From 530b0e308e3416cb97f0e085d08217fbbdd87428 Mon Sep 17 00:00:00 2001
From: Y4ssss <tz34055@163.com>
Date: Thu, 28 Oct 2021 09:54:47 +0800
Subject: [PATCH] feat: support to set cache expiration

---
 main.go         | 8 ++++----
 proxy/router.go | 5 ++++-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/main.go b/main.go
index 5fb1552..0703ebb 100644
--- a/main.go
+++ b/main.go
@@ -40,19 +40,18 @@ import (
 )
 
 var downloadRoot string
-
-const listExpire = proxy.ListExpire
-
 var listen, promListen string
 var cacheDir string
 var proxyHost string
 var excludeHost string
+var cacheExpire time.Duration
 
 func init() {
 	flag.StringVar(&excludeHost, "exclude", "", "exclude host pattern, you can exclude internal Git services")
 	flag.StringVar(&proxyHost, "proxy", "", "next hop proxy for Go Modules, recommend use https://gopropxy.io")
 	flag.StringVar(&cacheDir, "cacheDir", "", "Go Modules cache dir, default is $GOPATH/pkg/mod/cache/download")
 	flag.StringVar(&listen, "listen", "0.0.0.0:8081", "service listen address")
+	flag.DurationVar(&cacheExpire, "cacheExpire", 5*time.Minute, "Go Modules cache expiration (min), default is 5 min")
 	flag.Parse()
 
 	if os.Getenv("GIT_TERMINAL_PROMPT") == "" {
@@ -89,6 +88,7 @@ func main() {
 			Pattern:      excludeHost,
 			Proxy:        proxyHost,
 			DownloadRoot: downloadRoot,
+			CacheExpire:  cacheExpire,
 		})}
 	} else {
 		handle = &logger{proxy.NewServer(new(ops))}
@@ -195,7 +195,7 @@ func (*ops) List(ctx context.Context, mpath string) (proxy.File, error) {
 		return nil, err
 	}
 	file := filepath.Join(downloadRoot, escMod, "@v", "list")
-	if info, err := os.Stat(file); err == nil && time.Since(info.ModTime()) < listExpire {
+	if info, err := os.Stat(file); err == nil && time.Since(info.ModTime()) < cacheExpire {
 		return os.Open(file)
 	}
 	var list struct {
diff --git a/proxy/router.go b/proxy/router.go
index ffbc0d8..88920b5 100644
--- a/proxy/router.go
+++ b/proxy/router.go
@@ -30,6 +30,7 @@ type RouterOptions struct {
 	Pattern      string
 	Proxy        string
 	DownloadRoot string
+	CacheExpire  time.Duration
 }
 
 // A Router is the proxy HTTP server,
@@ -41,6 +42,7 @@ type Router struct {
 	proxy        *httputil.ReverseProxy
 	pattern      string
 	downloadRoot string
+	cacheExpire  time.Duration
 }
 
 func (router *Router) customModResponse(r *http.Response) error {
@@ -157,6 +159,7 @@ func NewRouter(srv *Server, opts *RouterOptions) *Router {
 		rt.proxy.ModifyResponse = rt.customModResponse
 		rt.pattern = opts.Pattern
 		rt.downloadRoot = opts.DownloadRoot
+		rt.cacheExpire = opts.CacheExpire
 	}
 	return rt
 }
@@ -215,7 +218,7 @@ func (rt *Router) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 			what := r.URL.Path[i+len("/@v/"):]
 			if what == "list" {
-				if time.Since(info.ModTime()) >= ListExpire {
+				if time.Since(info.ModTime()) >= rt.cacheExpire {
 					log.Printf("------ --- %s [proxy]\n", r.URL)
 					rt.proxy.ServeHTTP(mw, r)
 					totalRequest.With(prometheus.Labels{"mode": "proxy", "status": mw.status()}).Inc()