From dd692c710ad202905df273d9c25e66d332476ac9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Pedersen?=
 <bjorn.erik.pedersen@gmail.com>
Date: Fri, 21 Sep 2018 11:01:59 +0200
Subject: [PATCH] hugolib: Clear the page cache per render

This is a slight performance optimization with no functional effect.

See #5239
---
 hugolib/pageCache.go | 6 ++++++
 hugolib/site.go      | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/hugolib/pageCache.go b/hugolib/pageCache.go
index 15598a4f0..485da4ba3 100644
--- a/hugolib/pageCache.go
+++ b/hugolib/pageCache.go
@@ -44,6 +44,12 @@ func newPageCache() *pageCache {
 	return &pageCache{m: make(map[string][]pageCacheEntry)}
 }
 
+func (c *pageCache) clear() {
+	c.Lock()
+	defer c.Unlock()
+	c.m = make(map[string][]pageCacheEntry)
+}
+
 // get/getP gets a Pages slice from the cache matching the given key and
 // all the provided Pages slices.
 // If none found in cache, a copy of the first slice is created.
diff --git a/hugolib/site.go b/hugolib/site.go
index 59f0a9002..14f51f978 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -1012,6 +1012,8 @@ func (s *Site) setupSitePages() {
 }
 
 func (s *Site) render(config *BuildCfg, outFormatIdx int) (err error) {
+	// Clear the global page cache.
+	spc.clear()
 
 	if outFormatIdx == 0 {
 		if err = s.preparePages(); err != nil {
@@ -1514,8 +1516,6 @@ func (s *Site) resetBuildState() {
 
 	s.expiredCount = 0
 
-	spc = newPageCache()
-
 	for _, p := range s.rawAllPages {
 		p.subSections = Pages{}
 		p.parent = nil