/// <summary> /// Creates or updates folder in the remote storage. /// </summary> /// <param name="remoteStoragePath">Path of the folder to be created or updated in the remote storage.</param> /// <param name="newInfo">New information about the folder, such as modification date, attributes, custom data, etc.</param> /// <param name="mode">Specifies if a new folder should be created or existing folder should be updated.</param> /// <param name="lockInfo">Information about the lock. Caller passes null if the item is not locked.</param> /// <returns>New ETag returned from the remote storage.</returns> protected async Task <string> CreateOrUpdateFolderAsync(string remoteStoragePath, IFolderBasicInfo newInfo, FileMode mode, ServerLockInfo lockInfo = null) { // Get ETag and lock-token here and send it to the remote storage with the new item content/info if needed. if (mode == FileMode.Open) { // Get ETag. string eTag = await ETag.GetETagAsync(UserFileSystemPath); // Get lock-token. string lockToken = lockInfo?.LockToken; } DirectoryInfo remoteStorageItem = new DirectoryInfo(remoteStoragePath); try { Program.RemoteStorageMonitorInstance.Enabled = false; // Disable RemoteStorageMonitor to avoid circular calls. remoteStorageItem.Create(); string userFileSystemPath = Mapping.ReverseMapPath(remoteStoragePath); if (mode == FileMode.Open) { // Verify that the item in the remote storage is not modified since it was downloaded to the user file system. // In your real-life application you will send the ETag to the server as part of the update request. FileSystemItemBasicInfo itemInfo = Mapping.GetUserFileSysteItemBasicInfo(remoteStorageItem); if (!(await ETag.ETagEqualsAsync(userFileSystemPath, itemInfo))) { throw new ConflictException(Modified.Server, "Item is modified in the remote storage, ETags not equal."); } } // Update ETag/LastWriteTime in user file system, so the synchronyzation or remote storage monitor would not start the new update. // This is only required to avoid circular updates because of the simplicity of this sample. // In your real-life application you will receive a new ETag from server in the update response. string eTag = newInfo.LastWriteTime.DateTime.ToBinary().ToString(); await ETag.SetETagAsync(userFileSystemPath, eTag); remoteStorageItem.Attributes = newInfo.Attributes; remoteStorageItem.CreationTimeUtc = newInfo.CreationTime.DateTime; remoteStorageItem.LastWriteTimeUtc = newInfo.LastWriteTime.DateTime; remoteStorageItem.LastAccessTimeUtc = newInfo.LastAccessTime.DateTime; remoteStorageItem.LastWriteTimeUtc = newInfo.LastWriteTime.DateTime; return(eTag); } finally { Program.RemoteStorageMonitorInstance.Enabled = true; } }
/// <summary> /// Returns true if the item was created and must be synched to remote storage. /// </summary> /// <returns> /// True if the item was created in the user file system and does not exists /// in the remote storage. False otherwise. /// </returns> public static bool IsNew(this PlaceholderItem placeholder) { // ETag absence signals that the item is new. // However, ETag file may not exists during move operation, // additionally checking OriginalPath presence. // Can not rely on OriginalPath only, // because MS Office files are being deleted and re-created during transactional save. string originalPath = placeholder.GetOriginalPath(); bool eTagFileExists = File.Exists(ETag.GetETagFilePath(placeholder.Path)); return(!eTagFileExists && string.IsNullOrEmpty(originalPath)); }
/// <summary> /// Returns true if the remote storage ETag and user file system ETags are equal. False - otherwise. /// </summary> /// <param name="userFileSystemPath">User file system item.</param> /// <param name="remoteStorageItem">Remote storage item info.</param> /// <remarks> /// ETag is updated on the server during every document update and is sent to client with a file. /// During client->server update it is sent back to the remote storage together with a modified content. /// This ensures the changes on the server are not overwritten if the document on the server is modified. /// </remarks> internal static async Task <bool> ETagEqualsAsync(string userFileSystemPath, FileSystemItemBasicInfo remoteStorageItem) { string remoteStorageETag = remoteStorageItem.ETag; // Intstead of the real ETag we store remote storage LastWriteTime when // creating and updating files/folders. string userFileSystemETag = await ETag.GetETagAsync(userFileSystemPath); if (string.IsNullOrEmpty(userFileSystemETag)) { // No ETag associated with the file. This is a new file created in user file system. return(false); } return(remoteStorageETag == userFileSystemETag); }
/// <inheritdoc/> public async Task GetChildrenAsync(string pattern, IOperationContext operationContext, IFolderListingResultContext resultContext) { // This method has a 60 sec timeout. // To process longer requests and reset the timout timer call one of the following: // - resultContext.ReturnChildren() method. // - resultContext.ReportProgress() method. Logger.LogMessage($"IFolder.GetChildrenAsync({pattern})", UserFileSystemPath); IEnumerable <FileSystemItemBasicInfo> children = await new UserFolder(UserFileSystemPath).EnumerateChildrenAsync(pattern); // Filtering existing files/folders. This is only required to avoid extra errors in the log. List <IFileSystemItemBasicInfo> newChildren = new List <IFileSystemItemBasicInfo>(); foreach (IFileSystemItemBasicInfo child in children) { string userFileSystemItemPath = Path.Combine(UserFileSystemPath, child.Name); if (!FsPath.Exists(userFileSystemItemPath)) { Logger.LogMessage("Creating", child.Name); newChildren.Add(child); } } // To signal that the children enumeration is completed // always call ReturnChildren(), even if the folder is empty. resultContext.ReturnChildren(newChildren.ToArray(), newChildren.Count()); // Save ETags and set "locked by another user" icon. foreach (FileSystemItemBasicInfo child in children) { string userFileSystemItemPath = Path.Combine(UserFileSystemPath, child.Name); // Create ETags. // ETags must correspond with a server file/folder, NOT with a client placeholder. // It should NOT be moved/deleted/updated when a placeholder in the user file system is moved/deleted/updated. // It should be moved/deleted when a file/folder in the remote storage is moved/deleted. ETag.SetETagAsync(userFileSystemItemPath, child.ETag); // Set the lock icon and read-only attribute, to indicate that the item is locked by another user. new UserFileSystemRawItem(userFileSystemItemPath).SetLockedByAnotherUserAsync(child.LockedByAnotherUser); } }
/// <summary> /// Creates or updates file in the remote storage. /// </summary> /// <param name="remoteStoragePath">Path of the file to be created or updated in the remote storage.</param> /// <param name="newInfo">New information about the file, such as modification date, attributes, custom data, etc.</param> /// <param name="mode">Specifies if a new file should be created or existing file should be updated.</param> /// <param name="newContentStream">New file content or null if the file content is not modified.</param> /// <returns>New ETag returned from the remote storage.</returns> protected async Task <string> CreateOrUpdateFileAsync(string remoteStoragePath, IFileBasicInfo newInfo, FileMode mode, Stream newContentStream = null) { // Get ETag and lock-token here and send it to the remote storage with the new item content/info if needed. if (mode == FileMode.Open) { // Get ETag. string eTag = await ETag.GetETagAsync(UserFileSystemPath); // Get lock-token. string lockToken = Lock?.LockToken; } FileInfo remoteStorageItem = new FileInfo(remoteStoragePath); try { Program.RemoteStorageMonitorInstance.Enabled = false; // Disable RemoteStorageMonitor to avoid circular calls. // If another thread is trying to sync the same file, this call will fail in other threads. // In your implementation you must lock your remote storage file, or block it for reading and writing by other means. await using (FileStream remoteStorageStream = remoteStorageItem.Open(mode, FileAccess.Write, FileShare.None)) { string userFileSystemPath = Mapping.ReverseMapPath(remoteStoragePath); if (mode == FileMode.Open) { // Verify that the item in the remote storage is not modified since it was downloaded to the user file system. // In your real-life application you will send the ETag to the server as part of the update request. FileSystemItemBasicInfo itemInfo = Mapping.GetUserFileSysteItemBasicInfo(remoteStorageItem); if (!(await ETag.ETagEqualsAsync(userFileSystemPath, itemInfo))) { throw new ConflictException(Modified.Server, "Item is modified in the remote storage, ETags not equal."); } } // Update ETag/LastWriteTime in user file system, so the synchronyzation or remote storage monitor would not start the new update. // This is only required to avoid circular updates because of the simplicity of this sample. // In your real-life application you will receive a new ETag from the server in the update response // and return it from this method. string eTag = newInfo.LastWriteTime.ToBinary().ToString(); await ETag.SetETagAsync(userFileSystemPath, eTag); // Update remote storage file content. if (newContentStream != null) { await newContentStream.CopyToAsync(remoteStorageStream); remoteStorageStream.SetLength(newContentStream.Length); } // Update remote storage file basic info. WindowsFileSystemItem.SetFileInformation( remoteStorageStream.SafeFileHandle, newInfo.Attributes, newInfo.CreationTime, newInfo.LastWriteTime, newInfo.LastAccessTime, newInfo.LastWriteTime); return(eTag); } } finally { Program.RemoteStorageMonitorInstance.Enabled = true; } }