Remove obsolete gRPC client/server implementations and migrate to remote package

manager.go

@@ -2,6 +2,7 @@ package agate
 
 import (
 	"archive/zip"
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -31,6 +32,11 @@ func CreateSnapshotManager(metadataStore store.MetadataStore, blobStore store.Bl
 		return nil, errors.New("parameters can't be nil")
 	}
 
+	// Ensure logger is never nil.
+	if logger == nil {
+		logger = log.New(io.Discard, "", 0)
+	}
+
 	return &SnapshotManagerData{
 		metadataStore: metadataStore,
 		blobStore:     blobStore,
@@ -183,31 +189,24 @@ func (data *SnapshotManagerData) DeleteSnapshot(ctx context.Context, snapshotID
 		return errors.New("snapshot ID cannot be empty")
 	}
 
-	// First check if the snapshot exists and get its details
 	snapshot, err := data.metadataStore.GetSnapshotMetadata(ctx, snapshotID)
 	if err != nil {
-		if errors.Is(err, ErrNotFound) {
-			// If snapshot doesn't exist, return success (idempotent operation)
+		if errors.Is(err, store.ErrNotFound) {
 			return nil
 		}
 		return fmt.Errorf("failed to check if snapshot exists: %w", err)
 	}
 
-	// Get the parent ID of the snapshot being deleted
 	parentID := snapshot.ParentID
 
-	// Find all snapshots that have the deleted snapshot as their parent
-	// We need to update their parent ID to maintain the chain
 	opts := store.ListOptions{}
 	allSnapshots, err := data.metadataStore.ListSnapshotsMetadata(ctx, opts)
 	if err != nil {
 		return fmt.Errorf("failed to list snapshots: %w", err)
 	}
 
-	// Update parent references for any snapshots that have this one as a parent
 	for _, info := range allSnapshots {
 		if info.ParentID == snapshotID {
-			// Используем новый, более надежный метод для обновления только parent_id
 			if err := data.metadataStore.UpdateSnapshotParentID(ctx, info.ID, parentID); err != nil {
 				data.logger.Printf("WARNING: failed to update parent reference for snapshot %s: %v", info.ID, err)
 			} else {
@@ -216,16 +215,11 @@ func (data *SnapshotManagerData) DeleteSnapshot(ctx context.Context, snapshotID
 		}
 	}
 
-	// Delete the metadata first
 	if err := data.metadataStore.DeleteSnapshotMetadata(ctx, snapshotID); err != nil {
 		return fmt.Errorf("failed to delete snapshot metadata: %w", err)
 	}
 
-	// Then delete the blob
 	if err := data.blobStore.DeleteBlob(ctx, snapshotID); err != nil {
-		// Note: We don't return here because we've already deleted the metadata
-		// and the blob store should handle the case where the blob doesn't exist
-		// Log the error instead
 		data.logger.Printf("WARNING: failed to delete snapshot blob: %v", err)
 	}
 
@@ -392,22 +386,130 @@ func (data *SnapshotManagerData) UpdateSnapshotMetadata(ctx context.Context, sna
 		return errors.New("new name cannot be empty")
 	}
 
-	// Get the current snapshot metadata
 	snapshot, err := data.metadataStore.GetSnapshotMetadata(ctx, snapshotID)
 	if err != nil {
-		if errors.Is(err, ErrNotFound) {
+		if errors.Is(err, store.ErrNotFound) {
 			return ErrNotFound
 		}
 		return fmt.Errorf("failed to get snapshot metadata: %w", err)
 	}
 
-	// Update the name
 	snapshot.Name = newName
 
-	// Save the updated metadata
 	if err := data.metadataStore.SaveSnapshotMetadata(ctx, *snapshot); err != nil {
 		return fmt.Errorf("failed to update snapshot metadata: %w", err)
 	}
 
 	return nil
 }
+
+// diffArchiveReader is a wrapper around an *os.File that handles cleanup of temporary files.
+type diffArchiveReader struct {
+	*os.File
+	tempArchive string
+	tempStaging string
+}
+
+// Close closes the file and removes the temporary archive and staging directory.
+func (r *diffArchiveReader) Close() error {
+	err := r.File.Close()
+	os.Remove(r.tempArchive)
+	os.RemoveAll(r.tempStaging)
+	return err
+}
+
+func (data *SnapshotManagerData) StreamSnapshotDiff(ctx context.Context, snapshotID, parentID string, offset int64) (io.ReadCloser, error) {
+	targetSnap, err := data.metadataStore.GetSnapshotMetadata(ctx, snapshotID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get target snapshot metadata: %w", err)
+	}
+
+	parentFiles := make(map[string]string)
+	if parentID != "" {
+		parentSnap, err := data.metadataStore.GetSnapshotMetadata(ctx, parentID)
+		if err == nil {
+			for _, file := range parentSnap.Files {
+				if !file.IsDir {
+					parentFiles[file.Path] = file.SHA256
+				}
+			}
+		} else {
+			data.logger.Printf("Warning: failed to get parent snapshot %s, creating full diff: %v", parentID, err)
+		}
+	}
+
+	var filesToInclude []string
+	for _, file := range targetSnap.Files {
+		if file.IsDir {
+			continue
+		}
+		if parentHash, ok := parentFiles[file.Path]; !ok || parentHash != file.SHA256 {
+			filesToInclude = append(filesToInclude, file.Path)
+		}
+	}
+
+	if len(filesToInclude) == 0 {
+		return io.NopCloser(bytes.NewReader(nil)), nil
+	}
+
+	tempStagingDir, err := os.MkdirTemp(data.blobStore.GetBaseDir(), "diff-staging-*")
+	if err != nil {
+		return nil, fmt.Errorf("failed to create temp staging directory: %w", err)
+	}
+
+	targetBlobPath, err := data.blobStore.GetBlobPath(ctx, snapshotID)
+	if err != nil {
+		os.RemoveAll(tempStagingDir)
+		return nil, err
+	}
+
+	for _, filePath := range filesToInclude {
+		destPath := filepath.Join(tempStagingDir, filePath)
+		if err := os.MkdirAll(filepath.Dir(destPath), 0755); err != nil {
+			os.RemoveAll(tempStagingDir)
+			return nil, fmt.Errorf("failed to create dir for diff file: %w", err)
+		}
+
+		fileWriter, err := os.Create(destPath)
+		if err != nil {
+			os.RemoveAll(tempStagingDir)
+			return nil, err
+		}
+
+		err = archive.ExtractFileFromArchive(targetBlobPath, filePath, fileWriter)
+		fileWriter.Close()
+		if err != nil {
+			os.RemoveAll(tempStagingDir)
+			return nil, fmt.Errorf("failed to extract file %s for diff: %w", filePath, err)
+		}
+	}
+
+	tempArchivePath := filepath.Join(data.blobStore.GetBaseDir(), "diff-"+snapshotID+".zip")
+	if err := archive.CreateArchive(tempStagingDir, tempArchivePath); err != nil {
+		os.RemoveAll(tempStagingDir)
+		os.Remove(tempArchivePath)
+		return nil, fmt.Errorf("failed to create diff archive: %w", err)
+	}
+
+	archiveFile, err := os.Open(tempArchivePath)
+	if err != nil {
+		os.RemoveAll(tempStagingDir)
+		os.Remove(tempArchivePath)
+		return nil, err
+	}
+
+	if offset > 0 {
+		if _, err := archiveFile.Seek(offset, io.SeekStart); err != nil {
+			archiveFile.Close()
+			os.RemoveAll(tempStagingDir)
+			os.Remove(tempArchivePath)
+			return nil, fmt.Errorf("failed to seek in diff archive: %w", err)
+		}
+	}
+
+	return &diffArchiveReader{
+		File:        archiveFile,
+		tempArchive: tempArchivePath,
+		tempStaging: tempStagingDir,
+	}, nil
+}