output: Speed up layout calculations

```
BenchmarkLayout-4     4883          497           -89.82%

benchmark             old allocs     new allocs     delta
BenchmarkLayout-4     18             1              -94.44%

benchmark             old bytes     new bytes     delta
BenchmarkLayout-4     1624          32            -98.03%
```

diff --git a/hugolib/page.go b/hugolib/page.go
index cad9b398b7ec1a852ff27662bffce505a872fc74..1308aa49df2b213e1c6df76656eede3d380fc8f9 100644 (file)
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -190,6 +190,8 @@ type Page struct {
        permalink    string
        relPermalink string
 
+       layoutDescriptor output.LayoutDescriptor
+
        scratch *Scratch
 
        // It would be tempting to use the language set on the Site, but in they way we do
@@ -666,7 +668,7 @@ func (p *Page) layouts(layouts ...string) []string {
        }
 
        return p.s.layoutHandler.For(
-               p.createLayoutDescriptor(),
+               p.layoutDescriptor,
                layoutOverride,
                output.HTMLType)
 }
@@ -880,6 +882,7 @@ func (p *Page) initURLs() error {
        p.permalink = p.s.permalink(rel)
        rel = p.s.PathSpec.PrependBasePath(rel)
        p.relPermalink = rel
+       p.layoutDescriptor = p.createLayoutDescriptor()
        return nil
 }
 
@@ -1558,7 +1561,7 @@ func (p *Page) Hugo() *HugoInfo {
 func (p *Page) RSSlink() template.URL {
        // TODO(bep) we cannot have two of these
        // Remove in Hugo 0.20
-       helpers.Deprecated(".Page", "Use RSSlink", "RSSLink", true)
+       helpers.Deprecated(".Page", "RSSlink", "Use RSSLink", true)
        return p.RSSLink
 }
 

diff --git a/hugolib/site.go b/hugolib/site.go
index 0a90290e0e788449f1a99a4acc81c6afce7a887e..0959df3d5e0cb44adec39769dc05b0a74cfe8e21 100644 (file)
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -1656,7 +1656,7 @@ func (s *Site) kindFromSections(sections []string) string {
 }
 
 func (s *Site) layouts(p *PageOutput) []string {
-       return s.layoutHandler.For(p.createLayoutDescriptor(), "", p.outputFormat)
+       return s.layoutHandler.For(p.layoutDescriptor, "", p.outputFormat)
 }
 
 func (s *Site) preparePages() error {

diff --git a/output/layout.go b/output/layout.go
index c33ce3f0cc2fdea0f6ebac03ad417f05a898625d..833a6cf4aa60d58b61d957003f5adbdf414c8da2 100644 (file)
--- a/output/layout.go
+++ b/output/layout.go
@@ -17,6 +17,7 @@ import (
        "fmt"
        "path"
        "strings"
+       "sync"
 )
 
 // LayoutDescriptor describes how a layout should be chosen. This is
@@ -32,10 +33,19 @@ type LayoutDescriptor struct {
 // TODO(bep) output improve names
 type LayoutHandler struct {
        hasTheme bool
+
+       mu    sync.RWMutex
+       cache map[layoutCacheKey][]string
+}
+
+type layoutCacheKey struct {
+       d              LayoutDescriptor
+       layoutOverride string
+       f              Format
 }
 
 func NewLayoutHandler(hasTheme bool) *LayoutHandler {
-       return &LayoutHandler{hasTheme: hasTheme}
+       return &LayoutHandler{hasTheme: hasTheme, cache: make(map[layoutCacheKey][]string)}
 }
 
 const (
@@ -62,6 +72,16 @@ indexes/indexes.NAME.SUFFIX indexes/indexes.SUFFIX
 )
 
 func (l *LayoutHandler) For(d LayoutDescriptor, layoutOverride string, f Format) []string {
+
+       // We will get lots of requests for the same layouts, so avoid recalculations.
+       key := layoutCacheKey{d, layoutOverride, f}
+       l.mu.RLock()
+       if cacheVal, found := l.cache[key]; found {
+               l.mu.RUnlock()
+               return cacheVal
+       }
+       l.mu.RUnlock()
+
        var layouts []string
 
        layout := d.Layout
@@ -110,6 +130,10 @@ func (l *LayoutHandler) For(d LayoutDescriptor, layoutOverride string, f Format)
                return layoutsWithThemeLayouts
        }
 
+       l.mu.Lock()
+       l.cache[key] = layouts
+       l.mu.Unlock()
+
        return layouts
 }
 

diff --git a/output/layout_test.go b/output/layout_test.go
index e678197cae797aea80a3ec8f0e13272a25faf9b2..aa0657a365661f1588cb271bb525aaac7c9ca02e 100644 (file)
--- a/output/layout_test.go
+++ b/output/layout_test.go
@@ -73,4 +73,15 @@ func TestLayout(t *testing.T) {
                        }
                })
        }
+
+}
+
+func BenchmarkLayout(b *testing.B) {
+       descriptor := LayoutDescriptor{Kind: "taxonomyTerm", Section: "categories"}
+       l := NewLayoutHandler(false)
+
+       for i := 0; i < b.N; i++ {
+               layouts := l.For(descriptor, "", HTMLType)
+               require.NotEmpty(b, layouts)
+       }
 }