Initial Store & Forward Implementation (#2917)

This adds store & forward relays into dendrite for p2p.
A few things have changed:
- new relay api serves new http endpoints for s&f federation
- updated outbound federation queueing which will attempt to forward
using s&f if appropriate
- database entries to track s&f relays for other nodes

federationapi/storage/interface.go

@@ -20,11 +20,12 @@ import (
 
 	"github.com/matrix-org/gomatrixserverlib"
 
-	"github.com/matrix-org/dendrite/federationapi/storage/shared"
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/dendrite/federationapi/types"
 )
 
 type Database interface {
+	P2PDatabase
 	gomatrixserverlib.KeyDatabase
 
 	UpdateRoom(ctx context.Context, roomID string, addHosts []types.JoinedHost, removeHosts []string, purgeRoomFirst bool) (joinedHosts []types.JoinedHost, err error)
@@ -34,16 +35,16 @@ type Database interface {
 	// GetJoinedHostsForRooms returns the complete set of servers in the rooms given.
 	GetJoinedHostsForRooms(ctx context.Context, roomIDs []string, excludeSelf, excludeBlacklisted bool) ([]gomatrixserverlib.ServerName, error)
 
-	StoreJSON(ctx context.Context, js string) (*shared.Receipt, error)
+	StoreJSON(ctx context.Context, js string) (*receipt.Receipt, error)
 
-	GetPendingPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (pdus map[*shared.Receipt]*gomatrixserverlib.HeaderedEvent, err error)
-	GetPendingEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (edus map[*shared.Receipt]*gomatrixserverlib.EDU, err error)
+	GetPendingPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (pdus map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent, err error)
+	GetPendingEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (edus map[*receipt.Receipt]*gomatrixserverlib.EDU, err error)
 
-	AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *shared.Receipt) error
-	AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *shared.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error
+	AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, dbReceipt *receipt.Receipt) error
+	AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, dbReceipt *receipt.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error
 
-	CleanPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*shared.Receipt) error
-	CleanEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*shared.Receipt) error
+	CleanPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*receipt.Receipt) error
+	CleanEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*receipt.Receipt) error
 
 	GetPendingPDUServerNames(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
 	GetPendingEDUServerNames(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
@@ -54,6 +55,18 @@ type Database interface {
 	RemoveAllServersFromBlacklist() error
 	IsServerBlacklisted(serverName gomatrixserverlib.ServerName) (bool, error)
 
+	// Adds the server to the list of assumed offline servers.
+	// If the server already exists in the table, nothing happens and returns success.
+	SetServerAssumedOffline(ctx context.Context, serverName gomatrixserverlib.ServerName) error
+	// Removes the server from the list of assumed offline servers.
+	// If the server doesn't exist in the table, nothing happens and returns success.
+	RemoveServerAssumedOffline(ctx context.Context, serverName gomatrixserverlib.ServerName) error
+	// Purges all entries from the assumed offline table.
+	RemoveAllServersAssumedOffline(ctx context.Context) error
+	// Gets whether the provided server is present in the table.
+	// If it is present, returns true. If not, returns false.
+	IsServerAssumedOffline(ctx context.Context, serverName gomatrixserverlib.ServerName) (bool, error)
+
 	AddOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error
 	RenewOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error
 	GetOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string) (*types.OutboundPeek, error)
@@ -74,3 +87,21 @@ type Database interface {
 
 	PurgeRoom(ctx context.Context, roomID string) error
 }
+
+type P2PDatabase interface {
+	// Stores the given list of servers as relay servers for the provided destination server.
+	// Providing duplicates will only lead to a single entry and won't lead to an error.
+	P2PAddRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error
+
+	// Get the list of relay servers associated with the provided destination server.
+	// If no entry exists in the table, an empty list is returned and does not result in an error.
+	P2PGetRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName) ([]gomatrixserverlib.ServerName, error)
+
+	// Deletes any entries for the provided destination server that match the provided relayServers list.
+	// If any of the provided servers don't match an entry, nothing happens and no error is returned.
+	P2PRemoveRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error
+
+	// Deletes all entries for the provided destination server.
+	// If the destination server doesn't exist in the table, nothing happens and no error is returned.
+	P2PRemoveAllRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName) error
+}