[#59] morph: Adopt updated `neo-go` client API for subs

It does not use deprecated methods anymore but also adds more code that
removes. Future refactor that will affect more components will optimize
usage of the updated API.

Signed-off-by: Pavel Karpy <p.karpy@yadro.com>

pkg/morph/client/client.go

@@ -69,17 +69,12 @@ type Client struct {
 	// on every normal call.
 	switchLock *sync.RWMutex
 
-	// channel for ws notifications
 	notifications chan rpcclient.Notification
+	subsInfo      // protected with switchLock
 
 	// channel for internal stop
 	closeChan chan struct{}
 
-	// cached subscription information
-	subscribedEvents       map[util.Uint160]string
-	subscribedNotaryEvents map[util.Uint160]string
-	subscribedToNewBlocks  bool
-
 	// indicates that Client is not able to
 	// establish connection to any of the
 	// provided RPC endpoints

pkg/morph/client/constructor.go

@@ -9,8 +9,11 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	lru "github.com/hashicorp/golang-lru/v2"
+	"github.com/nspcc-dev/neo-go/pkg/core/block"
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -102,17 +105,22 @@ func New(key *keys.PrivateKey, opts ...Option) (*Client, error) {
 	}
 
 	cli := &Client{
-		cache:                  newClientCache(),
+		cache:         newClientCache(),
-		logger:                 cfg.logger,
+		logger:        cfg.logger,
-		acc:                    acc,
+		acc:           acc,
-		accAddr:                accAddr,
+		accAddr:       accAddr,
-		signer:                 cfg.signer,
+		signer:        cfg.signer,
-		cfg:                    *cfg,
+		cfg:           *cfg,
-		switchLock:             &sync.RWMutex{},
+		switchLock:    &sync.RWMutex{},
-		notifications:          make(chan rpcclient.Notification),
+		notifications: make(chan rpcclient.Notification),
-		subscribedEvents:       make(map[util.Uint160]string),
+		subsInfo: subsInfo{
-		subscribedNotaryEvents: make(map[util.Uint160]string),
+			blockRcv:               make(chan *block.Block),
-		closeChan:              make(chan struct{}),
+			notificationRcv:        make(chan *state.ContainedNotificationEvent),
+			notaryReqRcv:           make(chan *result.NotaryRequestEvent),
+			subscribedEvents:       make(map[util.Uint160]string),
+			subscribedNotaryEvents: make(map[util.Uint160]string),
+		},
+		closeChan: make(chan struct{}),
 	}
 
 	cli.endpoints.init(cfg.endpoints)

pkg/morph/client/multi.go

@@ -4,6 +4,11 @@ import (
 	"sort"
 	"time"
 
+	"github.com/nspcc-dev/neo-go/pkg/core/block"
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
+	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
 	"go.uber.org/zap"
 )
 
@@ -51,7 +56,8 @@ func (c *Client) switchRPC() bool {
 		c.logger.Info("connection to the new RPC node has been established",
 			zap.String("endpoint", newEndpoint))
 
-		if !c.restoreSubscriptions(cli, newEndpoint) {
+		subs, ok := c.restoreSubscriptions(cli, newEndpoint, false)
+		if !ok {
 			// new WS client does not allow
 			// restoring subscription, client
 			// could not work correctly =>
@@ -63,6 +69,7 @@ func (c *Client) switchRPC() bool {
 
 		c.client = cli
 		c.setActor(act)
+		c.subsInfo = subs
 
 		if c.cfg.switchInterval != 0 && !c.switchIsActive.Load() &&
 			c.endpoints.list[c.endpoints.curr].Priority != c.endpoints.list[0].Priority {
@@ -77,9 +84,14 @@ func (c *Client) switchRPC() bool {
 }
 
 func (c *Client) notificationLoop() {
+	var e any
+	var ok bool
+
 	for {
 		c.switchLock.RLock()
-		nChan := c.client.Notifications
+		bChan := c.blockRcv
+		nChan := c.notificationRcv
+		nrChan := c.notaryReqRcv
 		c.switchLock.RUnlock()
 
 		select {
@@ -93,57 +105,74 @@ func (c *Client) notificationLoop() {
 			c.close()
 
 			return
-		case n, ok := <-nChan:
+		case e, ok = <-bChan:
-			// notification channel is used as a connection
+		case e, ok = <-nChan:
-			// state: if it is closed, the connection is
+		case e, ok = <-nrChan:
-			// considered to be lost
+		}
-			if !ok {
-				if closeErr := c.client.GetError(); closeErr != nil {
-					c.logger.Warn("switching to the next RPC node",
-						zap.String("reason", closeErr.Error()),
-					)
-				} else {
-					// neo-go client was closed by calling `Close`
-					// method that happens only when the client has
-					// switched to the more prioritized RPC
-					continue
-				}
 
-				if !c.switchRPC() {
+		if ok {
-					c.logger.Error("could not establish connection to any RPC node")
+			c.routeEvent(e)
+			continue
+		}
 
-					// could not connect to all endpoints =>
+		if !c.reconnect() {
-					// switch client to inactive mode
+			return
-					c.inactiveMode()
-
-					return
-				}
-
-				// TODO(@carpawell): call here some callback retrieved in constructor
-				// of the client to allow checking chain state since during switch
-				// process some notification could be lost
-
-				continue
-			}
-
-			select {
-			case c.notifications <- n:
-				continue
-			case <-c.cfg.ctx.Done():
-				_ = c.UnsubscribeAll()
-				c.close()
-
-				return
-			case <-c.closeChan:
-				_ = c.UnsubscribeAll()
-				c.close()
-
-				return
-			}
 		}
 	}
 }
 
+func (c *Client) routeEvent(e any) {
+	typedNotification := rpcclient.Notification{Value: e}
+
+	switch e.(type) {
+	case *block.Block:
+		typedNotification.Type = neorpc.BlockEventID
+	case *state.ContainedNotificationEvent:
+		typedNotification.Type = neorpc.NotificationEventID
+	case *result.NotaryRequestEvent:
+		typedNotification.Type = neorpc.NotaryRequestEventID
+	}
+
+	select {
+	case c.notifications <- typedNotification:
+	case <-c.cfg.ctx.Done():
+		_ = c.UnsubscribeAll()
+		c.close()
+	case <-c.closeChan:
+		_ = c.UnsubscribeAll()
+		c.close()
+	}
+}
+
+func (c *Client) reconnect() bool {
+	if closeErr := c.client.GetError(); closeErr != nil {
+		c.logger.Warn("switching to the next RPC node",
+			zap.String("reason", closeErr.Error()),
+		)
+	} else {
+		// neo-go client was closed by calling `Close`
+		// method, that happens only when a client has
+		// switched to the more prioritized RPC
+		return true
+	}
+
+	if !c.switchRPC() {
+		c.logger.Error("could not establish connection to any RPC node")
+
+		// could not connect to all endpoints =>
+		// switch client to inactive mode
+		c.inactiveMode()
+
+		return false
+	}
+
+	// TODO(@carpawell): call here some callback retrieved in constructor
+	// of the client to allow checking chain state since during switch
+	// process some notification could be lost
+
+	return true
+}
+
 func (c *Client) switchToMostPrioritized() {
 	t := time.NewTicker(c.cfg.switchInterval)
 	defer t.Stop()
@@ -156,11 +185,12 @@ mainLoop:
 			return
 		case <-t.C:
 			c.switchLock.RLock()
+
 			endpointsCopy := make([]Endpoint, len(c.endpoints.list))
 			copy(endpointsCopy, c.endpoints.list)
-
 			currPriority := c.endpoints.list[c.endpoints.curr].Priority
 			highestPriority := c.endpoints.list[0].Priority
+
 			c.switchLock.RUnlock()
 
 			if currPriority == highestPriority {
@@ -186,7 +216,7 @@ mainLoop:
 					continue
 				}
 
-				if c.restoreSubscriptions(cli, tryE) {
+				if subs, ok := c.restoreSubscriptions(cli, tryE, true); ok {
 					c.switchLock.Lock()
 
 					// higher priority node could have been
@@ -201,6 +231,7 @@ mainLoop:
 					c.cache.invalidate()
 					c.client = cli
 					c.setActor(act)
+					c.subsInfo = subs
 					c.endpoints.curr = i
 
 					c.switchLock.Unlock()

pkg/morph/client/notifications.go

@@ -1,6 +1,10 @@
 package client
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/core/block"
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"go.uber.org/zap"
@@ -36,7 +40,7 @@ func (c *Client) SubscribeForExecutionNotifications(contract util.Uint160) error
 		return nil
 	}
 
-	id, err := c.client.SubscribeForExecutionNotifications(&contract, nil)
+	id, err := c.client.ReceiveExecutionNotifications(&neorpc.NotificationFilter{Contract: &contract}, c.notificationRcv)
 	if err != nil {
 		return err
 	}
@@ -59,17 +63,17 @@ func (c *Client) SubscribeForNewBlocks() error {
 		return ErrConnectionLost
 	}
 
-	if c.subscribedToNewBlocks {
+	if c.subscribedToBlocks {
 		// no need to subscribe one more time
 		return nil
 	}
 
-	_, err := c.client.SubscribeForNewBlocks(nil)
+	_, err := c.client.ReceiveBlocks(nil, c.blockRcv)
 	if err != nil {
 		return err
 	}
 
-	c.subscribedToNewBlocks = true
+	c.subscribedToBlocks = true
 
 	return nil
 }
@@ -99,7 +103,7 @@ func (c *Client) SubscribeForNotaryRequests(txSigner util.Uint160) error {
 		return nil
 	}
 
-	id, err := c.client.SubscribeForNotaryRequests(nil, &txSigner)
+	id, err := c.client.ReceiveNotaryRequests(&neorpc.TxFilter{Signer: &txSigner}, c.notaryReqRcv)
 	if err != nil {
 		return err
 	}
@@ -187,7 +191,7 @@ func (c *Client) UnsubscribeAll() error {
 	// no need to unsubscribe if there are
 	// no active subscriptions
 	if len(c.subscribedEvents) == 0 && len(c.subscribedNotaryEvents) == 0 &&
-		!c.subscribedToNewBlocks {
+		!c.subscribedToBlocks {
 		return nil
 	}
 
@@ -198,14 +202,32 @@ func (c *Client) UnsubscribeAll() error {
 
 	c.subscribedEvents = make(map[util.Uint160]string)
 	c.subscribedNotaryEvents = make(map[util.Uint160]string)
-	c.subscribedToNewBlocks = false
+	c.subscribedToBlocks = false
 
 	return nil
 }
 
-// restoreSubscriptions restores subscriptions according to
+// subsInfo includes channels for ws notifications;
-// cached information about them.
+// cached subscription information.
-func (c *Client) restoreSubscriptions(cli *rpcclient.WSClient, endpoint string) bool {
+type subsInfo struct {
+	blockRcv        chan *block.Block
+	notificationRcv chan *state.ContainedNotificationEvent
+	notaryReqRcv    chan *result.NotaryRequestEvent
+
+	subscribedToBlocks     bool
+	subscribedEvents       map[util.Uint160]string
+	subscribedNotaryEvents map[util.Uint160]string
+}
+
+// restoreSubscriptions restores subscriptions according to cached
+// information about them.
+//
+// If it is NOT a background operation switchLock MUST be held.
+// Returns a pair: the second is a restoration status and the first
+// one contains subscription information applied to the passed cli
+// and receivers for the updated subscriptions.
+// Does not change Client instance.
+func (c *Client) restoreSubscriptions(cli *rpcclient.WSClient, endpoint string, background bool) (si subsInfo, ok bool) {
 	var (
 		err error
 		id  string
@@ -214,72 +236,109 @@ func (c *Client) restoreSubscriptions(cli *rpcclient.WSClient, endpoint string)
 	stopCh := make(chan struct{})
 	defer close(stopCh)
 
+	blockRcv := make(chan *block.Block)
+	notificationRcv := make(chan *state.ContainedNotificationEvent)
+	notaryReqRcv := make(chan *result.NotaryRequestEvent)
+
 	// neo-go WS client says to _always_ read notifications
 	// from its channel. Subscribing to any notification
 	// while not reading them in another goroutine may
 	// lead to a dead-lock, thus that async side notification
 	// listening while restoring subscriptions
 	go func() {
+		var e any
+		var ok bool
+
 		for {
 			select {
 			case <-stopCh:
 				return
-			case n, ok := <-cli.Notifications:
+			case e, ok = <-blockRcv:
-				if !ok {
+			case e, ok = <-notificationRcv:
-					return
+			case e, ok = <-notaryReqRcv:
-				}
-
-				c.notifications <- n
 			}
+
+			if !ok {
+				return
+			}
+
+			if background {
+				// background client (test) switch, no need to send
+				// any notification, just preventing dead-lock
+				continue
+			}
+
+			c.routeEvent(e)
 		}
 	}()
 
+	if background {
+		c.switchLock.RLock()
+		defer c.switchLock.RUnlock()
+	}
+
+	si.subscribedToBlocks = c.subscribedToBlocks
+	si.subscribedEvents = copySubsMap(c.subscribedEvents)
+	si.subscribedNotaryEvents = copySubsMap(c.subscribedNotaryEvents)
+	si.blockRcv = blockRcv
+	si.notificationRcv = notificationRcv
+	si.notaryReqRcv = notaryReqRcv
+
 	// new block events restoration
-	if c.subscribedToNewBlocks {
+	if si.subscribedToBlocks {
-		_, err = cli.SubscribeForNewBlocks(nil)
+		_, err = cli.ReceiveBlocks(nil, blockRcv)
 		if err != nil {
 			c.logger.Error("could not restore block subscription after RPC switch",
 				zap.String("endpoint", endpoint),
 				zap.Error(err),
 			)
 
-			return false
+			return
 		}
 	}
 
 	// notification events restoration
-	for contract := range c.subscribedEvents {
+	for contract := range si.subscribedEvents {
 		contract := contract // See https://github.com/nspcc-dev/neo-go/issues/2890
-		id, err = cli.SubscribeForExecutionNotifications(&contract, nil)
+		id, err = cli.ReceiveExecutionNotifications(&neorpc.NotificationFilter{Contract: &contract}, notificationRcv)
 		if err != nil {
 			c.logger.Error("could not restore notification subscription after RPC switch",
 				zap.String("endpoint", endpoint),
 				zap.Error(err),
 			)
 
-			return false
+			return
 		}
 
-		c.subscribedEvents[contract] = id
+		si.subscribedEvents[contract] = id
 	}
 
 	// notary notification events restoration
 	if c.notary != nil {
-		for signer := range c.subscribedNotaryEvents {
+		for signer := range si.subscribedNotaryEvents {
 			signer := signer // See https://github.com/nspcc-dev/neo-go/issues/2890
-			id, err = cli.SubscribeForNotaryRequests(nil, &signer)
+			id, err = cli.ReceiveNotaryRequests(&neorpc.TxFilter{Signer: &signer}, notaryReqRcv)
 			if err != nil {
 				c.logger.Error("could not restore notary notification subscription after RPC switch",
 					zap.String("endpoint", endpoint),
 					zap.Error(err),
 				)
 
-				return false
+				return
 			}
 
-			c.subscribedNotaryEvents[signer] = id
+			si.subscribedNotaryEvents[signer] = id
 		}
 	}
 
-	return true
+	return si, true
+}
+
+func copySubsMap(m map[util.Uint160]string) map[util.Uint160]string {
+	newM := make(map[util.Uint160]string, len(m))
+	for k, v := range m {
+		newM[k] = v
+	}
+
+	return newM
 }