add caching to the static files

extensions/manifest/manifest.go

@@ -18,7 +18,7 @@ func init() {
 }
 
 func manifest(w Response, r Request) Output {
-	return Render("manifest", Locals{"sitename": SITENAME})
+	return Cache(Render("manifest", Locals{"sitename": SITENAME}))
 }
 
 func head(_ Page) template.HTML {

fs.go

@@ -56,6 +56,6 @@ func staticHandler(r Request) (Output, error) {
 		return nil, err
 	} else {
 		f.Close()
-		return server.ServeHTTP, nil
+		return Cache(server.ServeHTTP), nil
 	}
 }

page.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"time"
 
 	emojiAst "github.com/yuin/goldmark-emoji/ast"
@@ -49,7 +50,11 @@ type Page interface {
 
 type page struct {
 	name string
-	ast  ast.Node
+
+	l          sync.Mutex
+	lastUpdate time.Time
+	ast        ast.Node
+	content    *Markdown
 }
 
 func (p *page) Name() string {
@@ -66,11 +71,11 @@ func (p *page) Exists() bool {
 }
 
 func (p *page) Render() template.HTML {
-	content := p.Content()
-	content = PreProcess(content)
+	content := p.preProcessedContent()
+	ast := p.AST()
 
 	var buf bytes.Buffer
-	if err := MarkDownRenderer.Convert([]byte(content), &buf); err != nil {
+	if err := MarkDownRenderer.Renderer().Render(&buf, []byte(content), ast); err != nil {
 		return template.HTML(err.Error())
 	}
 
@@ -85,6 +90,22 @@ func (p *page) Content() Markdown {
 	return Markdown(dat)
 }
 
+func (p *page) preProcessedContent() Markdown {
+	p.l.Lock()
+	defer p.l.Unlock()
+
+	modtime := p.ModTime()
+
+	if p.content == nil || modtime.Equal(p.lastUpdate) {
+		c := p.Content()
+		c = PreProcess(c)
+		p.content = &c
+		p.lastUpdate = p.ModTime()
+	}
+
+	return Markdown(*p.content)
+}
+
 func (p *page) Delete() bool {
 	defer Trigger(AfterDelete, p)
 
@@ -123,8 +144,11 @@ func (p *page) ModTime() time.Time {
 }
 
 func (p *page) AST() ast.Node {
-	if p.ast == nil {
-		p.ast = MarkDownRenderer.Parser().Parse(text.NewReader([]byte(p.Content())))
+	lastModified := p.lastUpdate
+	content := p.preProcessedContent()
+
+	if p.ast == nil || p.lastUpdate != lastModified {
+		p.ast = MarkDownRenderer.Parser().Parse(text.NewReader([]byte(content)))
 	}
 
 	return p.ast

server.go

@@ -209,3 +209,11 @@ func requestLoggerHandler(h http.Handler) http.Handler {
 		h.ServeHTTP(w, r)
 	})
 }
+
+// Cache wraps Output and adds header to instruct the browser to cache the output
+func Cache(out Output) Output {
+	return func(w Response, r Request) {
+		w.Header().Add("Cache-Control", "max-age=604800")
+		out(w, r)
+	}
+}