Add basic Parser.Next based benchmark (#266)

parse_test.go

@@ -203,6 +203,40 @@ func BenchmarkParse(b *testing.B) {
 	}
 }
 
+func BenchmarkParser_NextAPI(b *testing.B) {
+	files, err := ioutil.ReadDir("./testdata")
+	if err != nil {
+		b.Fatalf("unable to read testdata/: %v", err)
+	}
+	for _, f := range files {
+		if !f.IsDir() && strings.HasSuffix(f.Name(), ".dcm") {
+			b.Run(f.Name(), func(b *testing.B) {
+
+				dcm, err := os.Open("./testdata/" + f.Name())
+				if err != nil {
+					b.Errorf("Unable to open %s. Error: %v", f.Name(), err)
+				}
+				defer dcm.Close()
+
+				data, err := ioutil.ReadAll(dcm)
+				if err != nil {
+					b.Errorf("Unable to read file into memory for benchmark: %v", err)
+				}
+
+				b.ResetTimer()
+				for i := 0; i < b.N; i++ {
+					r := bytes.NewReader(data)
+					p, _ := dicom.NewParser(r, int64(len(data)), nil)
+					var err error
+					for err == nil {
+						_, err = p.Next()
+					}
+				}
+			})
+		}
+	}
+}
+
 func Example_readFile() {
 	// See also: dicom.Parse, which uses a more generic io.Reader API.
 	dataset, _ := dicom.ParseFile("testdata/1.dcm", nil)