frostfs-node/pkg/morph/client/notifications.go

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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"
)
// Close closes connection to the remote side making
// this client instance unusable. Closes notification
// channel returned from Client.NotificationChannel(),
// Removes all subscription.
func (c *Client) Close() {
// closing should be done via the channel
// to prevent switching to another RPC node
// in the notification loop
close(c.closeChan)
}
// SubscribeForExecutionNotifications adds subscription for notifications
// generated during contract transaction execution to this instance of client.
//
// Returns ErrConnectionLost if client has not been able to establish
// connection to any of passed RPC endpoints.
func (c *Client) SubscribeForExecutionNotifications(contract util.Uint160) error {
c.switchLock.Lock()
defer c.switchLock.Unlock()
if c.inactive {
return ErrConnectionLost
}
_, subscribed := c.subscribedEvents[contract]
if subscribed {
// no need to subscribe one more time
return nil
}
id, err := c.client.ReceiveExecutionNotifications(&neorpc.NotificationFilter{Contract: &contract}, c.notificationRcv)
if err != nil {
return err
}
c.subscribedEvents[contract] = id
return nil
}
// SubscribeForNewBlocks adds subscription for new block events to this
// instance of client.
//
// Returns ErrConnectionLost if client has not been able to establish
// connection to any of passed RPC endpoints.
func (c *Client) SubscribeForNewBlocks() error {
c.switchLock.Lock()
defer c.switchLock.Unlock()
if c.inactive {
return ErrConnectionLost
}
if c.subscribedToBlocks {
// no need to subscribe one more time
return nil
}
_, err := c.client.ReceiveBlocks(nil, c.blockRcv)
if err != nil {
return err
}
c.subscribedToBlocks = true
return nil
}
// SubscribeForNotaryRequests adds subscription for notary request payloads
// addition or removal events to this instance of client. Passed txSigner is
// used as filter: subscription is only for the notary requests that must be
// signed by txSigner.
//
// Returns ErrConnectionLost if client has not been able to establish
// connection to any of passed RPC endpoints.
func (c *Client) SubscribeForNotaryRequests(txSigner util.Uint160) error {
if c.notary == nil {
panic(notaryNotEnabledPanicMsg)
}
c.switchLock.Lock()
defer c.switchLock.Unlock()
if c.inactive {
return ErrConnectionLost
}
_, subscribed := c.subscribedNotaryEvents[txSigner]
if subscribed {
// no need to subscribe one more time
return nil
}
id, err := c.client.ReceiveNotaryRequests(&neorpc.TxFilter{Signer: &txSigner}, c.notaryReqRcv)
if err != nil {
return err
}
c.subscribedNotaryEvents[txSigner] = id
return nil
}
// UnsubscribeContract removes subscription for given contract event stream.
//
// Returns ErrConnectionLost if client has not been able to establish
// connection to any of passed RPC endpoints.
func (c *Client) UnsubscribeContract(contract util.Uint160) error {
c.switchLock.Lock()
defer c.switchLock.Unlock()
if c.inactive {
return ErrConnectionLost
}
_, subscribed := c.subscribedEvents[contract]
if !subscribed {
// no need to unsubscribe contract
// without subscription
return nil
}
err := c.client.Unsubscribe(c.subscribedEvents[contract])
if err != nil {
return err
}
delete(c.subscribedEvents, contract)
return nil
}
// UnsubscribeNotaryRequest removes subscription for given notary requests
// signer.
//
// Returns ErrConnectionLost if client has not been able to establish
// connection to any of passed RPC endpoints.
func (c *Client) UnsubscribeNotaryRequest(signer util.Uint160) error {
if c.notary == nil {
panic(notaryNotEnabledPanicMsg)
}
c.switchLock.Lock()
defer c.switchLock.Unlock()
if c.inactive {
return ErrConnectionLost
}
_, subscribed := c.subscribedNotaryEvents[signer]
if !subscribed {
// no need to unsubscribe signer's
// requests without subscription
return nil
}
err := c.client.Unsubscribe(c.subscribedNotaryEvents[signer])
if err != nil {
return err
}
delete(c.subscribedNotaryEvents, signer)
return nil
}
// UnsubscribeAll removes all active subscriptions of current client.
//
// Returns ErrConnectionLost if client has not been able to establish
// connection to any of passed RPC endpoints.
func (c *Client) UnsubscribeAll() error {
c.switchLock.Lock()
defer c.switchLock.Unlock()
if c.inactive {
return ErrConnectionLost
}
// no need to unsubscribe if there are
// no active subscriptions
if len(c.subscribedEvents) == 0 && len(c.subscribedNotaryEvents) == 0 &&
!c.subscribedToBlocks {
return nil
}
err := c.client.UnsubscribeAll()
if err != nil {
return err
}
c.subscribedEvents = make(map[util.Uint160]string)
c.subscribedNotaryEvents = make(map[util.Uint160]string)
c.subscribedToBlocks = false
return nil
}
// subsInfo includes channels for ws notifications;
// cached subscription information.
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
)
stopCh := make(chan struct{})
defer close(stopCh)
blockRcv := make(chan *block.Block)
notificationRcv := make(chan *state.ContainedNotificationEvent)
notaryReqRcv := make(chan *result.NotaryRequestEvent)
c.startListen(stopCh, blockRcv, notificationRcv, notaryReqRcv, background)
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 si.subscribedToBlocks {
_, 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
}
}
// notification events restoration
for contract := range si.subscribedEvents {
contract := contract // See https://github.com/nspcc-dev/neo-go/issues/2890
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
}
si.subscribedEvents[contract] = id
}
// notary notification events restoration
if c.notary != nil {
for signer := range si.subscribedNotaryEvents {
signer := signer // See https://github.com/nspcc-dev/neo-go/issues/2890
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
}
si.subscribedNotaryEvents[signer] = id
}
}
return si, true
}
func (c *Client) startListen(stopCh <-chan struct{}, blockRcv <-chan *block.Block,
notificationRcv <-chan *state.ContainedNotificationEvent, notaryReqRcv <-chan *result.NotaryRequestEvent, background bool) {
// 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 e, ok = <-blockRcv:
case e, ok = <-notificationRcv:
case e, ok = <-notaryReqRcv:
}
if !ok {
return
}
if background {
// background client (test) switch, no need to send
// any notification, just preventing dead-lock
continue
}
c.routeEvent(e)
}
}()
}
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
}