Don't generate bluemonday policy for each requests https://tangled.org/pocka.jp/legit/issues/4 bluemonday's documentation says the policy creation/editing is not safe to use in multiple goroutines. Now only one policy exists in the entire application and no creation/editing is happening inside HTTP server's goroutine. This also brings performance improvements. On my machine, spamming repo summary page took 10ms~11ms med (avg), but with this patch they are now 7ms~8ms med (avg). k6 run --vus 30 --iterations 1000 ./tests/k6/spam_repo_summary.js Thank Anthony Wang for sending the original patch that brought this topic in.

Changes

3 changed files (+18/-10)

• routes/handler.go
  • @@ -3,6 +3,7 @@ package routes
    import ( "net/http" + "github.com/microcosm-cc/bluemonday" "github.com/pocka/legit/config" )
  • @@ -30,7 +31,10 @@ func (d *deps) Multiplex(w http.ResponseWriter, r *http.Request) {
    func Handlers(c *config.Config) *http.ServeMux { mux := http.NewServeMux() - d := deps{c} + d := deps{ + c: c, + ugcPolicy: bluemonday.UGCPolicy(), + } mux.HandleFunc("GET /", d.Index) mux.HandleFunc("GET /static/{file}", d.ServeStatic)
• routes/preview/renderer.go
  • @@ -20,14 +20,15 @@ type Renderer interface {
    Render(code []byte) ([]byte, error) } - type MarkdownToHtmlRenderer struct{} + type MarkdownToHtmlRenderer struct { + policy *bluemonday.Policy + } func (r MarkdownToHtmlRenderer) GetPreviewType() string { return "html" } func (r MarkdownToHtmlRenderer) Render(code []byte) ([]byte, error) { - sanitizer := bluemonday.UGCPolicy() parser := blackfriday.New(blackfriday.WithExtensions(blackfriday.CommonExtensions)) tree := parser.Parse(code)
  • @@ -63,15 +64,15 @@ func (r MarkdownToHtmlRenderer) Render(code []byte) ([]byte, error) {
    renderer.RenderFooter(&writer, tree) unsafe := blackfriday.Run(writer.Bytes(), blackfriday.WithExtensions(blackfriday.CommonExtensions)) - return sanitizer.SanitizeBytes(unsafe), nil + return r.policy.SanitizeBytes(unsafe), nil } - func GetPreviewRenderers(fileName string) []Renderer { + func GetPreviewRenderers(fileName string, bmPolicy *bluemonday.Policy) []Renderer { ext := filepath.Ext(fileName) switch ext { case ".md", ".mkd", ".markdown": - return []Renderer{MarkdownToHtmlRenderer{}} + return []Renderer{MarkdownToHtmlRenderer{bmPolicy}} default: return []Renderer{} }
• routes/routes.go
  • @@ -24,6 +24,9 @@ import (
    type deps struct { c *config.Config + + // ugcPolicy is a bluemonday policy for user generated content. + ugcPolicy *bluemonday.Policy } func (d *deps) Index(w http.ResponseWriter, r *http.Request) {
  • @@ -180,10 +183,10 @@ func (d *deps) RepoIndex(w http.ResponseWriter, r *http.Request) {
    writer.Bytes(), blackfriday.WithExtensions(blackfriday.CommonExtensions), ) - html := bluemonday.UGCPolicy().SanitizeBytes(unsafe) + html := d.ugcPolicy.SanitizeBytes(unsafe) readmeContent = template.HTML(html) default: - safe := bluemonday.UGCPolicy().SanitizeBytes([]byte(content)) + safe := d.ugcPolicy.SanitizeBytes([]byte(content)) readmeContent = template.HTML( fmt.Sprintf(`<pre>%s</pre>`, safe), )
  • @@ -334,7 +337,7 @@ func (d *deps) FileContent(w http.ResponseWriter, r *http.Request) {
    if r.URL.Query().Has("preview") { previewType := r.URL.Query().Get("preview") - for _, renderer := range preview.GetPreviewRenderers(treePath) { + for _, renderer := range preview.GetPreviewRenderers(treePath, d.ugcPolicy) { resolvedPreviewType := renderer.GetPreviewType() if previewType != "" && resolvedPreviewType != previewType {
  • @@ -387,7 +390,7 @@ func (d *deps) FileContent(w http.ResponseWriter, r *http.Request) {
    lines[i] = uint(i + 1) } - renderers := preview.GetPreviewRenderers(treePath) + renderers := preview.GetPreviewRenderers(treePath, d.ugcPolicy) previewTypes := make([]string, len(renderers)) for i, renderer := range renderers { previewTypes[i] = renderer.GetPreviewType()