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 {
@@ -27,6 +28,7 @@ func NewMemoryWriter(m map[uint64]*MemoryItem, key string, expiredAt int64, stat
 		locker:    locker,
 		item: &MemoryItem{
 			ExpiredAt:  expiredAt,
+			ModifiedAt: time.Now().Unix(),
 			Status:     status,
 		},
 		status:  status,

internal/nodes/http_request_cache.go

@@ -8,6 +8,7 @@ import (
 	"github.com/iwind/TeaGo/logs"
 	"net/http"
 	"strconv"
+	"time"
 )
 
 // 读取缓存
@@ -120,6 +121,7 @@ func (this *HTTPRequest) doCacheRead() (shouldStop bool) {
 	}
 	defer func() {
 		_ = reader.Close()
+		this.cacheRef = nil // 终止读取不再往下传递
 	}()
 
 	this.varMapping["cache.status"] = "HIT"
@@ -156,6 +158,45 @@ func (this *HTTPRequest) doCacheRead() (shouldStop bool) {
 	if addStatusHeader {
 		this.writer.Header().Set("X-Cache", "HIT, "+refType+", "+reader.TypeName())
 	}
+
+	// ETag
+	var respHeader = this.writer.Header()
+	var eTag = respHeader.Get("ETag")
+	var lastModifiedAt = reader.LastModified()
+	if len(eTag) == 0 {
+		if lastModifiedAt > 0 {
+			eTag = "\"" + strconv.FormatInt(lastModifiedAt, 10) + "\""
+			respHeader["ETag"] = []string{eTag}
+		}
+	}
+
+	// 支持 Last-Modified
+	var modifiedTime = respHeader.Get("Last-Modified")
+	if len(modifiedTime) == 0 {
+		if lastModifiedAt > 0 {
+			modifiedTime = time.Unix(lastModifiedAt, 0).Format("Mon, 02 Jan 2006 15:04:05 GMT")
+			if len(respHeader.Get("Last-Modified")) == 0 {
+				respHeader.Set("Last-Modified", modifiedTime)
+			}
+		}
+	}
+
+	// 支持 If-None-Match
+	if len(eTag) > 0 && this.requestHeader("If-None-Match") == eTag {
+		// 自定义Header
+		this.processResponseHeaders(http.StatusNotModified)
+		this.writer.WriteHeader(http.StatusNotModified)
+		return true
+	}
+
+	// 支持 If-Modified-Since
+	if len(modifiedTime) > 0 && this.requestHeader("If-Modified-Since") == modifiedTime {
+		// 自定义Header
+		this.processResponseHeaders(http.StatusNotModified)
+		this.writer.WriteHeader(http.StatusNotModified)
+		return true
+	}
+
 	this.processResponseHeaders(reader.Status())
 
 	// 输出Body
@@ -313,7 +354,6 @@ func (this *HTTPRequest) doCacheRead() (shouldStop bool) {
 		}
 	}
 
-	this.cacheRef = nil // 终止读取不再往下传递
 	this.isCached = true
 	return true
 }

internal/nodes/http_request_reverse_proxy.go

@@ -162,7 +162,7 @@ func (this *HTTPRequest) doReverseProxy() {
 			// TODO 如果超过最大失败次数，则下线
 
 			this.write502(err)
-			remotelogs.Println("HTTP_REQUEST_REVERSE_PROXY", this.RawReq.URL.String()+"': "+err.Error())
+			remotelogs.Warn("HTTP_REQUEST_REVERSE_PROXY", this.RawReq.URL.String()+"': "+err.Error())
 		} else {
 			// 是否为客户端方面的错误
 			isClientError := false