Introduce a tree map for all content

This commit introduces a new data structure to store pages and their resources.

This data structure is backed by radix trees.

This simplies tree operations, makes all pages a bundle,  and paves the way for #6310.

It also solves a set of annoying issues (see list below).

Not a motivation behind this, but this commit also makes Hugo in general a little bit faster and more memory effective (see benchmarks). Especially for partial rebuilds on content edits, but also when taxonomies is in use.

```
name                                   old time/op    new time/op    delta
SiteNew/Bundle_with_image/Edit-16        1.32ms ± 8%    1.00ms ± 9%  -24.42%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file/Edit-16    1.28ms ± 0%    0.94ms ± 0%  -26.26%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories/Edit-16      33.9ms ± 2%    21.8ms ± 1%  -35.67%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs/Edit-16            40.6ms ± 1%    37.7ms ± 3%   -7.20%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree/Edit-16        56.7ms ± 0%    51.7ms ± 1%   -8.82%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates/Edit-16      19.9ms ± 2%    18.3ms ± 3%   -7.64%  (p=0.029 n=4+4)
SiteNew/Page_collections/Edit-16         37.9ms ± 4%    34.0ms ± 2%  -10.28%  (p=0.029 n=4+4)
SiteNew/Bundle_with_image-16             10.7ms ± 0%    10.6ms ± 0%   -1.15%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file-16         10.8ms ± 0%    10.7ms ± 0%   -1.05%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories-16           43.2ms ± 1%    39.6ms ± 1%   -8.35%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs-16                 47.6ms ± 1%    47.3ms ± 0%     ~     (p=0.057 n=4+4)
SiteNew/Deep_content_tree-16             73.0ms ± 1%    74.2ms ± 1%     ~     (p=0.114 n=4+4)
SiteNew/Many_HTML_templates-16           37.9ms ± 0%    38.1ms ± 1%     ~     (p=0.114 n=4+4)
SiteNew/Page_collections-16              53.6ms ± 1%    54.7ms ± 1%   +2.09%  (p=0.029 n=4+4)

name                                   old alloc/op   new alloc/op   delta
SiteNew/Bundle_with_image/Edit-16         486kB ± 0%     430kB ± 0%  -11.47%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file/Edit-16     265kB ± 0%     209kB ± 0%  -21.06%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories/Edit-16      13.6MB ± 0%     8.8MB ± 0%  -34.93%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs/Edit-16            66.5MB ± 0%    63.9MB ± 0%   -3.95%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree/Edit-16        28.8MB ± 0%    25.8MB ± 0%  -10.55%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates/Edit-16      6.16MB ± 0%    5.56MB ± 0%   -9.86%  (p=0.029 n=4+4)
SiteNew/Page_collections/Edit-16         16.9MB ± 0%    16.0MB ± 0%   -5.19%  (p=0.029 n=4+4)
SiteNew/Bundle_with_image-16             2.28MB ± 0%    2.29MB ± 0%   +0.35%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file-16         2.07MB ± 0%    2.07MB ± 0%     ~     (p=0.114 n=4+4)
SiteNew/Tags_and_categories-16           14.3MB ± 0%    13.2MB ± 0%   -7.30%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs-16                 69.1MB ± 0%    69.0MB ± 0%     ~     (p=0.343 n=4+4)
SiteNew/Deep_content_tree-16             31.3MB ± 0%    31.8MB ± 0%   +1.49%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates-16           10.8MB ± 0%    10.9MB ± 0%   +1.11%  (p=0.029 n=4+4)
SiteNew/Page_collections-16              21.4MB ± 0%    21.6MB ± 0%   +1.15%  (p=0.029 n=4+4)

name                                   old allocs/op  new allocs/op  delta
SiteNew/Bundle_with_image/Edit-16         4.74k ± 0%     3.86k ± 0%  -18.57%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file/Edit-16     4.73k ± 0%     3.85k ± 0%  -18.58%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories/Edit-16        301k ± 0%      198k ± 0%  -34.14%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs/Edit-16              389k ± 0%      373k ± 0%   -4.07%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree/Edit-16          338k ± 0%      262k ± 0%  -22.63%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates/Edit-16        102k ± 0%       88k ± 0%  -13.81%  (p=0.029 n=4+4)
SiteNew/Page_collections/Edit-16           176k ± 0%      152k ± 0%  -13.32%  (p=0.029 n=4+4)
SiteNew/Bundle_with_image-16              26.8k ± 0%     26.8k ± 0%   +0.05%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file-16          26.8k ± 0%     26.8k ± 0%   +0.05%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories-16             273k ± 0%      245k ± 0%  -10.36%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs-16                   396k ± 0%      398k ± 0%   +0.39%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree-16               317k ± 0%      325k ± 0%   +2.53%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates-16             146k ± 0%      147k ± 0%   +0.98%  (p=0.029 n=4+4)
SiteNew/Page_collections-16                210k ± 0%      215k ± 0%   +2.44%  (p=0.029 n=4+4)
```

Fixes #6312
Fixes #6087
Fixes #6738
Fixes #6412
Fixes #6743
Fixes #6875
Fixes #6034
Fixes #6902
Fixes #6173
Fixes #6590

1 files changed, 8 insertions, 12 deletions

diff --git a/hugolib/pagebundler_test.go b/hugolib/pagebundler_test.go
index 62b041d7c..4566c5f97 100644
--- a/hugolib/pagebundler_test.go
+++ b/hugolib/pagebundler_test.go
@@ -20,6 +20,8 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/gohugoio/hugo/hugofs/files"
+
 	"github.com/gohugoio/hugo/helpers"
 
 	"github.com/gohugoio/hugo/hugofs"
@@ -101,7 +103,7 @@ func TestPageBundlerSiteRegular(t *testing.T) {
 						c.Assert(len(s.RegularPages()), qt.Equals, 8)
 
 						singlePage := s.getPage(page.KindPage, "a/1.md")
-						c.Assert(singlePage.BundleType(), qt.Equals, "")
+						c.Assert(singlePage.BundleType(), qt.Equals, files.ContentClass(""))
 
 						c.Assert(singlePage, qt.Not(qt.IsNil))
 						c.Assert(s.getPage("page", "a/1"), qt.Equals, singlePage)
@@ -148,12 +150,12 @@ func TestPageBundlerSiteRegular(t *testing.T) {
 
 						leafBundle1 := s.getPage(page.KindPage, "b/my-bundle/index.md")
 						c.Assert(leafBundle1, qt.Not(qt.IsNil))
-						c.Assert(leafBundle1.BundleType(), qt.Equals, "leaf")
+						c.Assert(leafBundle1.BundleType(), qt.Equals, files.ContentClassLeaf)
 						c.Assert(leafBundle1.Section(), qt.Equals, "b")
 						sectionB := s.getPage(page.KindSection, "b")
 						c.Assert(sectionB, qt.Not(qt.IsNil))
 						home, _ := s.Info.Home()
-						c.Assert(home.BundleType(), qt.Equals, "branch")
+						c.Assert(home.BundleType(), qt.Equals, files.ContentClassBranch)
 
 						// This is a root bundle and should live in the "home section"
 						// See https://github.com/gohugoio/hugo/issues/4332
@@ -387,12 +389,10 @@ func TestMultilingualDisableLanguage(t *testing.T) {
 	c.Assert(len(s.Pages()), qt.Equals, 16)
 	// No nn pages
 	c.Assert(len(s.AllPages()), qt.Equals, 16)
-	for _, p := range s.rawAllPages {
-		c.Assert(p.Language().Lang != "nn", qt.Equals, true)
-	}
-	for _, p := range s.AllPages() {
+	s.pageMap.withEveryBundlePage(func(p *pageState) bool {
 		c.Assert(p.Language().Lang != "nn", qt.Equals, true)
-	}
+		return false
+	})
 
 }
 
@@ -549,7 +549,6 @@ HEADLESS {{< myShort >}}
 	s := buildSingleSite(t, deps.DepsCfg{Fs: fs, Cfg: cfg}, BuildCfg{})
 
 	c.Assert(len(s.RegularPages()), qt.Equals, 1)
-	c.Assert(len(s.headlessPages), qt.Equals, 1)
 
 	regular := s.getPage(page.KindPage, "a/index")
 	c.Assert(regular.RelPermalink(), qt.Equals, "/s1/")
@@ -1147,18 +1146,15 @@ baseURL = "https://example.org"
 defaultContentLanguage = "en"
 defaultContentLanguageInSubDir = true
 disableKinds = ["taxonomyTerm", "taxonomy"]
-
 [languages]
 [languages.nn]
 languageName = "Nynorsk"
 weight = 2
 title = "Tittel på Nynorsk"
-
 [languages.en]
 title = "Title in English"
 languageName = "English"
 weight = 1
-
 `
 
 	pageContent := func(id string) string {