def get_connection(self, event: GetHttpConnection, *, reuse: bool = True) -> layer.CommandGenerator[None]:
# Do we already have a connection we can re-use?
if reuse:
for connection in self.connections:
# see "tricky multiplexing edge case" in make_http_connection for an explanation
conn_is_pending_or_h2 = (
connection.alpn == b"h2"
or connection in self.waiting_for_establishment
)
h2_to_h1 = self.context.client.alpn == b"h2" and not conn_is_pending_or_h2
connection_suitable = (
event.connection_spec_matches(connection)
and not h2_to_h1
)
if connection_suitable:
if connection in self.waiting_for_establishment:
self.waiting_for_establishment[connection].append(event)
return
elif connection.connected:
stream = self.command_sources.pop(event)
yield from self.event_to_child(stream, GetHttpConnectionCompleted(event, (connection, None)))
return
else:
pass # the connection is at least half-closed already, we want a new one.
can_use_context_connection = (
self.context.server not in self.connections and
self.context.server.connected and
event.connection_spec_matches(self.context.server)
)
context = self.context.fork()
stack = tunnel.LayerStack()
if not can_use_context_connection:
context.server = Server(event.address)
if event.tls:
context.server.sni = event.address[0]
if event.via:
assert event.via.scheme in ("http", "https")
http_proxy = Server(event.via.address)
if event.via.scheme == "https":
http_proxy.alpn_offers = tls.HTTP_ALPNS
http_proxy.sni = event.via.address[0]
stack /= tls.ServerTLSLayer(context, http_proxy)
send_connect = not (self.mode == HTTPMode.upstream and not event.tls)
stack /= _upstream_proxy.HttpUpstreamProxy(context, http_proxy, send_connect)
if event.tls:
stack /= tls.ServerTLSLayer(context)
stack /= HttpClient(context)
self.connections[context.server] = stack[0]
self.waiting_for_establishment[context.server].append(event)
yield from self.event_to_child(stack[0], events.Start())
def handle_connect_upstream(self):
assert self.context.server.via.scheme in ("http", "https")
http_proxy = Server(self.context.server.via.address)
stack = tunnel.LayerStack()
if self.context.server.via.scheme == "https":
http_proxy.sni = self.context.server.via.address[0]
stack /= tls.ServerTLSLayer(self.context, http_proxy)
stack /= _upstream_proxy.HttpUpstreamProxy(self.context, http_proxy, True)
self.child_layer = stack[0]
yield from self.handle_connect_finish()