Added backup --dry-run option.

duplicacy/duplicacy_main.go

@@ -623,12 +623,14 @@ func backupRepository(context *cli.Context) {
 
     enableVSS := context.Bool("vss")
 
+    dryRun := context.Bool("dry-run")
     uploadRateLimit := context.Int("limit-rate")
     storage.SetRateLimits(0, uploadRateLimit)
     backupManager := duplicacy.CreateBackupManager(preference.SnapshotID, storage, repository, password)
     duplicacy.SavePassword(*preference, "password", password)
 
     backupManager.SetupSnapshotCache(preference.Name)
+    backupManager.SetDryRun(dryRun)
     backupManager.Backup(repository, quickMode, threads, context.String("t"), showStatistics, enableVSS)
 
     runScript(context, preference.Name, "post")
@@ -1202,6 +1204,10 @@ func main() {
                     Usage: "the maximum upload rate (in kilobytes/sec)",
                     Argument: "<kB/s>",
                 },
+                cli.BoolFlag {
+                    Name:  "dry-run",
+                    Usage: "Dry run for testing, don't backup anything. Use with -stats and -d",
+                },
                 cli.BoolFlag {
                     Name:  "vss",
                     Usage: "enable the Volume Shadow Copy service (Windows only)",

src/duplicacy_backupmanager.go

@@ -36,6 +36,10 @@ type BackupManager struct {
 }
 
 
+func (manager *BackupManager) SetDryRun(dryRun bool) {
+    manager.config.dryRun = dryRun
+}
+
 
 // CreateBackupManager creates a backup manager using the specified 'storage'.  'snapshotID' is a unique id to
 // identify snapshots created for this repository.  'top' is the top directory of the repository.  'password' is the
@@ -630,7 +634,9 @@ func (manager *BackupManager) Backup(top string, quickMode bool, threads int, ta
     }
     skippedFiles = append(skippedFiles, fileReader.SkippedFiles...)
 
+    if !manager.config.dryRun {
         manager.SnapshotManager.CleanSnapshotCache(localSnapshot, nil)
+    }
     LOG_INFO("BACKUP_END", "Backup for %s at revision %d completed", top, localSnapshot.Revision)
 
     RunAtError = func() {}
@@ -1108,8 +1114,9 @@ func (manager *BackupManager) UploadSnapshot(chunkMaker *ChunkMaker, uploader *C
     }
 
     path := fmt.Sprintf("snapshots/%s/%d", manager.snapshotID, snapshot.Revision)
+    if !manager.config.dryRun {
         manager.SnapshotManager.UploadFile(path, path, description)
-
+    }
     return totalSnapshotChunkSize, numberOfNewSnapshotChunks, totalUploadedSnapshotChunkSize, totalUploadedSnapshotChunkBytes
 }
 
@@ -1598,7 +1605,9 @@ func (manager *BackupManager) CopySnapshots(otherManager *BackupManager, snapsho
     chunkUploader.Stop()
 
     for _, snapshot := range snapshots {
+        if !manager.config.dryRun {
             otherManager.storage.CreateDirectory(0, fmt.Sprintf("snapshots/%s", manager.snapshotID))
+        }
         description, _ := snapshot.MarshalJSON()
         path := fmt.Sprintf("snapshots/%s/%d", manager.snapshotID, snapshot.Revision)
         otherManager.SnapshotManager.UploadFile(path, path, description)

src/duplicacy_chunkuploader.go

@@ -134,11 +134,13 @@ func (uploader *ChunkUploader) Upload(threadIndex int, task ChunkUploadTask) boo
         return false
     }
 
+    if !uploader.config.dryRun {
         err = uploader.storage.UploadFile(threadIndex, chunkPath, chunk.GetBytes())
         if err != nil {
             LOG_ERROR("UPLOAD_CHUNK", "Failed to upload the chunk %s: %v", chunkID, err)
             return false
         }
+    }
 
     LOG_DEBUG("CHUNK_UPLOAD", "Chunk %s has been uploaded", chunkID)
     uploader.completionFunc(chunk, task.chunkIndex, false, chunkSize, chunk.GetLength())

src/duplicacy_config.go

@@ -55,6 +55,7 @@ type Config struct {
 
     chunkPool chan *Chunk                  `json:"-"`
     numberOfChunks int32
+    dryRun bool
 }
 
     // Create an alias to avoid recursive calls on Config.MarshalJSON

src/duplicacy_snapshotmanager.go

@@ -2215,10 +2215,12 @@ func (manager *SnapshotManager) DownloadFile(path string, derivationKey string)
         return nil
     }
 
+    if !manager.config.dryRun {
         err = manager.snapshotCache.UploadFile(0, path, manager.fileChunk.GetBytes())
         if err != nil {
             LOG_WARN("DOWNLOAD_FILE_CACHE", "Failed to add the file %s to the snapshot cache: %v", path, err)
         }
+    }
 
     LOG_DEBUG("DOWNLOAD_FILE", "Downloaded file %s", path)
 
@@ -2227,6 +2229,9 @@ func (manager *SnapshotManager) DownloadFile(path string, derivationKey string)
 
 // UploadFile uploads a non-chunk file from the storage.
 func (manager *SnapshotManager) UploadFile(path string, derivationKey string, content []byte) bool {
+    if manager.config.dryRun {
+        return true
+    }
     manager.fileChunk.Reset(false)
     manager.fileChunk.Write(content)