From b9d947e438a37b7145e3492ff031f5a5bf77b151 Mon Sep 17 00:00:00 2001
From: Till Faelligen <2353100+S7evinK@users.noreply.github.com>
Date: Mon, 2 Jan 2023 10:20:28 +0100
Subject: [PATCH] Further optimization

---
 syncapi/storage/shared/storage_sync.go | 28 +++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/syncapi/storage/shared/storage_sync.go b/syncapi/storage/shared/storage_sync.go
index 361fc9ff5..06c69ec16 100644
--- a/syncapi/storage/shared/storage_sync.go
+++ b/syncapi/storage/shared/storage_sync.go
@@ -5,11 +5,10 @@ import (
 	"database/sql"
 	"fmt"
 
-	"github.com/matrix-org/gomatrixserverlib"
-
 	"github.com/matrix-org/dendrite/internal/eventutil"
 	"github.com/matrix-org/dendrite/syncapi/types"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
 )
 
 type DatabaseTransaction struct {
@@ -332,7 +331,7 @@ func (d *DatabaseTransaction) GetStateDeltas(
 	stateNeededFiltered := stateNeeded
 	eventMapFiltered := eventMap
 	// avoid hitting the database if the result would be the same as above
-	if stateFilter != nil {
+	if !isStatefilterEmpty(stateFilter) {
 		stateNeededFiltered, eventMapFiltered, err = d.OutputEvents.SelectStateInRange(ctx, d.txn, r, stateFilter, allRoomIDs)
 	}
 
@@ -694,3 +693,26 @@ func (d *DatabaseTransaction) RelationsFor(ctx context.Context, roomID, eventID,
 
 	return events, prevBatch, nextBatch, nil
 }
+
+// TODO: move to GMSL
+func isStatefilterEmpty(filter *gomatrixserverlib.StateFilter) bool {
+	if filter == nil {
+		return true
+	}
+	switch {
+	case filter.NotTypes != nil && len(*filter.NotTypes) > 0:
+		return false
+	case filter.Types != nil && len(*filter.Types) > 0:
+		return false
+	case filter.Senders != nil && len(*filter.Senders) > 0:
+		return false
+	case filter.NotSenders != nil && len(*filter.NotSenders) > 0:
+		return false
+	case filter.NotRooms != nil && len(*filter.NotRooms) > 0:
+		return false
+	case filter.ContainsURL != nil:
+		return false
+	default:
+		return true
+	}
+}