fetchShares in the sharesstorageprovider does not parallelize stat requests

[butonic]

looking at the code ... we are sequentially stating all accepted shares. this will take ages and can be parallelized. maybe even cached

func (s *service) fetchShares(ctx context.Context, opaque *typesv1beta1.Opaque, arbitraryMetadataKeys []string, fieldMask *field_mask.FieldMask) ([]*collaboration.ReceivedShare, map[string]*provider.ResourceInfo, error) {
	sharingCollaborationClient, err := s.sharingCollaborationSelector.Next()
	if err != nil {
		return nil, nil, err
	}

	lsRes, err := sharingCollaborationClient.ListReceivedShares(ctx, &collaboration.ListReceivedSharesRequest{
		// FIXME filter by received shares for resource id - listing all shares is tooo expensive!
	})
	if err != nil {
		return nil, nil, errors.Wrap(err, "sharesstorageprovider: error calling ListReceivedSharesRequest")
	}
	if lsRes.Status.Code != rpc.Code_CODE_OK {
		return nil, nil, fmt.Errorf("sharesstorageprovider: error calling ListReceivedSharesRequest")
	}

	gatewayClient, err := s.gatewaySelector.Next()
	if err != nil {
		return nil, nil, err
	}

	shareMetaData := make(map[string]*provider.ResourceInfo, len(lsRes.Shares))
	for _, rs := range lsRes.Shares {
		// only stat accepted shares
		if rs.State != collaboration.ShareState_SHARE_STATE_ACCEPTED {
			continue
		}
		if rs.Share.ResourceId.SpaceId == "" {
			// convert backwards compatible share id
			rs.Share.ResourceId.StorageId, rs.Share.ResourceId.SpaceId = storagespace.SplitStorageID(rs.Share.ResourceId.StorageId)
		}
		sRes, err := gatewayClient.Stat(ctx, &provider.StatRequest{
			Opaque:                opaque,
			Ref:                   &provider.Reference{ResourceId: rs.Share.ResourceId},
			ArbitraryMetadataKeys: arbitraryMetadataKeys,
			FieldMask:             fieldMask,
		})
		if err != nil {
			appctx.GetLogger(ctx).Error().
				Err(err).
				Interface("resourceID", rs.Share.ResourceId).
				Msg("ListRecievedShares: failed to make stat call")
			continue
		}
		if sRes.Status.Code != rpc.Code_CODE_OK {
			appctx.GetLogger(ctx).Debug().
				Interface("resourceID", rs.Share.ResourceId).
				Interface("status", sRes.Status).
				Msg("ListRecievedShares: failed to stat the resource")
			continue
		}
		shareMetaData[rs.Share.Id.OpaqueId] = sRes.Info
	}

	return lsRes.Shares, shareMetaData, nil
}

fix by concurrently stating resources. make the number of concurrent go routines configurable.

[butonic]

related, but bitrotted: cs3org/reva#3940

[butonic]

fixed by cs3org/reva#4812

[butonic]

• make the concurrency configurable in ocis, it defaults to 5 but this could be tweaked