Go vs CGo benchmarks refactored (not TPCH)

benchmark/benchmarks.go

@@ -0,0 +1,111 @@
+// Copyright 2021 The Sqlite Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// this file contains pure benchmark functions
+// these may be wrapped by different runners
+package benchmark
+
+import (
+	"database/sql"
+	"testing"
+)
+
+// all benchmark of N functions to be run
+var allBenchmarksOfNRows = []bechmarkOfNRows{
+	benchmarkInsert,
+	benchmarkSelect,
+}
+
+// bechmarkOfNRows is a type for a function that is benchmarking something depending on rows count.
+type bechmarkOfNRows func(b *testing.B, db *sql.DB, nRows int)
+
+// benchmarkInsert measures insertion of nRows into empty test table
+// the insertion is carried line by line, inside a transaction, using single prepared statement
+// the passed db instance must be empty (fresh) and is NOT auto-closed inside the benchmark function
+func benchmarkInsert(b *testing.B, db *sql.DB, nRows int) {
+	// create test table (empty)
+	createTestTable(b, db, 0)
+
+	// prepare statement for insertion
+	s, err := db.Prepare("insert into t values(?)")
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer s.Close()
+
+	// measure from here
+	b.ResetTimer()
+
+	// do N times
+	for i := 0; i < b.N; i++ {
+		// remove data from test table
+		b.StopTimer()
+		if _, err := db.Exec("delete from t"); err != nil {
+			b.Fatal(err)
+		}
+		b.StartTimer()
+
+		// begin tx
+		if _, err := db.Exec("begin"); err != nil {
+			b.Fatal(err)
+		}
+
+		// insert nRows one by one via prepared statement
+		for i := 0; i < nRows; i++ {
+			if _, err := s.Exec(int64(i)); err != nil {
+				b.Fatal(err)
+			}
+		}
+
+		// commit tx
+		if _, err := db.Exec("commit"); err != nil {
+			b.Fatal(err)
+		}
+
+		b.StopTimer()
+	}
+}
+
+// benchmarkSelect measures select of nRows from a test table
+// the passed db instance must be empty (fresh) and is NOT auto-closed inside the benchmark function
+func benchmarkSelect(b *testing.B, db *sql.DB, nRows int) {
+	// create test table with data
+	createTestTable(b, db, nRows)
+
+	// scan destination
+	dst := 0
+
+	// measure from here
+	b.ResetTimer()
+
+	// do N times
+	for i := 0; i < b.N; i++ {
+		// prepare a rows to iterate on
+		b.StopTimer()
+		rows, err := db.Query("select * from t")
+		if err != nil {
+			b.Fatal(err)
+		}
+		b.StartTimer()
+
+		// iterate in rows
+		for i := 0; i < nRows; i++ {
+			if !rows.Next() {
+				b.Fatal(rows.Err()) // createTestTable did not insert enough records? that's strange
+			}
+
+			// scan yet another value
+			err = rows.Scan(&dst)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+		b.StopTimer()
+
+		if rows.Next() {
+			b.Fatal("expecting rows to be exhausted at this point")
+		}
+		rows.Close()
+	}
+}