Only invoke a given cached partial once

Note that this is backed by a LRU cache (which we soon shall see more usage of), so if you're a heavy user of cached partials it may be evicted and
refreshed if needed. But in most cases every partial is only invoked once.

This commit also adds a timeout (the global `timeout` config option) to make infinite recursion in partials
easier to reason about.

```
name              old time/op    new time/op    delta
IncludeCached-10    8.92ms ± 0%    8.48ms ± 1%   -4.87%  (p=0.016 n=4+5)

name              old alloc/op   new alloc/op   delta
IncludeCached-10    6.65MB ± 0%    5.17MB ± 0%  -22.32%  (p=0.002 n=6+6)

name              old allocs/op  new allocs/op  delta
IncludeCached-10      117k ± 0%       71k ± 0%  -39.44%  (p=0.002 n=6+6)
```

Closes #4086
Updates #9588

21 files changed, 345 insertions, 202 deletions

diff --git a/deps/deps.go b/deps/deps.go
index 02730e825..6842c7331 100644
--- a/deps/deps.go
+++ b/deps/deps.go
@@ -11,6 +11,7 @@ import (
 	"github.com/gohugoio/hugo/cache/filecache"
 	"github.com/gohugoio/hugo/common/hexec"
 	"github.com/gohugoio/hugo/common/loggers"
+	"github.com/gohugoio/hugo/common/types"
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/config/security"
 	"github.com/gohugoio/hugo/helpers"
@@ -298,11 +299,14 @@ func New(cfg DepsCfg) (*Deps, error) {
 
 	sp := source.NewSourceSpec(ps, nil, fs.Source)
 
-	timeoutms := cfg.Language.GetInt("timeout")
-	if timeoutms <= 0 {
-		timeoutms = 3000
+	timeout := 30 * time.Second
+	if cfg.Cfg.IsSet("timeout") {
+		v := cfg.Cfg.Get("timeout")
+		d, err := types.ToDurationE(v)
+		if err == nil {
+			timeout = d
+		}
 	}
-
 	ignoreErrors := cast.ToStringSlice(cfg.Cfg.Get("ignoreErrors"))
 	ignorableLogger := loggers.NewIgnorableLogger(logger, ignoreErrors...)
 
@@ -329,7 +333,7 @@ func New(cfg DepsCfg) (*Deps, error) {
 		BuildClosers:            &Closers{},
 		BuildState:              buildState,
 		Running:                 cfg.Running,
-		Timeout:                 time.Duration(timeoutms) * time.Millisecond,
+		Timeout:                 timeout,
 		globalErrHandler:        errorHandler,
 	}
 
diff --git a/go.mod b/go.mod
index bab064029..d67c4c3e3 100644
--- a/go.mod
+++ b/go.mod
@@ -13,6 +13,7 @@ require (
 	github.com/bep/godartsass v0.16.0
 	github.com/bep/golibsass v1.1.0
 	github.com/bep/gowebp v0.2.0
+	github.com/bep/lazycache v0.2.0
 	github.com/bep/overlayfs v0.6.0
 	github.com/bep/tmc v0.5.1
 	github.com/clbanning/mxj/v2 v2.5.7
@@ -103,6 +104,7 @@ require (
 	github.com/google/wire v0.5.0 // indirect
 	github.com/googleapis/gax-go/v2 v2.3.0 // indirect
 	github.com/googleapis/go-type-adapters v1.0.0 // indirect
+	github.com/hashicorp/golang-lru/v2 v2.0.1 // indirect
 	github.com/inconshreveable/mousetrap v1.0.1 // indirect
 	github.com/invopop/yaml v0.1.0 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
diff --git a/go.sum b/go.sum
index 637bff303..15b478479 100644
--- a/go.sum
+++ b/go.sum
@@ -179,6 +179,8 @@ github.com/bep/golibsass v1.1.0 h1:pjtXr00IJZZaOdfryNa9wARTB3Q0BmxC3/V1KNcgyTw=
 github.com/bep/golibsass v1.1.0/go.mod h1:DL87K8Un/+pWUS75ggYv41bliGiolxzDKWJAq3eJ1MA=
 github.com/bep/gowebp v0.2.0 h1:ZVfK8i9PpZqKHEmthQSt3qCnnHycbLzBPEsVtk2ch2Q=
 github.com/bep/gowebp v0.2.0/go.mod h1:ZhFodwdiFp8ehGJpF4LdPl6unxZm9lLFjxD3z2h2AgI=
+github.com/bep/lazycache v0.2.0 h1:HKrlZTrDxHIrNKqmnurH42ryxkngCMYLfBpyu40VcwY=
+github.com/bep/lazycache v0.2.0/go.mod h1:xUIsoRD824Vx0Q/n57+ZO7kmbEhMBOnTjM/iPixNGbg=
 github.com/bep/overlayfs v0.6.0 h1:sgLcq/qtIzbaQNl2TldGXOkHvqeZB025sPvHOQL+DYo=
 github.com/bep/overlayfs v0.6.0/go.mod h1:NFjSmn3kCqG7KX2Lmz8qT8VhPPCwZap3UNogXawoQHM=
 github.com/bep/tmc v0.5.1 h1:CsQnSC6MsomH64gw0cT5f+EwQDcvZz4AazKunFwTpuI=
@@ -238,8 +240,6 @@ github.com/envoyproxy/go-control-plane v0.9.9-0.20210512163311-63b5d3c536b0/go.m
 github.com/envoyproxy/go-control-plane v0.9.10-0.20210907150352-cf90f659a021/go.mod h1:AFq3mo9L8Lqqiid3OhADV3RfLJnjiw63cSpi+fDTRC0=
 github.com/envoyproxy/go-control-plane v0.10.2-0.20220325020618-49ff273808a1/go.mod h1:KJwIaB5Mv44NWtYuAOFCVOjcI94vtpEz2JU/D2v6IjE=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
-github.com/evanw/esbuild v0.15.18 h1:CM7eAoUjjNkZs1LH0p6fkwtADrbFr4JV2SlT1bUMjEo=
-github.com/evanw/esbuild v0.15.18/go.mod h1:iINY06rn799hi48UqEnaQvVfZWe6W9bET78LbvN8VWk=
 github.com/evanw/esbuild v0.17.0 h1:gGx9TCZDO9k9x1PJdizx6syIpUq29RwrtHWlgDIdQH8=
 github.com/evanw/esbuild v0.17.0/go.mod h1:iINY06rn799hi48UqEnaQvVfZWe6W9bET78LbvN8VWk=
 github.com/form3tech-oss/jwt-go v3.2.2+incompatible/go.mod h1:pbq4aXjuKjdthFRnoDwaVPLA+WlJuPGy+QneDUgJi2k=
@@ -401,6 +401,8 @@ github.com/hairyhenderson/go-codeowners v0.2.3-0.20201026200250-cdc7c0759690 h1:
 github.com/hairyhenderson/go-codeowners v0.2.3-0.20201026200250-cdc7c0759690/go.mod h1:8Qu9UmnhCRunfRv365Z3w+mT/WfLGKJiK+vugY9qNCU=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru/v2 v2.0.1 h1:5pv5N1lT1fjLg2VQ5KWc7kmucp2x/kvFOnxuVTqZ6x4=
+github.com/hashicorp/golang-lru/v2 v2.0.1/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
diff --git a/helpers/general.go b/helpers/general.go
index 462ec773d..c8a676829 100644
--- a/helpers/general.go
+++ b/helpers/general.go
@@ -23,7 +23,6 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
-	"strconv"
 	"strings"
 	"sync"
 	"unicode"
@@ -31,8 +30,6 @@ import (
 
 	"github.com/gohugoio/hugo/common/loggers"
 
-	"github.com/mitchellh/hashstructure"
-
 	"github.com/gohugoio/hugo/common/hugo"
 
 	"github.com/spf13/afero"
@@ -219,7 +216,7 @@ func ReaderContains(r io.Reader, subslice []byte) bool {
 // GetTitleFunc returns a func that can be used to transform a string to
 // title case.
 //
-// The supported styles are
+// # The supported styles are
 //
 // - "Go" (strings.Title)
 // - "AP" (see https://www.apstylebook.com/)
@@ -523,20 +520,3 @@ func PrintFs(fs afero.Fs, path string, w io.Writer) {
 		return nil
 	})
 }
-
-// HashString returns a hash from the given elements.
-// It will panic if the hash cannot be calculated.
-func HashString(elements ...any) string {
-	var o any
-	if len(elements) == 1 {
-		o = elements[0]
-	} else {
-		o = elements
-	}
-
-	hash, err := hashstructure.Hash(o, nil)
-	if err != nil {
-		panic(err)
-	}
-	return strconv.FormatUint(hash, 10)
-}
diff --git a/helpers/general_test.go b/helpers/general_test.go
index 75119f01d..95d9c5461 100644
--- a/helpers/general_test.go
+++ b/helpers/general_test.go
@@ -458,10 +458,3 @@ func BenchmarkUniqueStrings(b *testing.B) {
 		}
 	})
 }
-
-func TestHashString(t *testing.T) {
-	c := qt.New(t)
-
-	c.Assert(HashString("a", "b"), qt.Equals, "2712570657419664240")
-	c.Assert(HashString("ab"), qt.Equals, "590647783936702392")
-}
diff --git a/hugolib/page_test.go b/hugolib/page_test.go
index 1d9e3e348..939d06d41 100644
--- a/hugolib/page_test.go
+++ b/hugolib/page_test.go
@@ -24,6 +24,7 @@ import (
 
 	"github.com/bep/clock"
 	"github.com/gohugoio/hugo/htesting"
+	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/markup/asciidocext"
 	"github.com/gohugoio/hugo/markup/rst"
 	"github.com/gohugoio/hugo/tpl"
@@ -2001,3 +2002,37 @@ Page1: {{ $p1.Path }}
 
 	b.AssertFileContent("public/index.html", "Lang: no", filepath.FromSlash("Page1: a/B/C/Page1.md"))
 }
+
+func TestPageHashString(t *testing.T) {
+	files := `
+-- config.toml --
+baseURL = "https://example.org"
+[languages]
+[languages.en]
+weight = 1
+title = "English"
+[languages.no]
+weight = 2
+title = "Norsk"
+-- content/p1.md --
+---
+title: "p1"
+---
+-- content/p2.md --
+---
+title: "p2"
+---
+`
+
+	b := NewIntegrationTestBuilder(IntegrationTestConfig{
+		T:           t,
+		TxtarString: files,
+	}).Build()
+
+	p1 := b.H.Sites[0].RegularPages()[0]
+	p2 := b.H.Sites[0].RegularPages()[1]
+	sites := p1.Sites()
+
+	b.Assert(identity.HashString(p1), qt.Not(qt.Equals), identity.HashString(p2))
+	b.Assert(identity.HashString(sites[0]), qt.Not(qt.Equals), identity.HashString(sites[1]))
+}
diff --git a/hugolib/resource_chain_test.go b/hugolib/resource_chain_test.go
index 4edc2cb31..6249c0aad 100644
--- a/hugolib/resource_chain_test.go
+++ b/hugolib/resource_chain_test.go
@@ -26,11 +26,10 @@ import (
 	"testing"
 	"time"
 
-	"github.com/gohugoio/hugo/helpers"
-
 	qt "github.com/frankban/quicktest"
 
 	"github.com/gohugoio/hugo/common/loggers"
+	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/scss"
 )
 
@@ -122,7 +121,7 @@ FAILED REMOTE ERROR DETAILS CONTENT: |failed to fetch remote resource: Internal
 |StatusCode: 500|ContentLength: 16|ContentType: text/plain; charset=utf-8|
 
 
-`, helpers.HashString(ts.URL+"/sunset.jpg", map[string]any{})))
+`, identity.HashString(ts.URL+"/sunset.jpg", map[string]any{})))
 
 		b.AssertFileContent("public/styles.min.a1df58687c3c9cc38bf26532f7b4b2f2c2b0315dcde212376959995c04f11fef.css", "body{background-color:#add8e6}")
 		b.AssertFileContent("public//styles2.min.1cfc52986836405d37f9998a63fd6dd8608e8c410e5e3db1daaa30f78bc273ba.css", "body{background-color:orange}")
diff --git a/hugolib/site.go b/hugolib/site.go
index 2ffc3a346..0ca7a81b4 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -778,6 +778,10 @@ func (s *SiteInfo) DisqusShortname() string {
 	return s.Config().Services.Disqus.Shortname
 }
 
+func (s *SiteInfo) GetIdentity() identity.Identity {
+	return identity.KeyValueIdentity{Key: "site", Value: s.language.Lang}
+}
+
 // SiteSocial is a place to put social details on a site level. These are the
 // standard keys that themes will expect to have available, but can be
 // expanded to any others on a per site basis
diff --git a/identity/identity.go b/identity/identity.go
index 9236f0876..033409b80 100644
--- a/identity/identity.go
+++ b/identity/identity.go
@@ -1,3 +1,16 @@
+// Copyright 2023 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package identity
 
 import (
@@ -107,7 +120,7 @@ func (id KeyValueIdentity) Name() string {
 	return id.Key
 }
 
-// Provider provides the hashable Identity.
+// Provider provides the comparable Identity.
 type Provider interface {
 	// GetIdentity is for internal use.
 	GetIdentity() Identity
diff --git a/identity/identityhash.go b/identity/identityhash.go
new file mode 100644
index 000000000..ef7b5afa7
--- /dev/null
+++ b/identity/identityhash.go
@@ -0,0 +1,69 @@
+// Copyright 2023 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package identity
+
+import (
+	"strconv"
+
+	"github.com/mitchellh/hashstructure"
+)
+
+// HashString returns a hash from the given elements.
+// It will panic if the hash cannot be calculated.
+// Note that this hash should be used primarily for identity, not for change detection as
+// it in the more complex values (e.g. Page) will not hash the full content.
+func HashString(vs ...any) string {
+	hash := HashUint64(vs...)
+	return strconv.FormatUint(hash, 10)
+}
+
+// HashUint64 returns a hash from the given elements.
+// It will panic if the hash cannot be calculated.
+// Note that this hash should be used primarily for identity, not for change detection as
+// it in the more complex values (e.g. Page) will not hash the full content.
+func HashUint64(vs ...any) uint64 {
+	var o any
+	if len(vs) == 1 {
+		o = toHashable(vs[0])
+	} else {
+		elements := make([]any, len(vs))
+		for i, e := range vs {
+			elements[i] = toHashable(e)
+		}
+		o = elements
+	}
+
+	hash, err := hashstructure.Hash(o, nil)
+	if err != nil {
+		panic(err)
+	}
+	return hash
+}
+
+type keyer interface {
+	Key() string
+}
+
+// For structs, hashstructure.Hash only works on the exported fields,
+// so rewrite the input slice for known identity types.
+func toHashable(v any) any {
+	switch t := v.(type) {
+	case Provider:
+		return t.GetIdentity()
+	case keyer:
+		return t.Key()
+	default:
+		return v
+	}
+}
diff --git a/identity/identityhash_test.go b/identity/identityhash_test.go
new file mode 100644
index 000000000..378c0160d
--- /dev/null
+++ b/identity/identityhash_test.go
@@ -0,0 +1,45 @@
+// Copyright 2023 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package identity
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func TestHashString(t *testing.T) {
+	c := qt.New(t)
+
+	c.Assert(HashString("a", "b"), qt.Equals, "2712570657419664240")
+	c.Assert(HashString("ab"), qt.Equals, "590647783936702392")
+
+	var vals []any = []any{"a", "b", tstKeyer{"c"}}
+
+	c.Assert(HashString(vals...), qt.Equals, "12599484872364427450")
+	c.Assert(vals[2], qt.Equals, tstKeyer{"c"})
+
+}
+
+type tstKeyer struct {
+	key string
+}
+
+func (t tstKeyer) Key() string {
+	return t.key
+}
+
+func (t tstKeyer) String() string {
+	return "key: " + t.key
+}
diff --git a/metrics/metrics.go b/metrics/metrics.go
index c57b1177d..9715a3747 100644
--- a/metrics/metrics.go
+++ b/metrics/metrics.go
@@ -27,7 +27,7 @@ import (
 
 	"github.com/gohugoio/hugo/common/types"
 	"github.com/gohugoio/hugo/compare"
-	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/identity"
 )
 
 // The Provider interface defines an interface for measuring metrics.
@@ -242,7 +242,7 @@ func howSimilar(a, b any) int {
 		return 90
 	}
 
-	h1, h2 := helpers.HashString(a), helpers.HashString(b)
+	h1, h2 := identity.HashString(a), identity.HashString(b)
 	if h1 == h2 {
 		return 100
 	}
diff --git a/resources/image.go b/resources/image.go
index ea8a21156..547b3305f 100644
--- a/resources/image.go
+++ b/resources/image.go
@@ -33,6 +33,7 @@ import (
 	color_extractor "github.com/marekm4/color-extractor"
 
 	"github.com/gohugoio/hugo/common/paths"
+	"github.com/gohugoio/hugo/identity"
 
 	"github.com/disintegration/gift"
 
@@ -278,7 +279,7 @@ func (i *imageResource) Filter(filters ...any) (images.ImageResource, error) {
 		gfilters = append(gfilters, images.ToFilters(f)...)
 	}
 
-	conf.Key = helpers.HashString(gfilters)
+	conf.Key = identity.HashString(gfilters)
 	conf.TargetFormat = i.Format
 
 	return i.doWithImageConfig(conf, func(src image.Image) (image.Image, error) {
@@ -430,7 +431,7 @@ func (i *imageResource) getImageMetaCacheTargetPath() string {
 	}
 	p1, _ := paths.FileAndExt(df.file)
 	h, _ := i.hash()
-	idStr := helpers.HashString(h, i.size(), imageMetaVersionNumber, cfgHash)
+	idStr := identity.HashString(h, i.size(), imageMetaVersionNumber, cfgHash)
 	p := path.Join(df.dir, fmt.Sprintf("%s_%s.json", p1, idStr))
 	return p
 }
diff --git a/resources/images/config.go b/resources/images/config.go
index 6f562ff8e..09a7016c1 100644
--- a/resources/images/config.go
+++ b/resources/images/config.go
@@ -19,7 +19,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/media"
 
 	"errors"
@@ -139,7 +139,7 @@ func DecodeConfig(m map[string]any) (ImagingConfig, error) {
 
 	i := ImagingConfig{
 		Cfg:     defaultImaging,
-		CfgHash: helpers.HashString(m),
+		CfgHash: identity.HashString(m),
 	}
 
 	if err := mapstructure.WeakDecode(m, &i.Cfg); err != nil {
diff --git a/resources/images/filters_test.go b/resources/images/filters_test.go
index 84c8b540d..a8c5601d6 100644
--- a/resources/images/filters_test.go
+++ b/resources/images/filters_test.go
@@ -16,9 +16,8 @@ package images
 import (
 	"testing"
 
-	"github.com/gohugoio/hugo/helpers"
-
 	qt "github.com/frankban/quicktest"
+	"github.com/gohugoio/hugo/identity"
 )
 
 func TestFilterHash(t *testing.T) {
@@ -26,8 +25,8 @@ func TestFilterHash(t *testing.T) {
 
 	f := &Filters{}
 
-	c.Assert(helpers.HashString(f.Grayscale()), qt.Equals, helpers.HashString(f.Grayscale()))
-	c.Assert(helpers.HashString(f.Grayscale()), qt.Not(qt.Equals), helpers.HashString(f.Invert()))
-	c.Assert(helpers.HashString(f.Gamma(32)), qt.Not(qt.Equals), helpers.HashString(f.Gamma(33)))
-	c.Assert(helpers.HashString(f.Gamma(32)), qt.Equals, helpers.HashString(f.Gamma(32)))
+	c.Assert(identity.HashString(f.Grayscale()), qt.Equals, identity.HashString(f.Grayscale()))
+	c.Assert(identity.HashString(f.Grayscale()), qt.Not(qt.Equals), identity.HashString(f.Invert()))
+	c.Assert(identity.HashString(f.Gamma(32)), qt.Not(qt.Equals), identity.HashString(f.Gamma(33)))
+	c.Assert(identity.HashString(f.Gamma(32)), qt.Equals, identity.HashString(f.Gamma(32)))
 }
diff --git a/resources/internal/key.go b/resources/internal/key.go
index 1b45d4cc4..2b95871aa 100644
--- a/resources/internal/key.go
+++ b/resources/internal/key.go
@@ -13,7 +13,7 @@
 
 package internal
 
-import "github.com/gohugoio/hugo/helpers"
+import "github.com/gohugoio/hugo/identity"
 
 // ResourceTransformationKey are provided by the different transformation implementations.
 // It identifies the transformation (name) and its configuration (elements).
@@ -38,5 +38,5 @@ func (k ResourceTransformationKey) Value() string {
 		return k.Name
 	}
 
-	return k.Name + "_" + helpers.HashString(k.elements...)
+	return k.Name + "_" + identity.HashString(k.elements...)
 }
diff --git a/resources/page/site.go b/resources/page/site.go
index 8daff95ae..90fbd5551 100644
--- a/resources/page/site.go
+++ b/resources/page/site.go
@@ -18,6 +18,7 @@ import (
 	"time"
 
 	"github.com/gohugoio/hugo/common/maps"
+	"github.com/gohugoio/hugo/identity"
 
 	"github.com/gohugoio/hugo/config"
 
@@ -75,6 +76,9 @@ type Site interface {
 
 	// Returns a map of all the data inside /data.
 	Data() map[string]any
+
+	// Returns the identity of this site.
+	GetIdentity() identity.Identity
 }
 
 // Sites represents an ordered list of sites (languages).
@@ -117,6 +121,10 @@ func (t testSite) Current() Site {
 	return t
 }
 
+func (t testSite) GetIdentity() identity.Identity {
+	return identity.KeyValueIdentity{Key: "site", Value: t.l.Lang}
+}
+
 func (t testSite) IsServer() bool {
 	return false
 }
diff --git a/resources/resource_factories/create/remote.go b/resources/resource_factories/create/remote.go
index 1ae5e095b..8f1707ed0 100644
--- a/resources/resource_factories/create/remote.go
+++ b/resources/resource_factories/create/remote.go
@@ -30,7 +30,7 @@ import (
 	"github.com/gohugoio/hugo/common/hugio"
 	"github.com/gohugoio/hugo/common/maps"
 	"github.com/gohugoio/hugo/common/types"
-	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/media"
 	"github.com/gohugoio/hugo/resources"
 	"github.com/gohugoio/hugo/resources/resource"
@@ -235,9 +235,9 @@ func (c *Client) validateFromRemoteArgs(uri string, options fromRemoteOptions) e
 
 func calculateResourceID(uri string, optionsm map[string]any) string {
 	if key, found := maps.LookupEqualFold(optionsm, "key"); found {
-		return helpers.HashString(key)
+		return identity.HashString(key)
 	}
-	return helpers.HashString(uri, optionsm)
+	return identity.HashString(uri, optionsm)
 }
 
 func addDefaultHeaders(req *http.Request) {
diff --git a/tpl/partials/integration_test.go b/tpl/partials/integration_test.go
index bda5ddbd5..fcebe6c05 100644
--- a/tpl/partials/integration_test.go
+++ b/tpl/partials/integration_test.go
@@ -21,6 +21,8 @@ import (
 	"strings"
 	"testing"
 
+	qt "github.com/frankban/quicktest"
+
 	"github.com/gohugoio/hugo/htesting/hqt"
 	"github.com/gohugoio/hugo/hugolib"
 )
@@ -225,7 +227,7 @@ D1
 	b.Assert(got, hqt.IsSameString, expect)
 }
 
-//  gobench --package ./tpl/partials
+// gobench --package ./tpl/partials
 func BenchmarkIncludeCached(b *testing.B) {
 	files := `
 -- config.toml --
@@ -262,7 +264,7 @@ ABCDE
 	}
 	builders := make([]*hugolib.IntegrationTestBuilder, b.N)
 
-	for i, _ := range builders {
+	for i := range builders {
 		builders[i] = hugolib.NewIntegrationTestBuilder(cfg)
 	}
 
@@ -272,3 +274,53 @@ ABCDE
 		builders[i].Build()
 	}
 }
+
+func TestIncludeTimeout(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- config.toml --
+baseURL = 'http://example.com/'
+timeout = '200ms'
+-- layouts/index.html --
+{{ partials.Include "foo.html" . }}
+-- layouts/partials/foo.html --
+{{ partial "foo.html" . }}
+  `
+
+	b, err := hugolib.NewIntegrationTestBuilder(
+		hugolib.IntegrationTestConfig{
+			T:           t,
+			TxtarString: files,
+		},
+	).BuildE()
+
+	b.Assert(err, qt.Not(qt.IsNil))
+	b.Assert(err.Error(), qt.Contains, "timed out")
+
+}
+
+func TestIncludeCachedTimeout(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- config.toml --
+baseURL = 'http://example.com/'
+timeout = '200ms'
+-- layouts/index.html --
+{{ partials.IncludeCached "foo.html" . }}
+-- layouts/partials/foo.html --
+{{ partialCached "foo.html" . }}
+  `
+
+	b, err := hugolib.NewIntegrationTestBuilder(
+		hugolib.IntegrationTestConfig{
+			T:           t,
+			TxtarString: files,
+		},
+	).BuildE()
+
+	b.Assert(err, qt.Not(qt.IsNil))
+	b.Assert(err.Error(), qt.Contains, "timed out")
+
+}
diff --git a/tpl/partials/partials.go b/tpl/partials/partials.go
index eb4ebfe32..3b08604b7 100644
--- a/tpl/partials/partials.go
+++ b/tpl/partials/partials.go
@@ -17,19 +17,17 @@ package partials
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"html/template"
 	"io"
 	"io/ioutil"
-	"reflect"
 	"strings"
-	"sync"
 	"time"
 
-	texttemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate"
+	"github.com/bep/lazycache"
 
-	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/identity"
+	texttemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate"
 
 	"github.com/gohugoio/hugo/tpl"
 
@@ -42,32 +40,48 @@ import (
 var TestTemplateProvider deps.ResourceProvider
 
 type partialCacheKey struct {
-	name    string
-	variant any
+	Name     string
+	Variants []any
+}
+type includeResult struct {
+	name   string
+	result any
+	err    error
+}
+
+func (k partialCacheKey) Key() string {
+	if k.Variants == nil {
+		return k.Name
+	}
+	return identity.HashString(append([]any{k.Name}, k.Variants...)...)
 }
 
 func (k partialCacheKey) templateName() string {
-	if !strings.HasPrefix(k.name, "partials/") {
-		return "partials/" + k.name
+	if !strings.HasPrefix(k.Name, "partials/") {
+		return "partials/" + k.Name
 	}
-	return k.name
+	return k.Name
 }
 
-// partialCache represents a cache of partials protected by a mutex.
+// partialCache represents a LRU cache of partials.
 type partialCache struct {
-	sync.RWMutex
-	p map[partialCacheKey]any
+	cache *lazycache.Cache[string, includeResult]
 }
 
 func (p *partialCache) clear() {
-	p.Lock()
-	defer p.Unlock()
-	p.p = make(map[partialCacheKey]any)
+	p.cache.DeleteFunc(func(string, includeResult) bool {
+		return true
+	})
 }
 
 // New returns a new instance of the templates-namespaced template functions.
 func New(deps *deps.Deps) *Namespace {
-	cache := &partialCache{p: make(map[partialCacheKey]any)}
+	// This lazycache was introduced in Hugo 0.111.0.
+	// We're going to expand and consolidate all memory caches in Hugo using this,
+	// so just set a high limit for now.
+	lru := lazycache.New[string, includeResult](lazycache.Options{MaxEntries: 1000})
+
+	cache := &partialCache{cache: lru}
 	deps.BuildStartListeners.Add(
 		func() {
 			cache.clear()
@@ -103,21 +117,44 @@ func (c *contextWrapper) Set(in any) string {
 // A string if the partial is a text/template, or template.HTML when html/template.
 // Note that ctx is provided by Hugo, not the end user.
 func (ns *Namespace) Include(ctx context.Context, name string, contextList ...any) (any, error) {
-	name, result, err := ns.include(ctx, name, contextList...)
-	if err != nil {
-		return result, err
+	res := ns.includWithTimeout(ctx, name, contextList...)
+	if res.err != nil {
+		return nil, res.err
 	}
 
 	if ns.deps.Metrics != nil {
-		ns.deps.Metrics.TrackValue(name, result, false)
+		ns.deps.Metrics.TrackValue(res.name, res.result, false)
+	}
+
+	return res.result, nil
+}
+
+func (ns *Namespace) includWithTimeout(ctx context.Context, name string, dataList ...any) includeResult {
+	ctx, cancel := context.WithTimeout(ctx, ns.deps.Timeout)
+	defer cancel()
+
+	res := make(chan includeResult, 1)
+
+	go func() {
+		res <- ns.include(ctx, name, dataList...)
+	}()
+
+	select {
+	case r := <-res:
+		return r
+	case <-ctx.Done():
+		err := ctx.Err()
+		if err == context.DeadlineExceeded {
+			err = fmt.Errorf("partial %q timed out after %s. This is most likely due to infinite recursion. If this is just a slow template, you can try to increase the 'timeout' config setting.", name, ns.deps.Timeout)
+		}
+		return includeResult{err: err}
 	}
 
-	return result, nil
 }
 
 // include is a helper function that lookups and executes the named partial.
 // Returns the final template name and the rendered output.
-func (ns *Namespace) include(ctx context.Context, name string, dataList ...any) (string, any, error) {
+func (ns *Namespace) include(ctx context.Context, name string, dataList ...any) includeResult {
 	var data any
 	if len(dataList) > 0 {
 		data = dataList[0]
@@ -137,7 +174,7 @@ func (ns *Namespace) include(ctx context.Context, name string, dataList ...any)
 	}
 
 	if !found {
-		return "", "", fmt.Errorf("partial %q not found", name)
+		return includeResult{err: fmt.Errorf("partial %q not found", name)}
 	}
 
 	var info tpl.ParseInfo
@@ -164,7 +201,7 @@ func (ns *Namespace) include(ctx context.Context, name string, dataList ...any)
 	}
 
 	if err := ns.deps.Tmpl().ExecuteWithContext(ctx, templ, w, data); err != nil {
-		return "", nil, err
+		return includeResult{err: err}
 	}
 
 	var result any
@@ -177,101 +214,41 @@ func (ns *Namespace) include(ctx context.Context, name string, dataList ...any)
 		result = template.HTML(w.(fmt.Stringer).String())
 	}
 
-	return templ.Name(), result, nil
+	return includeResult{
+		name:   templ.Name(),
+		result: result,
+	}
+
 }
 
 // IncludeCached executes and caches partial templates.  The cache is created with name+variants as the key.
 // Note that ctx is provided by Hugo, not the end user.
 func (ns *Namespace) IncludeCached(ctx context.Context, name string, context any, variants ...any) (any, error) {
-	key, err := createKey(name, variants...)
-	if err != nil {
-		return nil, err
-	}
-
-	result, err := ns.getOrCreate(ctx, key, context)
-	if err == errUnHashable {
-		// Try one more
-		key.variant = helpers.HashString(key.variant)
-		result, err = ns.getOrCreate(ctx, key, context)
+	start := time.Now()
+	key := partialCacheKey{
+		Name:     name,
+		Variants: variants,
 	}
 
-	return result, err
-}
+	r, found, err := ns.cachedPartials.cache.GetOrCreate(key.Key(), func(string) (includeResult, error) {
+		r := ns.includWithTimeout(ctx, key.Name, context)
+		return r, r.err
+	})
 
-func createKey(name string, variants ...any) (partialCacheKey, error) {
-	var variant any
-
-	if len(variants) > 1 {
-		variant = helpers.HashString(variants...)
-	} else if len(variants) == 1 {
-		variant = variants[0]
-		t := reflect.TypeOf(variant)
-		switch t.Kind() {
-		// This isn't an exhaustive list of unhashable types.
-		// There may be structs with slices,
-		// but that should be very rare. We do recover from that situation
-		// below.
-		case reflect.Slice, reflect.Array, reflect.Map:
-			variant = helpers.HashString(variant)
-		}
+	if err != nil {
+		return nil, err
 	}
 
-	return partialCacheKey{name: name, variant: variant}, nil
-}
-
-var errUnHashable = errors.New("unhashable")
-
-func (ns *Namespace) getOrCreate(ctx context.Context, key partialCacheKey, context any) (result any, err error) {
-	start := time.Now()
-	defer func() {
-		if r := recover(); r != nil {
-			err = r.(error)
-			if strings.Contains(err.Error(), "unhashable type") {
-				ns.cachedPartials.RUnlock()
-				err = errUnHashable
-			}
-		}
-	}()
-
-	ns.cachedPartials.RLock()
-	p, ok := ns.cachedPartials.p[key]
-	ns.cachedPartials.RUnlock()
-
-	if ok {
-		if ns.deps.Metrics != nil {
-			ns.deps.Metrics.TrackValue(key.templateName(), p, true)
+	if ns.deps.Metrics != nil {
+		if found {
 			// The templates that gets executed is measured in Execute.
 			// We need to track the time spent in the cache to
 			// get the totals correct.
 			ns.deps.Metrics.MeasureSince(key.templateName(), start)
 
 		}
-		return p, nil
+		ns.deps.Metrics.TrackValue(key.templateName(), r.result, found)
 	}
 
-	// This needs to be done outside the lock.
-	// See #9588
-	_, p, err = ns.include(ctx, key.name, context)
-	if err != nil {
-		return nil, err
-	}
-
-	ns.cachedPartials.Lock()
-	defer ns.cachedPartials.Unlock()
-	// Double-check.
-	if p2, ok := ns.cachedPartials.p[key]; ok {
-		if ns.deps.Metrics != nil {
-			ns.deps.Metrics.TrackValue(key.templateName(), p, true)
-			ns.deps.Metrics.MeasureSince(key.templateName(), start)
-		}
-		return p2, nil
-
-	}
-	if ns.deps.Metrics != nil {
-		ns.deps.Metrics.TrackValue(key.templateName(), p, false)
-	}
-
-	ns.cachedPartials.p[key] = p
-
-	return p, nil
+	return r.result, nil
 }
diff --git a/tpl/partials/partials_test.go b/tpl/partials/partials_test.go
deleted file mode 100644
index 490354499..000000000
--- a/tpl/partials/partials_test.go
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright 2019 The Hugo Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package partials
-
-import (
-	"testing"
-
-	qt "github.com/frankban/quicktest"
-)
-
-func TestCreateKey(t *testing.T) {
-	c := qt.New(t)
-	m := make(map[any]bool)
-
-	create := func(name string, variants ...any) partialCacheKey {
-		k, err := createKey(name, variants...)
-		c.Assert(err, qt.IsNil)
-		m[k] = true
-		return k
-	}
-
-	for i := 0; i < 123; i++ {
-		c.Assert(create("a", "b"), qt.Equals, partialCacheKey{name: "a", variant: "b"})
-		c.Assert(create("a", "b", "c"), qt.Equals, partialCacheKey{name: "a", variant: "9629524865311698396"})
-		c.Assert(create("a", 1), qt.Equals, partialCacheKey{name: "a", variant: 1})
-		c.Assert(create("a", map[string]string{"a": "av"}), qt.Equals, partialCacheKey{name: "a", variant: "4809626101226749924"})
-		c.Assert(create("a", []string{"a", "b"}), qt.Equals, partialCacheKey{name: "a", variant: "2712570657419664240"})
-	}
-}