Cache the page's rendering context flags

This map can potentially be used many times for a given page, and altough the cost of re-creating the map should be minimal, caching it is simple -- and could save some GC and CPU cycles.

diff --git a/hugolib/page.go b/hugolib/page.go
index 9373104670f7f58e060a2b34de599476f045488d..c30728c0378c71b76c450bd85b59ed2e6da44e3a 100644 (file)
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -32,6 +32,7 @@ import (
        "path"
        "path/filepath"
        "strings"
+       "sync"
        "time"
 )
 
@@ -50,15 +51,17 @@ type Page struct {
        Tmpl            tpl.Template
        Markup          string
 
-       extension         string
-       contentType       string
-       renderable        bool
-       layout            string
-       linkTitle         string
-       frontmatter       []byte
-       rawContent        []byte
-       contentShortCodes map[string]string
-       plain             string // TODO should be []byte
+       extension                string
+       contentType              string
+       renderable               bool
+       layout                   string
+       linkTitle                string
+       frontmatter              []byte
+       rawContent               []byte
+       contentShortCodes        map[string]string
+       plain                    string // TODO should be []byte
+       renderingConfigFlags     map[string]bool
+       renderingConfigFlagsInit sync.Once
        PageMeta
        Source
        Position
@@ -187,21 +190,24 @@ func (p *Page) renderContent(content []byte) []byte {
 }
 
 func (p *Page) getRenderingConfigFlags() map[string]bool {
-       flags := make(map[string]bool)
 
-       pageParam := p.GetParam("blackfriday")
-       siteParam := viper.GetStringMap("blackfriday")
+       p.renderingConfigFlagsInit.Do(func() {
+               p.renderingConfigFlags = make(map[string]bool)
 
-       flags = cast.ToStringMapBool(siteParam)
+               pageParam := p.GetParam("blackfriday")
+               siteParam := viper.GetStringMap("blackfriday")
 
-       if pageParam != nil {
-               pageFlags := cast.ToStringMapBool(pageParam)
-               for key, value := range pageFlags {
-                       flags[key] = value
+               p.renderingConfigFlags = cast.ToStringMapBool(siteParam)
+
+               if pageParam != nil {
+                       pageFlags := cast.ToStringMapBool(pageParam)
+                       for key, value := range pageFlags {
+                               p.renderingConfigFlags[key] = value
+                       }
                }
-       }
+       })
 
-       return flags
+       return p.renderingConfigFlags
 }
 
 func (p *Page) isRenderingFlagEnabled(flag string) bool {