From 0f15c6bf903e623b5bc491e994e0e3f878bac37c Mon Sep 17 00:00:00 2001
From: Till Faelligen <2353100+S7evinK@users.noreply.github.com>
Date: Sat, 20 Jan 2024 20:34:04 +0100
Subject: [PATCH] Make 100 a const

---
 roomserver/api/perform.go | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/roomserver/api/perform.go b/roomserver/api/perform.go
index bdefbef83..9e00da2c0 100644
--- a/roomserver/api/perform.go
+++ b/roomserver/api/perform.go
@@ -90,6 +90,10 @@ type PerformBackfillRequest struct {
 	VirtualHost spec.ServerName `json:"virtual_host"`
 }
 
+// limitPrevEventIDs is the maximum of eventIDs we
+// return when calling PrevEventIDs.
+const limitPrevEventIDs = 100
+
 // PrevEventIDs returns the prev_event IDs of either 100 backwards extremities or
 // len(r.BackwardsExtremities). Limited to 100, due to Synapse/Dendrite stopping after reaching
 // this limit. (which sounds sane)
@@ -98,8 +102,8 @@ func (r *PerformBackfillRequest) PrevEventIDs() []string {
 
 	// Create a unique eventID map of either 100 or len(r.BackwardsExtremities).
 	// 100 since Synapse/Dendrite stops after reaching 100 events.
-	if len(r.BackwardsExtremities) > 100 {
-		uniqueIDs = make(map[string]struct{}, 100)
+	if len(r.BackwardsExtremities) > limitPrevEventIDs {
+		uniqueIDs = make(map[string]struct{}, limitPrevEventIDs)
 	} else {
 		uniqueIDs = make(map[string]struct{}, len(r.BackwardsExtremities))
 	}
@@ -109,7 +113,7 @@ outerLoop:
 		for _, evID := range pes {
 			uniqueIDs[evID] = struct{}{}
 			// We found enough unique eventIDs.
-			if len(uniqueIDs) >= 100 {
+			if len(uniqueIDs) >= limitPrevEventIDs {
 				break outerLoop
 			}
 		}