fix(scanner): improve M3U playlist import times (#2706)

core/playlists.go

@@ -1,8 +1,6 @@
 package core
 
 import (
-	"bufio"
-	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -20,6 +18,7 @@ import (
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/criteria"
 	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/utils/slice"
 )
 
 type Playlists interface {
@@ -133,34 +132,39 @@ func (s *playlists) parseNSP(ctx context.Context, pls *model.Playlist, file io.R
 
 func (s *playlists) parseM3U(ctx context.Context, pls *model.Playlist, baseDir string, reader io.Reader) (*model.Playlist, error) {
 	mediaFileRepository := s.ds.MediaFile(ctx)
-	scanner := bufio.NewScanner(reader)
-	scanner.Split(scanLines)
 	var mfs model.MediaFiles
-	for scanner.Scan() {
-		line := strings.TrimSpace(scanner.Text())
-		if strings.HasPrefix(line, "#PLAYLIST:") {
-			if split := strings.Split(line, ":"); len(split) >= 2 {
-				pls.Name = split[1]
+	for lines := range slice.CollectChunks[string](400, slice.LinesFrom(reader)) {
+		var filteredLines []string
+		for _, line := range lines {
+			line := strings.TrimSpace(line)
+			if strings.HasPrefix(line, "#PLAYLIST:") {
+				if split := strings.Split(line, ":"); len(split) >= 2 {
+					pls.Name = split[1]
+				}
+				continue
 			}
-			continue
+			// Skip empty lines and extended info
+			if line == "" || strings.HasPrefix(line, "#") {
+				continue
+			}
+			if strings.HasPrefix(line, "file://") {
+				line = strings.TrimPrefix(line, "file://")
+				line, _ = url.QueryUnescape(line)
+			}
+			if baseDir != "" && !filepath.IsAbs(line) {
+				line = filepath.Join(baseDir, line)
+			}
+			filteredLines = append(filteredLines, line)
 		}
-		// Skip empty lines and extended info
-		if line == "" || strings.HasPrefix(line, "#") {
-			continue
-		}
-		if strings.HasPrefix(line, "file://") {
-			line = strings.TrimPrefix(line, "file://")
-			line, _ = url.QueryUnescape(line)
-		}
-		if baseDir != "" && !filepath.IsAbs(line) {
-			line = filepath.Join(baseDir, line)
-		}
-		mf, err := mediaFileRepository.FindByPath(line)
+		found, err := mediaFileRepository.FindByPaths(filteredLines)
 		if err != nil {
-			log.Warn(ctx, "Path in playlist not found", "playlist", pls.Name, "path", line, err)
+			log.Warn(ctx, "Error reading files from DB", "playlist", pls.Name, err)
 			continue
 		}
-		mfs = append(mfs, *mf)
+		if len(found) != len(filteredLines) {
+			logMissingFiles(ctx, pls, filteredLines, found)
+		}
+		mfs = append(mfs, found...)
 	}
 	if pls.Name == "" {
 		pls.Name = time.Now().Format(time.RFC3339)
@@ -168,7 +172,20 @@ func (s *playlists) parseM3U(ctx context.Context, pls *model.Playlist, baseDir s
 	pls.Tracks = nil
 	pls.AddMediaFiles(mfs)
 
-	return pls, scanner.Err()
+	return pls, nil
+}
+
+func logMissingFiles(ctx context.Context, pls *model.Playlist, lines []string, found model.MediaFiles) {
+	missing := make(map[string]bool)
+	for _, line := range lines {
+		missing[line] = true
+	}
+	for _, mf := range found {
+		delete(missing, mf.Path)
+	}
+	for path := range missing {
+		log.Warn(ctx, "Path in playlist not found", "playlist", pls.Name, "path", path)
+	}
 }
 
 func (s *playlists) updatePlaylist(ctx context.Context, newPls *model.Playlist) error {
@@ -199,30 +216,6 @@ func (s *playlists) updatePlaylist(ctx context.Context, newPls *model.Playlist)
 	return s.ds.Playlist(ctx).Put(newPls)
 }
 
-// From https://stackoverflow.com/a/41433698
-func scanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
-	if atEOF && len(data) == 0 {
-		return 0, nil, nil
-	}
-	if i := bytes.IndexAny(data, "\r\n"); i >= 0 {
-		if data[i] == '\n' {
-			// We have a line terminated by single newline.
-			return i + 1, data[0:i], nil
-		}
-		advance = i + 1
-		if len(data) > i+1 && data[i+1] == '\n' {
-			advance += 1
-		}
-		return advance, data[0:i], nil
-	}
-	// If we're at EOF, we have a final, non-terminated line. Return it.
-	if atEOF {
-		return len(data), data, nil
-	}
-	// Request more data.
-	return 0, nil, nil
-}
-
 func (s *playlists) Update(ctx context.Context, playlistID string,
 	name *string, comment *string, public *bool,
 	idsToAdd []string, idxToRemove []int) error {

core/playlists_test.go

@@ -118,6 +118,15 @@ func (r *mockedMediaFile) FindByPath(s string) (*model.MediaFile, error) {
 	}, nil
 }
 
+func (r *mockedMediaFile) FindByPaths(paths []string) (model.MediaFiles, error) {
+	var mfs model.MediaFiles
+	for _, path := range paths {
+		mf, _ := r.FindByPath(path)
+		mfs = append(mfs, *mf)
+	}
+	return mfs, nil
+}
+
 type mockedPlaylist struct {
 	last *model.Playlist
 	model.PlaylistRepository

model/mediafile.go

@@ -265,6 +265,7 @@ type MediaFileRepository interface {
 	// Queries by path to support the scanner, no Annotations or Bookmarks required in the response
 	FindAllByPath(path string) (MediaFiles, error)
 	FindByPath(path string) (*MediaFile, error)
+	FindByPaths(paths []string) (MediaFiles, error)
 	FindPathsRecursively(basePath string) ([]string, error)
 	DeleteByPath(path string) (int64, error)
 

persistence/mediafile_repository.go

@@ -127,6 +127,15 @@ func (r *mediaFileRepository) FindByPath(path string) (*model.MediaFile, error)
 	return &res[0], nil
 }
 
+func (r *mediaFileRepository) FindByPaths(paths []string) (model.MediaFiles, error) {
+	sel := r.newSelect().Columns("*").Where(Eq{"path collate nocase": paths})
+	var res model.MediaFiles
+	if err := r.queryAll(sel, &res); err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
 func cleanPath(path string) string {
 	path = filepath.Clean(path)
 	if !strings.HasSuffix(path, string(os.PathSeparator)) {

scanner/playlist_importer.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/mattn/go-zglob"
 	"github.com/navidrome/navidrome/conf"
@@ -36,6 +37,7 @@ func (s *playlistImporter) processPlaylists(ctx context.Context, dir string) int
 		return count
 	}
 	for _, f := range files {
+		started := time.Now()
 		if strings.HasPrefix(f.Name(), ".") {
 			continue
 		}
@@ -47,9 +49,9 @@ func (s *playlistImporter) processPlaylists(ctx context.Context, dir string) int
 			continue
 		}
 		if pls.IsSmartPlaylist() {
-			log.Debug("Imported smart playlist", "name", pls.Name, "lastUpdated", pls.UpdatedAt, "path", pls.Path, "numTracks", pls.SongCount)
+			log.Debug("Imported smart playlist", "name", pls.Name, "lastUpdated", pls.UpdatedAt, "path", pls.Path, "elapsed", time.Since(started))
 		} else {
-			log.Debug("Imported playlist", "name", pls.Name, "lastUpdated", pls.UpdatedAt, "path", pls.Path, "numTracks", pls.SongCount)
+			log.Debug("Imported playlist", "name", pls.Name, "lastUpdated", pls.UpdatedAt, "path", pls.Path, "numTracks", len(pls.Tracks), "elapsed", time.Since(started))
 		}
 		s.cacheWarmer.PreCache(pls.CoverArtID())
 		count++

scanner/playlist_importer_test.go

@@ -77,6 +77,15 @@ func (r *mockedMediaFile) FindByPath(s string) (*model.MediaFile, error) {
 	}, nil
 }
 
+func (r *mockedMediaFile) FindByPaths(paths []string) (model.MediaFiles, error) {
+	var mfs model.MediaFiles
+	for _, path := range paths {
+		mf, _ := r.FindByPath(path)
+		mfs = append(mfs, *mf)
+	}
+	return mfs, nil
+}
+
 type mockedPlaylist struct {
 	model.PlaylistRepository
 }

utils/slice/slice.go

@@ -1,5 +1,12 @@
 package slice
 
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"iter"
+)
+
 func Map[T any, R any](t []T, mapFunc func(T) R) []R {
 	r := make([]R, len(t))
 	for i, e := range t {
@@ -79,3 +86,57 @@ func RangeByChunks[T any](items []T, chunkSize int, cb func([]T) error) error {
 	}
 	return nil
 }
+
+func LinesFrom(reader io.Reader) iter.Seq[string] {
+	return func(yield func(string) bool) {
+		scanner := bufio.NewScanner(reader)
+		scanner.Split(scanLines)
+		for scanner.Scan() {
+			if !yield(scanner.Text()) {
+				return
+			}
+		}
+	}
+}
+
+// From https://stackoverflow.com/a/41433698
+func scanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	if atEOF && len(data) == 0 {
+		return 0, nil, nil
+	}
+	if i := bytes.IndexAny(data, "\r\n"); i >= 0 {
+		if data[i] == '\n' {
+			// We have a line terminated by single newline.
+			return i + 1, data[0:i], nil
+		}
+		advance = i + 1
+		if len(data) > i+1 && data[i+1] == '\n' {
+			advance += 1
+		}
+		return advance, data[0:i], nil
+	}
+	// If we're at EOF, we have a final, non-terminated line. Return it.
+	if atEOF {
+		return len(data), data, nil
+	}
+	// Request more data.
+	return 0, nil, nil
+}
+
+func CollectChunks[T any](n int, it iter.Seq[T]) iter.Seq[[]T] {
+	return func(yield func([]T) bool) {
+		var s []T
+		for x := range it {
+			s = append(s, x)
+			if len(s) >= n {
+				if !yield(s) {
+					return
+				}
+				s = nil
+			}
+		}
+		if len(s) > 0 {
+			yield(s)
+		}
+	}
+}

utils/slice/slice_test.go

@@ -1,15 +1,19 @@
 package slice_test
 
 import (
+	"os"
+	"slices"
 	"strconv"
 	"testing"
 
+	"github.com/navidrome/navidrome/tests"
 	"github.com/navidrome/navidrome/utils/slice"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
 func TestSlice(t *testing.T) {
+	tests.Init(t, false)
 	RegisterFailHandler(Fail)
 	RunSpecs(t, "Slice Suite")
 }
@@ -90,4 +94,32 @@ var _ = Describe("Slice Utils", func() {
 			Expect(chunks[1]).To(HaveExactElements("d", "e"))
 		})
 	})
+
+	DescribeTable("LinesFrom",
+		func(path string, expected int) {
+			count := 0
+			file, _ := os.Open(path)
+			defer file.Close()
+			for _ = range slice.LinesFrom(file) {
+				count++
+			}
+			Expect(count).To(Equal(expected))
+		},
+		Entry("returns empty slice for an empty input", "tests/fixtures/empty.txt", 0),
+		Entry("returns the lines of a file", "tests/fixtures/playlists/pls1.m3u", 3),
+		Entry("returns empty if file does not exist", "tests/fixtures/NON-EXISTENT", 0),
+	)
+
+	DescribeTable("CollectChunks",
+		func(input []int, n int, expected [][]int) {
+			result := [][]int{}
+			for chunks := range slice.CollectChunks[int](n, slices.Values(input)) {
+				result = append(result, chunks)
+			}
+			Expect(result).To(Equal(expected))
+		},
+		Entry("returns empty slice for an empty input", []int{}, 1, [][]int{}),
+		Entry("returns the slice in one chunk if len < chunkSize", []int{1, 2, 3}, 10, [][]int{{1, 2, 3}}),
+		Entry("breaks up the slice if len > chunkSize", []int{1, 2, 3, 4, 5}, 3, [][]int{{1, 2, 3}, {4, 5}}),
+	)
 })