root / trunk / Pithos.Core / Agents / FileAgent.cs @ a27aa447
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using System; |
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using System.Collections.Generic; |
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using System.ComponentModel.Composition; |
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using System.Diagnostics; |
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using System.Diagnostics.Contracts; |
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using System.IO; |
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using System.Linq; |
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using System.Text; |
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using Pithos.Interfaces; |
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using Pithos.Network; |
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|
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namespace Pithos.Core.Agents |
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{ |
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[Export] |
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public class FileAgent |
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{ |
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Agent<WorkflowState> _agent; |
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private FileSystemWatcher _watcher; |
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|
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[Import] |
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public IStatusKeeper StatusKeeper { get; set; } |
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[Import] |
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public IPithosWorkflow Workflow { get; set; } |
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[Import] |
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public WorkflowAgent WorkflowAgent { get; set; } |
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|
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public string RootPath { get; private set; } |
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|
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public void Start(string rootPath) |
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{ |
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RootPath = rootPath; |
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_watcher = new FileSystemWatcher(rootPath); |
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_watcher.Changed += OnFileEvent; |
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_watcher.Created += OnFileEvent; |
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_watcher.Deleted += OnFileEvent; |
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_watcher.Renamed += OnRenameEvent; |
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_watcher.EnableRaisingEvents = true; |
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|
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|
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_agent = Agent<WorkflowState>.Start(inbox => |
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{ |
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Action loop = null; |
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loop = () => |
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{ |
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var message = inbox.Receive(); |
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var process = message.ContinueWith(t => |
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{ |
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var state = t.Result; |
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Process(state); |
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inbox.DoAsync(loop); |
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}); |
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|
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process.ContinueWith(t => |
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{ |
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inbox.DoAsync(loop); |
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if (t.IsFaulted) |
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{ |
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var ex = t.Exception.InnerException; |
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if (ex is OperationCanceledException) |
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inbox.Stop(); |
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Trace.TraceError("[ERROR] File Event Processing:\r{0}", ex); |
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} |
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}); |
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|
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}; |
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loop(); |
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}); |
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} |
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|
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public bool Pause |
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{ |
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get { return _watcher == null || !_watcher.EnableRaisingEvents; } |
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set |
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{ |
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if (_watcher != null) |
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_watcher.EnableRaisingEvents = !value; |
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} |
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} |
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|
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public string FragmentsPath { get; set; } |
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|
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public void Post(WorkflowState workflowState) |
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{ |
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_agent.Post(workflowState); |
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} |
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|
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public void Stop() |
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{ |
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if (_watcher != null) |
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{ |
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_watcher.Changed -= OnFileEvent; |
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_watcher.Created -= OnFileEvent; |
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_watcher.Deleted -= OnFileEvent; |
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_watcher.Renamed -= OnRenameEvent; |
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_watcher.Dispose(); |
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} |
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_watcher = null; |
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|
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_agent.Stop(); |
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} |
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|
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// Enumerate all files in the Pithos directory except those in the Fragment folder |
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// and files with a .ignore extension |
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public IEnumerable<string> EnumerateFiles(string searchPattern="*") |
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{ |
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var monitoredFiles = from filePath in Directory.EnumerateFileSystemEntries(RootPath, searchPattern, SearchOption.AllDirectories) |
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where !Ignore(filePath) |
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select filePath; |
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return monitoredFiles; |
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} |
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|
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public IEnumerable<FileInfo> EnumerateFileInfos(string searchPattern="*") |
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{ |
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var rootDir = new DirectoryInfo(RootPath); |
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var monitoredFiles = from file in rootDir.EnumerateFiles(searchPattern, SearchOption.AllDirectories) |
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where !Ignore(file.FullName) |
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select file; |
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return monitoredFiles; |
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} |
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|
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public IEnumerable<string> EnumerateFilesAsRelativeUrls(string searchPattern="*") |
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{ |
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var rootDir = new DirectoryInfo(RootPath); |
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var monitoredFiles = from file in rootDir.EnumerateFiles(searchPattern, SearchOption.AllDirectories) |
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where !Ignore(file.FullName) |
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select file.AsRelativeUrlTo(RootPath); |
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return monitoredFiles; |
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} |
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|
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|
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|
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|
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private bool Ignore(string filePath) |
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{ |
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if (filePath.StartsWith(FragmentsPath)) |
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return true; |
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return false; |
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} |
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|
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//Post a Change message for all events except rename |
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void OnFileEvent(object sender, FileSystemEventArgs e) |
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{ |
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//Ignore events that affect the Fragments folder |
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var filePath = e.FullPath; |
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if (Ignore(filePath)) |
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return; |
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_agent.Post(new WorkflowState { Path = filePath, FileName = e.Name, TriggeringChange = e.ChangeType }); |
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} |
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|
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|
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//Post a Change message for renames containing the old and new names |
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void OnRenameEvent(object sender, RenamedEventArgs e) |
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{ |
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var oldFullPath = e.OldFullPath; |
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var fullPath = e.FullPath; |
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if (Ignore(oldFullPath) || Ignore(fullPath)) |
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return; |
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|
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_agent.Post(new WorkflowState |
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{ |
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OldPath = oldFullPath, |
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OldFileName = e.OldName, |
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Path = fullPath, |
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FileName = e.Name, |
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TriggeringChange = e.ChangeType |
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}); |
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} |
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|
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|
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private void Process(WorkflowState state) |
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{ |
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Debug.Assert(!Ignore(state.Path)); |
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|
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var networkState = NetworkGate.GetNetworkState(state.Path); |
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//Skip if the file is already being downloaded or uploaded and |
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//the change is create or modify |
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if (networkState != NetworkOperation.None && |
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( |
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state.TriggeringChange == WatcherChangeTypes.Created || |
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state.TriggeringChange == WatcherChangeTypes.Changed |
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)) |
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return; |
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|
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try |
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{ |
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UpdateFileStatus(state); |
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UpdateOverlayStatus(state); |
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UpdateFileChecksum(state); |
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WorkflowAgent.Post(state); |
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} |
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catch (IOException exc) |
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{ |
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Trace.TraceWarning("File access error occured, retrying {0}\n{1}", state.Path, exc); |
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_agent.Post(state); |
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} |
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catch (Exception exc) |
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{ |
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Trace.TraceWarning("Error occured while indexing{0. The file will be skipped}\n{1}", state.Path, exc); |
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} |
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} |
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|
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private Dictionary<WatcherChangeTypes, FileStatus> _statusDict = new Dictionary<WatcherChangeTypes, FileStatus> |
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{ |
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{WatcherChangeTypes.Created,FileStatus.Created}, |
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{WatcherChangeTypes.Changed,FileStatus.Modified}, |
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{WatcherChangeTypes.Deleted,FileStatus.Deleted}, |
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{WatcherChangeTypes.Renamed,FileStatus.Renamed} |
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}; |
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|
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private WorkflowState UpdateFileStatus(WorkflowState state) |
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{ |
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Debug.Assert(!state.Path.Contains("fragments")); |
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Debug.Assert(!state.Path.EndsWith(".ignore", StringComparison.InvariantCultureIgnoreCase)); |
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|
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string path = state.Path; |
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FileStatus status = _statusDict[state.TriggeringChange]; |
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var oldStatus = Workflow.StatusKeeper.GetFileStatus(path); |
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if (status == oldStatus) |
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{ |
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state.Status = status; |
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state.Skip = true; |
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return state; |
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} |
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if (state.Status == FileStatus.Renamed) |
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Workflow.ClearFileStatus(path); |
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|
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state.Status = Workflow.SetFileStatus(path, status); |
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return state; |
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} |
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|
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private WorkflowState UpdateOverlayStatus(WorkflowState state) |
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{ |
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if (state.Skip) |
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return state; |
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|
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switch (state.Status) |
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{ |
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case FileStatus.Created: |
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case FileStatus.Modified: |
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this.StatusKeeper.SetFileOverlayStatus(state.Path, FileOverlayStatus.Modified); |
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break; |
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case FileStatus.Deleted: |
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this.StatusKeeper.RemoveFileOverlayStatus(state.Path); |
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break; |
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case FileStatus.Renamed: |
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this.StatusKeeper.RemoveFileOverlayStatus(state.OldPath); |
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this.StatusKeeper.SetFileOverlayStatus(state.Path, FileOverlayStatus.Modified); |
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break; |
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case FileStatus.Unchanged: |
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this.StatusKeeper.SetFileOverlayStatus(state.Path, FileOverlayStatus.Normal); |
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break; |
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} |
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|
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if (state.Status == FileStatus.Deleted) |
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NativeMethods.RaiseChangeNotification(Path.GetDirectoryName(state.Path)); |
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else |
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NativeMethods.RaiseChangeNotification(state.Path); |
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return state; |
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} |
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|
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|
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private WorkflowState UpdateFileChecksum(WorkflowState state) |
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{ |
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if (state.Skip) |
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return state; |
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|
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if (state.Status == FileStatus.Deleted) |
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return state; |
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var path = state.Path; |
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//Skip calculation for folders |
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if (Directory.Exists(path)) |
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return state; |
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string hash = Signature.CalculateMD5(path); |
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StatusKeeper.UpdateFileChecksum(path, hash); |
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state.Hash = hash; |
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return state; |
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} |
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|
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//Does the file exist in the container's local folder? |
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public bool Exists(string relativePath) |
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{ |
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if (String.IsNullOrWhiteSpace(relativePath)) |
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throw new ArgumentNullException("relativePath"); |
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//A RootPath must be set before calling this method |
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if (String.IsNullOrWhiteSpace(RootPath)) |
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throw new InvalidOperationException("RootPath was not set"); |
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Contract.EndContractBlock(); |
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//Create the absolute path by combining the RootPath with the relativePath |
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var absolutePath=Path.Combine(RootPath, relativePath); |
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//Is this a valid file? |
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if (File.Exists(absolutePath)) |
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return true; |
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//Or a directory? |
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if (Directory.Exists(RootPath)) |
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return true; |
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//Fail if it is neither |
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return false; |
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} |
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|
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public FileInfo GetFileInfo(string relativePath) |
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{ |
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if (String.IsNullOrWhiteSpace(relativePath)) |
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throw new ArgumentNullException("relativePath"); |
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//A RootPath must be set before calling this method |
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if (String.IsNullOrWhiteSpace(RootPath)) |
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throw new InvalidOperationException("RootPath was not set"); |
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Contract.EndContractBlock(); |
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|
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var absolutePath = Path.Combine(RootPath, relativePath); |
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Debug.Assert(File.Exists(absolutePath),String.Format("Path {0} doesn't exist",absolutePath)); |
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|
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return new FileInfo(absolutePath); |
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|
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} |
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|
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} |
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} |