From 9e6741e7f3e6db2acbaf3ed104c2de2680bcb198 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sat, 16 Feb 2019 14:37:31 +0100
Subject: [PATCH 1/3] add a fuzzer

---
 fuzztest/main.go | 115 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 fuzztest/main.go

diff --git a/fuzztest/main.go b/fuzztest/main.go
new file mode 100644
index 00000000..8f30f04c
--- /dev/null
+++ b/fuzztest/main.go
@@ -0,0 +1,115 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"github.com/allegro/bigcache"
+	"math/rand"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+)
+
+func fuzzDeletePutGet(ctx context.Context) {
+	c := bigcache.DefaultConfig(time.Second)
+	c.Shards = 1
+	c.MaxEntriesInWindow = 10
+	c.MaxEntriesInWindow = 10
+	c.HardMaxCacheSize = 1
+
+	cache, _ := bigcache.NewBigCache(c)
+	var wg sync.WaitGroup
+
+	// Deleter
+	wg.Add(1)
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				break
+			default:
+				r := uint8(rand.Int())
+				key := fmt.Sprintf("thekey%d", r)
+				cache.Delete(key)
+			}
+		}
+		wg.Done()
+	}()
+
+	// Setter
+	wg.Add(1)
+	go func() {
+		val := make([]byte, 1024)
+		for {
+			select {
+			case <-ctx.Done():
+				break
+			default:
+				r := byte(rand.Int())
+				key := fmt.Sprintf("thekey%d", r)
+
+				for j := 0; j < len(val); j++ {
+					val[j] = r
+				}
+				cache.Set(key, val)
+			}
+		}
+		wg.Done()
+	}()
+
+	// Getter
+	wg.Add(1)
+	go func() {
+		var (
+			val    = make([]byte, 1024)
+			hits   = uint64(0)
+			misses = uint64(0)
+		)
+		for {
+			select {
+			case <-ctx.Done():
+				break
+			default:
+				r := byte(rand.Int())
+				key := fmt.Sprintf("thekey%d", r)
+
+				for j := 0; j < len(val); j++ {
+					val[j] = r
+				}
+				if got, err := cache.Get(key); err == nil && !bytes.Equal(got, val) {
+					errStr := fmt.Sprintf("got %s ->\n %x\n expected:\n %x\n ", key, got, val)
+					panic(errStr)
+				} else {
+					if err == nil {
+						misses++
+					} else {
+						hits++
+					}
+				}
+				if total := hits + misses; total%1000000 == 0 {
+					percentage := float64(100) * float64(hits) / float64(total)
+					fmt.Printf("Hits %d (%.2f%%) misses %d \n", hits, percentage, misses)
+				}
+			}
+		}
+		wg.Done()
+	}()
+	wg.Wait()
+
+}
+func main() {
+
+	sigs := make(chan os.Signal, 1)
+	ctx, cancel := context.WithCancel(context.Background())
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+	fmt.Println("Press ctrl-c to exit")
+	go fuzzDeletePutGet(ctx)
+
+	<-sigs
+	fmt.Println("Exiting...")
+	cancel()
+
+}

From 8295df22446239f119e7e23d6840c720807f7141 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sat, 16 Feb 2019 15:30:15 +0100
Subject: [PATCH 2/3] fuzztest: correct stats

---
 fuzztest/main.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fuzztest/main.go b/fuzztest/main.go
index 8f30f04c..c477cb2e 100644
--- a/fuzztest/main.go
+++ b/fuzztest/main.go
@@ -84,9 +84,9 @@ func fuzzDeletePutGet(ctx context.Context) {
 					panic(errStr)
 				} else {
 					if err == nil {
-						misses++
-					} else {
 						hits++
+					} else {
+						misses++
 					}
 				}
 				if total := hits + misses; total%1000000 == 0 {

From d5bc869573def9fcc5706de5760ea726246f232d Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sat, 16 Feb 2019 21:49:13 +0100
Subject: [PATCH 3/3] fix unreachable code flaw

---
 fuzztest/main.go | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fuzztest/main.go b/fuzztest/main.go
index c477cb2e..f8acdfed 100644
--- a/fuzztest/main.go
+++ b/fuzztest/main.go
@@ -26,27 +26,28 @@ func fuzzDeletePutGet(ctx context.Context) {
 	// Deleter
 	wg.Add(1)
 	go func() {
+		defer wg.Done()
 		for {
 			select {
 			case <-ctx.Done():
-				break
+				return
 			default:
 				r := uint8(rand.Int())
 				key := fmt.Sprintf("thekey%d", r)
 				cache.Delete(key)
 			}
 		}
-		wg.Done()
 	}()
 
 	// Setter
 	wg.Add(1)
 	go func() {
+		defer wg.Done()
 		val := make([]byte, 1024)
 		for {
 			select {
 			case <-ctx.Done():
-				break
+				return
 			default:
 				r := byte(rand.Int())
 				key := fmt.Sprintf("thekey%d", r)
@@ -57,12 +58,12 @@ func fuzzDeletePutGet(ctx context.Context) {
 				cache.Set(key, val)
 			}
 		}
-		wg.Done()
 	}()
 
 	// Getter
 	wg.Add(1)
 	go func() {
+		defer wg.Done()
 		var (
 			val    = make([]byte, 1024)
 			hits   = uint64(0)
@@ -71,7 +72,7 @@ func fuzzDeletePutGet(ctx context.Context) {
 		for {
 			select {
 			case <-ctx.Done():
-				break
+				return
 			default:
 				r := byte(rand.Int())
 				key := fmt.Sprintf("thekey%d", r)
@@ -95,7 +96,6 @@ func fuzzDeletePutGet(ctx context.Context) {
 				}
 			}
 		}
-		wg.Done()
 	}()
 	wg.Wait()