feat: add bufferedReader for extract (#86)

Signed-off-by: Gaius <[email protected]>

Author: gaius-qi

pkg/backend/extract.go

@@ -17,6 +17,7 @@
 package backend
 
 import (
+	"bufio"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -29,6 +30,11 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
+const (
+	// defaultBufferSize is the default buffer size for reading the blob, default is 4MB.
+	defaultBufferSize = 4 * 1024 * 1024
+)
+
 // Extract extracts the model artifact.
 func (b *backend) Extract(ctx context.Context, target string, output string) error {
 	// parse the repository and tag from the target.
@@ -60,8 +66,8 @@ func exportModelArtifact(ctx context.Context, store storage.Storage, manifest oc
 		if err != nil {
 			return fmt.Errorf("failed to pull the blob from storage: %w", err)
 		}
-
 		defer reader.Close()
+		bufferedReader := bufio.NewReaderSize(reader, defaultBufferSize)
 
 		targetDir := output
 		// get the original filepath in order to restore the original repo structure.
@@ -71,7 +77,7 @@ func exportModelArtifact(ctx context.Context, store storage.Storage, manifest oc
 		}
 
 		// untar the blob to the target directory.
-		if err := archiver.Untar(reader, targetDir); err != nil {
+		if err := archiver.Untar(bufferedReader, targetDir); err != nil {
 			return fmt.Errorf("failed to untar the blob to output directory: %w", err)
 		}
 	}