From b0cddd1b238a762c59c768a768637b993947e622 Mon Sep 17 00:00:00 2001 From: GoEdgeLab Date: Thu, 16 Dec 2021 17:27:21 +0800 Subject: [PATCH] =?UTF-8?q?=E5=AE=9E=E7=8E=B0stale=20cache=E8=AF=BB?= =?UTF-8?q?=E5=8F=96?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- internal/caches/item.go | 1 + internal/caches/list_file.go | 48 ++++++++++++++++++-- internal/caches/storage_file.go | 37 +++++++++------ internal/caches/storage_interface.go | 2 +- internal/caches/storage_memory.go | 4 +- internal/nodes/api_stream.go | 2 +- internal/nodes/http_request.go | 19 ++++---- internal/nodes/http_request_auth.go | 2 +- internal/nodes/http_request_cache.go | 21 +++++---- internal/nodes/http_request_error.go | 16 ++++++- internal/nodes/http_request_fastcgi.go | 6 +-- internal/nodes/http_request_reverse_proxy.go | 16 +++---- internal/nodes/http_request_root.go | 6 +-- internal/nodes/http_request_url.go | 2 +- internal/nodes/http_request_websocket.go | 6 +-- internal/nodes/http_writer.go | 35 +++++++++++++- 16 files changed, 164 insertions(+), 59 deletions(-) diff --git a/internal/caches/item.go b/internal/caches/item.go index 58548c9..8374a61 100644 --- a/internal/caches/item.go +++ b/internal/caches/item.go @@ -22,6 +22,7 @@ type Item struct { Type ItemType `json:"type"` Key string `json:"key"` ExpiredAt int64 `json:"expiredAt"` + StaleAt int64 `json:"staleAt"` HeaderSize int64 `json:"headerSize"` BodySize int64 `json:"bodySize"` MetaSize int64 `json:"metaSize"` diff --git a/internal/caches/list_file.go b/internal/caches/list_file.go index f2f156a..35f6cfc 100644 --- a/internal/caches/list_file.go +++ b/internal/caches/list_file.go @@ -13,6 +13,7 @@ import ( _ "github.com/mattn/go-sqlite3" "os" "strconv" + "strings" "sync/atomic" "time" ) @@ -104,6 +105,12 @@ func (this *FileList) Init() error { return err } + // 检查staleAt字段 + err = this.checkStaleAtField() + if err != nil { + return err + } + // 读取总数量 row := this.db.QueryRow(`SELECT COUNT(*) FROM "` + this.itemsTableName + `"`) if row.Err() != nil { @@ -122,7 +129,7 @@ func (this *FileList) Init() error { return err } - this.insertStmt, err = this.db.Prepare(`INSERT INTO "` + this.itemsTableName + `" ("hash", "key", "headerSize", "bodySize", "metaSize", "expiredAt", "host", "serverId", "createdAt") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`) + this.insertStmt, err = this.db.Prepare(`INSERT INTO "` + this.itemsTableName + `" ("hash", "key", "headerSize", "bodySize", "metaSize", "expiredAt", "staleAt", "host", "serverId", "createdAt") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`) if err != nil { return err } @@ -142,7 +149,7 @@ func (this *FileList) Init() error { return err } - this.purgeStmt, err = this.db.Prepare(`SELECT "hash" FROM "` + this.itemsTableName + `" WHERE expiredAt<=? LIMIT ?`) + this.purgeStmt, err = this.db.Prepare(`SELECT "hash" FROM "` + this.itemsTableName + `" WHERE staleAt<=? LIMIT ?`) if err != nil { return err } @@ -182,7 +189,11 @@ func (this *FileList) Add(hash string, item *Item) error { return nil } - _, err := this.insertStmt.Exec(hash, item.Key, item.HeaderSize, item.BodySize, item.MetaSize, item.ExpiredAt, item.Host, item.ServerId, utils.UnixTime()) + if item.StaleAt == 0 { + item.StaleAt = item.ExpiredAt + } + + _, err := this.insertStmt.Exec(hash, item.Key, item.HeaderSize, item.BodySize, item.MetaSize, item.ExpiredAt, item.StaleAt, item.Host, item.ServerId, utils.UnixTime()) if err != nil { return err } @@ -474,6 +485,8 @@ func (this *FileList) Close() error { // 初始化 func (this *FileList) initTables(db *sql.DB, times int) error { { + // expiredAt - 过期时间，用来判断有无过期 + // staleAt - 陈旧最大时间，用来清理缓存 _, err := db.Exec(`CREATE TABLE IF NOT EXISTS "` + this.itemsTableName + `" ( "id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "hash" varchar(32), @@ -482,6 +495,7 @@ func (this *FileList) initTables(db *sql.DB, times int) error { "bodySize" integer DEFAULT 0, "metaSize" integer DEFAULT 0, "expiredAt" integer DEFAULT 0, + "staleAt" integer DEFAULT 0, "createdAt" integer DEFAULT 0, "host" varchar(128), "serverId" integer @@ -497,6 +511,11 @@ ON "` + this.itemsTableName + `" ( "expiredAt" ASC ); +CREATE INDEX IF NOT EXISTS "staleAt" +ON "` + this.itemsTableName + `" ( + "staleAt" ASC +); + CREATE UNIQUE INDEX IF NOT EXISTS "hash" ON "` + this.itemsTableName + `" ( "hash" ASC @@ -579,3 +598,26 @@ func (this *FileList) removeOldTables() error { } return nil } + +func (this *FileList) checkStaleAtField() error { + rows, err := this.db.Query(`SELECT staleAt FROM "` + this.itemsTableName + `"`) + if err != nil { + if strings.Contains(err.Error(), "no such column: staleAt") { // 暂时没有更好的判断方法 + _, err = this.db.Exec(`ALTER TABLE "` + this.itemsTableName + `" ADD COLUMN staleAt integer DEFAULT 0`) + if err != nil { + return err + } + + _, err = this.db.Exec(`UPDATE "` + this.itemsTableName + `" SET staleAt=expiredAt`) + if err != nil { + return err + } + } else { + return err + } + } else { + _ = rows.Close() + } + + return nil +} diff --git a/internal/caches/storage_file.go b/internal/caches/storage_file.go index 8ba5a0f..484b71f 100644 --- a/internal/caches/storage_file.go +++ b/internal/caches/storage_file.go @@ -204,14 +204,19 @@ func (this *FileStorage) Init() error { return nil } -func (this *FileStorage) OpenReader(key string) (Reader, error) { - return this.openReader(key, true) +func (this *FileStorage) OpenReader(key string, useStale bool) (Reader, error) { + return this.openReader(key, true, useStale) } -func (this *FileStorage) openReader(key string, allowMemory bool) (Reader, error) { +func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool) (Reader, error) { + // 使用陈旧缓存的时候，我们认为是短暂的，只需要从文件里检查即可 + if useStale { + allowMemory = false + } + // 先尝试内存缓存 if allowMemory && this.memoryStorage != nil { - reader, err := this.memoryStorage.OpenReader(key) + reader, err := this.memoryStorage.OpenReader(key, useStale) if err == nil { return reader, err } @@ -219,6 +224,17 @@ func (this *FileStorage) openReader(key string, allowMemory bool) (Reader, error hash, path := this.keyPath(key) + // 检查文件记录是否已过期 + if !useStale { + exists, err := this.list.Exist(hash) + if err != nil { + return nil, err + } + if !exists { + return nil, ErrNotFound + } + } + // TODO 尝试使用mmap加快读取速度 var isOk = false fp, err := os.OpenFile(path, os.O_RDONLY, 0444) @@ -235,15 +251,6 @@ func (this *FileStorage) openReader(key string, allowMemory bool) (Reader, error } }() - // 检查文件记录是否已过期 - exists, err := this.list.Exist(hash) - if err != nil { - return nil, err - } - if !exists { - return nil, ErrNotFound - } - reader := NewFileReader(fp) if err != nil { return nil, err @@ -923,7 +930,7 @@ func (this *FileStorage) hotLoop() { this.hotMap = map[string]*HotItem{} this.hotMapLocker.Unlock() - // 取Top10 + // 取Top10写入内存 if len(result) > 0 { sort.Slice(result, func(i, j int) bool { return result[i].Hits > result[j].Hits @@ -937,7 +944,7 @@ func (this *FileStorage) hotLoop() { var buf = make([]byte, 32*1024) for _, item := range result[:size] { - reader, err := this.openReader(item.Key, false) + reader, err := this.openReader(item.Key, false, false) if err != nil { continue } diff --git a/internal/caches/storage_interface.go b/internal/caches/storage_interface.go index 3d59f18..de10c3c 100644 --- a/internal/caches/storage_interface.go +++ b/internal/caches/storage_interface.go @@ -10,7 +10,7 @@ type StorageInterface interface { Init() error // OpenReader 读取缓存 - OpenReader(key string) (Reader, error) + OpenReader(key string, useStale bool) (reader Reader, err error) // OpenWriter 打开缓存写入器等待写入 OpenWriter(key string, expiredAt int64, status int) (Writer, error) diff --git a/internal/caches/storage_memory.go b/internal/caches/storage_memory.go index 0949b46..9d7df80 100644 --- a/internal/caches/storage_memory.go +++ b/internal/caches/storage_memory.go @@ -105,7 +105,7 @@ func (this *MemoryStorage) Init() error { } // OpenReader 读取缓存 -func (this *MemoryStorage) OpenReader(key string) (Reader, error) { +func (this *MemoryStorage) OpenReader(key string, useStale bool) (Reader, error) { hash := this.hash(key) this.locker.RLock() @@ -115,7 +115,7 @@ func (this *MemoryStorage) OpenReader(key string) (Reader, error) { return nil, ErrNotFound } - if item.ExpiredAt > utils.UnixTime() { + if useStale || (item.ExpiredAt > utils.UnixTime()) { reader := NewMemoryReader(item) err := reader.Init() if err != nil { diff --git a/internal/nodes/api_stream.go b/internal/nodes/api_stream.go index 222c054..7450bb8 100644 --- a/internal/nodes/api_stream.go +++ b/internal/nodes/api_stream.go @@ -236,7 +236,7 @@ func (this *APIStream) handleReadCache(message *pb.NodeStreamMessage) error { }() } - reader, err := storage.OpenReader(msg.Key) + reader, err := storage.OpenReader(msg.Key, false) if err != nil { if err == caches.ErrNotFound { this.replyFail(message.RequestId, "key not found") diff --git a/internal/nodes/http_request.go b/internal/nodes/http_request.go index 62378f7..03a5843 100644 --- a/internal/nodes/http_request.go +++ b/internal/nodes/http_request.go @@ -69,11 +69,14 @@ type HTTPRequest struct { rewriteRule *serverconfigs.HTTPRewriteRule // 匹配到的重写规则 rewriteReplace string // 重写规则的目标 rewriteIsExternalURL bool // 重写目标是否为外部URL - cacheRef *serverconfigs.HTTPCacheRef // 缓存设置 - cacheKey string // 缓存使用的Key - isCached bool // 是否已经被缓存 - isAttack bool // 是否是攻击请求 - requestBodyData []byte // 读取的Body内容 + + cacheRef *serverconfigs.HTTPCacheRef // 缓存设置 + cacheKey string // 缓存使用的Key + isCached bool // 是否已经被缓存 + cacheCanTryStale bool // 是否可以尝试使用Stale缓存 + + isAttack bool // 是否是攻击请求 + requestBodyData []byte // 读取的Body内容 // WAF相关 firewallPolicyId int64 @@ -137,7 +140,7 @@ func (this *HTTPRequest) Do() { // Web配置 err := this.configureWeb(this.Server.Web, true, 0) if err != nil { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) this.doEnd() return } @@ -224,7 +227,7 @@ func (this *HTTPRequest) doBegin() { var err error this.requestBodyData, err = ioutil.ReadAll(io.LimitReader(this.RawReq.Body, AccessLogMaxRequestBodySize)) if err != nil { - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, false) return } this.RawReq.Body = ioutil.NopCloser(io.MultiReader(bytes.NewBuffer(this.requestBodyData), this.RawReq.Body)) @@ -253,7 +256,7 @@ func (this *HTTPRequest) doBegin() { // 缓存 if this.web.Cache != nil && this.web.Cache.IsOn { - if this.doCacheRead() { + if this.doCacheRead(false) { return } } diff --git a/internal/nodes/http_request_auth.go b/internal/nodes/http_request_auth.go index 2728b97..e22d905 100644 --- a/internal/nodes/http_request_auth.go +++ b/internal/nodes/http_request_auth.go @@ -33,7 +33,7 @@ func (this *HTTPRequest) doAuth() (shouldStop bool) { return writer.StatusCode(), nil }, this.Format) if err != nil { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) return } if b { diff --git a/internal/nodes/http_request_cache.go b/internal/nodes/http_request_cache.go index 7cc65e6..d653921 100644 --- a/internal/nodes/http_request_cache.go +++ b/internal/nodes/http_request_cache.go @@ -17,7 +17,7 @@ import ( ) // 读取缓存 -func (this *HTTPRequest) doCacheRead() (shouldStop bool) { +func (this *HTTPRequest) doCacheRead(useStale bool) (shouldStop bool) { cachePolicy := this.Server.HTTPCachePolicy if cachePolicy == nil || !cachePolicy.IsOn { return @@ -148,11 +148,6 @@ func (this *HTTPRequest) doCacheRead() (shouldStop bool) { return true } - buf := bytePool32k.Get() - defer func() { - bytePool32k.Put(buf) - }() - var reader caches.Reader var err error @@ -161,16 +156,20 @@ func (this *HTTPRequest) doCacheRead() (shouldStop bool) { this.web.WebP.IsOn && this.web.WebP.MatchRequest(filepath.Ext(this.requestPath()), this.Format) && this.web.WebP.MatchAccept(this.requestHeader("Accept")) { - reader, _ = storage.OpenReader(key + webpSuffix) + reader, _ = storage.OpenReader(key+webpSuffix, useStale) } // 检查正常的文件 if reader == nil { - reader, err = storage.OpenReader(key) + reader, err = storage.OpenReader(key, useStale) if err != nil { if err == caches.ErrNotFound { // cache相关变量 this.varMapping["cache.status"] = "MISS" + + if this.web.Cache.Stale != nil && this.web.Cache.Stale.IsOn { + this.cacheCanTryStale = true + } return } @@ -187,6 +186,12 @@ func (this *HTTPRequest) doCacheRead() (shouldStop bool) { this.varMapping["cache.status"] = "HIT" this.logAttrs["cache.status"] = "HIT" + // 准备Buffer + buf := bytePool32k.Get() + defer func() { + bytePool32k.Put(buf) + }() + // 读取Header headerBuf := []byte{} err = reader.ReadHeader(buf, func(n int) (goNext bool, err error) { diff --git a/internal/nodes/http_request_error.go b/internal/nodes/http_request_error.go index 753478e..381f728 100644 --- a/internal/nodes/http_request_error.go +++ b/internal/nodes/http_request_error.go @@ -1,6 +1,7 @@ package nodes import ( + "github.com/iwind/TeaGo/lists" "github.com/iwind/TeaGo/types" "net/http" ) @@ -25,11 +26,24 @@ func (this *HTTPRequest) writeCode(code int) { _, _ = this.writer.Write([]byte(types.String(code) + " " + http.StatusText(code) + ": '" + this.requestFullURL() + "'" + " (Request Id: " + this.requestId + ")")) } -func (this *HTTPRequest) write50x(err error, statusCode int) { +func (this *HTTPRequest) write50x(err error, statusCode int, canTryStale bool) { if err != nil { this.addError(err) } + // 尝试从缓存中恢复 + if canTryStale && + this.cacheCanTryStale && + this.web.Cache.Stale != nil && + this.web.Cache.Stale.IsOn && + (len(this.web.Cache.Stale.Status) == 0 || lists.ContainsInt(this.web.Cache.Stale.Status, statusCode)) { + ok := this.doCacheRead(true) + if ok { + return + } + } + + // 显示自定义页面 if this.doPage(statusCode) { return } diff --git a/internal/nodes/http_request_fastcgi.go b/internal/nodes/http_request_fastcgi.go index 373b9bf..bf4435f 100644 --- a/internal/nodes/http_request_fastcgi.go +++ b/internal/nodes/http_request_fastcgi.go @@ -81,7 +81,7 @@ func (this *HTTPRequest) doFastcgi() (shouldStop bool) { client, err := fcgi.SharedPool(fastcgi.Network(), fastcgi.RealAddress(), uint(poolSize)).Client() if err != nil { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) return } @@ -159,13 +159,13 @@ func (this *HTTPRequest) doFastcgi() (shouldStop bool) { resp, stderr, err := client.Call(fcgiReq) if err != nil { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) return } if len(stderr) > 0 { err := errors.New("Fastcgi Error: " + strings.TrimSpace(string(stderr)) + " script: " + maps.NewMap(params).GetString("SCRIPT_FILENAME")) - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) return } diff --git a/internal/nodes/http_request_reverse_proxy.go b/internal/nodes/http_request_reverse_proxy.go index 3b875f8..687f358 100644 --- a/internal/nodes/http_request_reverse_proxy.go +++ b/internal/nodes/http_request_reverse_proxy.go @@ -41,7 +41,7 @@ func (this *HTTPRequest) doReverseProxy() { if origin == nil { err := errors.New(this.requestFullURL() + ": no available origin sites for reverse proxy") remotelogs.ServerError(this.Server.Id, "HTTP_REQUEST_REVERSE_PROXY", err.Error(), "", nil) - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, true) return } this.origin = origin // 设置全局变量是为了日志等处理 @@ -61,7 +61,7 @@ func (this *HTTPRequest) doReverseProxy() { if origin.Addr == nil { err := errors.New(this.requestFullURL() + ": origin '" + strconv.FormatInt(origin.Id, 10) + "' does not has a address") remotelogs.Error("HTTP_REQUEST_REVERSE_PROXY", err.Error()) - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, false) return } this.RawReq.URL.Scheme = origin.Addr.Protocol.Primary().Scheme() @@ -156,7 +156,7 @@ func (this *HTTPRequest) doReverseProxy() { client, err := SharedHTTPClientPool.Client(this, origin, originAddr, this.reverseProxy.ProxyProtocol) if err != nil { remotelogs.Error("HTTP_REQUEST_REVERSE_PROXY", err.Error()) - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, true) return } @@ -175,18 +175,18 @@ func (this *HTTPRequest) doReverseProxy() { SharedOriginStateManager.Fail(origin, this.reverseProxy, func() { this.reverseProxy.ResetScheduling() }) - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, true) remotelogs.Warn("HTTP_REQUEST_REVERSE_PROXY", this.RawReq.URL.String()+"': "+err.Error()) } else if httpErr.Err != context.Canceled { SharedOriginStateManager.Fail(origin, this.reverseProxy, func() { this.reverseProxy.ResetScheduling() }) if httpErr.Timeout() { - this.write50x(err, http.StatusGatewayTimeout) + this.write50x(err, http.StatusGatewayTimeout, true) } else if httpErr.Temporary() { - this.write50x(err, http.StatusServiceUnavailable) + this.write50x(err, http.StatusServiceUnavailable, true) } else { - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, true) } remotelogs.Warn("HTTP_REQUEST_REVERSE_PROXY", this.RawReq.URL.String()+"': "+err.Error()) } else { @@ -207,7 +207,7 @@ func (this *HTTPRequest) doReverseProxy() { } if !isClientError { - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, true) } } if resp != nil && resp.Body != nil { diff --git a/internal/nodes/http_request_root.go b/internal/nodes/http_request_root.go index 1b808e1..955afe5 100644 --- a/internal/nodes/http_request_root.go +++ b/internal/nodes/http_request_root.go @@ -110,7 +110,7 @@ func (this *HTTPRequest) doRoot() (isBreak bool) { } return } else { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, true) logs.Error(err) return true } @@ -139,7 +139,7 @@ func (this *HTTPRequest) doRoot() (isBreak bool) { } return } else { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, true) logs.Error(err) return true } @@ -284,7 +284,7 @@ func (this *HTTPRequest) doRoot() (isBreak bool) { reader, err := os.OpenFile(filePath, os.O_RDONLY, 0444) if err != nil { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, true) return true } diff --git a/internal/nodes/http_request_url.go b/internal/nodes/http_request_url.go index 9684ca6..3617771 100644 --- a/internal/nodes/http_request_url.go +++ b/internal/nodes/http_request_url.go @@ -35,7 +35,7 @@ func (this *HTTPRequest) doURL(method string, url string, host string, statusCod resp, err := client.Do(req) if err != nil { remotelogs.Error("HTTP_REQUEST_URL", req.URL.String()+": "+err.Error()) - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) return } defer func() { diff --git a/internal/nodes/http_request_websocket.go b/internal/nodes/http_request_websocket.go index 39d9855..d235904 100644 --- a/internal/nodes/http_request_websocket.go +++ b/internal/nodes/http_request_websocket.go @@ -43,7 +43,7 @@ func (this *HTTPRequest) doWebsocket() { // TODO 增加N次错误重试，重试的时候需要尝试不同的源站 originConn, err := OriginConnect(this.origin, this.RawReq.RemoteAddr) if err != nil { - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, false) return } defer func() { @@ -52,13 +52,13 @@ func (this *HTTPRequest) doWebsocket() { err = this.RawReq.Write(originConn) if err != nil { - this.write50x(err, http.StatusBadGateway) + this.write50x(err, http.StatusBadGateway, false) return } clientConn, _, err := this.writer.Hijack() if err != nil || clientConn == nil { - this.write50x(err, http.StatusInternalServerError) + this.write50x(err, http.StatusInternalServerError, false) return } defer func() { diff --git a/internal/nodes/http_writer.go b/internal/nodes/http_writer.go index b989212..ea4d78b 100644 --- a/internal/nodes/http_writer.go +++ b/internal/nodes/http_writer.go @@ -1,3 +1,5 @@ +// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved. + package nodes import ( @@ -413,10 +415,12 @@ func (this *HTTPWriter) Close() { if this.isOk { err := this.cacheWriter.Close() if err == nil { + var expiredAt = this.cacheWriter.ExpiredAt() this.cacheStorage.AddToList(&caches.Item{ Type: this.cacheWriter.ItemType(), Key: this.cacheWriter.Key(), - ExpiredAt: this.cacheWriter.ExpiredAt(), + ExpiredAt: expiredAt, + StaleAt: expiredAt + int64(this.calculateStaleLife()), HeaderSize: this.cacheWriter.HeaderSize(), BodySize: this.cacheWriter.BodySize(), Host: this.req.Host, @@ -690,3 +694,32 @@ func (this *HTTPWriter) prepareCache(size int64) { } } } + +// 计算stale时长 +func (this *HTTPWriter) calculateStaleLife() int { + var staleLife = 600 // TODO 可以在缓存策略里设置此时间 + var staleConfig = this.req.web.Cache.Stale + if staleConfig != nil && staleConfig.IsOn { + // 从Header中读取stale-if-error + var isDefinedInHeader = false + if staleConfig.SupportStaleIfErrorHeader { + var cacheControl = this.Header().Get("Cache-Control") + var pieces = strings.Split(cacheControl, ",") + for _, piece := range pieces { + var eqIndex = strings.Index(piece, "=") + if eqIndex > 0 && strings.TrimSpace(piece[:eqIndex]) == "stale-if-error" { + // 这里预示着如果stale-if-error=0，可以关闭stale功能 + staleLife = types.Int(strings.TrimSpace(piece[eqIndex+1:])) + isDefinedInHeader = true + break + } + } + } + + // 自定义 + if !isDefinedInHeader && staleConfig.Life != nil { + staleLife = types.Int(staleConfig.Life.Duration().Seconds()) + } + } + return staleLife +}