[FAB-8482] Context function implementation for SDK

- Added Context() function in sdk to create
  context client
- Added NewChannelContext() function fabsdk package
  to create channel context
- Removed SessionFactory
- Refactored contexts in channel, ledger, resource packages
- Created common/context package for context related interfaces

Change-Id: I2b06f13ee7b0239858506646ea250a7eb6942801
Signed-off-by: Sudesh Shetty <sudesh.shetty@securekey.com>

Makefile

@@ -325,8 +325,8 @@ dockerenv-latest-up: clean
 mock-gen:
 	mockgen -build_flags '$(GO_LDFLAGS_ARG)' github.com/hyperledger/fabric-sdk-go/pkg/context/api/core Config,Providers,IdentityManager | sed "s/github.com\/hyperledger\/fabric-sdk-go\/vendor\///g" | goimports > pkg/context/api/core/mocks/mockcoreapi.gen.go
 	mockgen -build_flags '$(GO_LDFLAGS_ARG)' github.com/hyperledger/fabric-sdk-go/pkg/context/api/fab ProposalProcessor,Providers | sed "s/github.com\/hyperledger\/fabric-sdk-go\/vendor\///g" | goimports > pkg/context/api/fab/mocks/mockfabapi.gen.go
-	mockgen -build_flags '$(GO_LDFLAGS_ARG)' github.com/hyperledger/fabric-sdk-go/pkg/context Providers | sed "s/github.com\/hyperledger\/fabric-sdk-go\/vendor\///g" | goimports > pkg/context/mocks/mockcontext.gen.go
-	mockgen -build_flags '$(GO_LDFLAGS_ARG)' github.com/hyperledger/fabric-sdk-go/pkg/fabsdk/api CoreProviderFactory,ServiceProviderFactory,SessionClientFactory | sed "s/github.com\/hyperledger\/fabric-sdk-go\/vendor\///g" | goimports > pkg/fabsdk/mocks/mockfabsdkapi.gen.go
+	mockgen -build_flags '$(GO_LDFLAGS_ARG)' github.com/hyperledger/fabric-sdk-go/pkg/common/context Providers,Client | sed "s/github.com\/hyperledger\/fabric-sdk-go\/vendor\///g" | goimports > pkg/common/context/mocks/mockcontext.gen.go
+	mockgen -build_flags '$(GO_LDFLAGS_ARG)' github.com/hyperledger/fabric-sdk-go/pkg/fabsdk/api CoreProviderFactory,ServiceProviderFactory | sed "s/github.com\/hyperledger\/fabric-sdk-go\/vendor\///g" | goimports > pkg/fabsdk/mocks/mockfabsdkapi.gen.go
 
 # TODO - Add cryptogen
 .PHONY: channel-config-gen

pkg/client/channel/chclient.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hyperledger/fabric-sdk-go/pkg/client/channel/invoke"
 	"github.com/hyperledger/fabric-sdk-go/pkg/client/common/discovery"
 	"github.com/hyperledger/fabric-sdk-go/pkg/client/common/discovery/greylist"
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/context"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/core"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/fab"
 	"github.com/hyperledger/fabric-sdk-go/pkg/errors/multi"
@@ -35,50 +36,54 @@ const (
 // An application that requires interaction with multiple channels should create a separate
 // instance of the channel client for each channel. Channel client supports non-admin functions only.
 type Client struct {
-	context    core.Providers
-	discovery  fab.DiscoveryService
-	selection  fab.SelectionService
+	context    context.Channel
 	membership fab.ChannelMembership
 	transactor fab.Transactor
 	eventHub   fab.EventHub
 	greylist   *greylist.Filter
 }
 
-// Context holds the providers and services needed to create a Client.
-type Context struct {
-	core.Providers
-	DiscoveryService fab.DiscoveryService
-	SelectionService fab.SelectionService
-	ChannelService   fab.ChannelService
+type customChannelContext struct {
+	context.Channel
+	discoveryService fab.DiscoveryService
+}
+
+func (ccc *customChannelContext) DiscoveryService() fab.DiscoveryService {
+	return ccc.discoveryService
 }
 
 // New returns a Client instance.
-func New(c Context) (*Client, error) {
+func New(c context.Channel) (*Client, error) {
+
 	greylistProvider := greylist.New(c.Config().TimeoutOrDefault(core.DiscoveryGreylistExpiry))
 
-	eventHub, err := c.ChannelService.EventHub()
+	if c.ChannelService() == nil {
+		return nil, errors.New("channel service not initialized")
+	}
+
+	eventHub, err := c.ChannelService().EventHub()
 	if err != nil {
 		return nil, errors.WithMessage(err, "event hub creation failed")
 	}
 
-	transactor, err := c.ChannelService.Transactor()
+	transactor, err := c.ChannelService().Transactor()
 	if err != nil {
 		return nil, errors.WithMessage(err, "transactor creation failed")
 	}
 
-	membership, err := c.ChannelService.Membership()
+	membership, err := c.ChannelService().Membership()
 	if err != nil {
 		return nil, errors.WithMessage(err, "membership creation failed")
 	}
 
+	customDiscoveryService := discovery.NewDiscoveryFilterService(c.DiscoveryService(), greylistProvider)
+
 	channelClient := Client{
-		greylist:   greylistProvider,
-		context:    c,
-		discovery:  discovery.NewDiscoveryFilterService(c.DiscoveryService, greylistProvider),
-		selection:  c.SelectionService,
+		context:    &customChannelContext{Channel: c, discoveryService: customDiscoveryService},
 		membership: membership,
 		transactor: transactor,
 		eventHub:   eventHub,
+		greylist:   greylistProvider,
 	}
 
 	return &channelClient, nil
@@ -157,8 +162,8 @@ func (cc *Client) prepareHandlerContexts(request Request, o opts) (*invoke.Reque
 	}
 
 	clientContext := &invoke.ClientContext{
-		Selection:  cc.selection,
-		Discovery:  cc.discovery,
+		Selection:  cc.context.SelectionService(),
+		Discovery:  cc.context.DiscoveryService(),
 		Membership: cc.membership,
 		Transactor: cc.transactor,
 		EventHub:   cc.eventHub,

pkg/client/channel/chclient_test.go

@@ -16,7 +16,8 @@ import (
 
 	"github.com/hyperledger/fabric-sdk-go/pkg/client/channel/invoke"
 	txnmocks "github.com/hyperledger/fabric-sdk-go/pkg/client/common/mocks"
-	"github.com/hyperledger/fabric-sdk-go/pkg/context"
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/context"
+	contextImpl "github.com/hyperledger/fabric-sdk-go/pkg/context"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/core"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/fab"
 	"github.com/hyperledger/fabric-sdk-go/pkg/errors/retry"
@@ -30,6 +31,7 @@ import (
 
 const (
 	testAddress = "127.0.0.1:47882"
+	channelID   = "testChannel"
 )
 
 func TestTxProposalResponseFilter(t *testing.T) {
@@ -449,29 +451,21 @@ func TestMultiErrorPropogation(t *testing.T) {
 }
 
 func TestDiscoveryGreylist(t *testing.T) {
+
 	testPeer1 := fcmocks.NewMockPeer("Peer1", "http://peer1.com")
 	testPeer1.Error = status.New(status.EndorserClientStatus,
 		status.ConnectionFailed.ToInt32(), "test", []interface{}{testPeer1.URL()})
 
-	fabCtx := setupTestContext()
-
-	orderer := fcmocks.NewMockOrderer("", nil)
-	testChannelSvc, err := setupTestChannelService(fabCtx, []fab.Orderer{orderer})
+	selectionService, err := setupTestSelection(nil, nil)
 	assert.Nil(t, err, "Got error %s", err)
+	selectionService.SelectAll = true
 
 	discoveryService, err := setupTestDiscovery(nil, []fab.Peer{testPeer1})
 	assert.Nil(t, err, "Got error %s", err)
 
-	selectionService, err := setupTestSelection(nil, nil)
-	assert.Nil(t, err, "Got error %s", err)
-	selectionService.SelectAll = true
+	fabCtx := setupCustomTestContext(t, selectionService, discoveryService, nil)
+	ctx := contextImpl.NewChannel(fabCtx, channelID)
 
-	ctx := Context{
-		Providers:        fabCtx,
-		DiscoveryService: discoveryService,
-		SelectionService: selectionService,
-		ChannelService:   testChannelSvc,
-	}
 	chClient, err := New(ctx)
 	assert.Nil(t, err, "Got error %s", err)
 
@@ -491,7 +485,7 @@ func TestDiscoveryGreylist(t *testing.T) {
 	assert.EqualValues(t, status.NoPeersFound.ToInt32(), s.Code, "expected No Peers Found status on greylist")
 	assert.Equal(t, 1, testPeer1.ProcessProposalCalls, "expected peer 1 to be greylisted")
 	// Wait for greylist expiry
-	time.Sleep(ctx.Config().TimeoutOrDefault(core.DiscoveryGreylistExpiry))
+	time.Sleep(ctx.Providers().Config().TimeoutOrDefault(core.DiscoveryGreylistExpiry))
 	testPeer1.ProcessProposalCalls = 0
 	testPeer1.Error = status.New(status.EndorserServerStatus, int32(common.Status_SERVICE_UNAVAILABLE), "test", nil)
 	// Try again
@@ -506,20 +500,19 @@ func TestDiscoveryGreylist(t *testing.T) {
 }
 
 func setupTestChannelService(ctx context.Client, orderers []fab.Orderer) (fab.ChannelService, error) {
-	const channelName = "testChannel"
 	chProvider, err := fcmocks.NewMockChannelProvider(ctx)
 	if err != nil {
 		return nil, errors.WithMessage(err, "mock channel provider creation failed")
 	}
 
-	chService, err := chProvider.ChannelService(ctx, channelName)
+	chService, err := chProvider.ChannelService(ctx, channelID)
 	if err != nil {
 		return nil, errors.WithMessage(err, "mock channel service creation failed")
 	}
 
 	transactor := txnmocks.MockTransactor{
 		Ctx:       ctx,
-		ChannelID: channelName,
+		ChannelID: channelID,
 		Orderers:  orderers,
 	}
 	chService.(*fcmocks.MockChannelService).SetTransactor(&transactor)
@@ -533,6 +526,31 @@ func setupTestContext() context.Client {
 	return ctx
 }
 
+func setupCustomTestContext(t *testing.T, selectionService fab.SelectionService, discoveryService fab.DiscoveryService, orderers []fab.Orderer) context.Client {
+	user := fcmocks.NewMockUser("test")
+	ctx := fcmocks.NewMockContext(user)
+
+	if orderers == nil {
+		orderer := fcmocks.NewMockOrderer("", nil)
+		orderers = []fab.Orderer{orderer}
+	}
+
+	testChannelSvc, err := setupTestChannelService(ctx, orderers)
+	assert.Nil(t, err, "Got error %s", err)
+
+	//Modify for custom mocks to test scenarios
+	selectionProvider := ctx.MockProviderContext.SelectionProvider()
+	selectionProvider.(*fcmocks.MockSelectionProvider).SetCustomSelectionService(selectionService)
+
+	channelProvider := ctx.MockProviderContext.ChannelProvider()
+	channelProvider.(*fcmocks.MockChannelProvider).SetCustomChannelService(testChannelSvc)
+
+	discoveryProvider := ctx.MockProviderContext.DiscoveryProvider()
+	discoveryProvider.(*fcmocks.MockStaticDiscoveryProvider).SetCustomDiscoveryService(discoveryService)
+
+	return ctx
+}
+
 func setupTestDiscovery(discErr error, peers []fab.Peer) (fab.DiscoveryService, error) {
 
 	mockDiscovery, err := txnmocks.NewMockDiscoveryProvider(discErr, peers)
@@ -560,11 +578,6 @@ func setupChannelClient(peers []fab.Peer, t *testing.T) *Client {
 
 func setupChannelClientWithError(discErr error, selectionErr error, peers []fab.Peer, t *testing.T) *Client {
 
-	fabCtx := setupTestContext()
-	orderer := fcmocks.NewMockOrderer("", nil)
-	testChannelSvc, err := setupTestChannelService(fabCtx, []fab.Orderer{orderer})
-	assert.Nil(t, err, "Got error %s", err)
-
 	discoveryService, err := setupTestDiscovery(discErr, nil)
 	if err != nil {
 		t.Fatalf("Failed to setup discovery service: %s", err)
@@ -575,12 +588,10 @@ func setupChannelClientWithError(discErr error, selectionErr error, peers []fab.
 		t.Fatalf("Failed to setup discovery service: %s", err)
 	}
 
-	ctx := Context{
-		Providers:        fabCtx,
-		DiscoveryService: discoveryService,
-		SelectionService: selectionService,
-		ChannelService:   testChannelSvc,
-	}
+	fabCtx := setupCustomTestContext(t, selectionService, discoveryService, nil)
+
+	ctx := contextImpl.NewChannel(fabCtx, channelID)
+
 	ch, err := New(ctx)
 	if err != nil {
 		t.Fatalf("Failed to create new channel client: %s", err)
@@ -592,22 +603,16 @@ func setupChannelClientWithError(discErr error, selectionErr error, peers []fab.
 func setupChannelClientWithNodes(peers []fab.Peer,
 	orderers []fab.Orderer, t *testing.T) *Client {
 
-	fabCtx := setupTestContext()
-	testChannelSvc, err := setupTestChannelService(fabCtx, orderers)
-	assert.Nil(t, err, "Got error %s", err)
-
 	discoveryService, err := setupTestDiscovery(nil, nil)
 	assert.Nil(t, err, "Failed to setup discovery service")
 
 	selectionService, err := setupTestSelection(nil, peers)
 	assert.Nil(t, err, "Failed to setup discovery service")
 
-	ctx := Context{
-		Providers:        fabCtx,
-		DiscoveryService: discoveryService,
-		SelectionService: selectionService,
-		ChannelService:   testChannelSvc,
-	}
+	fabCtx := setupCustomTestContext(t, selectionService, discoveryService, orderers)
+
+	ctx := contextImpl.NewChannel(fabCtx, channelID)
+
 	ch, err := New(ctx)
 	assert.Nil(t, err, "Failed to create new channel client")
 

pkg/client/channel/invoke/txnhandler_test.go

@@ -15,7 +15,7 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	txnmocks "github.com/hyperledger/fabric-sdk-go/pkg/client/common/mocks"
-	"github.com/hyperledger/fabric-sdk-go/pkg/context"
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/context"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/fab"
 	fcmocks "github.com/hyperledger/fabric-sdk-go/pkg/fab/mocks"
 )

pkg/client/common/mocks/mocktransactor.go

@@ -7,7 +7,7 @@ SPDX-License-Identifier: Apache-2.0
 package mocks
 
 import (
-	"github.com/hyperledger/fabric-sdk-go/pkg/context"
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/context"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/fab"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fab/txn"
 	"github.com/pkg/errors"

pkg/client/ledger/ledger.go

@@ -12,8 +12,7 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
-	"github.com/hyperledger/fabric-sdk-go/pkg/context"
-	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/core"
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/context"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context/api/fab"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fab/channel"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fab/chconfig"
@@ -36,27 +35,13 @@ const (
 // An application that requires interaction with multiple channels should create a separate
 // instance of the ledger client for each channel. Ledger client supports specific queries only.
 type Client struct {
-	provider  core.Providers
-	identity  context.Identity
+	context   context.Client
 	discovery fab.DiscoveryService
 	ledger    *channel.Ledger
 	filter    TargetFilter
 	chName    string
 }
 
-// Context holds the providers and services needed to create a Client.
-type Context struct {
-	core.Providers
-	context.Identity
-	DiscoveryService fab.DiscoveryService
-	ChannelService   fab.ChannelService
-}
-
-type fabContext struct {
-	core.Providers
-	context.Identity
-}
-
 // MSPFilter is default filter
 type MSPFilter struct {
 	mspID string
@@ -68,17 +53,21 @@ func (f *MSPFilter) Accept(peer fab.Peer) bool {
 }
 
 // New returns a Client instance.
-func New(c Context, chName string, opts ...ClientOption) (*Client, error) {
+func New(c context.Client, chName string, opts ...ClientOption) (*Client, error) {
 
 	l, err := channel.NewLedger(c, chName)
 	if err != nil {
 		return nil, err
 	}
 
+	discoveryService, err := c.DiscoveryProvider().NewDiscoveryService(chName)
+	if err != nil {
+		return nil, err
+	}
+
 	ledgerClient := Client{
-		provider:  c,
-		identity:  c,
-		discovery: c.DiscoveryService,
+		context:   c,
+		discovery: discoveryService,
 		ledger:    l,
 		chName:    chName,
 	}
@@ -284,12 +273,7 @@ func (c *Client) QueryConfig(options ...RequestOption) (fab.ChannelCfg, error) {
 		return nil, errors.WithMessage(err, "failed to determine target peers for QueryConfig")
 	}
 
-	ctx := fabContext{
-		Providers: c.provider,
-		Identity:  c.identity,
-	}
-
-	channelConfig, err := chconfig.New(ctx, c.chName, chconfig.WithPeers(targets), chconfig.WithMinResponses(opts.MinTargets))
+	channelConfig, err := chconfig.New(c.context, c.chName, chconfig.WithPeers(targets), chconfig.WithMinResponses(opts.MinTargets))
 	if err != nil {
 		return nil, errors.WithMessage(err, "QueryConfig failed")
 	}