Add new scanner algorithm, can be enabled with DevNewScanner config option

scanner/load_tree.go

@@ -0,0 +1,109 @@
+package scanner
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/deluan/navidrome/consts"
+	"github.com/deluan/navidrome/log"
+	"github.com/deluan/navidrome/utils"
+)
+
+type dirMap = map[string]time.Time
+
+func loadDirTree(ctx context.Context, rootFolder string) (dirMap, error) {
+	newMap := make(map[string]time.Time)
+	err := loadMap(ctx, rootFolder, rootFolder, newMap)
+	if err != nil {
+		log.Error(ctx, "Error loading directory tree", err)
+	}
+	return newMap, err
+}
+
+func loadMap(ctx context.Context, rootPath string, currentFolder string, dirMap dirMap) error {
+	children, lastUpdated, err := loadDir(ctx, currentFolder)
+	if err != nil {
+		return err
+	}
+	for _, c := range children {
+		err := loadMap(ctx, rootPath, c, dirMap)
+		if err != nil {
+			return err
+		}
+	}
+
+	dir := filepath.Clean(currentFolder)
+	dirMap[dir] = lastUpdated
+
+	return nil
+}
+
+func loadDir(ctx context.Context, dirPath string) (children []string, lastUpdated time.Time, err error) {
+	dirInfo, err := os.Stat(dirPath)
+	if err != nil {
+		log.Error(ctx, "Error stating dir", "path", dirPath, err)
+		return
+	}
+	lastUpdated = dirInfo.ModTime()
+
+	files, err := ioutil.ReadDir(dirPath)
+	if err != nil {
+		log.Error(ctx, "Error reading dir", "path", dirPath, err)
+		return
+	}
+	for _, f := range files {
+		isDir, err := isDirOrSymlinkToDir(dirPath, f)
+		// Skip invalid symlinks
+		if err != nil {
+			continue
+		}
+		if isDir && !isDirIgnored(dirPath, f) && isDirReadable(dirPath, f) {
+			children = append(children, filepath.Join(dirPath, f.Name()))
+		} else {
+			if f.ModTime().After(lastUpdated) {
+				lastUpdated = f.ModTime()
+			}
+		}
+	}
+	return
+}
+
+// isDirOrSymlinkToDir returns true if and only if the dirInfo represents a file
+// system directory, or a symbolic link to a directory. Note that if the dirInfo
+// is not a directory but is a symbolic link, this method will resolve by
+// sending a request to the operating system to follow the symbolic link.
+// Copied from github.com/karrick/godirwalk
+func isDirOrSymlinkToDir(baseDir string, dirInfo os.FileInfo) (bool, error) {
+	if dirInfo.IsDir() {
+		return true, nil
+	}
+	if dirInfo.Mode()&os.ModeSymlink == 0 {
+		return false, nil
+	}
+	// Does this symlink point to a directory?
+	dirInfo, err := os.Stat(filepath.Join(baseDir, dirInfo.Name()))
+	if err != nil {
+		return false, err
+	}
+	return dirInfo.IsDir(), nil
+}
+
+// isDirIgnored returns true if the directory represented by dirInfo contains an
+// `ignore` file (named after consts.SkipScanFile)
+func isDirIgnored(baseDir string, dirInfo os.FileInfo) bool {
+	_, err := os.Stat(filepath.Join(baseDir, dirInfo.Name(), consts.SkipScanFile))
+	return err == nil
+}
+
+// isDirReadable returns true if the directory represented by dirInfo is readable
+func isDirReadable(baseDir string, dirInfo os.FileInfo) bool {
+	path := filepath.Join(baseDir, dirInfo.Name())
+	res, err := utils.IsDirReadable(path)
+	if !res {
+		log.Debug("Warning: Skipping unreadable directory", "path", path, err)
+	}
+	return res
+}