localPath, serverHash.BlockSize, serverHash.BlockHash, 2);
 882
 883             //And compare it with the server's hash
 884             var upHashes = serverHash.GetHashesAsStrings();
 885             var localHashes = treeHash.HashDictionary;
 886             for (int i = 0; i < upHashes.Length; i++)
 887             {
 888                 //For every non-matching hash
 889                 var upHash = upHashes[i];
 890                 if (!localHashes.ContainsKey(upHash))
 891                 {
 892                     StatusNotification.Notify(new CloudNotification { Data = cloudFile });
 893
 894                     if (blockUpdater.UseOrphan(i, upHash))
 895                     {
 896                         Log.InfoFormat("[BLOCK GET] ORPHAN FOUND for {0} of {1} for {2}", i, upHashes.Length, localPath);
 897                         continue;
 898                     }
 899                     Log.InfoFormat("[BLOCK GET] START {0} of {1} for {2}", i, upHashes.Length, localPath);
 900                     var start = i*serverHash.BlockSize;
 901                     //To download the last block just pass a null for the end of the range
 902                     long? end = null;
 903                     if (i < upHashes.Length - 1 )
 904                         end= ((i + 1)*serverHash.BlockSize) ;
 905
 906                     //Download the missing block
 907                     var block = await client.GetBlock(cloudFile.Account, cloudFile.Container, relativeUrl, start, end);
 908
 909                     //and store it
 910                     blockUpdater.StoreBlock(i, block);
 911
 912
 913                     Log.InfoFormat("[BLOCK GET] FINISH {0} of {1} for {2}", i, upHashes.Length, localPath);
 914                 }
 915             }
 916
 917             //Want to avoid notifications if no changes were made
 918             var hasChanges = blockUpdater.HasBlocks;
 919             blockUpdater.Commit();
 920
 921             if (hasChanges)
 922                 //Notify listeners that a local file has changed
 923                 StatusNotification.NotifyChangedFile(localPath);
 924
 925             Log.InfoFormat("[BLOCK GET] COMPLETE {0}", localPath);
 926         }
 927
 928
 929         private async Task UploadCloudFile(CloudAction action)
 930         {
 931             if (action == null)
 932                 throw new ArgumentNullException("action");
 933             Contract.EndContractBlock();
 934
 935             try
 936             {
 937                 var accountInfo = action.AccountInfo;
 938
 939                 var fileInfo = action.LocalFile;
 940
 941                 if (fileInfo.Extension.Equals("ignore", StringComparison.InvariantCultureIgnoreCase))
 942                     return;
 943
 944                 var relativePath = fileInfo.AsRelativeTo(accountInfo.AccountPath);
 945                 if (relativePath.StartsWith(FolderConstants.OthersFolder))
 946                 {
 947                     var parts = relativePath.Split('\\');
 948                     var accountName = parts[1];
 949                     var oldName = accountInfo.UserName;
 950                     var absoluteUri = accountInfo.StorageUri.AbsoluteUri;
 951                     var nameIndex = absoluteUri.IndexOf(oldName);
 952                     var root = absoluteUri.Substring(0, nameIndex);
 953
 954                     accountInfo = new AccountInfo
 955                     {
 956                         UserName = accountName,
 957                         AccountPath = Path.Combine(accountInfo.AccountPath, parts[0], parts[1]),
 958                         StorageUri = new Uri(root + accountName),
 959                         BlockHash = accountInfo.BlockHash,
 960                         BlockSize = accountInfo.BlockSize,
 961                         Token = accountInfo.Token
 962                     };
 963                 }
 964
 965
 966                 var fullFileName = fileInfo.GetProperCapitalization();
 967                 using (var gate = NetworkGate.Acquire(fullFileName, NetworkOperation.Uploading))
 968                 {
 969                     //Abort if the file is already being uploaded or downloaded
 970                     if (gate.Failed)
 971                         return;
 972
 973                     var cloudFile = action.CloudFile;
 974                     var account = cloudFile.Account ?? accountInfo.UserName;
 975
 976                     var client = new CloudFilesClient(accountInfo);
 977                     //Even if GetObjectInfo times out, we can proceed with the upload
 978                     var info = client.GetObjectInfo(account, cloudFile.Container, cloudFile.Name);
 979
 980                     //If this is a read-only file, do not upload changes
 981                     if (info.AllowedTo == "read")
 982                         return;
 983
 984                     //TODO: Check how a directory hash is calculated -> All dirs seem to have the same hash
 985                     if (fileInfo is DirectoryInfo)
 986                     {
 987                         //If the directory doesn't exist the Hash property will be empty
 988                         if (String.IsNullOrWhiteSpace(info.Hash))
 989                             //Go on and create the directory
 990                             await client.PutObject(account, cloudFile.Container, cloudFile.Name, fullFileName, String.Empty, "application/directory");
 991                     }
 992                     else
 993                     {
 994
 995                         var cloudHash = info.Hash.ToLower();
 996
 997                         var hash = action.LocalHash.Value;
 998                         var topHash = action.TopHash.Value;
 999
1000                         //If the file hashes match, abort the upload
1001                         if (hash == cloudHash || topHash == cloudHash)
1002                         {
1003                             //but store any metadata changes
1004                             StatusKeeper.StoreInfo(fullFileName, info);
1005                             Log.InfoFormat("Skip upload of {0}, hashes match", fullFileName);
1006                             return;
1007                         }
1008
1009
1010                         //Mark the file as modified while we upload it
1011                         StatusKeeper.SetFileOverlayStatus(fullFileName, FileOverlayStatus.Modified);
1012                         //And then upload it
1013
1014                         //Upload even small files using the Hashmap. The server may already contain
1015                         //the relevant block
1016
1017                         //First, calculate the tree hash
1018                         var treeHash = await Signature.CalculateTreeHashAsync(fullFileName, accountInfo.BlockSize,
1019                                                                               accountInfo.BlockHash, 2);
1020
1021                         await UploadWithHashMap(accountInfo, cloudFile, fileInfo as FileInfo, cloudFile.Name, treeHash);
1022                     }
1023                     //If everything succeeds, change the file and overlay status to normal
1024                     StatusKeeper.SetFileState(fullFileName, FileStatus.Unchanged, FileOverlayStatus.Normal);
1025                 }
1026                 //Notify the Shell to update the overlays
1027                 NativeMethods.RaiseChangeNotification(fullFileName);
1028                 StatusNotification.NotifyChangedFile(fullFileName);
1029             }
1030             catch (AggregateException ex)
1031             {
1032                 var exc = ex.InnerException as WebException;
1033                 if (exc == null)
1034                     throw ex.InnerException;
1035                 if (HandleUploadWebException(action, exc))
1036                     return;
1037                 throw;
1038             }
1039             catch (WebException ex)
1040             {
1041                 if (HandleUploadWebException(action, ex))
1042                     return;
1043                 throw;
1044             }
1045             catch (Exception ex)
1046             {
1047                 Log.Error("Unexpected error while uploading file", ex);
1048                 throw;
1049             }
1050
1051         }
1052
1053
1054
1055         private bool HandleUploadWebException(CloudAction action, WebException exc)
1056         {
1057             var response = exc.Response as HttpWebResponse;
1058             if (response == null)
1059                 throw exc;
1060             if (response.StatusCode == HttpStatusCode.Unauthorized)
1061             {
1062                 Log.Error("Not allowed to upload file", exc);
1063                 var message = String.Format("Not allowed to uplad file {0}", action.LocalFile.FullName);
1064                 StatusKeeper.SetFileState(action.LocalFile.FullName, FileStatus.Unchanged, FileOverlayStatus.Normal);
1065                 StatusNotification.NotifyChange(message, TraceLevel.Warning);
1066                 return true;
1067             }
1068             return false;
1069         }
1070
1071         public async Task UploadWithHashMap(AccountInfo accountInfo,ObjectInfo cloudFile,FileInfo fileInfo,string url,TreeHash treeHash)
1072         {
1073             if (accountInfo == null)
1074                 throw new ArgumentNullException("accountInfo");
1075             if (cloudFile==null)
1076                 throw new ArgumentNullException("cloudFile");
1077             if (fileInfo == null)
1078                 throw new ArgumentNullException("fileInfo");
1079             if (String.IsNullOrWhiteSpace(url))
1080                 throw new ArgumentNullException(url);
1081             if (treeHash==null)
1082                 throw new ArgumentNullException("treeHash");
1083             if (String.IsNullOrWhiteSpace(cloudFile.Container) )
1084                 throw new ArgumentException("Invalid container","cloudFile");
1085             Contract.EndContractBlock();
1086
1087             var fullFileName = fileInfo.GetProperCapitalization();
1088
1089             var account = cloudFile.Account ?? accountInfo.UserName;
1090             var container = cloudFile.Container ;
1091
1092             var client = new CloudFilesClient(accountInfo);
1093             //Send the hashmap to the server
1094             var missingHashes =  await client.PutHashMap(account, container, url, treeHash);
1095             //If the server returns no missing hashes, we are done
1096             while (missingHashes.Count > 0)
1097             {
1098
1099                 var buffer = new byte[accountInfo.BlockSize];
1100                 foreach (var missingHash in missingHashes)
1101                 {
1102                     //Find the proper block
1103                     var blockIndex = treeHash.HashDictionary[missingHash];
1104                     var offset = blockIndex*accountInfo.BlockSize;
1105
1106                     var read = fileInfo.Read(buffer, offset, accountInfo.BlockSize);
1107
1108                     try
1109                     {
1110                         //And upload the block
1111                         await client.PostBlock(account, container, buffer, 0, read);
1112                         Log.InfoFormat("[BLOCK] Block {0} of {1} uploaded", blockIndex, fullFileName);
1113                     }
1114                     catch (Exception exc)
1115                     {
1116                         Log.ErrorFormat("[ERROR] uploading block {0} of {1}\n{2}", blockIndex, fullFileName, exc);
1117                     }
1118
1119                 }
1120
1121                 //Repeat until there are no more missing hashes
1122                 missingHashes = await client.PutHashMap(account, container, url, treeHash);
1123             }
1124         }
1125
1126
1127         public void AddAccount(AccountInfo accountInfo)
1128         {
1129             if (!_accounts.Contains(accountInfo))
1130                 _accounts.Add(accountInfo);
1131         }
1132     }
1133
1134
1135
1136
1137 }