From ee36e2d46d3392a6a40891cce59c53556a6f16b3 Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@kastelo.net>
Date: Tue, 24 Jan 2017 08:26:45 +0000
Subject: [PATCH] lib/weakhash: Limit number of hits for any given weakhash

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3925
---
 lib/weakhash/weakhash.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/weakhash/weakhash.go b/lib/weakhash/weakhash.go
index 1d3c0eb1..36450920 100644
--- a/lib/weakhash/weakhash.go
+++ b/lib/weakhash/weakhash.go
@@ -16,6 +16,9 @@ import (
 
 const (
 	Size = 4
+
+	// don't track more hits than this for any given weakhash
+	maxWeakhashFinderHits = 10
 )
 
 // Find finds all the blocks of the given size within io.Reader that matches
@@ -49,7 +52,7 @@ func Find(ir io.Reader, hashesToFind []uint32, size int) (map[uint32][]int64, er
 	var hash uint32
 	for {
 		hash = hf.Sum32()
-		if existing, ok := offsets[hash]; ok {
+		if existing, ok := offsets[hash]; ok && len(existing) < maxWeakhashFinderHits {
 			offsets[hash] = append(existing, i)
 		}
 		i++