实现缓存策略的部分功能

internal/caches/writer.go

@@ -1,71 +1,19 @@
 package caches
 
-import (
-	"os"
-	"sync"
-)
+// 缓存内容写入接口
+type Writer interface {
+	// 写入数据
+	Write(data []byte) (n int, err error)
 
-type Writer struct {
-	rawWriter  *os.File
-	key        string
-	size       int64
-	expiredAt  int64
-	locker     *sync.RWMutex
-	isReleased bool
-}
-
-func NewWriter(rawWriter *os.File, key string, expiredAt int64, locker *sync.RWMutex) *Writer {
-	return &Writer{
-		key:       key,
-		rawWriter: rawWriter,
-		expiredAt: expiredAt,
-		locker:    locker,
-	}
-}
-
-// 写入数据
-func (this *Writer) Write(data []byte) error {
-	n, err := this.rawWriter.Write(data)
-	this.size += int64(n)
-	if err != nil {
-		_ = this.rawWriter.Close()
-		_ = os.Remove(this.rawWriter.Name())
-		this.Release()
-	}
-
-	return err
-}
-
-// 关闭
-func (this *Writer) Close() error {
-	// 写入结束符
-	_, err := this.rawWriter.WriteString("\n$$$")
-	if err != nil {
-		_ = os.Remove(this.rawWriter.Name())
-	}
-
-	this.Release()
-
-	return err
-}
-
-func (this *Writer) Size() int64 {
-	return this.size
-}
-
-func (this *Writer) ExpiredAt() int64 {
-	return this.expiredAt
-}
-
-func (this *Writer) Key() string {
-	return this.key
-}
-
-// 释放锁，一定要调用
-func (this *Writer) Release() {
-	if this.isReleased {
-		return
-	}
-	this.isReleased = true
-	this.locker.Unlock()
+	// 关闭
+	Close() error
+
+	// 丢弃
+	Discard() error
+
+	// Key
+	Key() string
+
+	// 过期时间
+	ExpiredAt() int64
 }