From 51c403313431da2005a41793960d2c0690f69015 Mon Sep 17 00:00:00 2001
From: bibenga <{ID}+{username}@users.noreply.github.com>
Date: Sat, 23 Aug 2025 14:13:33 +0000
Subject: [PATCH 1/3] adds NOTICE and update license

---
 NOTICE                               |  6 +++++
 internal/hash/hash.go                | 33 ++++++++++++++--------------
 internal/utils/utils.go              |  3 ++-
 intlinkedhashmap/intlinkedhashmap.go |  4 +++-
 linkedhashmap/linkedhashmap.go       | 18 ++++++++++++++-
 linkedmap/linkedmap.go               |  4 +++-
 maps.go                              |  2 ++
 7 files changed, 49 insertions(+), 21 deletions(-)
 create mode 100644 NOTICE

diff --git a/NOTICE b/NOTICE
new file mode 100644
index 0000000..1f44c29
--- /dev/null
+++ b/NOTICE
@@ -0,0 +1,6 @@
+OrderedMap
+Copyright 2025 bibenga
+
+This product includes software developed at
+The Apache Software Foundation (https://www.apache.org/),
+originally part of Apache Commons Collections.
diff --git a/internal/hash/hash.go b/internal/hash/hash.go
index f7779df..a07c086 100644
--- a/internal/hash/hash.go
+++ b/internal/hash/hash.go
@@ -1,30 +1,29 @@
+// Portions Copyright 2025 bibenga
+//
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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
+//
+//	https://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 hash
 
 import "orderedmap"
 
-func FnvIntHash32[T orderedmap.Integer](x T) uint32 {
-	const (
-		offset = 2166136261
-		prime  = 16777619
-	)
-
-	x64 := uint64(x)
-	hash := uint32(offset)
-	for i := range 8 {
-		b := byte(x64 >> (i * 8))
-		hash ^= uint32(b)
-		hash *= prime
-	}
-	return hash
-}
-
 func MapHash32(h uint32) uint32 {
 	h += ^(h << 9)
 	h ^= h >> 14
 	h += h << 4
 	h ^= h >> 10
 	return h
-	// return FnvIntHash32(h)
 }
 
 func MapHashIndex(hashCode uint32, dataSize int) int {
diff --git a/internal/utils/utils.go b/internal/utils/utils.go
index d4f3149..63a4628 100644
--- a/internal/utils/utils.go
+++ b/internal/utils/utils.go
@@ -1,3 +1,4 @@
+// Copyright 2025 bibenga
 package utils
 
 import (
@@ -5,7 +6,7 @@ import (
 	"orderedmap"
 )
 
-func ToString[K, V any](name string, m orderedmap.Map[K, V]) string {
+func MapToString[K, V any](name string, m orderedmap.Map[K, V]) string {
 	str := name + "["
 	first := true
 	for k, v := range m.Items() {
diff --git a/intlinkedhashmap/intlinkedhashmap.go b/intlinkedhashmap/intlinkedhashmap.go
index d07676c..62f670a 100644
--- a/intlinkedhashmap/intlinkedhashmap.go
+++ b/intlinkedhashmap/intlinkedhashmap.go
@@ -1,3 +1,5 @@
+// Portions of this file are based on Apache Commons Collections,
+// licensed under the Apache License, Version 2.0.
 package intlinkedhashmap
 
 import (
@@ -333,5 +335,5 @@ func (m *IntLinkedHashMap[K, V]) Items() iter.Seq2[K, V] {
 }
 
 func (m *IntLinkedHashMap[K, V]) String() string {
-	return utils.ToString("IntLinkedHashMap", m)
+	return utils.MapToString("IntLinkedHashMap", m)
 }
diff --git a/linkedhashmap/linkedhashmap.go b/linkedhashmap/linkedhashmap.go
index fa3bc82..507a946 100644
--- a/linkedhashmap/linkedhashmap.go
+++ b/linkedhashmap/linkedhashmap.go
@@ -1,3 +1,19 @@
+// Portions Copyright 2025 bibenga
+//
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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
+//
+//	https://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 linkedhashmap
 
 import (
@@ -319,5 +335,5 @@ func (m *LinkedHashMap[K, V]) Items() iter.Seq2[K, V] {
 }
 
 func (m *LinkedHashMap[K, V]) String() string {
-	return utils.ToString("LinkedHashMap", m)
+	return utils.MapToString("LinkedHashMap", m)
 }
diff --git a/linkedmap/linkedmap.go b/linkedmap/linkedmap.go
index 0d5ec8f..0d06fec 100644
--- a/linkedmap/linkedmap.go
+++ b/linkedmap/linkedmap.go
@@ -1,3 +1,5 @@
+// Copyright 2025 bibenga
+// Inspired by Apache Commons Collections (Apache License 2.0)
 package linkedmap
 
 import (
@@ -135,5 +137,5 @@ func (m *LinkedMap[K, V]) Items() iter.Seq2[K, V] {
 }
 
 func (m *LinkedMap[K, V]) String() string {
-	return utils.ToString("LinkedMap", m)
+	return utils.MapToString("LinkedMap", m)
 }
diff --git a/maps.go b/maps.go
index 607d98b..99b7964 100644
--- a/maps.go
+++ b/maps.go
@@ -1,3 +1,5 @@
+// This implementation is inspired by Apache Commons Collections
+// (licensed under the Apache License, Version 2.0).
 package orderedmap
 
 import "iter"

From 5e8bd64c7353e09adb6bac45bb82f55f535f6fd1 Mon Sep 17 00:00:00 2001
From: bibenga <{ID}+{username}@users.noreply.github.com>
Date: Sat, 23 Aug 2025 14:13:57 +0000
Subject: [PATCH 2/3] deletes Fnv

---
 tests/general_test.go | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/tests/general_test.go b/tests/general_test.go
index 6e24893..0f35b1b 100644
--- a/tests/general_test.go
+++ b/tests/general_test.go
@@ -1,8 +1,6 @@
 package tests
 
 import (
-	"encoding/binary"
-	"hash/fnv"
 	"orderedmap"
 	"orderedmap/internal/hash"
 	"orderedmap/intlinkedhashmap"
@@ -14,24 +12,6 @@ import (
 type Factory func() orderedmap.Map[int, int]
 type StdFactory func() map[int]int
 
-func TestFnvIntHash32(t *testing.T) {
-	values := []int64{0, 1, 42, 12345, -1, -123456789}
-	for _, v := range values {
-		// we count through native fnv.New32a()
-		h := fnv.New32a()
-		buf := make([]byte, 8)
-		binary.LittleEndian.PutUint64(buf, uint64(v))
-		h.Write(buf)
-		want := h.Sum32()
-
-		got := hash.FnvIntHash32(v)
-
-		if got != want {
-			t.Errorf("fnvInt(%d) = %d, want %d", v, got, want)
-		}
-	}
-}
-
 func TestIntLinkedHashMap(t *testing.T) {
 	factory := func() orderedmap.Map[int, int] {
 		return intlinkedhashmap.NewDefault[int, int]()

From 8521b7dd1be4333ea8b5969f38c206dc399ce5de Mon Sep 17 00:00:00 2001
From: bibenga <{ID}+{username}@users.noreply.github.com>
Date: Sat, 23 Aug 2025 14:14:50 +0000
Subject: [PATCH 3/3] update header

---
 tests/benchmark1_test.go | 2 ++
 tests/benchmark2_test.go | 2 ++
 tests/general_test.go    | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/tests/benchmark1_test.go b/tests/benchmark1_test.go
index a538fd1..f07f48a 100644
--- a/tests/benchmark1_test.go
+++ b/tests/benchmark1_test.go
@@ -1,3 +1,5 @@
+// Copyright 2025 bibenga
+// Inspired by Apache Commons Collections (Apache License 2.0)
 package tests
 
 import (
diff --git a/tests/benchmark2_test.go b/tests/benchmark2_test.go
index b6064cf..2daef0e 100644
--- a/tests/benchmark2_test.go
+++ b/tests/benchmark2_test.go
@@ -1,3 +1,5 @@
+// Copyright 2025 bibenga
+// Inspired by Apache Commons Collections (Apache License 2.0)
 package tests
 
 import (
diff --git a/tests/general_test.go b/tests/general_test.go
index 0f35b1b..7071c1d 100644
--- a/tests/general_test.go
+++ b/tests/general_test.go
@@ -1,3 +1,5 @@
+// Copyright 2025 bibenga
+// Inspired by Apache Commons Collections (Apache License 2.0)
 package tests
 
 import (