From f2ea95a453f91f80f6cdfa87cd2430dcf9cbe1e2 Mon Sep 17 00:00:00 2001
From: Liudon <i.mu@qq.com>
Date: Thu, 9 Apr 2026 16:04:02 +0800
Subject: [PATCH] perf: use map lookup instead of slice scan in NewKey() and
 NewSection()

---
 bench_test.go  | 34 ++++++++++++++++++++++++++++++++++
 file.go        |  2 +-
 helper.go      | 24 ------------------------
 helper_test.go | 27 ---------------------------
 section.go     |  2 +-
 5 files changed, 36 insertions(+), 53 deletions(-)
 delete mode 100644 helper.go
 delete mode 100644 helper_test.go

diff --git a/bench_test.go b/bench_test.go
index 9fd72f0..5ba8027 100644
--- a/bench_test.go
+++ b/bench_test.go
@@ -15,6 +15,7 @@
 package ini
 
 import (
+	"fmt"
 	"testing"
 )
 
@@ -114,3 +115,36 @@ func Benchmark_Key_SetValue_VisSection(b *testing.B) {
 		sec.Key("NAME").SetValue("10")
 	}
 }
+
+func Benchmark_NewKey_With_N_Keys(b *testing.B) {
+	for _, n := range []int{10, 100, 500, 1000} {
+		b.Run(fmt.Sprintf("keys=%d", n), func(b *testing.B) {
+			f := Empty()
+			sec, _ := f.NewSection("bench")
+			for i := 0; i < n; i++ {
+				sec.NewKey(fmt.Sprintf("key%d", i), "val")
+			}
+			target := fmt.Sprintf("key%d", n-1)
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				sec.NewKey(target, "newval")
+			}
+		})
+	}
+}
+
+func Benchmark_NewSection_With_N_Sections(b *testing.B) {
+	for _, n := range []int{10, 100, 500, 1000} {
+		b.Run(fmt.Sprintf("sections=%d", n), func(b *testing.B) {
+			f := Empty()
+			for i := 0; i < n; i++ {
+				f.NewSection(fmt.Sprintf("sec%d", i))
+			}
+			target := fmt.Sprintf("sec%d", n-1)
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				f.NewSection(target)
+			}
+		})
+	}
+}
diff --git a/file.go b/file.go
index f8b2240..2a37fa9 100644
--- a/file.go
+++ b/file.go
@@ -94,7 +94,7 @@ func (f *File) NewSection(name string) (*Section, error) {
 		defer f.lock.Unlock()
 	}
 
-	if !f.options.AllowNonUniqueSections && inSlice(name, f.sectionList) {
+	if !f.options.AllowNonUniqueSections && f.sections[name] != nil {
 		return f.sections[name][0], nil
 	}
 
diff --git a/helper.go b/helper.go
deleted file mode 100644
index f9d80a6..0000000
--- a/helper.go
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright 2019 Unknwon
-//
-// Licensed under the Apache License, Version 2.0 (the "License"): you may
-// not use this file except in compliance with the License. You may obtain
-// a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-// License for the specific language governing permissions and limitations
-// under the License.
-
-package ini
-
-func inSlice(str string, s []string) bool {
-	for _, v := range s {
-		if str == v {
-			return true
-		}
-	}
-	return false
-}
diff --git a/helper_test.go b/helper_test.go
deleted file mode 100644
index 439ad3b..0000000
--- a/helper_test.go
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2019 Unknwon
-//
-// Licensed under the Apache License, Version 2.0 (the "License"): you may
-// not use this file except in compliance with the License. You may obtain
-// a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-// License for the specific language governing permissions and limitations
-// under the License.
-
-package ini
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestIsInSlice(t *testing.T) {
-	ss := []string{"a", "b", "c"}
-	assert.True(t, inSlice("a", ss))
-	assert.False(t, inSlice("d", ss))
-}
diff --git a/section.go b/section.go
index a3615d8..f885e57 100644
--- a/section.go
+++ b/section.go
@@ -75,7 +75,7 @@ func (s *Section) NewKey(name, val string) (*Key, error) {
 		defer s.f.lock.Unlock()
 	}
 
-	if inSlice(name, s.keyList) {
+	if _, ok := s.keys[name]; ok {
 		if s.f.options.AllowShadows {
 			if err := s.keys[name].addShadow(val); err != nil {
 				return nil, err