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

   1 #region
   2 /* -----------------------------------------------------------------------
   3  * <copyright file="NetworkAgent.cs" company="GRNet">
   4  *
   5  * Copyright 2011-2012 GRNET S.A. All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or
   8  * without modification, are permitted provided that the following
   9  * conditions are met:
  10  *
  11  *   1. Redistributions of source code must retain the above
  12  *      copyright notice, this list of conditions and the following
  13  *      disclaimer.
  14  *
  15  *   2. Redistributions in binary form must reproduce the above
  16  *      copyright notice, this list of conditions and the following
  17  *      disclaimer in the documentation and/or other materials
  18  *      provided with the distribution.
  19  *
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
  22  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
  25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  31  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  * The views and conclusions contained in the software and
  35  * documentation are those of the authors and should not be
  36  * interpreted as representing official policies, either expressed
  37  * or implied, of GRNET S.A.
  38  * </copyright>
  39  * -----------------------------------------------------------------------
  40  */
  41 #endregion
  42
  43 using System;
  44 using System.Collections.Generic;
  45 using System.ComponentModel.Composition;
  46 using System.Diagnostics;
  47 using System.Diagnostics.Contracts;
  48 using System.IO;
  49 using System.Linq;
  50 using System.Net;
  51 using System.Reflection;
  52 using System.Threading;
  53 using System.Threading.Tasks;
  54 using Castle.ActiveRecord;
  55 using Pithos.Interfaces;
  56 using Pithos.Network;
  57 using log4net;
  58
  59 namespace Pithos.Core.Agents
  60 {
  61     [Export]
  62     public class NetworkAgent
  63     {
  64         private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
  65
  66         private Agent<CloudAction> _agent;
  67
  68         [System.ComponentModel.Composition.Import]
  69         private DeleteAgent DeleteAgent { get; set; }
  70
  71         [System.ComponentModel.Composition.Import]
  72         public IStatusKeeper StatusKeeper { get; set; }
  73
  74         private IStatusNotification _statusNotification;
  75         public IStatusNotification StatusNotification
  76         {
  77             get { return _statusNotification; }
  78             set
  79             {
  80                 _statusNotification = value;
  81                 DeleteAgent.StatusNotification = value;
  82                 Uploader.StatusNotification = value;
  83                 Downloader.StatusNotification = value;
  84             }
  85         }
  86
  87
  88         [System.ComponentModel.Composition.Import]
  89         public IPithosSettings Settings { get; set; }
  90
  91         private Uploader _uploader;
  92
  93         [System.ComponentModel.Composition.Import]
  94         public Uploader Uploader
  95         {
  96             get { return _uploader; }
  97             set
  98             {
  99                 _uploader = value;
 100                 _uploader.UnpauseEvent = _unPauseEvent;
 101             }
 102         }
 103
 104         private Downloader _downloader;
 105
 106         [System.ComponentModel.Composition.Import]
 107         public Downloader Downloader
 108         {
 109             get { return _downloader; }
 110             set
 111             {
 112                 _downloader = value;
 113                 _downloader.UnpauseEvent = _unPauseEvent;
 114             }
 115         }
 116
 117         [System.ComponentModel.Composition.Import]
 118         public Selectives Selectives { get; set; }
 119
 120         //The Proceed signals the poll agent that it can proceed with polling.
 121         //Essentially it stops the poll agent to give priority to the network agent
 122         //Initially the event is signalled because we don't need to pause
 123         private readonly AsyncManualResetEvent _proceedEvent = new AsyncManualResetEvent(true);
 124         private Agents.Selectives _selectives;
 125         private bool _pause;
 126
 127         public AsyncManualResetEvent ProceedEvent
 128         {
 129             get { return _proceedEvent; }
 130         }
 131
 132         private readonly AsyncManualResetEvent _unPauseEvent = new AsyncManualResetEvent(true);
 133
 134         private CancellationTokenSource _currentOperationCancellation=new CancellationTokenSource();
 135
 136         public void CancelCurrentOperation()
 137         {
 138             //What does it mean to cancel the current upload/download?
 139             //Obviously, the current operation will be cancelled by throwing
 140             //a cancellation exception.
 141             //
 142             //The default behavior is to retry any operations that throw.
 143             //Obviously this is not what we want in this situation.
 144             //The cancelled operation should NOT bea retried.
 145             //
 146             //This can be done by catching the cancellation exception
 147             //and avoiding the retry.
 148             //
 149
 150             //Have to reset the cancellation source - it is not possible to reset the source
 151             //Have to prevent a case where an operation requests a token from the old source
 152             var oldSource = Interlocked.Exchange(ref _currentOperationCancellation, new CancellationTokenSource());
 153             oldSource.Cancel();
 154
 155         }
 156
 157         public void Start()
 158         {
 159             if (_agent != null)
 160                 return;
 161
 162             if (Log.IsDebugEnabled)
 163                 Log.Debug("Starting Network Agent");
 164
 165             _agent = Agent<CloudAction>.Start(inbox =>
 166             {
 167                 Action loop = null;
 168                 loop = () =>
 169                 {
 170                     DeleteAgent.ProceedEvent.Wait();
 171                     _unPauseEvent.Wait();
 172                     var message = inbox.Receive();
 173                     var process=message.Then(Process,inbox.CancellationToken);
 174                     inbox.LoopAsync(process, loop);
 175                 };
 176                 loop();
 177             });
 178
 179         }
 180
 181         private async Task Process(CloudAction action)
 182         {
 183             if (action == null)
 184                 throw new ArgumentNullException("action");
 185             if (action.AccountInfo==null)
 186                 throw new ArgumentException("The action.AccountInfo is empty","action");
 187             Contract.EndContractBlock();
 188
 189
 190
 191
 192             using (ThreadContext.Stacks["Operation"].Push(action.ToString()))
 193             {
 194
 195                 var cloudFile = action.CloudFile;
 196                 var downloadPath = action.GetDownloadPath();
 197
 198                 try
 199                 {
 200                     StatusNotification.SetPithosStatus(PithosStatus.LocalSyncing,"Processing");
 201                     _proceedEvent.Reset();
 202
 203                     var accountInfo = action.AccountInfo;
 204
 205                     if (action.Action == CloudActionType.DeleteCloud)
 206                     {
 207                         //Redirect deletes to the delete agent
 208                         DeleteAgent.Post((CloudDeleteAction)action);
 209                     }
 210                     if (DeleteAgent.IsDeletedFile(action))
 211                     {
 212                         //Clear the status of already deleted files to avoid reprocessing
 213                         if (action.LocalFile != null)
 214                             StatusKeeper.ClearFileStatus(action.LocalFile.FullName);
 215                     }
 216                     else
 217                     {
 218                         switch (action.Action)
 219                         {
 220                             case CloudActionType.UploadUnconditional:
 221                                 //Abort if the file was deleted before we reached this point
 222                                 var uploadAction = (CloudUploadAction) action;
 223                                 ProcessChildUploads(uploadAction);
 224                                 await Uploader.UploadCloudFile(uploadAction ,CurrentOperationCancelToken);
 225                                 break;
 226                             case CloudActionType.DownloadUnconditional:
 227                                 await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
 228                                 break;
 229                             case CloudActionType.RenameCloud:
 230                                 var moveAction = (CloudMoveAction)action;
 231                                 RenameCloudFile(accountInfo, moveAction);
 232                                 break;
 233                             case CloudActionType.RenameLocal:
 234                                 RenameLocalFile(accountInfo, action);
 235                                 break;
 236                             case CloudActionType.MustSynch:
 237                                 if (!File.Exists(downloadPath) && !Directory.Exists(downloadPath))
 238                                 {
 239                                     await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
 240                                 }
 241                                 else
 242                                 {
 243                                     await SyncFiles(accountInfo, action);
 244                                 }
 245                                 break;
 246                         }
 247                     }
 248                     Log.InfoFormat("End Processing {0}:{1}->{2}", action.Action, action.LocalFile,
 249                                            action.CloudFile.Name);
 250                 }
 251 /*
 252                 catch (WebException exc)
 253                 {
 254                     Log.ErrorFormat("[WEB ERROR] {0} : {1} -> {2} due to exception\r\n{3}", action.Action, action.LocalFile, action.CloudFile, exc);
 255
 256
 257                     //Actions that resulted in server errors should be retried
 258                     var response = exc.Response as HttpWebResponse;
 259                     if (response != null && response.StatusCode >= HttpStatusCode.InternalServerError)
 260                     {
 261                         _agent.Post(action);
 262                         Log.WarnFormat("[REQUEUE] {0} : {1} -> {2}", action.Action, action.LocalFile, action.CloudFile);
 263                     }
 264                 }
 265 */
 266                 catch (OperationCanceledException ex)
 267                 {
 268                     Log.WarnFormat("Cancelling [{0}]",ex);
 269                 }
 270                 catch (DirectoryNotFoundException)
 271                 {
 272                     Log.ErrorFormat("{0} : {1} -> {2}  failed because the directory was not found.\n Rescheduling a delete",
 273                         action.Action, action.LocalFile, action.CloudFile);
 274                     //Post a delete action for the missing file
 275                     Post(new CloudDeleteAction(action));
 276                 }
 277                 catch (FileNotFoundException)
 278                 {
 279                     Log.ErrorFormat("{0} : {1} -> {2}  failed because the file was not found.\n Rescheduling a delete",
 280                         action.Action, action.LocalFile, action.CloudFile);
 281                     //Post a delete action for the missing file
 282                     Post(new CloudDeleteAction(action));
 283                 }
 284                 catch (Exception exc)
 285                 {
 286                     Log.ErrorFormat("[REQUEUE] {0} : {1} -> {2} due to exception\r\n{3}",
 287                                      action.Action, action.LocalFile, action.CloudFile, exc);
 288
 289                     _agent.Post(action);
 290                 }
 291                 finally
 292                 {
 293                     if (_agent.IsEmpty)
 294                         _proceedEvent.Set();
 295                     UpdateStatus(PithosStatus.LocalComplete);
 296                 }
 297             }
 298         }
 299
 300         private void ProcessChildUploads(CloudUploadAction uploadAction)
 301         {
 302             if (!uploadAction.IsCreation || !(uploadAction.LocalFile is DirectoryInfo))
 303                 return;
 304
 305             var dirInfo = uploadAction.LocalFile as DirectoryInfo;
 306
 307             var account = uploadAction.AccountInfo;
 308             var folderActions = from info in dirInfo.EnumerateDirectories("*", SearchOption.AllDirectories)
 309                           select
 310                               new CloudUploadAction(account, info, null, account.BlockSize, account.BlockHash,
 311                                                     uploadAction, true);
 312             var fileActions = from info in dirInfo.EnumerateFiles("*", SearchOption.AllDirectories)
 313                           select
 314                               new CloudUploadAction(account, info, null, account.BlockSize, account.BlockHash,
 315                                                     uploadAction, true);
 316             //Post folder actions first, to ensure the selective folders are updated
 317             folderActions.ApplyAction(PostUploadAction);
 318             fileActions.ApplyAction(PostUploadAction);
 319         }
 320
 321         private void PostUploadAction(CloudUploadAction action)
 322         {
 323             var state = StatusKeeper.GetStateByFilePath(action.LocalFile.FullName);
 324             if (state != null)
 325                 state.Delete();
 326             //StatusKeeper.SetFileState(action.LocalFile.FullName,FileStatus.Created,FileOverlayStatus.Normal,String.Empty);
 327             state = FileState.CreateFor(action.LocalFile);
 328             //StatusKeeper.SetFileStatus();
 329             state.FileStatus = FileStatus.Created;
 330             state.OverlayStatus = FileOverlayStatus.Normal;
 331             state.Create();
 332             action.FileState = state;
 333             Post(action);
 334         }
 335
 336         private CancellationToken CurrentOperationCancelToken
 337         {
 338             get { return _currentOperationCancellation.Token; }
 339         }
 340
 341
 342         private void UpdateStatus(PithosStatus status)
 343         {
 344             StatusNotification.SetPithosStatus(status);
 345             //StatusNotification.Notify(new Notification());
 346         }
 347
 348         private void RenameLocalFile(AccountInfo accountInfo, CloudAction action)
 349         {
 350             if (accountInfo == null)
 351                 throw new ArgumentNullException("accountInfo");
 352             if (action == null)
 353                 throw new ArgumentNullException("action");
 354             if (action.LocalFile == null)
 355                 throw new ArgumentException("The action's local file is not specified", "action");
 356             if (!Path.IsPathRooted(action.LocalFile.FullName))
 357                 throw new ArgumentException("The action's local file path must be absolute", "action");
 358             if (action.CloudFile == null)
 359                 throw new ArgumentException("The action's cloud file is not specified", "action");
 360             Contract.EndContractBlock();
 361             using (ThreadContext.Stacks["Operation"].Push("RenameLocalFile"))
 362             {
 363
 364                 //We assume that the local file already exists, otherwise the poll agent
 365                 //would have issued a download request
 366
 367                 var currentInfo = action.CloudFile;
 368                 var previousInfo = action.CloudFile.Previous;
 369                 var fileAgent = FileAgent.GetFileAgent(accountInfo);
 370
 371                 var previousRelativepath = previousInfo.RelativeUrlToFilePath(accountInfo.UserName);
 372                 var previousFile = fileAgent.GetFileSystemInfo(previousRelativepath);
 373
 374                 //In every case we need to move the local file first
 375                 MoveLocalFile(accountInfo, previousFile, fileAgent, currentInfo);
 376             }
 377         }
 378
 379         private void MoveLocalFile(AccountInfo accountInfo, FileSystemInfo previousFile, FileAgent fileAgent,
 380                                    ObjectInfo currentInfo)
 381         {
 382             var currentRelativepath = currentInfo.RelativeUrlToFilePath(accountInfo.UserName);
 383             var newPath = Path.Combine(fileAgent.RootPath, currentRelativepath);
 384
 385             var isFile= (previousFile is FileInfo);
 386             var previousFullPath = isFile?
 387                 FileInfoExtensions.GetProperFilePathCapitalization(previousFile.FullName):
 388                 FileInfoExtensions.GetProperDirectoryCapitalization(previousFile.FullName);
 389
 390             using (NetworkGate.Acquire(previousFullPath, NetworkOperation.Renaming))
 391             using (NetworkGate.Acquire(newPath,NetworkOperation.Renaming))
 392             using (new SessionScope(FlushAction.Auto))
 393             {
 394                 if (isFile)
 395                     (previousFile as FileInfo).MoveTo(newPath);
 396                 else
 397                 {
 398                     (previousFile as DirectoryInfo).MoveTo(newPath);
 399                 }
 400                 var state = StatusKeeper.GetStateByFilePath(previousFullPath);
 401                 state.FilePath = newPath;
 402                 state.SaveCopy();
 403                 StatusKeeper.SetFileState(previousFullPath,FileStatus.Deleted,FileOverlayStatus.Deleted, "Deleted");
 404             }
 405         }
 406
 407         private async Task SyncFiles(AccountInfo accountInfo,CloudAction action)
 408         {
 409             if (accountInfo == null)
 410                 throw new ArgumentNullException("accountInfo");
 411             if (action==null)
 412                 throw new ArgumentNullException("action");
 413             if (action.LocalFile==null)
 414                 throw new ArgumentException("The action's local file is not specified","action");
 415             if (!Path.IsPathRooted(action.LocalFile.FullName))
 416                 throw new ArgumentException("The action's local file path must be absolute","action");
 417             if (action.CloudFile== null)
 418                 throw new ArgumentException("The action's cloud file is not specified", "action");
 419             Contract.EndContractBlock();
 420             using (ThreadContext.Stacks["Operation"].Push("SyncFiles"))
 421             {
 422
 423                 //var localFile = action.LocalFile;
 424                 var cloudFile = action.CloudFile;
 425                 var downloadPath = action.LocalFile.GetProperCapitalization();
 426
 427                 var cloudHash = cloudFile.Hash.ToLower();
 428                 var previousCloudHash = cloudFile.PreviousHash == null?null: cloudFile.PreviousHash.ToLower();
 429                 var localHash = action.TreeHash.Value.TopHash.ToHashString();// LocalHash.Value.ToLower();
 430                 //var topHash = action.TopHash.Value.ToLower();
 431
 432                 if(cloudFile.IsDirectory && action.LocalFile is DirectoryInfo)
 433                 {
 434                     Log.InfoFormat("Skipping folder {0} , exists in server", downloadPath);
 435                     return;
 436                 }
 437
 438                 //At this point we know that an object has changed on the server and that a local
 439                 //file already exists. We need to decide whether the file has only changed on
 440                 //the server or there is a conflicting change on the client.
 441                 //
 442
 443                 //If the hashes match, we are done
 444                 if (cloudFile != ObjectInfo.Empty && cloudHash == localHash)
 445                 {
 446                     Log.InfoFormat("Skipping {0}, hashes match", downloadPath);
 447                     return;
 448                 }
 449
 450                 //If the local and remote files have 0 length their hashes will not match
 451                 if (!cloudFile.IsDirectory && cloudFile.Bytes==0 && action.LocalFile is FileInfo && (action.LocalFile as FileInfo).Length==0 )
 452                 {
 453                     Log.InfoFormat("Skipping {0}, files are empty", downloadPath);
 454                     return;
 455                 }
 456
 457                 //The hashes DON'T match. We need to sync
 458
 459                 // If the previous tophash matches the local tophash, the file was only changed on the server.
 460                 if (localHash == previousCloudHash)
 461                 {
 462                     await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
 463                 }
 464                 else
 465                 {
 466                     //If the previous and local hash don't match, there was a local conflict
 467                     //that was not uploaded to the server. We have a conflict
 468                     ReportConflictForMismatch(downloadPath);
 469                 }
 470             }
 471         }
 472
 473         private void ReportConflictForMismatch(string downloadPath)
 474         {
 475             if (String.IsNullOrWhiteSpace(downloadPath))
 476                 throw new ArgumentNullException("downloadPath");
 477             Contract.EndContractBlock();
 478
 479             StatusKeeper.SetFileState(downloadPath,FileStatus.Conflict, FileOverlayStatus.Conflict,"File changed at the server");
 480             UpdateStatus(PithosStatus.HasConflicts);
 481             var message = String.Format("Conflict detected for file {0}", downloadPath);
 482             Log.Warn(message);
 483             StatusNotification.NotifyChange(message, TraceLevel.Warning);
 484         }
 485
 486         public void Post(CloudAction cloudAction)
 487         {
 488             if (cloudAction == null)
 489                 throw new ArgumentNullException("cloudAction");
 490             if (cloudAction.AccountInfo==null)
 491                 throw new ArgumentException("The CloudAction.AccountInfo is empty","cloudAction");
 492             Contract.EndContractBlock();
 493
 494             DeleteAgent.ProceedEvent.Wait();
 495
 496             if (cloudAction is CloudDeleteAction)
 497                 DeleteAgent.Post((CloudDeleteAction)cloudAction);
 498             else
 499                 _agent.Post(cloudAction);
 500         }
 501
 502
 503         public IEnumerable<CloudAction> GetEnumerable()
 504         {
 505             return _agent.GetEnumerable();
 506         }
 507
 508         public Task GetDeleteAwaiter()
 509         {
 510             return DeleteAgent.ProceedEvent.WaitAsync();
 511         }
 512         public CancellationToken CancellationToken
 513         {
 514             get { return _agent.CancellationToken; }
 515         }
 516
 517         public bool Pause
 518         {
 519             get {
 520                 return _pause;
 521             }
 522             set {
 523                 _pause = value;
 524                 if (_pause)
 525                     _unPauseEvent.Reset();
 526                 else
 527                 {
 528                     _unPauseEvent.Set();
 529                 }
 530             }
 531         }
 532
 533
 534         private void RenameCloudFile(AccountInfo accountInfo,CloudMoveAction action)
 535         {
 536             if (accountInfo==null)
 537                 throw new ArgumentNullException("accountInfo");
 538             if (action==null)
 539                 throw new ArgumentNullException("action");
 540             if (action.CloudFile==null)
 541                 throw new ArgumentException("CloudFile","action");
 542             if (action.LocalFile==null)
 543                 throw new ArgumentException("LocalFile","action");
 544             if (action.OldLocalFile==null)
 545                 throw new ArgumentException("OldLocalFile","action");
 546             if (action.OldCloudFile==null)
 547                 throw new ArgumentException("OldCloudFile","action");
 548             Contract.EndContractBlock();
 549
 550             using (ThreadContext.Stacks["Operation"].Push("RenameCloudFile"))
 551             {
 552
 553                 var newFilePath = action.LocalFile.FullName;
 554
 555                 //How do we handle concurrent renames and deletes/uploads/downloads?
 556                 //* A conflicting upload means that a file was renamed before it had a chance to finish uploading
 557                 //  This should never happen as the network agent executes only one action at a time
 558                 //* A conflicting download means that the file was modified on the cloud. While we can go on and complete
 559                 //  the rename, there may be a problem if the file is downloaded in blocks, as subsequent block requests for the
 560                 //  same name will fail.
 561                 //  This should never happen as the network agent executes only one action at a time.
 562                 //* A conflicting delete can happen if the rename was followed by a delete action that didn't have the chance
 563                 //  to remove the rename from the queue.
 564                 //  We can probably ignore this case. It will result in an error which should be ignored
 565
 566
 567                 //The local file is already renamed
 568                 StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Modified).Wait();
 569
 570
 571                 var account = action.CloudFile.Account ?? accountInfo.UserName;
 572                 var container = action.CloudFile.Container;
 573
 574                 var client = new CloudFilesClient(accountInfo);
 575                 //TODO: What code is returned when the source file doesn't exist?
 576                 client.MoveObject(account, container, action.OldCloudFile.Name, container, action.CloudFile.Name);
 577
 578                 StatusKeeper.SetFileStatus(newFilePath, FileStatus.Unchanged);
 579                 StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Normal).Wait();
 580                 NativeMethods.RaiseChangeNotification(newFilePath);
 581             }
 582         }
 583
 584
 585
 586
 587     }
 588
 589
 590
 591
 592 }