X benchmarks for Iterate + fstail

t/neo/storage/fs1/cmd/fstail/fstail.go

@@ -128,6 +128,9 @@ func fsTail(w io.Writer, path string, ntxn int) (err error) {
 	txnh := fs1.TxnHeader{}
 	data := []byte{}
 
+
+	// TODO use SeqBufReader instead of f and check speedup
+
 	// start iterating at tail.
 	// this should get EOF but read txnh.LenPrev ok.
 	err = txnh.Load(f, topPos, fs1.LoadAll)

t/neo/storage/fs1/cmd/fstail/fstail_test.go

@@ -29,7 +29,7 @@ func diff(a, b string) string {
 	return dmp.DiffPrettyText(diffv)
 }
 
-func TestFsDump(t *testing.T) {
+func TestFsTail(t *testing.T) {
 	buf := bytes.Buffer{}
 
 	err := fsTail(&buf, "../../testdata/1.fs", 1000000)
@@ -43,3 +43,12 @@ func TestFsDump(t *testing.T) {
 		t.Errorf("dump different:\n%v", diff(dumpOk, buf.String()))
 	}
 }
+
+func BenchmarkFsTail(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		err := fsTail(ioutil.Discard, "../../testdata/1.fs", 1000000)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}

t/neo/storage/fs1/filestorage_test.go

@@ -80,7 +80,7 @@ func checkLoad(t *testing.T, fs *FileStorage, xid zodb.Xid, expect oidLoadedOk)
 	}
 }
 
-func xfsopen(t *testing.T, path string) *FileStorage {
+func xfsopen(t testing.TB, path string) *FileStorage {
 	fs, err := Open(path)
 	if err != nil {
 		t.Fatal(err)
@@ -265,3 +265,42 @@ func TestIterate(t *testing.T) {
 	// also check 0..tidMax
 	testIterate(t, fs, 0, zodb.TidMax, _1fs_dbEntryv[:])
 }
+
+func BenchmarkIterate(b *testing.B) {
+	fs := xfsopen(b, "testdata/1.fs")	// TODO open ro
+	defer exc.XRun(fs.Close)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		iter := fs.Iterate(zodb.Tid(0), zodb.TidMax)
+
+		for {
+			txni, dataIter, err := iter.NextTxn()
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+				b.Fatal(err)
+			}
+
+			// use txni
+			_ = txni.Tid
+
+			for {
+				datai, err := dataIter.NextData()
+				if err != nil {
+					if err == io.EOF {
+						break
+					}
+					b.Fatal(err)
+				}
+
+				// use datai
+				_ = datai.Data
+			}
+
+		}
+	}
+
+	b.StopTimer()
+}