frame: Fix Frame.Parse benchmark and add Frame.Hash benchmark.

frame/frame_test.go

@@ -63,17 +63,55 @@ func BenchmarkFrameParse(b *testing.B) {
 	// in the repository, but is available for download at
 	//
 	//    http://freesound.org/people/jarfil/sounds/151185/
-	stream, err := flac.Open("../testdata/benchmark/151185.flac")
-	if err != nil {
-		b.Fatal(err)
-	}
 	for i := 0; i < b.N; i++ {
-		_, err := stream.ParseNext()
+		stream, err := flac.Open("../testdata/benchmark/151185.flac")
 		if err != nil {
-			if err == io.EOF {
-				break
+			b.Fatal(err)
+		}
+		for {
+			_, err := stream.ParseNext()
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+				stream.Close()
+				b.Fatal(err)
 			}
+		}
+		stream.Close()
+	}
+}
+
+func BenchmarkFrameHash(b *testing.B) {
+	// The file 151185.flac is a 119.5 MB public domain FLAC file used to
+	// benchmark the flac library. Because of its size, it has not been included
+	// in the repository, but is available for download at
+	//
+	//    http://freesound.org/people/jarfil/sounds/151185/
+	for i := 0; i < b.N; i++ {
+		stream, err := flac.Open("../testdata/benchmark/151185.flac")
+		if err != nil {
 			b.Fatal(err)
 		}
+		md5sum := md5.New()
+		for {
+			frame, err := stream.ParseNext()
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+				stream.Close()
+				b.Fatal(err)
+			}
+			frame.Hash(md5sum)
+		}
+		stream.Close()
+		want := stream.Info.MD5sum[:]
+		got := md5sum.Sum(nil)
+		// Verify the decoded audio samples by comparing the MD5 checksum that is
+		// stored in StreamInfo with the computed one.
+		if !bytes.Equal(got, want) {
+			b.Fatalf("MD5 checksum mismatch for decoded audio samples; expected %32x, got %32x", want, got)
+		}
 	}
 }