From 9e845cb116ce6081443c70707aa6a76f4af3f9cf Mon Sep 17 00:00:00 2001
From: Deluan <deluan@deluan.com>
Date: Mon, 18 May 2020 14:37:01 -0400
Subject: [PATCH] Skip scanning folders if they contain a `.ndignore` file.
 Closes #297

---
 consts/consts.go                        |  3 ++-
 scanner/change_detector.go              | 22 ++++++++++++++--------
 scanner/change_detector_test.go         | 12 ++++++++++++
 tests/fixtures/ignored_folder/.ndignore |  0
 4 files changed, 28 insertions(+), 9 deletions(-)
 create mode 100644 tests/fixtures/ignored_folder/.ndignore

diff --git a/consts/consts.go b/consts/consts.go
index d8f667bdd..1664dc514 100644
--- a/consts/consts.go
+++ b/consts/consts.go
@@ -28,7 +28,8 @@ const (
 	RequestThrottleBacklogLimit   = 100
 	RequestThrottleBacklogTimeout = time.Minute
 
-	I18nFolder = "i18n"
+	I18nFolder   = "i18n"
+	SkipScanFile = ".ndignore"
 )
 
 // Cache options
diff --git a/scanner/change_detector.go b/scanner/change_detector.go
index 459975d0d..dc64d6eee 100644
--- a/scanner/change_detector.go
+++ b/scanner/change_detector.go
@@ -5,6 +5,7 @@ import (
 	"path/filepath"
 	"time"
 
+	"github.com/deluan/navidrome/consts"
 	"github.com/deluan/navidrome/log"
 )
 
@@ -66,7 +67,7 @@ func (s *ChangeDetector) loadDir(dirPath string) (children []string, lastUpdated
 		if err != nil {
 			continue
 		}
-		if isDir {
+		if isDir && !IsDirIgnored(dirPath, f) {
 			children = append(children, filepath.Join(dirPath, f.Name()))
 		} else {
 			if f.ModTime().After(lastUpdated) {
@@ -77,24 +78,29 @@ func (s *ChangeDetector) loadDir(dirPath string) (children []string, lastUpdated
 	return
 }
 
-// IsDirOrSymlinkToDir returns true if and only if the Dirent represents a file
-// system directory, or a symbolic link to a directory. Note that if the Dirent
+// IsDirOrSymlinkToDir returns true if and only if the dirent represents a file
+// system directory, or a symbolic link to a directory. Note that if the dirent
 // 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, info os.FileInfo) (bool, error) {
-	if info.IsDir() {
+func IsDirOrSymlinkToDir(baseDir string, dirent os.FileInfo) (bool, error) {
+	if dirent.IsDir() {
 		return true, nil
 	}
-	if info.Mode()&os.ModeSymlink == 0 {
+	if dirent.Mode()&os.ModeSymlink == 0 {
 		return false, nil
 	}
 	// Does this symlink point to a directory?
-	info, err := os.Stat(filepath.Join(baseDir, info.Name()))
+	dirent, err := os.Stat(filepath.Join(baseDir, dirent.Name()))
 	if err != nil {
 		return false, err
 	}
-	return info.IsDir(), nil
+	return dirent.IsDir(), nil
+}
+
+func IsDirIgnored(baseDir string, dirent os.FileInfo) bool {
+	_, err := os.Stat(filepath.Join(baseDir, dirent.Name(), consts.SkipScanFile))
+	return err == nil
 }
 
 func (s *ChangeDetector) loadMap(dirMap dirInfoMap, path string, since time.Time, maybe bool) error {
diff --git a/scanner/change_detector_test.go b/scanner/change_detector_test.go
index d68afb618..556e5806d 100644
--- a/scanner/change_detector_test.go
+++ b/scanner/change_detector_test.go
@@ -129,6 +129,18 @@ var _ = Describe("ChangeDetector", func() {
 			Expect(IsDirOrSymlinkToDir("tests/fixtures", dir)).To(BeFalse())
 		})
 	})
+
+	Describe("IsDirIgnored", func() {
+		baseDir := filepath.Join("tests", "fixtures")
+		It("returns false for normal dirs", func() {
+			dir, _ := os.Stat(filepath.Join(baseDir, "empty_folder"))
+			Expect(IsDirIgnored(baseDir, dir)).To(BeFalse())
+		})
+		It("returns true when folder contains .ndignore file", func() {
+			dir, _ := os.Stat(filepath.Join(baseDir, "ignored_folder"))
+			Expect(IsDirIgnored(baseDir, dir)).To(BeTrue())
+		})
+	})
 })
 
 // I hate time-based tests....
diff --git a/tests/fixtures/ignored_folder/.ndignore b/tests/fixtures/ignored_folder/.ndignore
new file mode 100644
index 000000000..e69de29bb