From 2b0d4a52363b8683a594066bf78786fca3ac881a Mon Sep 17 00:00:00 2001
From: Ben Morrison <ben@gbmor.dev>
Date: Thu, 23 May 2019 02:16:41 -0400
Subject: caching some static assets

---
 cache.go    | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 handlers.go | 24 ++++--------------------
 init.go     | 13 +++++++++++++
 3 files changed, 68 insertions(+), 20 deletions(-)

diff --git a/cache.go b/cache.go
index 2ed21f3..214d185 100644
--- a/cache.go
+++ b/cache.go
@@ -1,8 +1,10 @@
 package main
 
 import (
+	"io/ioutil"
 	"log"
 	"net"
+	"os"
 	"strings"
 	"time"
 
@@ -185,3 +187,52 @@ func pullDatabase() {
 		log.Printf("Error while pulling DB into registry cache: %v\n", err)
 	}
 }
+
+// pingAssets checks if the local static assets
+// need to be re-cached. If they do, they are
+// pulled back into memory from disk.
+func pingAssets() {
+
+	cssStat, err := os.Stat("assets/style.css")
+	if err != nil {
+		log.Printf("%v\n", err)
+	}
+	/*
+		indexStat, err := os.Stat("assets/tmpl/index.html")
+		if err != nil {
+			log.Printf("%v\n", err)
+		}
+
+		indexMod := staticCache.indexMod*/
+	cssMod := staticCache.cssMod
+	/*
+		if !indexMod.Equal(indexStat.ModTime()) {
+			var err error
+			tmpls, err = template.ParseFiles("assets/tmpl/index.html")
+			if err != nil {
+				log.Printf("%v\n", err)
+			}
+			buf := bytes.NewBuffer(staticCache.index)
+
+			confObj.Mu.RLock()
+			err = tmpls.ExecuteTemplate(buf, "index.html", confObj.Instance)
+			confObj.Mu.RUnlock()
+			if err != nil {
+				log.Printf("%v\n", err)
+			}
+
+			staticCache.index = buf.Bytes()
+			staticCache.indexMod = indexStat.ModTime()
+		}
+	*/
+	if !cssMod.Equal(cssStat.ModTime()) {
+
+		css, err := ioutil.ReadFile("assets/style.css")
+		if err != nil {
+			log.Printf("%v\n", err)
+		}
+
+		staticCache.css = css
+		staticCache.cssMod = cssStat.ModTime()
+	}
+}
diff --git a/handlers.go b/handlers.go
index 7f05f8f..1e01619 100644
--- a/handlers.go
+++ b/handlers.go
@@ -3,7 +3,6 @@ package main
 import (
 	"crypto/sha256"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -175,30 +174,15 @@ func apiTagsHandler(w http.ResponseWriter, r *http.Request) {
 // files aren't served directly.
 func cssHandler(w http.ResponseWriter, r *http.Request) {
 
-	// read the raw bytes of the stylesheet
-	css, err := ioutil.ReadFile("assets/style.css")
-	if err != nil {
-		if os.IsNotExist(err) {
-			log404(w, r, err)
-			return
-		}
-		log500(w, r, err)
-		return
-	}
-
-	// Get the mod time for the etag header
-	stat, err := os.Stat("assets/style.css")
-	if err != nil {
-		log.Printf("Couldn't stat CSS file to send ETag header: %v\n", err)
-	}
-
 	// Sending the sha256 sum of the modtime in hexadecimal for the ETag header
-	etag := fmt.Sprintf("%x", sha256.Sum256([]byte(stat.ModTime().String())))
+	etag := fmt.Sprintf("%x", sha256.Sum256([]byte(staticCache.cssMod.String())))
 
 	w.Header().Set("ETag", "\""+etag+"\"")
 	w.Header().Set("Content-Type", cssutf8)
 
-	n, err := w.Write(css)
+	pingAssets()
+
+	n, err := w.Write(staticCache.css)
 	if err != nil || n == 0 {
 		log500(w, r, err)
 		return
diff --git a/init.go b/init.go
index 8e7fe2f..25beeed 100644
--- a/init.go
+++ b/init.go
@@ -42,6 +42,19 @@ var twtxtCache = registry.NewIndex()
 // remote registry listing
 var remoteRegistries = &RemoteRegistries{}
 
+// static assets cache
+var staticCache = &struct {
+	index    []byte
+	indexMod time.Time
+	css      []byte
+	cssMod   time.Time
+}{
+	index:    nil,
+	indexMod: time.Time{},
+	css:      nil,
+	cssMod:   time.Time{},
+}
+
 func initGetwtxt() {
 	checkFlags()
 	titleScreen()
-- 
cgit 1.4.1-2-gfad0