From 9ec78729fabb46e35fcdb760ba403cdf120bb432 Mon Sep 17 00:00:00 2001
From: Weizhen Wang <wangweizhen@pingcap.com>
Date: Fri, 15 Sep 2023 11:42:09 +0800
Subject: [PATCH] statistics: use slices.BinarySearchFunc to simple
 TopN.FindTopN (#46996)

ref pingcap/tidb#45933
---
 statistics/cmsketch.go | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/statistics/cmsketch.go b/statistics/cmsketch.go
index 7a51a5e466..ed924b39e0 100644
--- a/statistics/cmsketch.go
+++ b/statistics/cmsketch.go
@@ -639,13 +639,8 @@ func (c *TopN) FindTopN(d []byte) int {
 	if c == nil {
 		return -1
 	}
-	match := false
-	idx := sort.Search(len(c.TopN), func(i int) bool {
-		cmpRst := bytes.Compare(c.TopN[i].Encoded, d)
-		if cmpRst == 0 {
-			match = true
-		}
-		return cmpRst >= 0
+	idx, match := slices.BinarySearchFunc(c.TopN, d, func(a TopNMeta, b []byte) int {
+		return bytes.Compare(a.Encoded, b)
 	})
 	if !match {
 		return -1