public static Task Run(Snapshots.ISnapshotService snapshot, Options options, BackupStatsCollector stats, BackupDatabase database) { return(AutomationExtensions.RunTask( new { Input = Channels.ProcessedFiles.ForRead, ProgressChannel = Channels.ProgressEvents.ForWrite, Output = Channels.AcceptedChangedFile.ForWrite }, async self => { var EMPTY_METADATA = Utility.WrapMetadata(new Dictionary <string, string>(), options); // Pre-cache the option variables here to simplify and // speed up repeated option access below var SKIPFILESLARGERTHAN = options.SkipFilesLargerThan; // Zero and max both indicate no size limit if (SKIPFILESLARGERTHAN == long.MaxValue) { SKIPFILESLARGERTHAN = 0; } var DISABLEFILETIMECHECK = options.DisableFiletimeCheck; var CHECKFILETIMEONLY = options.CheckFiletimeOnly; var SKIPMETADATA = options.SkipMetadata; while (true) { var e = await self.Input.ReadAsync(); long filestatsize = -1; try { filestatsize = snapshot.GetFileSize(e.Path); } catch (Exception ex) { Logging.Log.WriteExplicitMessage(FILELOGTAG, "FailedToReadSize", ex, "Failed to read size of file: {0}", e.Path); } await stats.AddExaminedFile(filestatsize); // Stop now if the file is too large var tooLargeFile = SKIPFILESLARGERTHAN != 0 && filestatsize >= 0 && filestatsize > SKIPFILESLARGERTHAN; if (tooLargeFile) { Logging.Log.WriteVerboseMessage(FILELOGTAG, "SkipCheckTooLarge", "Skipped checking file, because the size exceeds limit {0}", e.Path); await self.ProgressChannel.WriteAsync(new ProgressEvent() { Filepath = e.Path, Length = filestatsize, Type = EventType.FileSkipped }); continue; } // Invalid ID indicates a new file var isNewFile = e.OldId < 0; // If we disable the filetime check, we always assume that the file has changed // Otherwise we check that the timestamps are different or if any of them are empty var timestampChanged = DISABLEFILETIMECHECK || e.LastWrite != e.OldModified || e.LastWrite.Ticks == 0 || e.OldModified.Ticks == 0; // Avoid generating a new matadata blob if timestamp has not changed // and we only check for timestamp changes if (CHECKFILETIMEONLY && !timestampChanged && !isNewFile) { Logging.Log.WriteVerboseMessage(FILELOGTAG, "SkipCheckNoTimestampChange", "Skipped checking file, because timestamp was not updated {0}", e.Path); try { await database.AddUnmodifiedAsync(e.OldId, e.LastWrite); } catch (Exception ex) { if (ex.IsRetiredException()) { throw; } Logging.Log.WriteWarningMessage(FILELOGTAG, "FailedToAddFile", ex, "Failed while attempting to add unmodified file to database: {0}", e.Path); } await self.ProgressChannel.WriteAsync(new ProgressEvent() { Filepath = e.Path, Length = filestatsize, Type = EventType.FileSkipped }); continue; } // If we have have disabled the filetime check, we do not have the metadata info // but we want to know if the metadata is potentially changed if (!isNewFile && DISABLEFILETIMECHECK) { var tp = await database.GetMetadataHashAndSizeForFileAsync(e.OldId); if (tp != null) { e.OldMetaSize = tp.Item1; e.OldMetaHash = tp.Item2; } } // Compute current metadata e.MetaHashAndSize = SKIPMETADATA ? EMPTY_METADATA : Utility.WrapMetadata(MetadataGenerator.GenerateMetadata(e.Path, e.Attributes, options, snapshot), options); e.MetadataChanged = !SKIPMETADATA && (e.MetaHashAndSize.Blob.Length != e.OldMetaSize || e.MetaHashAndSize.FileHash != e.OldMetaHash); // Check if the file is new, or something indicates a change var filesizeChanged = filestatsize < 0 || e.LastFileSize < 0 || filestatsize != e.LastFileSize; if (isNewFile || timestampChanged || filesizeChanged || e.MetadataChanged) { Logging.Log.WriteVerboseMessage(FILELOGTAG, "CheckFileForChanges", "Checking file for changes {0}, new: {1}, timestamp changed: {2}, size changed: {3}, metadatachanged: {4}, {5} vs {6}", e.Path, isNewFile, timestampChanged, filesizeChanged, e.MetadataChanged, e.LastWrite, e.OldModified); await self.Output.WriteAsync(e); } else { Logging.Log.WriteVerboseMessage(FILELOGTAG, "SkipCheckNoMetadataChange", "Skipped checking file, because no metadata was updated {0}", e.Path); try { await database.AddUnmodifiedAsync(e.OldId, e.LastWrite); } catch (Exception ex) { Logging.Log.WriteWarningMessage(FILELOGTAG, "FailedToAddFile", ex, "Failed while attempting to add unmodified file to database: {0}", e.Path); } await self.ProgressChannel.WriteAsync(new ProgressEvent() { Filepath = e.Path, Length = filestatsize, Type = EventType.FileSkipped }); } } })); }