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 actions = from file in dirInfo.EnumerateFiles("*", SearchOption.AllDirectories)
 309                           select
 310                               new CloudUploadAction(account, file, null, account.BlockSize, account.BlockHash,
 311                                                     uploadAction, true);
 312             foreach (var action in actions)
 313             {
 314                 var state=StatusKeeper.GetStateByFilePath(action.LocalFile.FullName);
 315                 if (state!=null)
 316                     state.Delete();
 317                 //StatusKeeper.SetFileState(action.LocalFile.FullName,FileStatus.Created,FileOverlayStatus.Normal,String.Empty);
 318                 state=FileState.CreateFor(action.LocalFile);
 319                 //StatusKeeper.SetFileStatus();
 320                 state.FileStatus = FileStatus.Created;
 321                 state.OverlayStatus=FileOverlayStatus.Normal;
 322                 state.Create();
 323                 action.FileState = state;
 324                 Post(action);
 325             }
 326         }
 327
 328         private CancellationToken CurrentOperationCancelToken
 329         {
 330             get { return _currentOperationCancellation.Token; }
 331         }
 332
 333
 334         private void UpdateStatus(PithosStatus status)
 335         {
 336             StatusNotification.SetPithosStatus(status);
 337             //StatusNotification.Notify(new Notification());
 338         }
 339
 340         private void RenameLocalFile(AccountInfo accountInfo, CloudAction action)
 341         {
 342             if (accountInfo == null)
 343                 throw new ArgumentNullException("accountInfo");
 344             if (action == null)
 345                 throw new ArgumentNullException("action");
 346             if (action.LocalFile == null)
 347                 throw new ArgumentException("The action's local file is not specified", "action");
 348             if (!Path.IsPathRooted(action.LocalFile.FullName))
 349                 throw new ArgumentException("The action's local file path must be absolute", "action");
 350             if (action.CloudFile == null)
 351                 throw new ArgumentException("The action's cloud file is not specified", "action");
 352             Contract.EndContractBlock();
 353             using (ThreadContext.Stacks["Operation"].Push("RenameLocalFile"))
 354             {
 355
 356                 //We assume that the local file already exists, otherwise the poll agent
 357                 //would have issued a download request
 358
 359                 var currentInfo = action.CloudFile;
 360                 var previousInfo = action.CloudFile.Previous;
 361                 var fileAgent = FileAgent.GetFileAgent(accountInfo);
 362
 363                 var previousRelativepath = previousInfo.RelativeUrlToFilePath(accountInfo.UserName);
 364                 var previousFile = fileAgent.GetFileSystemInfo(previousRelativepath);
 365
 366                 //In every case we need to move the local file first
 367                 MoveLocalFile(accountInfo, previousFile, fileAgent, currentInfo);
 368             }
 369         }
 370
 371         private void MoveLocalFile(AccountInfo accountInfo, FileSystemInfo previousFile, FileAgent fileAgent,
 372                                    ObjectInfo currentInfo)
 373         {
 374             var currentRelativepath = currentInfo.RelativeUrlToFilePath(accountInfo.UserName);
 375             var newPath = Path.Combine(fileAgent.RootPath, currentRelativepath);
 376
 377             var isFile= (previousFile is FileInfo);
 378             var previousFullPath = isFile?
 379                 FileInfoExtensions.GetProperFilePathCapitalization(previousFile.FullName):
 380                 FileInfoExtensions.GetProperDirectoryCapitalization(previousFile.FullName);
 381
 382             using (NetworkGate.Acquire(previousFullPath, NetworkOperation.Renaming))
 383             using (NetworkGate.Acquire(newPath,NetworkOperation.Renaming))
 384             using (new SessionScope(FlushAction.Auto))
 385             {
 386                 if (isFile)
 387                     (previousFile as FileInfo).MoveTo(newPath);
 388                 else
 389                 {
 390                     (previousFile as DirectoryInfo).MoveTo(newPath);
 391                 }
 392                 var state = StatusKeeper.GetStateByFilePath(previousFullPath);
 393                 state.FilePath = newPath;
 394                 state.SaveCopy();
 395                 StatusKeeper.SetFileState(previousFullPath,FileStatus.Deleted,FileOverlayStatus.Deleted, "Deleted");
 396             }
 397         }
 398
 399         private async Task SyncFiles(AccountInfo accountInfo,CloudAction action)
 400         {
 401             if (accountInfo == null)
 402                 throw new ArgumentNullException("accountInfo");
 403             if (action==null)
 404                 throw new ArgumentNullException("action");
 405             if (action.LocalFile==null)
 406                 throw new ArgumentException("The action's local file is not specified","action");
 407             if (!Path.IsPathRooted(action.LocalFile.FullName))
 408                 throw new ArgumentException("The action's local file path must be absolute","action");
 409             if (action.CloudFile== null)
 410                 throw new ArgumentException("The action's cloud file is not specified", "action");
 411             Contract.EndContractBlock();
 412             using (ThreadContext.Stacks["Operation"].Push("SyncFiles"))
 413             {
 414
 415                 //var localFile = action.LocalFile;
 416                 var cloudFile = action.CloudFile;
 417                 var downloadPath = action.LocalFile.GetProperCapitalization();
 418
 419                 var cloudHash = cloudFile.Hash.ToLower();
 420                 var previousCloudHash = cloudFile.PreviousHash == null?null: cloudFile.PreviousHash.ToLower();
 421                 var localHash = action.TreeHash.Value.TopHash.ToHashString();// LocalHash.Value.ToLower();
 422                 //var topHash = action.TopHash.Value.ToLower();
 423
 424                 if(cloudFile.IsDirectory && action.LocalFile is DirectoryInfo)
 425                 {
 426                     Log.InfoFormat("Skipping folder {0} , exists in server", downloadPath);
 427                     return;
 428                 }
 429
 430                 //At this point we know that an object has changed on the server and that a local
 431                 //file already exists. We need to decide whether the file has only changed on
 432                 //the server or there is a conflicting change on the client.
 433                 //
 434
 435                 //If the hashes match, we are done
 436                 if (cloudFile != ObjectInfo.Empty && cloudHash == localHash)
 437                 {
 438                     Log.InfoFormat("Skipping {0}, hashes match", downloadPath);
 439                     return;
 440                 }
 441
 442                 //If the local and remote files have 0 length their hashes will not match
 443                 if (!cloudFile.IsDirectory && cloudFile.Bytes==0 && action.LocalFile is FileInfo && (action.LocalFile as FileInfo).Length==0 )
 444                 {
 445                     Log.InfoFormat("Skipping {0}, files are empty", downloadPath);
 446                     return;
 447                 }
 448
 449                 //The hashes DON'T match. We need to sync
 450
 451                 // If the previous tophash matches the local tophash, the file was only changed on the server.
 452                 if (localHash == previousCloudHash)
 453                 {
 454                     await Downloader.DownloadCloudFile(accountInfo, cloudFile, downloadPath, CurrentOperationCancelToken);
 455                 }
 456                 else
 457                 {
 458                     //If the previous and local hash don't match, there was a local conflict
 459                     //that was not uploaded to the server. We have a conflict
 460                     ReportConflictForMismatch(downloadPath);
 461                 }
 462             }
 463         }
 464
 465         private void ReportConflictForMismatch(string downloadPath)
 466         {
 467             if (String.IsNullOrWhiteSpace(downloadPath))
 468                 throw new ArgumentNullException("downloadPath");
 469             Contract.EndContractBlock();
 470
 471             StatusKeeper.SetFileState(downloadPath,FileStatus.Conflict, FileOverlayStatus.Conflict,"File changed at the server");
 472             UpdateStatus(PithosStatus.HasConflicts);
 473             var message = String.Format("Conflict detected for file {0}", downloadPath);
 474             Log.Warn(message);
 475             StatusNotification.NotifyChange(message, TraceLevel.Warning);
 476         }
 477
 478         public void Post(CloudAction cloudAction)
 479         {
 480             if (cloudAction == null)
 481                 throw new ArgumentNullException("cloudAction");
 482             if (cloudAction.AccountInfo==null)
 483                 throw new ArgumentException("The CloudAction.AccountInfo is empty","cloudAction");
 484             Contract.EndContractBlock();
 485
 486             DeleteAgent.ProceedEvent.Wait();
 487
 488             if (cloudAction is CloudDeleteAction)
 489                 DeleteAgent.Post((CloudDeleteAction)cloudAction);
 490             else
 491                 _agent.Post(cloudAction);
 492         }
 493
 494
 495         public IEnumerable<CloudAction> GetEnumerable()
 496         {
 497             return _agent.GetEnumerable();
 498         }
 499
 500         public Task GetDeleteAwaiter()
 501         {
 502             return DeleteAgent.ProceedEvent.WaitAsync();
 503         }
 504         public CancellationToken CancellationToken
 505         {
 506             get { return _agent.CancellationToken; }
 507         }
 508
 509         public bool Pause
 510         {
 511             get {
 512                 return _pause;
 513             }
 514             set {
 515                 _pause = value;
 516                 if (_pause)
 517                     _unPauseEvent.Reset();
 518                 else
 519                 {
 520                     _unPauseEvent.Set();
 521                 }
 522             }
 523         }
 524
 525
 526         private void RenameCloudFile(AccountInfo accountInfo,CloudMoveAction action)
 527         {
 528             if (accountInfo==null)
 529                 throw new ArgumentNullException("accountInfo");
 530             if (action==null)
 531                 throw new ArgumentNullException("action");
 532             if (action.CloudFile==null)
 533                 throw new ArgumentException("CloudFile","action");
 534             if (action.LocalFile==null)
 535                 throw new ArgumentException("LocalFile","action");
 536             if (action.OldLocalFile==null)
 537                 throw new ArgumentException("OldLocalFile","action");
 538             if (action.OldCloudFile==null)
 539                 throw new ArgumentException("OldCloudFile","action");
 540             Contract.EndContractBlock();
 541
 542             using (ThreadContext.Stacks["Operation"].Push("RenameCloudFile"))
 543             {
 544
 545                 var newFilePath = action.LocalFile.FullName;
 546
 547                 //How do we handle concurrent renames and deletes/uploads/downloads?
 548                 //* A conflicting upload means that a file was renamed before it had a chance to finish uploading
 549                 //  This should never happen as the network agent executes only one action at a time
 550                 //* A conflicting download means that the file was modified on the cloud. While we can go on and complete
 551                 //  the rename, there may be a problem if the file is downloaded in blocks, as subsequent block requests for the
 552                 //  same name will fail.
 553                 //  This should never happen as the network agent executes only one action at a time.
 554                 //* A conflicting delete can happen if the rename was followed by a delete action that didn't have the chance
 555                 //  to remove the rename from the queue.
 556                 //  We can probably ignore this case. It will result in an error which should be ignored
 557
 558
 559                 //The local file is already renamed
 560                 StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Modified).Wait();
 561
 562
 563                 var account = action.CloudFile.Account ?? accountInfo.UserName;
 564                 var container = action.CloudFile.Container;
 565
 566                 var client = new CloudFilesClient(accountInfo);
 567                 //TODO: What code is returned when the source file doesn't exist?
 568                 client.MoveObject(account, container, action.OldCloudFile.Name, container, action.CloudFile.Name);
 569
 570                 StatusKeeper.SetFileStatus(newFilePath, FileStatus.Unchanged);
 571                 StatusKeeper.SetFileOverlayStatus(newFilePath, FileOverlayStatus.Normal).Wait();
 572                 NativeMethods.RaiseChangeNotification(newFilePath);
 573             }
 574         }
 575
 576
 577
 578
 579     }
 580
 581
 582
 583
 584 }