Added backup --dry-run option.

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...)
 
-    manager.SnapshotManager.CleanSnapshotCache(localSnapshot, nil)
+    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() {}
@@ -1048,7 +1054,7 @@ func (manager *BackupManager) UploadSnapshot(chunkMaker *ChunkMaker, uploader *C
                 if _, found := chunkCache[chunkID]; found {
                     completionFunc(chunk, 0, true, chunk.GetLength(), 0)
                 } else {
-                    uploader.StartChunk(chunk, len(sequence))
+                     uploader.StartChunk(chunk, len(sequence))
                 }
                 sequence = append(sequence, chunk.GetHash())
             },
@@ -1108,8 +1114,9 @@ func (manager *BackupManager) UploadSnapshot(chunkMaker *ChunkMaker, uploader *C
     }
 
     path := fmt.Sprintf("snapshots/%s/%d", manager.snapshotID, snapshot.Revision)
-    manager.SnapshotManager.UploadFile(path, path, description)
-
+    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 {
-        otherManager.storage.CreateDirectory(0, fmt.Sprintf("snapshots/%s", manager.snapshotID))
+        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

@@ -134,10 +134,12 @@ func (uploader *ChunkUploader) Upload(threadIndex int, task ChunkUploadTask) boo
         return false
     }
 
-    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
+    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)

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

@@ -2215,9 +2215,11 @@ func (manager *SnapshotManager) DownloadFile(path string, derivationKey string)
         return nil
     }
 
-    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)
+    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)