缓存支持ETag和Last-Modified

internal/caches/reader.go

@@ -12,6 +12,9 @@ type Reader interface {
 	// Status 状态码
 	Status() int
 
+	// LastModified 最后修改时间
+	LastModified() int64
+
 	// ReadHeader 读取Header
 	ReadHeader(buf []byte, callback ReaderFunc) error
 

internal/caches/reader_file.go

@@ -114,6 +114,14 @@ func (this *FileReader) Status() int {
 	return this.status
 }
 
+func (this *FileReader) LastModified() int64 {
+	stat, err := this.fp.Stat()
+	if err != nil {
+		return 0
+	}
+	return stat.ModTime().Unix()
+}
+
 func (this *FileReader) HeaderSize() int64 {
 	return int64(this.headerSize)
 }

internal/caches/reader_memory.go

@@ -24,6 +24,10 @@ func (this *MemoryReader) Status() int {
 	return this.item.Status
 }
 
+func (this *MemoryReader) LastModified() int64 {
+	return this.item.ModifiedAt
+}
+
 func (this *MemoryReader) HeaderSize() int64 {
 	return int64(len(this.item.HeaderValue))
 }

internal/caches/storage_memory.go

@@ -19,6 +19,7 @@ type MemoryItem struct {
 	BodyValue   []byte
 	Status      int
 	IsDone      bool
+	ModifiedAt  int64
 }
 
 func (this *MemoryItem) IsExpired() bool {

internal/caches/writer_memory.go

@@ -3,6 +3,7 @@ package caches
 import (
 	"github.com/cespare/xxhash"
 	"sync"
+	"time"
 )
 
 type MemoryWriter struct {
@@ -26,8 +27,9 @@ func NewMemoryWriter(m map[uint64]*MemoryItem, key string, expiredAt int64, stat
 		expiredAt: expiredAt,
 		locker:    locker,
 		item: &MemoryItem{
-			ExpiredAt: expiredAt,
-			Status:    status,
+			ExpiredAt:  expiredAt,
+			ModifiedAt: time.Now().Unix(),
+			Status:     status,
 		},
 		status:  status,
 		endFunc: endFunc,