hugolib: Create the permalink once only

diff --git a/hugolib/page.go b/hugolib/page.go
index 43ec4a360da40ff77bf8c50348fdb6c57273f7d4..adbcf4b0749e7f56dda31521de67429185557ded 100644 (file)
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -192,6 +192,7 @@ type Page struct {
        RSSLink template.HTML
 
        URLPath
+       permalink *url.URL
 
        paginator *Pager
 
@@ -211,6 +212,7 @@ type pageInit struct {
        plainInit           sync.Once
        plainWordsInit      sync.Once
        renderingConfigInit sync.Once
+       pageURLInit         sync.Once
 }
 
 // IsNode returns whether this is an item of one of the list types in Hugo,
@@ -724,7 +726,25 @@ func (p *Page) analyzePage() {
        })
 }
 
-func (p *Page) permalink() (*url.URL, error) {
+func (p *Page) getPermalink() *url.URL {
+       p.pageURLInit.Do(func() {
+               u, err := p.createPermalink()
+               if err != nil {
+                       jww.ERROR.Printf("Failed to create permalink for page %q: %s", p.FullFilePath(), err)
+                       p.permalink = new(url.URL)
+                       return
+               }
+
+               p.permalink = u
+       })
+
+       // The link may be modified by the receiver, so create a copy.
+       l := *p.permalink
+
+       return &l
+}
+
+func (p *Page) createPermalink() (*url.URL, error) {
        // TODO(bep) this should probably be set once during build. Maybe.
        // And simplified.
        baseURL := string(p.Site.BaseURL)
@@ -842,12 +862,7 @@ func (p *Page) IsExpired() bool {
 }
 
 func (p *Page) Permalink() string {
-       link, err := p.permalink()
-       if err != nil {
-               return ""
-       }
-
-       return link.String()
+       return p.getPermalink().String()
 }
 
 func (p *Page) URL() string {
@@ -862,10 +877,7 @@ func (p *Page) URL() string {
 }
 
 func (p *Page) RelPermalink() string {
-       link, err := p.permalink()
-       if err != nil {
-               return ""
-       }
+       link := p.getPermalink()
 
        if viper.GetBool("canonifyURLs") {
                // replacements for relpermalink with baseURL on the form http://myhost.com/sub/ will fail later on