Make cache memory bound

Fixes gohugoio#7425

cache/namedmemcache/named_cache.go

@@ -18,10 +18,14 @@ package namedmemcache
 
 import (
 	"sync"
+	"time"
 
 	"github.com/BurntSushi/locker"
+	"github.com/karlseguin/ccache"
 )
 
+var cc = ccache.New(ccache.Configure().MaxSize(100).ItemsToPrune(100))
+
 // Cache holds the cached values.
 type Cache struct {
 	nlocker *locker.Locker
@@ -58,10 +62,11 @@ func (c *Cache) Clear() {
 // key is invoced only once for this cache.
 func (c *Cache) GetOrCreate(key string, create func() (interface{}, error)) (interface{}, error) {
 	c.mu.RLock()
-	entry, found := c.cache[key]
+	v := cc.Get(key)
 	c.mu.RUnlock()
 
-	if found {
+	if v != nil {
+		entry := v.Value().(cacheEntry)
 		return entry.value, entry.err
 	}
 
@@ -72,7 +77,7 @@ func (c *Cache) GetOrCreate(key string, create func() (interface{}, error)) (int
 	value, err := create()
 
 	c.mu.Lock()
-	c.cache[key] = cacheEntry{value: value, err: err}
+	cc.Set(key, cacheEntry{value: value, err: err}, time.Minute)
 	c.mu.Unlock()
 
 	return value, err

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/google/go-cmp v0.3.2-0.20191028172631-481baca67f93
 	github.com/gorilla/websocket v1.4.1
 	github.com/jdkato/prose v1.1.1
+	github.com/karlseguin/ccache v2.0.3+incompatible
 	github.com/kr/pretty v0.2.0 // indirect
 	github.com/kyokomi/emoji v2.2.1+incompatible
 	github.com/magefile/mage v1.9.0

go.sum

@@ -212,6 +212,9 @@ github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
+github.com/karlseguin/ccache v1.0.1 h1:0gpC6z1qtv0cKmsi5Su5tTB6bJ2vm9bfOLACpDEB/Ro=
+github.com/karlseguin/ccache v2.0.3+incompatible h1:j68C9tWOROiOLWTS/kCGg9IcJG+ACqn5+0+t8Oh83UU=
+github.com/karlseguin/ccache v2.0.3+incompatible/go.mod h1:CM9tNPzT6EdRh14+jiW8mEF9mkNZuuE51qmgGYUB93w=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=