实现open file cache

internal/caches/open_file_pool.go

@@ -0,0 +1,76 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package caches
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/utils"
+	"github.com/TeaOSLab/EdgeNode/internal/utils/linkedlist"
+)
+
+type OpenFilePool struct {
+	c        chan *OpenFile
+	linkItem *linkedlist.Item
+	filename string
+	version  int64
+}
+
+func NewOpenFilePool(filename string) *OpenFilePool {
+	var pool = &OpenFilePool{
+		filename: filename,
+		c:        make(chan *OpenFile, 1024),
+		version:  utils.UnixTimeMilli(),
+	}
+	pool.linkItem = linkedlist.NewItem(pool)
+	return pool
+}
+
+func (this *OpenFilePool) Filename() string {
+	return this.filename
+}
+
+func (this *OpenFilePool) Get() (*OpenFile, bool) {
+	select {
+	case file := <-this.c:
+		err := file.SeekStart()
+		if err != nil {
+			_ = file.Close()
+			return nil, true
+		}
+		file.version = this.version
+
+		return file, true
+	default:
+		return nil, false
+	}
+}
+
+func (this *OpenFilePool) Put(file *OpenFile) bool {
+	if file.version > 0 && file.version != this.version {
+		_ = file.Close()
+		return false
+	}
+	select {
+	case this.c <- file:
+		return true
+	default:
+		// 多余的直接关闭
+		_ = file.Close()
+		return false
+	}
+}
+
+func (this *OpenFilePool) Len() int {
+	return len(this.c)
+}
+
+func (this *OpenFilePool) Close() {
+Loop:
+	for {
+		select {
+		case file := <-this.c:
+			_ = file.Close()
+		default:
+			break Loop
+		}
+	}
+}