Add basic "post resource publish support"

Fixes #7146

5 files changed, 183 insertions, 4 deletions

diff --git a/hugolib/filesystems/basefs.go b/hugolib/filesystems/basefs.go
index 47d6d11f5..57a95a037 100644
--- a/hugolib/filesystems/basefs.go
+++ b/hugolib/filesystems/basefs.go
@@ -345,7 +345,7 @@ func NewBase(p *paths.Paths, logger *loggers.Logger, options ...func(*BaseFs) er
 		logger = loggers.NewWarningLogger()
 	}
 
-	publishFs := afero.NewBasePathFs(fs.Destination, p.AbsPublishDir)
+	publishFs := hugofs.NewBaseFileDecorator(afero.NewBasePathFs(fs.Destination, p.AbsPublishDir))
 
 	b := &BaseFs{
 		PublishFs: publishFs,
diff --git a/hugolib/hugo_sites_build.go b/hugolib/hugo_sites_build.go
index 15eca4bb3..6a65605fc 100644
--- a/hugolib/hugo_sites_build.go
+++ b/hugolib/hugo_sites_build.go
@@ -17,7 +17,17 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"os"
 	"runtime/trace"
+	"strings"
+
+	"github.com/gohugoio/hugo/common/para"
+	"github.com/gohugoio/hugo/config"
+	"github.com/gohugoio/hugo/resources/postpub"
+
+	"github.com/spf13/afero"
+
+	"github.com/gohugoio/hugo/resources/resource"
 
 	"github.com/gohugoio/hugo/output"
 
@@ -138,6 +148,10 @@ func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {
 		}
 	}
 
+	if err := h.postProcess(); err != nil {
+		h.SendError(err)
+	}
+
 	if h.Metrics != nil {
 		var b bytes.Buffer
 		h.Metrics.WriteMetrics(&b)
@@ -321,3 +335,90 @@ func (h *HugoSites) render(config *BuildCfg) error {
 
 	return nil
 }
+
+func (h *HugoSites) postProcess() error {
+	var toPostProcess []resource.OriginProvider
+	for _, s := range h.Sites {
+		for _, v := range s.ResourceSpec.PostProcessResources {
+			toPostProcess = append(toPostProcess, v)
+		}
+	}
+
+	if len(toPostProcess) == 0 {
+		return nil
+	}
+
+	workers := para.New(config.GetNumWorkerMultiplier())
+	g, _ := workers.Start(context.Background())
+
+	handleFile := func(filename string) error {
+
+		content, err := afero.ReadFile(h.BaseFs.PublishFs, filename)
+		if err != nil {
+			return err
+		}
+
+		k := 0
+		changed := false
+
+		for {
+			l := bytes.Index(content[k:], []byte(postpub.PostProcessPrefix))
+			if l == -1 {
+				break
+			}
+			m := bytes.Index(content[k+l:], []byte(postpub.PostProcessSuffix)) + len(postpub.PostProcessSuffix)
+
+			low, high := k+l, k+l+m
+
+			field := content[low:high]
+
+			forward := l + m
+
+			for i, r := range toPostProcess {
+				if r == nil {
+					panic(fmt.Sprintf("resource %d to post process is nil", i+1))
+				}
+				v, ok := r.GetFieldString(string(field))
+				if ok {
+					content = append(content[:low], append([]byte(v), content[high:]...)...)
+					changed = true
+					forward = len(v)
+					break
+				}
+			}
+
+			k += forward
+		}
+
+		if changed {
+			return afero.WriteFile(h.BaseFs.PublishFs, filename, content, 0666)
+		}
+
+		return nil
+
+	}
+
+	_ = afero.Walk(h.BaseFs.PublishFs, "", func(path string, info os.FileInfo, err error) error {
+		if info == nil || info.IsDir() {
+			return nil
+		}
+
+		if !strings.HasSuffix(path, "html") {
+			return nil
+		}
+
+		g.Run(func() error {
+			return handleFile(path)
+		})
+
+		return nil
+	})
+
+	// Prepare for a new build.
+	for _, s := range h.Sites {
+		s.ResourceSpec.PostProcessResources = make(map[string]postpub.PostPublishedResource)
+	}
+
+	return g.Wait()
+
+}
diff --git a/hugolib/page__common.go b/hugolib/page__common.go
index be6bb090b..d1c7ba866 100644
--- a/hugolib/page__common.go
+++ b/hugolib/page__common.go
@@ -86,7 +86,8 @@ type pageCommon struct {
 	resource.ResourceDataProvider
 	resource.ResourceMetaProvider
 	resource.ResourceParamsProvider
-	resource.ResourceTypesProvider
+	resource.ResourceTypeProvider
+	resource.MediaTypeProvider
 	resource.TranslationKeyProvider
 	compare.Eqer
 
diff --git a/hugolib/page__new.go b/hugolib/page__new.go
index 938c13d7c..9ec089f27 100644
--- a/hugolib/page__new.go
+++ b/hugolib/page__new.go
@@ -49,7 +49,8 @@ func newPageBase(metaProvider *pageMeta) (*pageState, error) {
 			PageMetaProvider:        metaProvider,
 			RelatedKeywordsProvider: metaProvider,
 			OutputFormatsProvider:   page.NopPage,
-			ResourceTypesProvider:   pageTypesProvider,
+			ResourceTypeProvider:    pageTypesProvider,
+			MediaTypeProvider:       pageTypesProvider,
 			RefProvider:             page.NopPage,
 			ShortcodeInfoProvider:   page.NopPage,
 			LanguageProvider:        s,
diff --git a/hugolib/resource_chain_test.go b/hugolib/resource_chain_test.go
index 8bca6c7b5..0d0c9203a 100644
--- a/hugolib/resource_chain_test.go
+++ b/hugolib/resource_chain_test.go
@@ -14,13 +14,16 @@
 package hugolib
 
 import (
+	"fmt"
 	"io"
+	"math/rand"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/gohugoio/hugo/common/herrors"
 
@@ -352,6 +355,80 @@ Edited content.
 	}
 }
 
+func TestResourceChainPostProcess(t *testing.T) {
+	t.Parallel()
+
+	rnd := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+	b := newTestSitesBuilder(t)
+	b.WithContent("page1.md", "---\ntitle: Page1\n---")
+	b.WithContent("page2.md", "---\ntitle: Page2\n---")
+
+	b.WithTemplates(
+		"_default/single.html", `{{ $hello := "<h1>     Hello World!   </h1>" | resources.FromString "hello.html" | minify  | fingerprint "md5" | resources.PostProcess }}
+HELLO: {{ $hello.RelPermalink }}	
+`,
+		"index.html", `Start.
+{{ $hello := "<h1>     Hello World!   </h1>" | resources.FromString "hello.html" | minify  | fingerprint "md5" | resources.PostProcess }}
+
+HELLO: {{ $hello.RelPermalink }}|Integrity: {{ $hello.Data.Integrity }}|MediaType: {{ $hello.MediaType.Type }}
+HELLO2: Name: {{ $hello.Name }}|Content: {{ $hello.Content }}|Title: {{ $hello.Title }}|ResourceType: {{ $hello.ResourceType }}
+
+`+strings.Repeat("a b", rnd.Intn(10)+1)+`
+
+
+End.`)
+
+	b.Running()
+	b.Build(BuildCfg{})
+	b.AssertFileContent("public/index.html",
+		`Start.
+HELLO: /hello.min.a2d1cb24f24b322a7dad520414c523e9.html|Integrity: md5-otHLJPJLMip9rVIEFMUj6Q==|MediaType: text/html
+HELLO2: Name: hello.html|Content: <h1>Hello World!</h1>|Title: hello.html|ResourceType: html
+End.`)
+
+	b.AssertFileContent("public/page1/index.html", `HELLO: /hello.min.a2d1cb24f24b322a7dad520414c523e9.html`)
+	b.AssertFileContent("public/page2/index.html", `HELLO: /hello.min.a2d1cb24f24b322a7dad520414c523e9.html`)
+
+}
+
+func BenchmarkResourceChainPostProcess(b *testing.B) {
+
+	for i := 0; i < b.N; i++ {
+		b.StopTimer()
+		s := newTestSitesBuilder(b)
+		for i := 0; i < 300; i++ {
+			s.WithContent(fmt.Sprintf("page%d.md", i+1), "---\ntitle: Page\n---")
+		}
+		s.WithTemplates("_default/single.html", `Start.
+Some text.
+
+
+{{ $hello1 := "<h1>     Hello World 2!   </h1>" | resources.FromString "hello.html" | minify  | fingerprint "md5" | resources.PostProcess }}
+{{ $hello2 := "<h1>     Hello World 2!   </h1>" | resources.FromString (printf "%s.html" .Path) | minify  | fingerprint "md5" | resources.PostProcess }}
+
+Some more text.
+
+HELLO: {{ $hello1.RelPermalink }}|Integrity: {{ $hello1.Data.Integrity }}|MediaType: {{ $hello1.MediaType.Type }}
+
+Some more text.
+
+HELLO2: Name: {{ $hello2.Name }}|Content: {{ $hello2.Content }}|Title: {{ $hello2.Title }}|ResourceType: {{ $hello2.ResourceType }}
+
+Some more text.
+
+HELLO2_2: Name: {{ $hello2.Name }}|Content: {{ $hello2.Content }}|Title: {{ $hello2.Title }}|ResourceType: {{ $hello2.ResourceType }}
+
+End.
+`)
+
+		b.StartTimer()
+		s.Build(BuildCfg{})
+
+	}
+
+}
+
 func TestResourceChains(t *testing.T) {
 	t.Parallel()
 
@@ -769,7 +846,6 @@ func TestResourceChainPostCSS(t *testing.T) {
 	}
 
 	if runtime.GOOS == "windows" {
-		// TODO(bep)
 		t.Skip("skip npm test on Windows")
 	}