update

scanner/ignore_checker.go

@@ -0,0 +1,163 @@
+package scanner
+
+import (
+	"bufio"
+	"context"
+	"io/fs"
+	"path"
+	"strings"
+
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/log"
+	ignore "github.com/sabhiram/go-gitignore"
+)
+
+// IgnoreChecker manages .ndignore patterns using a stack-based approach.
+// Use Push() to add patterns when entering a folder, Pop() when leaving,
+// and ShouldIgnore() to check if a path should be ignored.
+type IgnoreChecker struct {
+	fsys            fs.FS
+	patternStack    [][]string        // Stack of patterns for each folder level
+	currentPatterns []string          // Flattened current patterns
+	matcher         *ignore.GitIgnore // Compiled matcher for current patterns
+}
+
+// newIgnoreChecker creates a new IgnoreChecker for the given filesystem.
+func newIgnoreChecker(fsys fs.FS) *IgnoreChecker {
+	return &IgnoreChecker{
+		fsys:         fsys,
+		patternStack: make([][]string, 0),
+	}
+}
+
+// Push loads .ndignore patterns from the specified folder and adds them to the pattern stack.
+// Use this when entering a folder during directory tree traversal.
+func (ic *IgnoreChecker) Push(ctx context.Context, folder string) error {
+	patterns := ic.loadPatternsFromFolder(ctx, folder)
+	ic.patternStack = append(ic.patternStack, patterns)
+	ic.rebuildCurrentPatterns()
+	return nil
+}
+
+// Pop removes the most recent patterns from the stack.
+// Use this when leaving a folder during directory tree traversal.
+func (ic *IgnoreChecker) Pop() {
+	if len(ic.patternStack) > 0 {
+		ic.patternStack = ic.patternStack[:len(ic.patternStack)-1]
+		ic.rebuildCurrentPatterns()
+	}
+}
+
+// PushAllParents pushes patterns from root down to the target path.
+// This is a convenience method for when you need to check a specific path
+// without recursively walking the tree. It handles the common pattern of
+// pushing all parent directories from root to the target.
+// This method is optimized to compile patterns only once at the end.
+func (ic *IgnoreChecker) PushAllParents(ctx context.Context, targetPath string) error {
+	if targetPath == "." || targetPath == "" {
+		// Simple case: just push root
+		return ic.Push(ctx, ".")
+	}
+
+	// Load patterns for root
+	patterns := ic.loadPatternsFromFolder(ctx, ".")
+	ic.patternStack = append(ic.patternStack, patterns)
+
+	// Load patterns for each parent directory
+	currentPath := "."
+	parts := strings.Split(path.Clean(targetPath), "/")
+	for _, part := range parts {
+		if part == "." || part == "" {
+			continue
+		}
+		currentPath = path.Join(currentPath, part)
+		patterns = ic.loadPatternsFromFolder(ctx, currentPath)
+		ic.patternStack = append(ic.patternStack, patterns)
+	}
+
+	// Rebuild and compile patterns only once at the end
+	ic.rebuildCurrentPatterns()
+	return nil
+}
+
+// ShouldIgnore checks if the given path should be ignored based on the current patterns.
+// Returns true if the path matches any ignore pattern, false otherwise.
+func (ic *IgnoreChecker) ShouldIgnore(ctx context.Context, relPath string) bool {
+	// Handle root/empty path - never ignore
+	if relPath == "" || relPath == "." {
+		return false
+	}
+
+	// If no patterns loaded, nothing to ignore
+	if ic.matcher == nil {
+		return false
+	}
+
+	matches := ic.matcher.MatchesPath(relPath)
+	if matches {
+		log.Trace(ctx, "Scanner: Ignoring entry matching .ndignore", "path", relPath)
+	}
+	return matches
+}
+
+// loadPatternsFromFolder reads the .ndignore file in the specified folder and returns the patterns.
+// If the file doesn't exist, returns an empty slice.
+// If the file exists but is empty, returns a pattern to ignore everything ("**/*").
+func (ic *IgnoreChecker) loadPatternsFromFolder(ctx context.Context, folder string) []string {
+	ignoreFilePath := path.Join(folder, consts.ScanIgnoreFile)
+	var patterns []string
+
+	// Check if .ndignore file exists
+	if _, err := fs.Stat(ic.fsys, ignoreFilePath); err != nil {
+		// No .ndignore file in this folder
+		return patterns
+	}
+
+	// Read and parse the .ndignore file
+	ignoreFile, err := ic.fsys.Open(ignoreFilePath)
+	if err != nil {
+		log.Warn(ctx, "Scanner: Error opening .ndignore file", "path", ignoreFilePath, err)
+		return patterns
+	}
+	defer ignoreFile.Close()
+
+	lineScanner := bufio.NewScanner(ignoreFile)
+	for lineScanner.Scan() {
+		line := strings.TrimSpace(lineScanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue // Skip empty lines, whitespace-only lines, and comments
+		}
+		patterns = append(patterns, line)
+	}
+
+	if err := lineScanner.Err(); err != nil {
+		log.Warn(ctx, "Scanner: Error reading .ndignore file", "path", ignoreFilePath, err)
+		return patterns
+	}
+
+	// If the .ndignore file is empty, ignore everything
+	if len(patterns) == 0 {
+		log.Trace(ctx, "Scanner: .ndignore file is empty, ignoring everything", "path", folder)
+		patterns = []string{"**/*"}
+	}
+
+	return patterns
+}
+
+// rebuildCurrentPatterns flattens the pattern stack into currentPatterns and recompiles the matcher.
+func (ic *IgnoreChecker) rebuildCurrentPatterns() {
+	ic.currentPatterns = make([]string, 0)
+	for _, patterns := range ic.patternStack {
+		ic.currentPatterns = append(ic.currentPatterns, patterns...)
+	}
+	ic.compilePatterns()
+}
+
+// compilePatterns compiles the current patterns into a GitIgnore matcher.
+func (ic *IgnoreChecker) compilePatterns() {
+	if len(ic.currentPatterns) == 0 {
+		ic.matcher = nil
+		return
+	}
+	ic.matcher = ignore.CompileIgnoreLines(ic.currentPatterns...)
+}