[FAB-11170] Refactor discovery client cache

changed name and type field maxMemorySize in signer.go,
changed code of signer.go to skip putting in memory if maxSize is 0,
changed parameter in CLI from 10 to 0 in stub.go,
updated tests

Change-Id: Ib3c81dafe09a3e267973399d53846aaae9c07689
Signed-off-by: Inbar Badian <Inbar.Badian@ibm.com>

discovery/client/client.go

@@ -535,7 +535,7 @@ type endorsementDescriptor struct {
 }
 
 // NewClient creates a new Client instance
-func NewClient(createConnection Dialer, s Signer, signerCacheSize int) *Client {
+func NewClient(createConnection Dialer, s Signer, signerCacheSize uint) *Client {
 	return &Client{
 		createConnection: createConnection,
 		signRequest:      NewMemoizeSigner(s, signerCacheSize).Sign,

discovery/client/client_test.go

@@ -42,7 +42,7 @@ import (
 )
 
 const (
-	signerCacheSize = 1
+	signerCacheSize uint = 1
 )
 
 var (

discovery/client/signer.go

@@ -16,19 +16,19 @@ import (
 // MemoizeSigner signs messages with the same signature
 // if the message was signed recently
 type MemoizeSigner struct {
-	maxMemorySize int
+	maxEntries uint
 	sync.RWMutex
 	memory map[string][]byte
 	sign   Signer
 }
 
 // NewMemoizeSigner creates a new MemoizeSigner that signs
 // message with the given sign function
-func NewMemoizeSigner(signFunc Signer, maxMemorySize int) *MemoizeSigner {
+func NewMemoizeSigner(signFunc Signer, maxEntries uint) *MemoizeSigner {
 	return &MemoizeSigner{
-		maxMemorySize: maxMemorySize,
-		memory:        make(map[string][]byte),
-		sign:          signFunc,
+		maxEntries: maxEntries,
+		memory:     make(map[string][]byte),
+		sign:       signFunc,
 	}
 }
 
@@ -57,25 +57,28 @@ func (ms *MemoizeSigner) lookup(msg []byte) ([]byte, bool) {
 }
 
 func (ms *MemoizeSigner) memorize(msg, signature []byte) {
+	if ms.maxEntries == 0 {
+		return
+	}
 	ms.RLock()
-	shouldShrink := len(ms.memory) >= ms.maxMemorySize
+	shouldShrink := len(ms.memory) >= (int)(ms.maxEntries)
 	ms.RUnlock()
 
 	if shouldShrink {
 		ms.shrinkMemory()
 	}
-
 	ms.Lock()
 	defer ms.Unlock()
 	ms.memory[msgDigest(msg)] = signature
+
 }
 
 // evict evicts random messages from memory
-// until its size is smaller than maxMemorySize
+// until its size is smaller than maxEntries
 func (ms *MemoizeSigner) shrinkMemory() {
 	ms.Lock()
 	defer ms.Unlock()
-	for len(ms.memory) > ms.maxMemorySize {
+	for len(ms.memory) > (int)(ms.maxEntries) {
 		ms.evictFromMemory()
 	}
 }

discovery/client/signer_test.go

@@ -7,6 +7,8 @@ SPDX-License-Identifier: Apache-2.0
 package discovery
 
 import (
+	"crypto/rand"
+	"io"
 	"sync"
 	"sync/atomic"
 	"testing"
@@ -37,17 +39,17 @@ func TestSameMessage(t *testing.T) {
 }
 
 func TestDifferentMessages(t *testing.T) {
-	n := 5
+	var n uint = 5
 	var signedInvokedCount uint32
 	sign := func(msg []byte) ([]byte, error) {
 		atomic.AddUint32(&signedInvokedCount, 1)
 		return msg, nil
 	}
 
 	ms := NewMemoizeSigner(sign, n)
-	parallelSignRange := func(start, end int) {
+	parallelSignRange := func(start, end uint) {
 		var wg sync.WaitGroup
-		wg.Add(end - start)
+		wg.Add((int)(end - start))
 		for i := start; i < end; i++ {
 			i := i
 			go func() {
@@ -86,3 +88,17 @@ func TestFailure(t *testing.T) {
 	_, err := ms.Sign([]byte{1, 2, 3})
 	assert.Equal(t, "something went wrong", err.Error())
 }
+
+func TestNotSavingInMem(t *testing.T) {
+	sign := func(_ []byte) ([]byte, error) {
+		b := make([]byte, 30)
+		_, err := io.ReadFull(rand.Reader, b)
+		assert.NoError(t, err)
+		return b, nil
+	}
+	ms := NewMemoizeSigner(sign, 0)
+	sig1, _ := ms.sign(([]byte)("aa"))
+	sig2, _ := ms.sign(([]byte)("aa"))
+	assert.NotEqual(t, sig1, sig2)
+
+}

discovery/cmd/stub.go

@@ -61,7 +61,7 @@ func (stub *ClientStub) Send(server string, conf common.Config, req *discovery.R
 	timeout, cancel := context.WithTimeout(context.Background(), defaultTimeout)
 	defer cancel()
 
-	disc := discovery.NewClient(comm.NewDialer(server), signer.Sign, 10)
+	disc := discovery.NewClient(comm.NewDialer(server), signer.Sign, 0)
 
 	resp, err := disc.Send(timeout, req, &AuthInfo{
 		ClientIdentity:    signer.Creator,

discovery/test/integration_test.go

@@ -494,7 +494,7 @@ func createClientAndService(t *testing.T, testdir string) (*client, *service) {
 	assert.NoError(t, err)
 
 	wrapperClient := &client{AuthInfo: authInfo, conn: conn}
-	signerCacheSize := 10
+	var signerCacheSize uint = 10
 	c := disc.NewClient(wrapperClient.newConnection, signer.Sign, signerCacheSize)
 	wrapperClient.Client = c
 	service := &service{Server: gRPCServer.Server(), lc: lc, sup: sup}