Improve local server (#6)

* don't interrupt watcher on error

* don't halt build on missing file

* extract buildFile function

* build the site with concurrent workers

* improve fsnotify event treatment and output

commands/serve.go

@@ -1,7 +1,6 @@
 package commands
 
 import (
-	"errors"
 	"fmt"
 	"io/fs"
 	"net/http"
@@ -86,15 +85,9 @@ func setupWatcher(config *config.Config) (*fsnotify.Watcher, error) {
 					return
 				}
 
-				// some events can be received for temporary files, e.g. .#backup files generated by emacs while editing .org
-				// when events regarding such files arrive, discard them here instead of triggering a faulty rebuild
-				if _, err := os.Stat(event.Name); errors.Is(err, os.ErrNotExist) {
-					// FIXME change to log debug
-					fmt.Println("ignoring temporary file", event.Name)
-					continue
-				}
-				// chmod events are noisy, ignore them
-				if !event.Has(fsnotify.Chmod) {
+				// chmod events are noisy, ignore them. also skip create events
+				// which we assume meaningless until the write that comes next
+				if event.Has(fsnotify.Chmod) || event.Has(fsnotify.Create) {
 					continue
 				}
 
@@ -103,15 +96,17 @@ func setupWatcher(config *config.Config) (*fsnotify.Watcher, error) {
 				// since new nested directories could be triggering this change, and we need to watch those too
 				// and since re-watching files is a noop, I just re-add the entire src everytime there's a change
 				if err := addAll(watcher, config); err != nil {
-					fmt.Println("error:", err)
-					return
+					fmt.Println("couldn't add watchers:", err)
+					continue
 				}
 
 				if err := rebuild(config); err != nil {
-					fmt.Println("error:", err)
-					return
+					fmt.Println("build error:", err)
+					continue
 				}
 
+				fmt.Println("done\nserver listening at", config.SiteUrl)
+
 			case err, ok := <-watcher.Errors:
 				if !ok {
 					return

site/site.go

@@ -7,8 +7,10 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"runtime"
 	"slices"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/facundoolano/jorge/config"
@@ -131,7 +133,7 @@ func (site *Site) loadTemplates() error {
 			templ, err := templates.Parse(site.templateEngine, path)
 			// if something fails or this is not a template, skip
 			if err != nil || templ == nil {
-				return err
+				return checkFileError(err)
 			}
 
 			// set site related (?) metadata. Not sure if this should go elsewhere
@@ -191,8 +193,12 @@ func (site *Site) Build() error {
 	os.RemoveAll(site.Config.TargetDir)
 	os.Mkdir(site.Config.SrcDir, FILE_RW_MODE)
 
+	wg, files := spawnBuildWorkers(site)
+	defer wg.Wait()
+	defer close(files)
+
 	// walk the source directory, creating directories and files at the target dir
-	return filepath.WalkDir(site.Config.SrcDir, func(path string, entry fs.DirEntry, err error) error {
+	err := filepath.WalkDir(site.Config.SrcDir, func(path string, entry fs.DirEntry, err error) error {
 		if err != nil {
 			return err
 		}
@@ -203,20 +209,51 @@ func (site *Site) Build() error {
 		if entry.IsDir() {
 			return os.MkdirAll(targetPath, FILE_RW_MODE)
 		}
+		// if it's a file (either static or template) send the path to a worker to build in target
+		files <- path
+		return nil
+	})
+
+	return err
+}
+
+// Create a channel to send paths to build and a worker pool to handle them concurrently
+func spawnBuildWorkers(site *Site) (*sync.WaitGroup, chan string) {
+
+	var wg sync.WaitGroup
+	files := make(chan string, 20)
+
+	for range runtime.NumCPU() {
+		wg.Add(1)
+		go func(files <-chan string) {
+			defer wg.Done()
+			for path := range files {
+				site.buildFile(path)
+			}
+		}(files)
+	}
+	return &wg, files
+}
+
+func (site *Site) buildFile(path string) error {
+	subpath, _ := filepath.Rel(site.Config.SrcDir, path)
+	targetPath := filepath.Join(site.Config.TargetDir, subpath)
 
 	var contentReader io.Reader
+	var err error
 	templ, found := site.templates[path]
 	if !found {
 		// if no template found at location, treat the file as static write its contents to target
 		if site.Config.LinkStatic {
 			// dev optimization: link static files instead of copying them
 			abs, _ := filepath.Abs(path)
-				return os.Symlink(abs, targetPath)
+			err = os.Symlink(abs, targetPath)
+			return checkFileError(err)
 		}
 
 		srcFile, err := os.Open(path)
 		if err != nil {
-				return err
+			return checkFileError(err)
 		}
 		defer srcFile.Close()
 		contentReader = srcFile
@@ -240,12 +277,10 @@ func (site *Site) Build() error {
 	contentReader = site.minify(targetExt, contentReader)
 
 	// write the file contents over to target
-		fmt.Println("writing", targetPath)
 	return writeToFile(targetPath, contentReader)
-	})
 }
 
-func (site Site) render(templ *templates.Template) ([]byte, error) {
+func (site *Site) render(templ *templates.Template) ([]byte, error) {
 	ctx := map[string]interface{}{
 		"site": map[string]interface{}{
 			"config": site.Config.AsContext(),
@@ -281,6 +316,19 @@ func (site Site) render(templ *templates.Template) ([]byte, error) {
 	return content, nil
 }
 
+func checkFileError(err error) error {
+	// When walking the source dir it can happen that a file is present when walking starts
+	// but missing or inaccessible when trying to open it (this is particularly frequent with
+	// backup files from emacs and when running the dev server). We don't want to halt the build
+	// process in that situation, just inform and continue.
+	if os.IsNotExist(err) {
+		// don't abort on missing files, usually spurious temps
+		fmt.Println("skipping missing file", err)
+		return nil
+	}
+	return err
+}
+
 func writeToFile(targetPath string, source io.Reader) error {
 	targetFile, err := os.Create(targetPath)
 	if err != nil {
@@ -293,6 +341,7 @@ func writeToFile(targetPath string, source io.Reader) error {
 		return err
 	}
 
+	fmt.Println("added", targetPath)
 	return targetFile.Sync()
 }