实现open file cache

internal/utils/linkedlist/item.go

@@ -0,0 +1,14 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package linkedlist
+
+type Item struct {
+	prev *Item
+	next *Item
+
+	Value interface{}
+}
+
+func NewItem(value interface{}) *Item {
+	return &Item{Value: value}
+}

internal/utils/linkedlist/list.go

@@ -0,0 +1,93 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package linkedlist
+
+type List struct {
+	head  *Item
+	end   *Item
+	count int
+}
+
+func NewList() *List {
+	return &List{}
+}
+
+func (this *List) Head() *Item {
+	return this.head
+}
+
+func (this *List) End() *Item {
+	return this.end
+}
+
+func (this *List) Push(item *Item) {
+	if item == nil {
+		return
+	}
+
+	// 如果已经在末尾了，则do nothing
+	if this.end == item {
+		return
+	}
+
+	if item.prev != nil || item.next != nil || this.head == item {
+		this.Remove(item)
+	}
+	this.add(item)
+}
+
+func (this *List) Remove(item *Item) {
+	if item == nil {
+		return
+	}
+	if item.prev != nil {
+		item.prev.next = item.next
+	}
+	if item.next != nil {
+		item.next.prev = item.prev
+	}
+	if item == this.head {
+		this.head = item.next
+	}
+	if item == this.end {
+		this.end = item.prev
+	}
+
+	item.prev = nil
+	item.next = nil
+	this.count--
+}
+
+func (this *List) Len() int {
+	return this.count
+}
+
+func (this *List) Range(f func(item *Item) (goNext bool)) {
+	for e := this.head; e != nil; e = e.next {
+		goNext := f(e)
+		if !goNext {
+			break
+		}
+	}
+}
+
+func (this *List) Reset() {
+	this.head = nil
+	this.end = nil
+}
+
+func (this *List) add(item *Item) {
+	if item == nil {
+		return
+	}
+	if this.end != nil {
+		this.end.next = item
+		item.prev = this.end
+		item.next = nil
+	}
+	this.end = item
+	if this.head == nil {
+		this.head = item
+	}
+	this.count++
+}

internal/utils/linkedlist/list_test.go

@@ -0,0 +1,82 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package linkedlist_test
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/utils/linkedlist"
+	"runtime"
+	"testing"
+)
+
+func TestNewList_Memory(t *testing.T) {
+	var stat1 = &runtime.MemStats{}
+	runtime.ReadMemStats(stat1)
+
+	var list = linkedlist.NewList()
+	for i := 0; i < 1_000_000; i++ {
+		var item = &linkedlist.Item{}
+		list.Push(item)
+	}
+
+	var stat2 = &runtime.MemStats{}
+	runtime.ReadMemStats(stat2)
+	t.Log((stat2.HeapInuse-stat1.HeapInuse)/1024/1024, "MB")
+	t.Log(list.Len())
+
+	var count = 0
+	list.Range(func(item *linkedlist.Item) (goNext bool) {
+		count++
+		return true
+	})
+	t.Log(count)
+}
+
+func TestList_Push(t *testing.T) {
+	var list = linkedlist.NewList()
+	list.Push(linkedlist.NewItem(1))
+	list.Push(linkedlist.NewItem(2))
+
+	var item3 = linkedlist.NewItem(3)
+	list.Push(item3)
+
+	var item4 = linkedlist.NewItem(4)
+	list.Push(item4)
+	list.Range(func(item *linkedlist.Item) (goNext bool) {
+		t.Log(item.Value)
+		return true
+	})
+
+	t.Log("=== after push3 ===")
+	list.Push(item3)
+	list.Range(func(item *linkedlist.Item) (goNext bool) {
+		t.Log(item.Value)
+		return true
+	})
+
+	t.Log("=== after push4 ===")
+	list.Push(item4)
+	list.Push(item3)
+	list.Push(item3)
+	list.Push(item3)
+	list.Push(item4)
+	list.Push(item4)
+	list.Range(func(item *linkedlist.Item) (goNext bool) {
+		t.Log(item.Value)
+		return true
+	})
+
+	t.Log("=== after remove ===")
+	list.Remove(item3)
+	list.Range(func(item *linkedlist.Item) (goNext bool) {
+		t.Log(item.Value)
+		return true
+	})
+}
+
+func BenchmarkList_Add(b *testing.B) {
+	var list = linkedlist.NewList()
+	for i := 0; i < b.N; i++ {
+		var item = &linkedlist.Item{}
+		list.Push(item)
+	}
+}