different db's per instance

fuzz/README.md

@@ -0,0 +1,6 @@
+IPFS Datastore Fuzzer
+====
+
+The fuzzer provides a [go fuzzer](https://github.com/dvyukov/go-fuzz) interface
+to the Datastore interface. This can be used for fuzz testing of datastore
+implementations.

fuzz/fuzzer.go

@@ -3,23 +3,31 @@ package fuzzer
 import (
 	"context"
 	"io"
+	"io/ioutil"
+	"os"
+	"sync"
 	"sync/atomic"
 
 	ds "github.com/ipfs/go-datastore"
-	"github.com/ipfs/go-ds-badger"
+	badger "github.com/ipfs/go-ds-badger"
 )
 
+type donefunc func() error
+
 // DsOpener is the concrete datastore. that Fuzz will fuzz against.
-var DsOpener func() ds.TxnDatastore
+var DsOpener func() (ds.TxnDatastore, donefunc)
 var dsInst ds.TxnDatastore
+var df donefunc
 
 // Threads is a measure of concurrency.
 var Threads int
+var wg sync.WaitGroup
 
 func init() {
-	DsOpener = func() ds.TxnDatastore {
-		d, _ := badger.NewDatastore("tmp", &badger.DefaultOptions)
-		return d
+	DsOpener = func() (ds.TxnDatastore, donefunc) {
+		dir, _ := ioutil.TempDir("", "fuzz*")
+		d, _ := badger.NewDatastore(dir, &badger.DefaultOptions)
+		return d, func() error { return os.RemoveAll(dir) }
 	}
 	Threads = 1
 
@@ -31,11 +39,10 @@ func setup() ([]chan byte, context.CancelFunc) {
 	// TODO: dynamic thread starting.
 	ctx, cncl := context.WithCancel(context.Background())
 
-	if dsInst != nil {
-		dsInst.Close()
-	}
-	dsInst = DsOpener()
+	cleanup()
+	dsInst, df = DsOpener()
 
+	wg.Add(Threads)
 	drivers := make([]chan byte, Threads)
 	for i := 0; i < Threads; i++ {
 		drivers[i] = make(chan byte, 15)
@@ -44,6 +51,13 @@ func setup() ([]chan byte, context.CancelFunc) {
 	return drivers, cncl
 }
 
+func cleanup() {
+	if dsInst != nil {
+		dsInst.Close()
+		df()
+	}
+}
+
 // Fuzz is a go-fuzzer compatible input point for replaying
 // data (interpreted as a script of commands)
 // to a chosen ipfs datastore implementation
@@ -54,7 +68,8 @@ func Fuzz(data []byte) int {
 		close(drivers[i])
 	}
 	cncl()
-	dsInst.Close()
+	wg.Wait()
+	cleanup()
 	return 0
 }
 
@@ -79,7 +94,8 @@ func FuzzStream(data io.Reader) int {
 		close(drivers[i])
 	}
 	cncl()
-	dsInst.Close()
+	wg.Wait()
+	cleanup()
 	return 0
 }
 
@@ -111,6 +127,7 @@ type state struct {
 }
 
 func threadDriver(ctx context.Context, cmnds chan byte) error {
+	defer wg.Done()
 	s := state{}
 	s.reader = dsInst
 	s.writer = dsInst

go.mod

@@ -1,6 +1,7 @@
 module github.com/ipfs/go-datastore
 
 require (
+	github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813 // indirect
 	github.com/google/uuid v1.1.1
 	github.com/ipfs/go-ds-badger v0.2.1
 	github.com/ipfs/go-ipfs-delay v0.0.0-20181109222059-70721b86a9a8

go.sum

@@ -14,6 +14,8 @@ github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2 h1:tdlZCpZ/P9DhczC
 github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dustin/go-humanize v1.0.0 h1:VSnTsYCnlFHaM2/igO1h6X3HA71jcobQuxemgkq4zYo=
 github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
+github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813 h1:NgO45/5mBLRVfiXerEFzH6ikcZ7DNRPS639xFg3ENzU=
+github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813/go.mod h1:11Gm+ccJnvAhCNLlf5+cS9KjtbaD5I5zaZpFMsTHWTw=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=