invoices: subscribe single invoice

This commit is contained in:
Joost Jager 2018-12-20 18:54:11 +01:00
parent 436dd41c77
commit acb0162443
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GPG Key ID: A61B9D4C393C59C7
2 changed files with 205 additions and 34 deletions

@ -37,13 +37,15 @@ type InvoiceRegistry struct {
cdb *channeldb.DB
clientMtx sync.Mutex
nextClientID uint32
notificationClients map[uint32]*InvoiceSubscription
clientMtx sync.Mutex
nextClientID uint32
notificationClients map[uint32]*InvoiceSubscription
singleNotificationClients map[uint32]*SingleInvoiceSubscription
newSubscriptions chan *InvoiceSubscription
subscriptionCancels chan uint32
invoiceEvents chan *invoiceEvent
newSubscriptions chan *InvoiceSubscription
newSingleSubscriptions chan *SingleInvoiceSubscription
subscriptionCancels chan uint32
invoiceEvents chan *invoiceEvent
// debugInvoices is a map which stores special "debug" invoices which
// should be only created/used when manual tests require an invoice
@ -64,14 +66,16 @@ func NewRegistry(cdb *channeldb.DB,
activeNetParams *chaincfg.Params) *InvoiceRegistry {
return &InvoiceRegistry{
cdb: cdb,
debugInvoices: make(map[lntypes.Hash]*channeldb.Invoice),
notificationClients: make(map[uint32]*InvoiceSubscription),
newSubscriptions: make(chan *InvoiceSubscription),
subscriptionCancels: make(chan uint32),
invoiceEvents: make(chan *invoiceEvent, 100),
activeNetParams: activeNetParams,
quit: make(chan struct{}),
cdb: cdb,
debugInvoices: make(map[lntypes.Hash]*channeldb.Invoice),
notificationClients: make(map[uint32]*InvoiceSubscription),
singleNotificationClients: make(map[uint32]*SingleInvoiceSubscription),
newSubscriptions: make(chan *InvoiceSubscription),
newSingleSubscriptions: make(chan *SingleInvoiceSubscription),
subscriptionCancels: make(chan uint32),
invoiceEvents: make(chan *invoiceEvent, 100),
activeNetParams: activeNetParams,
quit: make(chan struct{}),
}
}
@ -96,6 +100,7 @@ func (i *InvoiceRegistry) Stop() {
// instance where invoices are settled.
type invoiceEvent struct {
state channeldb.ContractState
hash lntypes.Hash
invoice *channeldb.Invoice
}
@ -107,9 +112,9 @@ func (i *InvoiceRegistry) invoiceEventNotifier() {
for {
select {
// A new invoice subscription has just arrived! We'll query for
// any backlog notifications, then add it to the set of
// clients.
// A new invoice subscription for all invoices has just arrived!
// We'll query for any backlog notifications, then add it to the
// set of clients.
case newClient := <-i.newSubscriptions:
// Before we add the client to our set of active
// clients, we'll first attempt to deliver any backlog
@ -128,6 +133,23 @@ func (i *InvoiceRegistry) invoiceEventNotifier() {
// continue.
i.notificationClients[newClient.id] = newClient
// A new single invoice subscription has arrived. We'll query
// for any backlog notifications, then add it to the set of
// clients.
case newClient := <-i.newSingleSubscriptions:
err := i.deliverSingleBacklogEvents(newClient)
if err != nil {
log.Errorf("Unable to deliver backlog invoice "+
"notifications: %v", err)
}
log.Infof("New single invoice subscription "+
"client: id=%v, hash=%v",
newClient.id, newClient.hash,
)
i.singleNotificationClients[newClient.id] = newClient
// A client no longer wishes to receive invoice notifications.
// So we'll remove them from the set of active clients.
case clientID := <-i.subscriptionCancels:
@ -135,11 +157,13 @@ func (i *InvoiceRegistry) invoiceEventNotifier() {
"client=%v", clientID)
delete(i.notificationClients, clientID)
delete(i.singleNotificationClients, clientID)
// A sub-systems has just modified the invoice state, so we'll
// dispatch notifications to all registered clients.
case event := <-i.invoiceEvents:
i.dispatchToClients(event)
i.dispatchToSingleClients(event)
case <-i.quit:
return
@ -147,6 +171,26 @@ func (i *InvoiceRegistry) invoiceEventNotifier() {
}
}
// dispatchToSingleClients passes the supplied event to all notification clients
// that subscribed to all the invoice this event applies to.
func (i *InvoiceRegistry) dispatchToSingleClients(event *invoiceEvent) {
// Dispatch to single invoice subscribers.
for _, client := range i.singleNotificationClients {
if client.hash != event.hash {
continue
}
select {
case client.ntfnQueue.ChanIn() <- &invoiceEvent{
state: event.state,
invoice: event.invoice,
}:
case <-i.quit:
return
}
}
}
// dispatchToClients passes the supplied event to all notification clients that
// subscribed to all invoices. Add and settle indices are used to make sure that
// clients don't receive duplicate or unwanted events.
@ -227,6 +271,7 @@ func (i *InvoiceRegistry) deliverBacklogEvents(client *InvoiceSubscription) erro
if err != nil {
return err
}
settleEvents, err := i.cdb.InvoicesSettledSince(client.settleIndex)
if err != nil {
return err
@ -249,6 +294,7 @@ func (i *InvoiceRegistry) deliverBacklogEvents(client *InvoiceSubscription) erro
return fmt.Errorf("registry shutting down")
}
}
for _, settleEvent := range settleEvents {
// We re-bind the loop variable to ensure we don't hold onto
// the loop reference causing is to point to the same item.
@ -267,6 +313,37 @@ func (i *InvoiceRegistry) deliverBacklogEvents(client *InvoiceSubscription) erro
return nil
}
// deliverSingleBacklogEvents will attempt to query the invoice database to
// retrieve the current invoice state and deliver this to the subscriber. Single
// invoice subscribers will always receive the current state right after
// subscribing. Only in case the invoice does not yet exist, nothing is sent
// yet.
func (i *InvoiceRegistry) deliverSingleBacklogEvents(
client *SingleInvoiceSubscription) error {
invoice, err := i.cdb.LookupInvoice(client.hash)
// It is possible that the invoice does not exist yet, but the client is
// already watching it in anticipation.
if err == channeldb.ErrInvoiceNotFound {
return nil
}
if err != nil {
return err
}
err = client.notify(&invoiceEvent{
hash: client.hash,
invoice: &invoice,
state: invoice.Terms.State,
})
if err != nil {
return err
}
return nil
}
// AddDebugInvoice adds a debug invoice for the specified amount, identified
// by the passed preimage. Once this invoice is added, subsystems within the
// daemon add/forward HTLCs that are able to obtain the proper preimage
@ -300,7 +377,9 @@ func (i *InvoiceRegistry) AddDebugInvoice(amt btcutil.Amount,
// redemption in the case that we're the final destination. We also return the
// addIndex of the newly created invoice which monotonically increases for each
// new invoice added.
func (i *InvoiceRegistry) AddInvoice(invoice *channeldb.Invoice) (uint64, error) {
func (i *InvoiceRegistry) AddInvoice(invoice *channeldb.Invoice,
paymentHash lntypes.Hash) (uint64, error) {
i.Lock()
defer i.Unlock()
@ -315,7 +394,7 @@ func (i *InvoiceRegistry) AddInvoice(invoice *channeldb.Invoice) (uint64, error)
// Now that we've added the invoice, we'll send dispatch a message to
// notify the clients of this new invoice.
i.notifyClients(invoice, channeldb.ContractOpen)
i.notifyClients(paymentHash, invoice, channeldb.ContractOpen)
return addIndex, nil
}
@ -392,19 +471,21 @@ func (i *InvoiceRegistry) SettleInvoice(rHash lntypes.Hash,
log.Infof("Payment received: %v", spew.Sdump(invoice))
i.notifyClients(invoice, channeldb.ContractSettled)
i.notifyClients(rHash, invoice, channeldb.ContractSettled)
return nil
}
// notifyClients notifies all currently registered invoice notification clients
// of a newly added/settled invoice.
func (i *InvoiceRegistry) notifyClients(invoice *channeldb.Invoice,
func (i *InvoiceRegistry) notifyClients(hash lntypes.Hash,
invoice *channeldb.Invoice,
state channeldb.ContractState) {
event := &invoiceEvent{
state: state,
invoice: invoice,
hash: hash,
}
select {
@ -413,13 +494,25 @@ func (i *InvoiceRegistry) notifyClients(invoice *channeldb.Invoice,
}
}
// invoiceSubscriptionKit defines that are common to both all invoice
// subscribers and single invoice subscribers.
type invoiceSubscriptionKit struct {
id uint32
inv *InvoiceRegistry
ntfnQueue *queue.ConcurrentQueue
cancelled uint32 // To be used atomically.
cancelChan chan struct{}
wg sync.WaitGroup
}
// InvoiceSubscription represents an intent to receive updates for newly added
// or settled invoices. For each newly added invoice, a copy of the invoice
// will be sent over the NewInvoices channel. Similarly, for each newly settled
// invoice, a copy of the invoice will be sent over the SettledInvoices
// channel.
type InvoiceSubscription struct {
cancelled uint32 // To be used atomically.
invoiceSubscriptionKit
// NewInvoices is a channel that we'll use to send all newly created
// invoices with an invoice index greater than the specified
@ -443,21 +536,23 @@ type InvoiceSubscription struct {
// greater than this will be dispatched before any new notifications
// are sent out.
settleIndex uint64
}
ntfnQueue *queue.ConcurrentQueue
// SingleInvoiceSubscription represents an intent to receive updates for a
// specific invoice.
type SingleInvoiceSubscription struct {
invoiceSubscriptionKit
id uint32
hash lntypes.Hash
inv *InvoiceRegistry
cancelChan chan struct{}
wg sync.WaitGroup
// Updates is a channel that we'll use to send all invoice events for
// the invoice that is subscribed to.
Updates chan *channeldb.Invoice
}
// Cancel unregisters the InvoiceSubscription, freeing any previously allocated
// resources.
func (i *InvoiceSubscription) Cancel() {
func (i *invoiceSubscriptionKit) Cancel() {
if !atomic.CompareAndSwapUint32(&i.cancelled, 0, 1) {
return
}
@ -473,6 +568,16 @@ func (i *InvoiceSubscription) Cancel() {
i.wg.Wait()
}
func (i *invoiceSubscriptionKit) notify(event *invoiceEvent) error {
select {
case i.ntfnQueue.ChanIn() <- event:
case <-i.inv.quit:
return fmt.Errorf("registry shutting down")
}
return nil
}
// SubscribeNotifications returns an InvoiceSubscription which allows the
// caller to receive async notifications when any invoices are settled or
// added. The invoiceIndex parameter is a streaming "checkpoint". We'll start
@ -484,9 +589,11 @@ func (i *InvoiceRegistry) SubscribeNotifications(addIndex, settleIndex uint64) *
SettledInvoices: make(chan *channeldb.Invoice),
addIndex: addIndex,
settleIndex: settleIndex,
inv: i,
ntfnQueue: queue.NewConcurrentQueue(20),
cancelChan: make(chan struct{}),
invoiceSubscriptionKit: invoiceSubscriptionKit{
inv: i,
ntfnQueue: queue.NewConcurrentQueue(20),
cancelChan: make(chan struct{}),
},
}
client.ntfnQueue.Start()
@ -551,3 +658,67 @@ func (i *InvoiceRegistry) SubscribeNotifications(addIndex, settleIndex uint64) *
return client
}
// SubscribeSingleInvoice returns an SingleInvoiceSubscription which allows the
// caller to receive async notifications for a specific invoice.
func (i *InvoiceRegistry) SubscribeSingleInvoice(
hash lntypes.Hash) *SingleInvoiceSubscription {
client := &SingleInvoiceSubscription{
Updates: make(chan *channeldb.Invoice),
invoiceSubscriptionKit: invoiceSubscriptionKit{
inv: i,
ntfnQueue: queue.NewConcurrentQueue(20),
cancelChan: make(chan struct{}),
},
hash: hash,
}
client.ntfnQueue.Start()
i.clientMtx.Lock()
client.id = i.nextClientID
i.nextClientID++
i.clientMtx.Unlock()
// Before we register this new invoice subscription, we'll launch a new
// goroutine that will proxy all notifications appended to the end of
// the concurrent queue to the two client-side channels the caller will
// feed off of.
i.wg.Add(1)
go func() {
defer i.wg.Done()
for {
select {
// A new invoice event has been sent by the
// invoiceRegistry. We will dispatch the event to the
// client.
case ntfn := <-client.ntfnQueue.ChanOut():
invoiceEvent := ntfn.(*invoiceEvent)
select {
case client.Updates <- invoiceEvent.invoice:
case <-client.cancelChan:
return
case <-i.quit:
return
}
case <-client.cancelChan:
return
case <-i.quit:
return
}
}
}()
select {
case i.newSingleSubscriptions <- client:
case <-i.quit:
}
return client
}

@ -3320,7 +3320,7 @@ func (r *rpcServer) AddInvoice(ctx context.Context,
)
// With all sanity checks passed, write the invoice to the database.
addIndex, err := r.server.invoices.AddInvoice(newInvoice)
addIndex, err := r.server.invoices.AddInvoice(newInvoice, rHash)
if err != nil {
return nil, err
}