[DEV-9154] Private data rollback MVCC_READ_CONFLICT

Test to ensure that private data is rolled back on an MVCC_READ_CONFLICT

Change-Id: I577ebfa8ebd63e9023667967771c21acfdd5bec7
Signed-off-by: George Aristy <george.aristy@securekey.com>

test/fixtures/testdata/src/github.com/example_pvt_cc/example_pvt_cc.go

@@ -9,6 +9,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/hyperledger/fabric/core/chaincode/shim"
@@ -30,6 +31,7 @@ const (
 	putBothFunc       = "putboth"
 	getAndPutBothFunc = "getandputboth"
 	invokeCCFunc      = "invokecc"
+	addToIntFunc	  = "addToInt"
 )
 
 // ExampleCC example chaincode that puts and gets state and private data
@@ -216,6 +218,43 @@ func (cc *ExampleCC) getAndPutBoth(stub shim.ChaincodeStubInterface, args []stri
 	return shim.Success(nil)
 }
 
+// Adds a given int amount to the value stored in the given private collection's key, storing the result using the same key.
+// If the given key does not already exist then it will be added and stored with the given amount.
+func (cc *ExampleCC) addToInt(stub shim.ChaincodeStubInterface, args[]string) pb.Response {
+	if len(args) != 3 {
+		return shim.Error("Invalid args. Expecting collection, key, amountToAdd")
+	}
+
+	coll := args[0]
+	key := args[1]
+	amountToAdd, err := strconv.Atoi(args[2])
+	if err != nil {
+		return shim.Error("Invalid arg: amountToAdd is not an int")
+	}
+
+	oldValue, err := stub.GetPrivateData(coll, key)
+	if err != nil {
+		return shim.Error(fmt.Sprintf("Error getting private data for collection [%s] and key [%s]: %s", coll, key, err))
+	}
+
+	var oldValueInt int
+	if oldValue != nil {
+		oldValueInt, err = strconv.Atoi(string(oldValue))
+		if err != nil {
+			return shim.Error(fmt.Sprintf("Error parsing existing amount [%s]: %s", string(oldValue), err))
+		}
+	} else {
+		oldValueInt = 0
+	}
+
+	newValueInt := oldValueInt + amountToAdd
+	if err := stub.PutPrivateData(coll, key, []byte(strconv.Itoa(newValueInt))); err != nil {
+		return shim.Error(fmt.Sprintf("Error storing new sum [%s] to key [%s] in private collection [%s]: %s", newValueInt, key, coll, err))
+	}
+
+	return shim.Success(nil)
+}
+
 type argStruct struct {
 	Args []string `json:"Args"`
 }
@@ -259,6 +298,7 @@ func (cc *ExampleCC) initRegistry() {
 	cc.funcRegistry[putBothFunc] = cc.putBoth
 	cc.funcRegistry[getAndPutBothFunc] = cc.getAndPutBoth
 	cc.funcRegistry[invokeCCFunc] = cc.invokeCC
+	cc.funcRegistry[addToIntFunc] = cc.addToInt
 }
 
 func (cc *ExampleCC) functions() []string {

test/integration/pkg/client/channel/channel_client_pvt_test.go

@@ -9,8 +9,14 @@ SPDX-License-Identifier: Apache-2.0
 package channel
 
 import (
+	"strconv"
+	"strings"
+	"sync"
 	"testing"
 
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/errors/multi"
+	"github.com/stretchr/testify/assert"
+
 	"github.com/stretchr/testify/require"
 
 	"github.com/hyperledger/fabric-sdk-go/pkg/client/channel"
@@ -137,6 +143,74 @@ func TestPrivateDataWithOrgDown(t *testing.T) {
 	})
 }
 
+// Data in a private data collection must be left untouched if the client receives an MVCC_READ_CONFLICT error.
+// We test this by submitting two cumulative changes to a private data collection, ensuring that the MVCC_READ_CONFLICT error
+// is reproduced, then asserting that only one of the changes was applied.
+func TestChannelClientRollsBackPvtDataIfMvccReadConflict(t *testing.T) {
+	orgsContext := setupMultiOrgContext(t, mainSDK)
+	require.NoError(t, integration.EnsureChannelCreatedAndPeersJoined(t, mainSDK, orgChannelID, "orgchannel.tx", orgsContext))
+	// private data collection used for test
+	const coll = "collection1"
+	// collection key used for test
+	const key = "collection_key"
+	ccID := integration.GenerateExamplePvtID(true)
+	collConfig, err := newCollectionConfig(coll, "OR('Org1MSP.member','Org2MSP.member','Org3MSP.member')", 0, 2, 1000)
+	require.NoError(t, err)
+	require.NoError(t, integration.InstallExamplePvtChaincode(orgsContext, ccID))
+	require.NoError(t, integration.InstantiateExamplePvtChaincode(orgsContext, orgChannelID, ccID, "OR('Org1MSP.member','Org2MSP.member','Org3MSP.member')", collConfig))
+	ctxProvider := mainSDK.ChannelContext(orgChannelID, fabsdk.WithUser(org1User), fabsdk.WithOrg(org1Name))
+	chClient, err := channel.New(ctxProvider)
+	require.NoError(t, err)
+
+	var errMtx sync.Mutex
+	errs := multi.Errors{}
+	var wg sync.WaitGroup
+
+	// test function; invokes a CC function that mutates the private data collection
+	changePvtData := func(amount int) {
+		defer wg.Done()
+		_, err := chClient.Execute(
+			channel.Request{
+				ChaincodeID: ccID,
+				Fcn:         "addToInt",
+				Args:        [][]byte{[]byte(coll), []byte(key), []byte(strconv.Itoa(amount))},
+			},
+		)
+		if err != nil {
+			errMtx.Lock()
+			errs = append(errs, err)
+			errMtx.Unlock()
+			return
+		}
+	}
+
+	// expected value at the end of the test
+	const expected = 10
+
+	wg.Add(2)
+	go changePvtData(expected)
+	go changePvtData(expected)
+	wg.Wait()
+
+	// ensure the MVCC_READ_CONFLICT was reproduced
+	require.Truef(t, len(errs) > 0 && strings.Contains(errs[0].Error(), "MVCC_READ_CONFLICT"), "could not reproduce MVCC_READ_CONFLICT")
+
+	// read current value of private data collection
+	resp, err := chClient.Query(
+		channel.Request{
+			ChaincodeID: ccID,
+			Fcn:         "getprivate",
+			Args:        [][]byte{[]byte(coll), []byte(key)},
+		},
+	)
+	require.NoErrorf(t, err, "error attempting to read private data")
+
+	actual, err := strconv.Atoi(string(resp.Payload))
+	require.NoError(t, err)
+
+	assert.Truef(t, actual == expected, "Private data not rolled back during MVCC_READ_CONFLICT")
+}
+
 func newCollectionConfig(colName, policy string, reqPeerCount, maxPeerCount int32, blockToLive uint64) (*cb.CollectionConfig, error) {
 	p, err := cauthdsl.FromString(policy)
 	if err != nil {