From 633d626e79d0c88cebaafeff32443783868a3c96 Mon Sep 17 00:00:00 2001
From: Tim Ebert <timebertt@gmail.com>
Date: Thu, 19 Oct 2023 08:26:12 +0200
Subject: [PATCH] [WIP] Experiment with CPU load

---
 webhosting-operator/main.go                   | 60 +++++++++++++++++++
 .../controllers/webhosting/reconcile_test.go  | 55 +++++++++++++++++
 .../scenario/reconcile/reconcile.go           |  9 ++-
 3 files changed, 119 insertions(+), 5 deletions(-)
 create mode 100644 webhosting-operator/main.go
 create mode 100644 webhosting-operator/pkg/controllers/webhosting/reconcile_test.go

diff --git a/webhosting-operator/main.go b/webhosting-operator/main.go
new file mode 100644
index 00000000..34e87720
--- /dev/null
+++ b/webhosting-operator/main.go
@@ -0,0 +1,60 @@
+/*
+Copyright 2023 Tim Ebert.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+func main() {
+	// size := 1 << 4 // 16
+	size := 1 << 12 // 4 KiB
+	// size := 1 << 14 // 16 KiB
+	data := make([]byte, size)
+	fmt.Printf("len: %d\n", len(data))
+	rand.Read(data)
+
+	// b := (&big.Int{}).SetBytes(data)
+	// fmt.Printf("len: %d\n", len(b.Bytes()))
+	// // fmt.Printf("data (hex): %s\n", b.Text(16))
+	// fmt.Printf("data (10): %s\n", b.Text(10))
+	// b2 := big.NewInt(3)
+
+	n, _ := strconv.ParseInt(os.Args[1], 10, 64)
+
+	var s uint64
+	// b.Mul(b, b2)
+	// b.Div(b, b2)
+	// // truncate b so that it doesn't allocate more memory
+	// b.SetBytes(b.Bytes()[:size])
+
+	for i := 0; i < int(n); i++ {
+		for j := 0; j <= len(data)-8; j += 8 {
+			u := binary.BigEndian.Uint64(data[j : j+8])
+			s += u * u
+		}
+	}
+	// fmt.Printf("sum: %d\n", s)
+
+	// fmt.Printf("len: %d\n", len(b.Bytes()))
+	// // fmt.Printf("data (hex): %s\n", b.Text(16))
+	// fmt.Printf("data (10): %s\n", b.Text(10))
+}
diff --git a/webhosting-operator/pkg/controllers/webhosting/reconcile_test.go b/webhosting-operator/pkg/controllers/webhosting/reconcile_test.go
new file mode 100644
index 00000000..ed73d373
--- /dev/null
+++ b/webhosting-operator/pkg/controllers/webhosting/reconcile_test.go
@@ -0,0 +1,55 @@
+/*
+Copyright 2023 Tim Ebert.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package webhosting
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"io"
+	"math/rand"
+	"testing"
+)
+
+func BenchmarkHash100(b *testing.B) {
+	data := make([]byte, 2<<12)
+	_, _ = rand.New(rand.NewSource(0)).Read(data) // always returns a nil pointer per documentation
+	b.ReportAllocs()
+
+	for i := 0; i < b.N; i++ {
+		h := sha256.New()
+		for i := 0; i < 100; i++ {
+			h.Write(data)
+		}
+		// hopefully the compiler doesn't optimize this away
+		fmt.Fprint(io.Discard, h.Sum(nil))
+	}
+}
+
+func BenchmarkSHA256(b *testing.B) {
+	data := make([]byte, 2<<12)
+	_, _ = rand.New(rand.NewSource(0)).Read(data) // always returns a nil pointer per documentation
+	b.ReportAllocs()
+
+	h := sha256.New()
+	for i := 0; i < b.N; i++ {
+		h.Reset()
+		for j := 0; j < 100; j++ {
+			h.Write(data)
+		}
+	}
+	fmt.Println(h.Sum(nil))
+}
diff --git a/webhosting-operator/pkg/experiment/scenario/reconcile/reconcile.go b/webhosting-operator/pkg/experiment/scenario/reconcile/reconcile.go
index 3999c753..2dadce91 100644
--- a/webhosting-operator/pkg/experiment/scenario/reconcile/reconcile.go
+++ b/webhosting-operator/pkg/experiment/scenario/reconcile/reconcile.go
@@ -19,7 +19,6 @@ package reconcile
 import (
 	"context"
 	"fmt"
-	"math/rand"
 	"time"
 
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -67,11 +66,11 @@ func (s *scenario) Prepare(ctx context.Context) error {
 	}
 
 	s.Log.Info("Preparing websites")
-	// random 4 KiB data to add to all websites
-	data := make([]byte, 1<<12)
-	_, _ = rand.New(rand.NewSource(0)).Read(data) // always returns a nil error per documentation
+	// // random 4 KiB data to add to all websites
+	// data := make([]byte, 1<<12)
+	// _, _ = rand.New(rand.NewSource(0)).Read(data) // always returns a nil error per documentation
 
-	if err := generator.CreateWebsites(ctx, s.Client, 10000, generator.WithLabels(s.Labels), generator.WithData(data)); err != nil {
+	if err := generator.CreateWebsites(ctx, s.Client, 10000, generator.WithLabels(s.Labels)); err != nil {
 		return err
 	}