Merge 3b508c1 into fe0a7b6

discovery/gossiper.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/davecgh/go-spew/spew"
 	"github.com/go-errors/errors"
+	"github.com/lightningnetwork/lnd/autopilot"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnwallet"
@@ -107,12 +108,12 @@ type Config struct {
 }
 
 // AuthenticatedGossiper is a subsystem which is responsible for receiving
-// announcements validate them and apply the changes to router, syncing
-// lightning network with newly connected nodes, broadcasting announcements
+// announcements, validating them and applying the changes to router, syncing
+// the lightning network with newly connected nodes, broadcasting announcements
 // after validation, negotiating the channel announcement proofs exchange and
 // handling the premature announcements. All outgoing announcements are
 // expected to be properly signed as dictated in BOLT#7, additionally, all
-// incoming message are expected to be well formed and signed. Invalid messages
+// incoming messages are expected to be well formed and signed. Invalid messages
 // will be rejected by this struct.
 type AuthenticatedGossiper struct {
 	// Parameters which are needed to properly handle the start and stop of
@@ -319,6 +320,76 @@ func (d *AuthenticatedGossiper) ProcessLocalAnnouncement(msg lnwire.Message,
 	return nMsg.err
 }
 
+// ChannelUpdateID is a unique identifier for ChannelUpdate messages, as
+// channel updates can be identified by the (ShortChannelID, Flags) tuple
+type ChannelUpdateID struct {
+	// ShortChannelID represents the set of data which is needed to retrieve all
+	// necessary data to validate the channel existence.
+	channelID lnwire.ShortChannelID
+
+	// Flags least-significant bit must be set to 0 if the creating node
+	// corresponds to the first node in the previously sent channel
+	// announcement and 1 otherwise.
+	Flags uint16
+}
+
+// deDupedAnnouncements de-duplicates announcements that have been
+// added to the batch. Internally, announcements are stored in three maps
+// (one each for channel announcements, channel updates, and node
+// announcements). These maps keep track of unique announcements and
+// ensure no announcements are duplicated
+// TODO(flaurida): remove announcementBatch in networkHandler after replacing it
+type deDupedAnnouncements struct {
+	// channel announcements are identified by the short channel id field
+	channelAnnouncements map[lnwire.ShortChannelID]lnwire.Message
+
+	// channel updates are identified by the channel update id field
+	channelUpdates map[ChannelUpdateID]lnwire.Message
+
+	// node announcements are identified by node id field
+	nodeAnnouncements map[autopilot.NodeID]lnwire.Message
+}
+
+// Reset operates on deDupedAnnouncements to reset storage of announcements
+func (d *deDupedAnnouncements) Reset() {
+	// storage of each type of announcement (channel anouncements, channel
+	// updates, node announcements) is set to an empty map where the
+	// approprate key points to the corresponding lnwire.Message
+	d.channelAnnouncements = make(map[lnwire.ShortChannelID]lnwire.Message)
+	d.channelUpdates = make(map[ChannelUpdateID]lnwire.Message)
+	d.nodeAnnouncements = make(map[autopilot.NodeID]lnwire.Message)
+}
+
+// Batch returns the set of de-duplicated announcements to be sent out
+// during the next announcement epoch, in the order of channel announcements,
+// channel updates, and node announcements
+func (d *deDupedAnnouncements) Batch() []lnwire.Message {
+	// get the total number of announcements
+	numAnnouncements := len(d.channelAnnouncements) + len(d.channelUpdates) + len(d.nodeAnnouncements)
+
+	// create an empty array of lnwire.Messages with a length equal to
+	// the total number of announcements
+	announcements := make([]lnwire.Message, 0, numAnnouncements)
+
+	// add the channel announcements to the array first
+	for _, message := range d.channelAnnouncements {
+		announcements = append(announcements, message)
+	}
+
+	// then the channel updates
+	for _, message := range d.channelUpdates {
+		announcements = append(announcements, message)
+	}
+
+	// then the node announcements
+	for _, message := range d.nodeAnnouncements {
+		announcements = append(announcements, message)
+	}
+
+	// return the array of lnwire.messages
+	return announcements
+}
+
 // networkHandler is the primary goroutine that drives this service. The roles
 // of this goroutine includes answering queries related to the state of the
 // network, syncing up newly connected peers, and also periodically

lnwire/short_channel_id.go

@@ -1,6 +1,6 @@
 package lnwire
 
-// ShortChannelID represent the set of data which is needed to retrieve all
+// ShortChannelID represents the set of data which is needed to retrieve all
 // necessary data to validate the channel existence.
 type ShortChannelID struct {
 	// BlockHeight is the height of the block where funding transaction