Support early cancel of HTTP requests

If HTTP clients close their connection then no more work will be done by
the server. Previously many handlers were doing needless work in this
situation.

src/library/library.go

@@ -139,25 +139,25 @@ type Library interface {
 	// Search the library using a search string. It will match against Artist, Album
 	// and Title. Will OR the results. So it is "return anything which Artist matches or
 	// Album matches or Title matches".
-	Search(args SearchArgs) []SearchResult
+	Search(ctx context.Context, args SearchArgs) []SearchResult
 
 	// SearchAlbums searches the library for the given terms and returns matching
 	// albums. It may look into artist names, song names and actual album names.
-	SearchAlbums(args SearchArgs) []Album
+	SearchAlbums(ctx context.Context, args SearchArgs) []Album
 
 	// SearchArtists searches the library for the given terms and returns matching
 	// artists. It looks into the artist name only.
-	SearchArtists(args SearchArgs) []Artist
+	SearchArtists(ctx context.Context, args SearchArgs) []Artist
 
 	// Returns the real filesystem path. Requires the media ID.
-	GetFilePath(mediaID int64) string
+	GetFilePath(ctx context.Context, mediaID int64) string
 
 	// Returns search result will all the files of this album.
-	GetAlbumFiles(albumID int64) []TrackInfo
+	GetAlbumFiles(ctx context.Context, albumID int64) []TrackInfo
 
 	// GetArtistAlbums returns all the albums which this artist has an at least
 	// on track in.
-	GetArtistAlbums(artistID int64) []Album
+	GetArtistAlbums(ctx context.Context, artistID int64) []Album
 
 	// GetTrack returns information for particular track identified by its
 	// media ID.

src/library/library_test.go

@@ -229,7 +229,7 @@ func TestSearch(t *testing.T) {
 		_ = lib.Truncate()
 	}()
 
-	found := lib.Search(SearchArgs{
+	found := lib.Search(ctx, SearchArgs{
 		Query: "Buggy",
 	})
 
@@ -333,7 +333,7 @@ func TestAddingNewFiles(t *testing.T) {
 		t.Errorf("Expected to find 3 tracks but found %d", tracks)
 	}
 
-	found := library.Search(SearchArgs{Query: "Tittled Track"})
+	found := library.Search(ctx, SearchArgs{Query: "Tittled Track"})
 
 	if len(found) != 1 {
 		t.Fatalf("Expected to find one track but found %d", len(found))
@@ -456,7 +456,7 @@ func TestGettingAFile(t *testing.T) {
 		t.Fatalf("File not found: %s", err)
 	}
 
-	filePath := library.GetFilePath(trackID)
+	filePath := library.GetFilePath(ctx, trackID)
 
 	suffix := "/test_files/library/test_file_two.mp3"
 
@@ -501,7 +501,7 @@ func TestScaning(t *testing.T) {
 	testErrorAfter(t, 10*time.Second, ch, "Scanning library took too long")
 
 	for _, track := range []string{"Another One", "Payback", "Tittled Track"} {
-		found := lib.Search(SearchArgs{Query: track})
+		found := lib.Search(ctx, SearchArgs{Query: track})
 
 		if len(found) != 1 {
 			t.Errorf("%s was not found after the scan", track)
@@ -547,7 +547,7 @@ func TestRescanning(t *testing.T) {
 	}
 
 	for _, track := range []string{"Another One", "Payback", "Tittled Track"} {
-		found := lib.Search(SearchArgs{Query: track})
+		found := lib.Search(ctx, SearchArgs{Query: track})
 
 		if len(found) != 1 {
 			t.Errorf("%s was not found after the scan", track)
@@ -561,7 +561,9 @@ func TestSQLInjections(t *testing.T) {
 	lib := getScannedLibrary(ctx, t)
 	defer func() { _ = lib.Truncate() }()
 
-	found := lib.Search(SearchArgs{Query: `not-such-thing" OR 1=1 OR t.name="kleopatra`})
+	found := lib.Search(ctx, SearchArgs{
+		Query: `not-such-thing" OR 1=1 OR t.name="kleopatra`,
+	})
 
 	if len(found) != 0 {
 		t.Errorf("Successful sql injection in a single query")
@@ -581,7 +583,7 @@ func TestGetAlbumFiles(t *testing.T) {
 	}
 
 	albumID, _ := lib.GetAlbumID("Album Of Tests", albumPaths[0])
-	albumFiles := lib.GetAlbumFiles(albumID)
+	albumFiles := lib.GetAlbumFiles(ctx, albumID)
 
 	if len(albumFiles) != 2 {
 		t.Errorf("Expected 2 files in the album but found %d", len(albumFiles))
@@ -620,31 +622,31 @@ func TestRemoveFileFunction(t *testing.T) {
 	lib := getScannedLibrary(ctx, t)
 	defer func() { _ = lib.Truncate() }()
 
-	found := lib.Search(SearchArgs{Query: "Another One"})
+	found := lib.Search(ctx, SearchArgs{Query: "Another One"})
 
 	if len(found) != 1 {
 		t.Fatalf(`Expected searching for 'Another One' to return one `+
 			`result but they were %d`, len(found))
 	}
 
-	fsPath := lib.GetFilePath(found[0].ID)
+	fsPath := lib.GetFilePath(ctx, found[0].ID)
 
 	lib.removeFile(fsPath)
 
-	found = lib.Search(SearchArgs{Query: "Another One"})
+	found = lib.Search(ctx, SearchArgs{Query: "Another One"})
 
 	if len(found) != 0 {
 		t.Error(`Did not expect to find Another One but it was there.`)
 	}
 }
 
-func checkAddedSong(lib *LocalLibrary, t *testing.T) {
-	found := lib.Search(SearchArgs{Query: "Added Song"})
+func checkAddedSong(ctx context.Context, lib *LocalLibrary, t *testing.T) {
+	found := lib.Search(ctx, SearchArgs{Query: "Added Song"})
 
 	if len(found) != 1 {
 		filePaths := []string{}
 		for _, track := range found {
-			filePath := lib.GetFilePath(track.ID)
+			filePath := lib.GetFilePath(ctx, track.ID)
 			filePaths = append(filePaths, fmt.Sprintf("%d: %s", track.ID, filePath))
 		}
 		t.Fatalf("Expected one result, got %d for Added Song: %+v. Paths:\n%s",
@@ -670,8 +672,8 @@ func checkAddedSong(lib *LocalLibrary, t *testing.T) {
 	}
 }
 
-func checkSong(lib *LocalLibrary, song MediaFile, t *testing.T) {
-	found := lib.Search(SearchArgs{Query: song.Title()})
+func checkSong(ctx context.Context, lib *LocalLibrary, song MediaFile, t *testing.T) {
+	found := lib.Search(ctx, SearchArgs{Query: song.Title()})
 
 	if len(found) != 1 {
 		t.Fatalf("Expected one result, got %d for %s: %+v",
@@ -728,7 +730,7 @@ func TestAddingManyFilesSimultaniously(t *testing.T) {
 	}
 
 	for _, song := range mediaFiles {
-		checkSong(lib, song, t)
+		checkSong(ctx, lib, song, t)
 	}
 }
 
@@ -778,7 +780,7 @@ func TestAlbumsWithDifferentArtists(t *testing.T) {
 		}
 	}
 
-	found := lib.Search(SearchArgs{Query: "Return Of The Bugs"})
+	found := lib.Search(ctx, SearchArgs{Query: "Return Of The Bugs"})
 
 	if len(found) != 3 {
 		t.Fatalf("Expected to find 3 tracks but found %d", len(found))
@@ -855,7 +857,7 @@ func TestDifferentAlbumsWithTheSameName(t *testing.T) {
 		}
 	}
 
-	found := lib.Search(SearchArgs{Query: "Return Of The Bugs"})
+	found := lib.Search(ctx, SearchArgs{Query: "Return Of The Bugs"})
 
 	if len(found) != 3 {
 		t.Errorf("Expected to find 3 tracks but found %d", len(found))
@@ -1056,7 +1058,7 @@ func TestLocalLibraryGetArtistAlbums(t *testing.T) {
 	}
 
 	var artistID int64
-	results := lib.Search(SearchArgs{Query: artistName})
+	results := lib.Search(ctx, SearchArgs{Query: artistName})
 	for _, track := range results {
 		if track.Artist == artistName {
 			artistID = track.ArtistID
@@ -1068,7 +1070,7 @@ func TestLocalLibraryGetArtistAlbums(t *testing.T) {
 		t.Fatalf("could not find artist `%s`", artistName)
 	}
 
-	artistAlbums := lib.GetArtistAlbums(artistID)
+	artistAlbums := lib.GetArtistAlbums(ctx, artistID)
 	if len(expected) != len(artistAlbums) {
 		t.Errorf("expected %d albums but got %d", len(expected), len(artistAlbums))
 	}

src/library/library_watch_test.go

@@ -60,7 +60,7 @@ func TestMovingFileIntoLibrary(t *testing.T) {
 
 	time.Sleep(100 * time.Millisecond)
 
-	checkAddedSong(lib, t)
+	checkAddedSong(ctx, lib, t)
 }
 
 func TestRemovingFile(t *testing.T) {
@@ -83,7 +83,7 @@ func TestRemovingFile(t *testing.T) {
 	lib := getScannedLibrary(ctx, t)
 	defer func() { _ = lib.Truncate() }()
 
-	results := lib.Search(SearchArgs{Query: ""})
+	results := lib.Search(ctx, SearchArgs{Query: ""})
 
 	if len(results) != 4 {
 		t.Errorf("Expected 4 files in the result set but found %d", len(results))
@@ -95,7 +95,7 @@ func TestRemovingFile(t *testing.T) {
 
 	time.Sleep(100 * time.Millisecond)
 
-	results = lib.Search(SearchArgs{Query: ""})
+	results = lib.Search(ctx, SearchArgs{Query: ""})
 	if len(results) != 3 {
 		t.Errorf("Expected 3 files in the result set but found %d", len(results))
 	}
@@ -143,15 +143,15 @@ func TestAddingAndRemovingDirectory(t *testing.T) {
 
 	time.Sleep(100 * time.Millisecond)
 
-	checkAddedSong(lib, t)
+	checkAddedSong(ctx, lib, t)
 
 	if err := os.RemoveAll(movedDir); err != nil {
 		t.Error(err)
 	}
 
 	time.Sleep(100 * time.Millisecond)
 
-	results := lib.Search(SearchArgs{Query: ""})
+	results := lib.Search(ctx, SearchArgs{Query: ""})
 
 	if len(results) != 3 {
 		t.Errorf("Expected 3 songs but found %d", len(results))
@@ -198,7 +198,7 @@ func TestMovingDirectory(t *testing.T) {
 	lib := getScannedLibrary(ctx, t)
 	defer func() { _ = lib.Truncate() }()
 
-	checkAddedSong(lib, t)
+	checkAddedSong(ctx, lib, t)
 
 	if err := os.Rename(movedDir, secondPlace); err != nil {
 		t.Error(err)
@@ -208,21 +208,21 @@ func TestMovingDirectory(t *testing.T) {
 
 	time.Sleep(100 * time.Millisecond)
 
-	checkAddedSong(lib, t)
+	checkAddedSong(ctx, lib, t)
 
-	found := lib.Search(SearchArgs{Query: ""})
+	found := lib.Search(ctx, SearchArgs{Query: ""})
 
 	if len(found) != 4 {
 		t.Errorf("Expected to find 4 tracks but found %d", len(found))
 	}
 
-	found = lib.Search(SearchArgs{Query: "Added Song"})
+	found = lib.Search(ctx, SearchArgs{Query: "Added Song"})
 
 	if len(found) != 1 {
 		t.Fatalf("Did not find exactly one 'Added Song'. Found %d files", len(found))
 	}
 
-	foundPath := lib.GetFilePath(found[0].ID)
+	foundPath := lib.GetFilePath(ctx, found[0].ID)
 	expectedPath := filepath.Join(secondPlace, "test_file_added.mp3")
 
 	if _, err := os.Stat(expectedPath); err != nil {
@@ -259,7 +259,7 @@ func TestAddingNewFile(t *testing.T) {
 
 	time.Sleep(100 * time.Millisecond)
 
-	checkAddedSong(lib, t)
+	checkAddedSong(ctx, lib, t)
 }
 
 func TestAddingNonRelatedFile(t *testing.T) {
@@ -276,7 +276,7 @@ func TestAddingNonRelatedFile(t *testing.T) {
 	newFile := filepath.Join(testFiles, "library", "not_related")
 
 	testLibFiles := func() {
-		results := lib.Search(SearchArgs{Query: ""})
+		results := lib.Search(ctx, SearchArgs{Query: ""})
 		if len(results) != 3 {
 			t.Errorf("Expected 3 files in the library but found %d", len(results))
 		}