GCP Storage Bucket binding: Bulk file transfer (#3811)

Signed-off-by: nelson.parente <nelson_parente@live.com.pt>
Co-authored-by: Yaron Schneider <schneider.yaron@live.com>

bindings/gcp/bucket/bucket.go

@@ -25,10 +25,12 @@ import (
 	"net/url"
 	"reflect"
 	"strconv"
+	"sync"
 	"time"
 
 	"cloud.google.com/go/storage"
 	"github.com/google/uuid"
+	"go.uber.org/multierr"
 	"google.golang.org/api/googleapi"
 	"google.golang.org/api/iterator"
 	"google.golang.org/api/option"
@@ -49,8 +51,9 @@ const (
 	metadataKey = "key"
 	maxResults  = 1000
 
-	metadataKeyBC = "name"
-	signOperation = "sign"
+	metadataKeyBC    = "name"
+	signOperation    = "sign"
+	bulkGetOperation = "bulkGet"
 )
 
 // GCPStorage allows saving data to GCP bucket storage.
@@ -138,6 +141,7 @@ func (g *GCPStorage) Operations() []bindings.OperationKind {
 		bindings.DeleteOperation,
 		bindings.ListOperation,
 		signOperation,
+		bulkGetOperation,
 	}
 }
 
@@ -155,6 +159,8 @@ func (g *GCPStorage) Invoke(ctx context.Context, req *bindings.InvokeRequest) (*
 		return g.list(ctx, req)
 	case signOperation:
 		return g.sign(ctx, req)
+	case bulkGetOperation:
+		return g.bulkGet(ctx, req)
 	default:
 		return nil, fmt.Errorf("unsupported operation %s", req.Operation)
 	}
@@ -404,3 +410,91 @@ func (g *GCPStorage) signObject(bucket, object, ttl string) (string, error) {
 	}
 	return u, nil
 }
+
+type objectData struct {
+	Name  string              `json:"name"`
+	Data  []byte              `json:"data"`
+	Attrs storage.ObjectAttrs `json:"attrs"`
+}
+
+func (g *GCPStorage) bulkGet(ctx context.Context, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
+	metadata, err := g.metadata.mergeWithRequestMetadata(req)
+	if err != nil {
+		return nil, fmt.Errorf("gcp binding error while merging metadata : %w", err)
+	}
+
+	if g.metadata.Bucket == "" {
+		return nil, errors.New("gcp bucket binding error: bucket is required")
+	}
+
+	var allObjs []*storage.ObjectAttrs
+	it := g.client.Bucket(g.metadata.Bucket).Objects(ctx, nil)
+	for {
+		attrs, err2 := it.Next()
+		if err2 == iterator.Done {
+			break
+		}
+		allObjs = append(allObjs, attrs)
+	}
+
+	var wg sync.WaitGroup
+	objectsCh := make(chan objectData, len(allObjs))
+	errCh := make(chan error, len(allObjs))
+
+	for i, obj := range allObjs {
+		wg.Add(1)
+		go func(idx int, object *storage.ObjectAttrs) {
+			defer wg.Done()
+
+			rc, err3 := g.client.Bucket(g.metadata.Bucket).Object(object.Name).NewReader(ctx)
+			if err3 != nil {
+				errCh <- err3
+				return
+			}
+			defer rc.Close()
+
+			data, readErr := io.ReadAll(rc)
+			if readErr != nil {
+				errCh <- readErr
+				return
+			}
+
+			if metadata.EncodeBase64 {
+				encoded := b64.StdEncoding.EncodeToString(data)
+				data = []byte(encoded)
+			}
+
+			objectsCh <- objectData{
+				Name:  object.Name,
+				Data:  data,
+				Attrs: *object,
+			}
+		}(i, obj)
+	}
+
+	wg.Wait()
+	close(errCh)
+
+	var multiErr error
+	for err := range errCh {
+		multierr.AppendInto(&multiErr, err)
+	}
+
+	if multiErr != nil {
+		return nil, multiErr
+	}
+
+	response := make([]objectData, 0, len(allObjs))
+	for obj := range objectsCh {
+		response = append(response, obj)
+	}
+
+	jsonResponse, err := json.Marshal(response)
+	if err != nil {
+		return nil, fmt.Errorf("gcp bucket binding error while marshalling bulk get response: %w", err)
+	}
+
+	return &bindings.InvokeResponse{
+		Data: jsonResponse,
+	}, nil
+}

bindings/gcp/bucket/bucket_test.go

@@ -254,3 +254,14 @@ func TestDeleteOption(t *testing.T) {
 		require.Error(t, err)
 	})
 }
+
+func TestBulkGetOption(t *testing.T) {
+	gs := GCPStorage{logger: logger.NewLogger("test")}
+	gs.metadata = &gcpMetadata{}
+
+	t.Run("return error if bucket is missing", func(t *testing.T) {
+		r := bindings.InvokeRequest{}
+		_, err := gs.bulkGet(t.Context(), &r)
+		require.Error(t, err)
+	})
+}