Implement defer

Closes gohugoio#8086

cache/httpcache/httpcache.go

@@ -83,7 +83,6 @@ func (c *Config) Compile() (ConfigCompiled, error) {
 }
 
 // PollConfig holds the configuration for polling remote resources to detect changes in watch mode.
-// TODO1 make sure this enabled only in watch mode.
 type PollConfig struct {
 	// What remote resources to apply this configuration to.
 	For GlobMatcher

common/herrors/errors.go

@@ -131,6 +131,9 @@ func ImproveIfNilPointer(inErr error) (outErr error) {
 	call := m[1]
 	field := m[2]
 	parts := strings.Split(call, ".")
+	if len(parts) < 2 {
+		return
+	}
 	receiverName := parts[len(parts)-2]
 	receiver := strings.Join(parts[:len(parts)-1], ".")
 	s := fmt.Sprintf("– %s is nil; wrap it in if or with: {{ with %s }}{{ .%s }}{{ end }}", receiverName, receiver, field)

common/hugio/hasBytesWriter.go

@@ -17,24 +17,35 @@ import (
 	"bytes"
 )
 
-// HasBytesWriter is a writer that will set Match to true if the given pattern
-// is found in the stream.
+// HasBytesWriter is a writer will match against a slice of patterns.
 type HasBytesWriter struct {
-	Match   bool
-	Pattern []byte
+	Patterns []*HasBytesPattern
 
 	i    int
 	done bool
 	buff []byte
 }
 
+type HasBytesPattern struct {
+	Match   bool
+	Pattern []byte
+}
+
+func (h *HasBytesWriter) patternLen() int {
+	l := 0
+	for _, p := range h.Patterns {
+		l += len(p.Pattern)
+	}
+	return l
+}
+
 func (h *HasBytesWriter) Write(p []byte) (n int, err error) {
 	if h.done {
 		return len(p), nil
 	}
 
 	if len(h.buff) == 0 {
-		h.buff = make([]byte, len(h.Pattern)*2)
+		h.buff = make([]byte, h.patternLen()*2)
 	}
 
 	for i := range p {
@@ -46,11 +57,23 @@ func (h *HasBytesWriter) Write(p []byte) (n int, err error) {
 			h.i = len(h.buff) / 2
 		}
 
-		if bytes.Contains(h.buff, h.Pattern) {
-			h.Match = true
-			h.done = true
-			return len(p), nil
+		for _, pp := range h.Patterns {
+			if bytes.Contains(h.buff, pp.Pattern) {
+				pp.Match = true
+				done := true
+				for _, ppp := range h.Patterns {
+					if !ppp.Match {
+						done = false
+						break
+					}
+				}
+				if done {
+					h.done = true
+				}
+				return len(p), nil
+			}
 		}
+
 	}
 
 	return len(p), nil

common/hugio/hasBytesWriter_test.go

@@ -34,8 +34,11 @@ func TestHasBytesWriter(t *testing.T) {
 		var b bytes.Buffer
 
 		h := &HasBytesWriter{
-			Pattern: []byte("__foo"),
+			Patterns: []*HasBytesPattern{
+				{Pattern: []byte("__foo")},
+			},
 		}
+
 		return h, io.MultiWriter(&b, h)
 	}
 
@@ -46,19 +49,19 @@ func TestHasBytesWriter(t *testing.T) {
 	for i := 0; i < 22; i++ {
 		h, w := neww()
 		fmt.Fprintf(w, rndStr()+"abc __foobar"+rndStr())
-		c.Assert(h.Match, qt.Equals, true)
+		c.Assert(h.Patterns[0].Match, qt.Equals, true)
 
 		h, w = neww()
 		fmt.Fprintf(w, rndStr()+"abc __f")
 		fmt.Fprintf(w, "oo bar"+rndStr())
-		c.Assert(h.Match, qt.Equals, true)
+		c.Assert(h.Patterns[0].Match, qt.Equals, true)
 
 		h, w = neww()
 		fmt.Fprintf(w, rndStr()+"abc __moo bar")
-		c.Assert(h.Match, qt.Equals, false)
+		c.Assert(h.Patterns[0].Match, qt.Equals, false)
 	}
 
 	h, w := neww()
 	fmt.Fprintf(w, "__foo")
-	c.Assert(h.Match, qt.Equals, true)
+	c.Assert(h.Patterns[0].Match, qt.Equals, true)
 }

common/maps/cache.go

@@ -74,6 +74,26 @@ func (c *Cache[K, T]) ForEeach(f func(K, T)) {
 	}
 }
 
+func (c *Cache[K, T]) Drain() map[K]T {
+	c.Lock()
+	m := c.m
+	c.m = make(map[K]T)
+	c.Unlock()
+	return m
+}
+
+func (c *Cache[K, T]) Len() int {
+	c.RLock()
+	defer c.RUnlock()
+	return len(c.m)
+}
+
+func (c *Cache[K, T]) Reset() {
+	c.Lock()
+	c.m = make(map[K]T)
+	c.Unlock()
+}
+
 // SliceCache is a simple thread safe cache backed by a map.
 type SliceCache[T any] struct {
 	m map[string][]T

deps/deps.go

@@ -15,6 +15,7 @@ import (
 	"github.com/gohugoio/hugo/cache/filecache"
 	"github.com/gohugoio/hugo/common/hexec"
 	"github.com/gohugoio/hugo/common/loggers"
+	"github.com/gohugoio/hugo/common/maps"
 	"github.com/gohugoio/hugo/common/types"
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/config/allconfig"
@@ -161,20 +162,29 @@ func (d *Deps) Init() error {
 	}
 
 	if d.PathSpec == nil {
-		hashBytesReceiverFunc := func(name string, match bool) {
-			if !match {
-				return
+		hashBytesReceiverFunc := func(name string, match []byte) {
+			s := string(match)
+			switch s {
+			case postpub.PostProcessPrefix:
+				d.BuildState.AddFilenameWithPostPrefix(name)
+			case tpl.HugoDeferredTemplatePrefix:
+				d.BuildState.DeferredExecutions.FilenamesWithPostPrefix.Set(name, true)
 			}
-			d.BuildState.AddFilenameWithPostPrefix(name)
 		}
 
 		// Skip binary files.
 		mediaTypes := d.Conf.GetConfigSection("mediaTypes").(media.Types)
-		hashBytesSHouldCheck := func(name string) bool {
+		hashBytesShouldCheck := func(name string) bool {
 			ext := strings.TrimPrefix(filepath.Ext(name), ".")
 			return mediaTypes.IsTextSuffix(ext)
 		}
-		d.Fs.PublishDir = hugofs.NewHasBytesReceiver(d.Fs.PublishDir, hashBytesSHouldCheck, hashBytesReceiverFunc, []byte(postpub.PostProcessPrefix))
+		d.Fs.PublishDir = hugofs.NewHasBytesReceiver(
+			d.Fs.PublishDir,
+			hashBytesShouldCheck,
+			hashBytesReceiverFunc,
+			[]byte(tpl.HugoDeferredTemplatePrefix),
+			[]byte(postpub.PostProcessPrefix))
+
 		pathSpec, err := helpers.NewPathSpec(d.Fs, d.Conf, d.Log)
 		if err != nil {
 			return err
@@ -371,10 +381,41 @@ type BuildState struct {
 	// A set of filenames in /public that
 	// contains a post-processing prefix.
 	filenamesWithPostPrefix map[string]bool
+
+	filenamesWithDefferedExecution map[string]bool
+
+	DeferredExecutions *DeferredExecutions
+
+	// Deferred executions grouped by rendering context.
+	DeferredExecutionsGroupedByRenderingContext map[tpl.RenderingContext]*DeferredExecutions
+}
+
+type DeferredExecutions struct {
+	// A set of filenames in /public that
+	// contains a post-processing prefix.
+	FilenamesWithPostPrefix *maps.Cache[string, bool]
+
+	// Maps a placeholder to a deferred execution.
+	Executions *maps.Cache[string, *tpl.DeferredExecution]
 }
 
 var _ identity.SignalRebuilder = (*BuildState)(nil)
 
+func (b *BuildState) StartRenderingStage(r tpl.RenderingContext) {
+	if b.DeferredExecutionsGroupedByRenderingContext == nil {
+		b.DeferredExecutionsGroupedByRenderingContext = make(map[tpl.RenderingContext]*DeferredExecutions)
+	}
+	b.DeferredExecutions = &DeferredExecutions{
+		Executions:              maps.NewCache[string, *tpl.DeferredExecution](),
+		FilenamesWithPostPrefix: maps.NewCache[string, bool](),
+	}
+}
+
+func (b *BuildState) StopRenderingStage(r tpl.RenderingContext) {
+	b.DeferredExecutionsGroupedByRenderingContext[r] = b.DeferredExecutions
+	b.DeferredExecutions = nil
+}
+
 func (b *BuildState) SignalRebuild(ids ...identity.Identity) {
 	b.OnSignalRebuild(ids...)
 }
@@ -399,6 +440,12 @@ func (b *BuildState) GetFilenamesWithPostPrefix() []string {
 	return filenames
 }
 
+func (b *BuildState) AddDeferredExecution(id string, d *tpl.DeferredExecution) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.DeferredExecutions.Executions.Set(id, d)
+}
+
 func (b *BuildState) Incr() int {
 	return int(atomic.AddUint64(&b.counter, uint64(1)))
 }

hugofs/hasbytes_fs.go

@@ -28,12 +28,12 @@ var (
 type hasBytesFs struct {
 	afero.Fs
 	shouldCheck      func(name string) bool
-	hasBytesCallback func(name string, match bool)
-	pattern          []byte
+	hasBytesCallback func(name string, match []byte)
+	patterns         [][]byte
 }
 
-func NewHasBytesReceiver(delegate afero.Fs, shouldCheck func(name string) bool, hasBytesCallback func(name string, match bool), pattern []byte) afero.Fs {
-	return &hasBytesFs{Fs: delegate, shouldCheck: shouldCheck, hasBytesCallback: hasBytesCallback, pattern: pattern}
+func NewHasBytesReceiver(delegate afero.Fs, shouldCheck func(name string) bool, hasBytesCallback func(name string, match []byte), patterns ...[]byte) afero.Fs {
+	return &hasBytesFs{Fs: delegate, shouldCheck: shouldCheck, hasBytesCallback: hasBytesCallback, patterns: patterns}
 }
 
 func (fs *hasBytesFs) UnwrapFilesystem() afero.Fs {
@@ -60,10 +60,15 @@ func (fs *hasBytesFs) wrapFile(f afero.File) afero.File {
 	if !fs.shouldCheck(f.Name()) {
 		return f
 	}
+	patterns := make([]*hugio.HasBytesPattern, len(fs.patterns))
+	for i, p := range fs.patterns {
+		patterns[i] = &hugio.HasBytesPattern{Pattern: p}
+	}
+
 	return &hasBytesFile{
 		File: f,
 		hbw: &hugio.HasBytesWriter{
-			Pattern: fs.pattern,
+			Patterns: patterns,
 		},
 		hasBytesCallback: fs.hasBytesCallback,
 	}
@@ -74,7 +79,7 @@ func (fs *hasBytesFs) Name() string {
 }
 
 type hasBytesFile struct {
-	hasBytesCallback func(name string, match bool)
+	hasBytesCallback func(name string, match []byte)
 	hbw              *hugio.HasBytesWriter
 	afero.File
 }
@@ -88,6 +93,10 @@ func (h *hasBytesFile) Write(p []byte) (n int, err error) {
 }
 
 func (h *hasBytesFile) Close() error {
-	h.hasBytesCallback(h.Name(), h.hbw.Match)
+	for _, p := range h.hbw.Patterns {
+		if p.Match {
+			h.hasBytesCallback(h.Name(), p.Pattern)
+		}
+	}
 	return h.File.Close()
 }