Merge branch 'safe_file_access'

DragonQ · May 19, 2017 · e26d6c6 · e26d6c6
2 parents 183dc6f + 1695f83
commit e26d6c6
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Showing 3 changed files with 124 additions and 48 deletions.
diff --git a/FileParser.vb b/FileParser.vb
@@ -6,17 +6,24 @@ Imports MusicFolderSyncer.Codec.CodecType
 Imports MusicFolderSyncer.SyncSettings.TranscodeMode
 Imports System.IO
 Imports System.Environment
+Imports System.Threading
 #End Region
 
 Class FileParser
 
+    Implements IDisposable
+
     Private ProcessID As Int32
+    Private Shared FileTimeout As Int32 = 60
     ReadOnly Property FilePath As String
+    Private FileLock As Boolean
     Private MyGlobalSyncSettings As GlobalSyncSettings
     Private SyncSettings As SyncSettings()
+    Private SourceFileStream As FileStream = Nothing
 
 #Region " New "
     Public Sub New(ByRef NewGlobalSyncSettings As GlobalSyncSettings, ByVal NewProcessID As Int32, ByVal NewFilePath As String, Optional NewSyncSettings As SyncSettings = Nothing)
+
         ProcessID = NewProcessID
         FilePath = NewFilePath
         MyGlobalSyncSettings = NewGlobalSyncSettings
@@ -25,10 +32,72 @@ Class FileParser
         Else
             SyncSettings = {NewSyncSettings}
         End If
+
+        SourceFileStream = WaitForFile(FilePath, FileMode.Open, FileAccess.Read, FileShare.Read, FileTimeout)
+        If SourceFileStream Is Nothing Then
+            MyLog.Write(ProcessID, "Could not get file system lock on source file: """ & FilePath.Substring(MyGlobalSyncSettings.SourceDirectory.Length) & """.", Warning)
+            FileLock = False
+        Else
+            FileLock = True
+        End If
+
     End Sub
 #End Region
 
+    Public Overridable Sub Dispose() Implements IDisposable.Dispose
+        If Not SourceFileStream Is Nothing Then
+            SourceFileStream.Close()
+        End If
+    End Sub
+
 #Region " Transfer File To Sync Folder "
+    Private Shared Function SafeCopy(SourceFileStream As FileStream, SyncFilePath As String) As ReturnObject
+
+        Dim MyReturnObject As ReturnObject
+
+        Try
+            If SourceFileStream Is Nothing Then Throw New Exception("Could not get file system lock on source file.")
+            Using NewFile As FileStream = WaitForFile(SyncFilePath, FileMode.CreateNew, FileAccess.Write, FileShare.None, FileTimeout)
+                If Not NewFile Is Nothing Then
+                    SourceFileStream.CopyTo(NewFile)
+                    MyReturnObject = New ReturnObject(True, "", Nothing)
+                Else
+                    MyReturnObject = New ReturnObject(False, "Could not get file system lock on destination file.", Nothing)
+                End If
+            End Using
+        Catch ex As Exception
+            MyReturnObject = New ReturnObject(False, ex.Message, 0)
+        End Try
+
+        Return MyReturnObject
+
+    End Function
+
+    Private Shared Function WaitForFile(fullPath As String, mode As FileMode, access As FileAccess, share As FileShare, timeoutSeconds As Int32) As FileStream
+        Dim msBetweenTries As Int32 = 500
+        Dim numTries As Int32 = CInt(Math.Ceiling(timeoutSeconds / (msBetweenTries / 1000)))
+
+        For count As Integer = 0 To numTries
+            Dim fs As FileStream = Nothing
+
+            Try
+                fs = New FileStream(fullPath, mode, access, share)
+
+                fs.ReadByte()
+                fs.Seek(0, SeekOrigin.Begin)
+
+                Return fs
+            Catch generatedExceptionName As IOException
+                If fs IsNot Nothing Then
+                    fs.Dispose()
+                End If
+                Thread.Sleep(msBetweenTries)
+            End Try
+        Next
+
+        Return Nothing
+    End Function
+
     Public Function TransferToSyncFolder() As ReturnObject
 
         Dim MyReturnObject As ReturnObject
@@ -49,7 +118,8 @@ Class FileParser
                                 SyncSetting.Encoder.GetFileExtensions(0)
                         Else
                             Directory.CreateDirectory(Path.GetDirectoryName(SyncFilePath))
-                            File.Copy(FilePath, SyncFilePath, True)
+                            Dim Result As ReturnObject = SafeCopy(SourceFileStream, SyncFilePath)
+                            If Not Result.Success Then Throw New Exception(Result.ErrorMessage)
                         End If
 
                         Dim NewFile As New FileInfo(SyncFilePath)
@@ -144,7 +214,8 @@ Class FileParser
                                 TranscodeFile(SyncFilePath, SyncSetting)
                             Else
                                 Directory.CreateDirectory(Path.GetDirectoryName(SyncFilePath))
-                                File.Copy(FilePath, SyncFilePath, True)
+                                Dim Result As ReturnObject = SafeCopy(SourceFileStream, SyncFilePath)
+                                If Not Result.Success Then Throw New Exception(Result.ErrorMessage)
                             End If
 
                             MyLog.Write(ProcessID, "...successfully added file to sync folder.", Information)
@@ -257,6 +328,11 @@ Class FileParser
 
     Private Function CheckFileTags(MyCodec As Codec, SyncSetting As SyncSettings) As Boolean
 
+        If FileLock = False Then
+            MyLog.Write(ProcessID, "...could not obtain file tags. Could not get file system lock on source file.", Warning)
+            Return False
+        End If
+
         Dim TagsObject As ReturnObject = MyCodec.MatchTag(FilePath, SyncSetting.GetWatcherTags)
 
         If TagsObject.Success Then

diff --git a/NewSyncWindow.xaml.vb b/NewSyncWindow.xaml.vb
@@ -580,9 +580,9 @@ Public Class NewSyncWindow
             Dim TransferResult As ReturnObject
 
             Try
-                Dim MyFileParser As New FileParser(MyGlobalSyncSettings, ProcessID, FilePath, SingleSyncSettings)
-                TransferResult = MyFileParser.TransferToSyncFolder()
-
+                Using MyFileParser As New FileParser(MyGlobalSyncSettings, ProcessID, FilePath, SingleSyncSettings)
+                    TransferResult = MyFileParser.TransferToSyncFolder()
+                End Using
                 If TransferResult.Success Then
                     Dim NewSize As Int64 = CType(TransferResult.MyObject, Int64)
 

diff --git a/TrayApp.vb b/TrayApp.vb
@@ -199,14 +199,14 @@ Public Class TrayApp
 
         If FilterMatch(e.Name) Then
             MyLog.Write(FileID, "File renamed: " & e.FullPath, Information)
-            Dim MyFileParser As New FileParser(UserGlobalSyncSettings, FileID, e.FullPath)
-            Dim Result As ReturnObject = MyFileParser.RenameInSyncFolder(e.OldFullPath) 'RenameInSyncFolder(MyFileParser, e.OldFullPath)
-            If Result.Success Then
-                If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File renamed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
-            Else
-                If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File rename failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
-            End If
-            MyFileParser = Nothing
+            Using MyFileParser As New FileParser(UserGlobalSyncSettings, FileID, e.FullPath)
+                Dim Result As ReturnObject = MyFileParser.RenameInSyncFolder(e.OldFullPath)
+                If Result.Success Then
+                    If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File renamed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
+                Else
+                    If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File rename failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
+                End If
+            End Using
         End If
 
         If Interlocked.Equals(FileID, MaxFileID) Then
@@ -221,41 +221,41 @@ Public Class TrayApp
         'Handles changed and new files
 
         If FilterMatch(e.Name) Then
-            Dim MyFileParser As New FileParser(UserGlobalSyncSettings, FileID, e.FullPath)
-            Select Case e.ChangeType
-                Case Is = IO.WatcherChangeTypes.Changed
-                    MyLog.Write(FileID, "Source file changed: " & e.FullPath, Information)
-                    Dim Result As ReturnObject = MyFileParser.DeleteInSyncFolder()
-
-                    If Result.Success Then
-                        Result = MyFileParser.TransferToSyncFolder()
-                    End If
-
-                    If Result.Success Then
-                        If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
-                    Else
-                        If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processing failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
-                    End If
-                Case Is = IO.WatcherChangeTypes.Created
-                    MyLog.Write(FileID, "Source file created: " & e.FullPath, Information)
-                    Dim Result As ReturnObject = MyFileParser.TransferToSyncFolder()
-
-                    If Result.Success Then
-                        If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
-                    Else
-                        If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processing failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
-                    End If
-                Case Is = IO.WatcherChangeTypes.Deleted
-                    MyLog.Write(FileID, "Source file deleted: " & e.FullPath, Information)
-                    Dim Result As ReturnObject = MyFileParser.DeleteInSyncFolder()
-
-                    If Result.Success Then
-                        If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File deleted:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
-                    Else
-                        If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File deletion failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
-                    End If
-            End Select
-            MyFileParser = Nothing
+            Using MyFileParser As New FileParser(UserGlobalSyncSettings, FileID, e.FullPath)
+                Select Case e.ChangeType
+                    Case Is = IO.WatcherChangeTypes.Changed
+                        MyLog.Write(FileID, "Source file changed: " & e.FullPath, Information)
+                        Dim Result As ReturnObject = MyFileParser.DeleteInSyncFolder()
+
+                        If Result.Success Then
+                            Result = MyFileParser.TransferToSyncFolder()
+                        End If
+
+                        If Result.Success Then
+                            If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
+                        Else
+                            If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processing failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
+                        End If
+                    Case Is = IO.WatcherChangeTypes.Created
+                        MyLog.Write(FileID, "Source file created: " & e.FullPath, Information)
+                        Dim Result As ReturnObject = MyFileParser.TransferToSyncFolder()
+
+                        If Result.Success Then
+                            If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
+                        Else
+                            If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File processing failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
+                        End If
+                    Case Is = IO.WatcherChangeTypes.Deleted
+                        MyLog.Write(FileID, "Source file deleted: " & e.FullPath, Information)
+                        Dim Result As ReturnObject = MyFileParser.DeleteInSyncFolder()
+
+                        If Result.Success Then
+                            If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File deleted:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Info)
+                        Else
+                            If Tray.Visible Then Tray.ShowBalloonTip(BalloonTime, "File deletion failed:", e.FullPath.Substring(UserGlobalSyncSettings.SourceDirectory.Length), ToolTipIcon.Error)
+                        End If
+                End Select
+            End Using
         End If
 
         If Interlocked.Equals(FileID, MaxFileID) Then