benchmark fix and update

Fixed double insert bug in BenchmarkE2EGocqlInsert. Modernized other
benchmarks to use new API that releases query where applicable. Updated
benchmark results with new version of libraries and Scylla 2.2.

Fixes #61

README.md

@@ -103,12 +103,12 @@ Gocqlx is fast, this is a benchmark result comparing `gocqlx` to raw `gocql`
 on a local machine, Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz.
 
 ```
-BenchmarkE2EGocqlInsert-4         500000            258434 ns/op            2627 B/op         59 allocs/op
+BenchmarkE2EGocqlInsert            20000             86713 ns/op            2030 B/op         33 allocs/op
-BenchmarkE2EGocqlxInsert-4       1000000            120257 ns/op            1555 B/op         34 allocs/op
+BenchmarkE2EGocqlxInsert           20000             87882 ns/op            2030 B/op         33 allocs/op
-BenchmarkE2EGocqlGet-4           1000000            131424 ns/op            1970 B/op         55 allocs/op
+BenchmarkE2EGocqlGet               20000             94308 ns/op            1504 B/op         29 allocs/op
-BenchmarkE2EGocqlxGet-4          1000000            131981 ns/op            2322 B/op         58 allocs/op
+BenchmarkE2EGocqlxGet              20000             95722 ns/op            2128 B/op         33 allocs/op
-BenchmarkE2EGocqlSelect-4          30000           2588562 ns/op           34605 B/op        946 allocs/op
+BenchmarkE2EGocqlSelect             1000           1792469 ns/op           43595 B/op        921 allocs/op
-BenchmarkE2EGocqlxSelect-4         30000           2637187 ns/op           27718 B/op        951 allocs/op
+BenchmarkE2EGocqlxSelect            1000           1839574 ns/op           36986 B/op        927 allocs/op
 ```
 
 See the benchmark in [benchmark_test.go](https://github.com/scylladb/gocqlx/blob/master/benchmark_test.go).

benchmark_test.go

@@ -78,15 +78,10 @@ func BenchmarkE2EGocqlInsert(b *testing.B) {
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		// prepare
 		p := people[i%len(people)]
 		if err := q.Bind(p.ID, p.FirstName, p.LastName, p.Email, p.Gender, p.IPAddress).Exec(); err != nil {
 			b.Fatal(err)
 		}
-		// insert
-		if err := q.Exec(); err != nil {
-			b.Fatal(err)
-		}
 	}
 }
 
@@ -105,7 +100,6 @@ func BenchmarkE2EGocqlxInsert(b *testing.B) {
 	defer q.Release()
 
 	b.ResetTimer()
-
 	for i := 0; i < b.N; i++ {
 		p := people[i%len(people)]
 		if err := q.BindStruct(p).Exec(); err != nil {
@@ -157,10 +151,11 @@ func BenchmarkE2EGocqlxGet(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		// prepare
-		q := session.Query(stmt)
+		q := session.Query(stmt).Bind(people[i%len(people)].ID)
-		q.Bind(people[i%len(people)].ID)
+		// get and release
-		// get
+		if err := gocqlx.Query(q, nil).GetRelease(&p); err != nil {
-		gocqlx.Get(&p, q)
+			b.Fatal(err)
+		}
 	}
 }
 
@@ -213,8 +208,8 @@ func BenchmarkE2EGocqlxSelect(b *testing.B) {
 		// prepare
 		q := session.Query(stmt)
 		var v []*benchPerson
-		// select
+		// select and release
-		if err := gocqlx.Select(&v, q); err != nil {
+		if err := gocqlx.Query(q, nil).SelectRelease(&v); err != nil {
 			b.Fatal(err)
 		}
 	}