Add upstreamrefresh chain element (networkservicemesh#1324)

Signed-off-by: Artem Glazychev <artem.glazychev@xored.com>
Signed-off-by: anastasia.malysheva <anastasia.malysheva@xored.com>

pkg/networkservice/common/upstreamrefresh/client.go

@@ -0,0 +1,91 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package upstreamrefresh
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"google.golang.org/grpc"
+	"google.golang.org/protobuf/types/known/emptypb"
+
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/clientconn"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+	"github.com/networkservicemesh/sdk/pkg/tools/extend"
+	"github.com/networkservicemesh/sdk/pkg/tools/postpone"
+)
+
+type upstreamRefreshClient struct {
+	chainCtx      context.Context
+	localNotifier *notifier
+}
+
+// NewClient - returns a new upstreamrefresh chain element
+func NewClient(chainCtx context.Context, opts ...Option) networkservice.NetworkServiceClient {
+	o := &options{}
+	for _, opt := range opts {
+		opt(o)
+	}
+
+	return &upstreamRefreshClient{
+		chainCtx:      chainCtx,
+		localNotifier: o.localNotifier,
+	}
+}
+
+func (u *upstreamRefreshClient) Request(ctx context.Context, request *networkservice.NetworkServiceRequest, opts ...grpc.CallOption) (*networkservice.Connection, error) {
+	closeCtxFunc := postpone.ContextWithValues(ctx)
+	// Cancel any existing eventLoop
+	if cancelEventLoop, loaded := loadAndDelete(ctx); loaded {
+		cancelEventLoop()
+	}
+
+	conn, err := next.Client(ctx).Request(ctx, request, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	u.localNotifier.subscribe(conn.GetId())
+
+	cc, ccLoaded := clientconn.Load(ctx)
+	if ccLoaded {
+		cancelEventLoop, eventLoopErr := newEventLoop(
+			extend.WithValuesFromContext(u.chainCtx, ctx), cc, conn, u.localNotifier)
+		if eventLoopErr != nil {
+			closeCtx, closeCancel := closeCtxFunc()
+			defer closeCancel()
+			_, _ = next.Client(closeCtx).Close(closeCtx, conn)
+			return nil, errors.Wrap(eventLoopErr, "unable to monitor")
+		}
+		store(ctx, cancelEventLoop)
+	}
+	return conn, nil
+}
+
+func (u *upstreamRefreshClient) Close(ctx context.Context, conn *networkservice.Connection, opts ...grpc.CallOption) (*emptypb.Empty, error) {
+	// Unsubscribe from local notifications
+	u.localNotifier.unsubscribe(conn.GetId())
+
+	// Cancel any existing eventLoop
+	if cancelEventLoop, loaded := loadAndDelete(ctx); loaded {
+		cancelEventLoop()
+	}
+
+	return next.Client(ctx).Close(ctx, conn, opts...)
+}

pkg/networkservice/common/upstreamrefresh/client_filter.go

@@ -0,0 +1,97 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package upstreamrefresh
+
+import (
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/tools/log"
+)
+
+type clientFilter struct {
+	conn *networkservice.Connection
+	networkservice.MonitorConnection_MonitorConnectionsClient
+
+	logger log.Logger
+}
+
+func newClientFilter(client networkservice.MonitorConnection_MonitorConnectionsClient, conn *networkservice.Connection, logger log.Logger) networkservice.MonitorConnection_MonitorConnectionsClient {
+	return &clientFilter{
+		MonitorConnection_MonitorConnectionsClient: client,
+		conn: conn,
+
+		logger: logger,
+	}
+}
+
+func (c *clientFilter) Recv() (*networkservice.ConnectionEvent, error) {
+	for {
+		eventIn, err := c.MonitorConnection_MonitorConnectionsClient.Recv()
+		if err != nil {
+			return nil, err
+		}
+		eventOut := &networkservice.ConnectionEvent{
+			Type:        networkservice.ConnectionEventType_UPDATE,
+			Connections: make(map[string]*networkservice.Connection),
+		}
+		for _, connIn := range eventIn.GetConnections() {
+			if eventIn.GetType() != networkservice.ConnectionEventType_UPDATE {
+				continue
+			}
+
+			connIn = connIn.Clone()
+			// If we don't have enough PathSegments connIn doesn't match e.conn
+			if len(connIn.GetPath().GetPathSegments()) < int(c.conn.GetPath().GetIndex()+1) {
+				continue
+			}
+			// If the e.conn isn't in the expected PathSegment connIn doesn't match e.conn
+			if connIn.GetPath().GetPathSegments()[int(c.conn.GetPath().GetIndex())].GetId() != c.conn.GetId() {
+				continue
+			}
+			// If the current index isn't the index of e.conn or what comes after it connIn doesn't match e.conn
+			if !(connIn.GetPath().GetIndex() == c.conn.GetPath().GetIndex() || connIn.GetPath().GetIndex() == c.conn.GetPath().GetIndex()+1) {
+				continue
+			}
+
+			// Construct the outgoing Connection
+			connOut := c.conn.Clone()
+			connOut.Path = connIn.Path
+			connOut.GetPath().Index = c.conn.GetPath().GetIndex()
+			connOut.Context = connIn.Context
+			connOut.State = connIn.State
+
+			// If it's deleted, mark the event state down
+			if eventIn.GetType() == networkservice.ConnectionEventType_DELETE {
+				connOut.State = networkservice.State_DOWN
+			}
+
+			// If the connection hasn't changed... don't send the event
+			if connOut.Equals(c.conn) {
+				continue
+			}
+
+			// Add the Connection to the outgoing event
+			eventOut.GetConnections()[connOut.GetId()] = connOut
+
+			// Update the event we are watching for:
+			c.conn = connOut
+		}
+		if len(eventOut.GetConnections()) > 0 {
+			return eventOut, nil
+		}
+	}
+}

pkg/networkservice/common/upstreamrefresh/doc.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package upstreamrefresh provides a client chain element that receives monitor connectionEvents
+// and processes those that have refresh_requested state
+package upstreamrefresh

pkg/networkservice/common/upstreamrefresh/eventloop.go

@@ -0,0 +1,141 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package upstreamrefresh
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"google.golang.org/grpc"
+
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/begin"
+	"github.com/networkservicemesh/sdk/pkg/tools/log"
+)
+
+type eventLoop struct {
+	eventLoopCtx  context.Context
+	conn          *networkservice.Connection
+	eventFactory  begin.EventFactory
+	client        networkservice.MonitorConnection_MonitorConnectionsClient
+	localNotifier *notifier
+	logger        log.Logger
+}
+
+func newEventLoop(ctx context.Context, cc grpc.ClientConnInterface, conn *networkservice.Connection, ln *notifier) (context.CancelFunc, error) {
+	conn = conn.Clone()
+
+	ev := begin.FromContext(ctx)
+	if ev == nil {
+		return func() {}, nil
+	}
+
+	// Create new eventLoopCtx and store its eventLoopCancel
+	eventLoopCtx, eventLoopCancel := context.WithCancel(ctx)
+
+	// Create selector to only ask for events related to our Connection
+	selector := &networkservice.MonitorScopeSelector{
+		PathSegments: []*networkservice.PathSegment{
+			{
+				Id:   conn.GetCurrentPathSegment().GetId(),
+				Name: conn.GetCurrentPathSegment().GetName(),
+			},
+		},
+	}
+
+	client, err := networkservice.NewMonitorConnectionClient(cc).MonitorConnections(eventLoopCtx, selector)
+	if err != nil {
+		eventLoopCancel()
+		return nil, errors.WithStack(err)
+	}
+
+	// get the initial state transfer and use it to detect whether we have a real connection or not
+	_, err = client.Recv()
+	if err != nil {
+		eventLoopCancel()
+		return nil, errors.WithStack(err)
+	}
+
+	logger := log.FromContext(ctx).WithField("upstreamrefresh", "eventLoop")
+	cev := &eventLoop{
+		eventLoopCtx:  eventLoopCtx,
+		conn:          conn,
+		eventFactory:  ev,
+		client:        newClientFilter(client, conn, logger),
+		localNotifier: ln,
+		logger:        logger,
+	}
+
+	// Start the eventLoop
+	go cev.eventLoop()
+	return eventLoopCancel, nil
+}
+
+func (cev *eventLoop) eventLoop() {
+	upstreamCh := cev.monitorUpstream()
+	var localCh <-chan struct{}
+
+	if cev.localNotifier.get(cev.conn.GetId()) != nil {
+		localCh = cev.localNotifier.get(cev.conn.GetId())
+	}
+
+	select {
+	case _, ok := <-upstreamCh:
+		if !ok {
+			// Connection closed
+			return
+		}
+		cev.logger.Debug("refresh requested from upstream")
+
+		<-cev.eventFactory.Request()
+		cev.localNotifier.notify(cev.eventLoopCtx, cev.conn.GetId())
+
+	case _, ok := <-localCh:
+		if !ok {
+			// Unsubscribed
+			return
+		}
+		cev.logger.Debug("refresh requested from other connection")
+		<-cev.eventFactory.Request()
+	case <-cev.eventLoopCtx.Done():
+		return
+	}
+}
+
+func (cev *eventLoop) monitorUpstream() <-chan struct{} {
+	res := make(chan struct{}, 1)
+
+	go func() {
+		defer close(res)
+
+		for {
+			eventIn, err := cev.client.Recv()
+			if cev.eventLoopCtx.Err() != nil || err != nil {
+				return
+			}
+
+			// Handle event
+			if eventIn.GetConnections()[cev.conn.GetId()].GetState() == networkservice.State_REFRESH_REQUESTED {
+				res <- struct{}{}
+				return
+			}
+		}
+	}()
+
+	return res
+}

pkg/networkservice/common/upstreamrefresh/gen.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package upstreamrefresh
+
+import (
+	"sync"
+)
+
+type typeCh = chan struct{}
+
+//go:generate go-syncmap -output notifier_map.gen.go -type notifierMap<string,typeCh>
+
+// clientMap - sync.Map with key == string and value == chan struct{}
+type notifierMap sync.Map