Add bootstrap RPC methods

This is the new way for initializing RPC connections. It replaces the
deprecated restore functionality

capnp/helpers/helpers.pxd

@@ -30,6 +30,7 @@ cdef extern from "capnp/helpers/rpcHelper.h":
     Capability.Client restoreHelper(RpcSystem&, MessageReader&)
     Capability.Client restoreHelper(RpcSystem&, AnyPointer.Reader&)
     Capability.Client restoreHelper(RpcSystem&, AnyPointer.Builder&)
+    Capability.Client bootstrapHelper(RpcSystem&)
     RpcSystem makeRpcClientWithRestorer(TwoPartyVatNetwork&, PyRestorer&)
     PyPromise connectServer(TaskSet &, PyRestorer &, AsyncIoContext *, StringPtr)
 

capnp/helpers/rpcHelper.h

@@ -73,6 +73,13 @@ capnp::Capability::Client restoreHelper(capnp::RpcSystem<capnp::rpc::twoparty::S
     return client.restore(hostId, objectId);
 }
 
+capnp::Capability::Client bootstrapHelper(capnp::RpcSystem<capnp::rpc::twoparty::SturdyRefHostId>& client) {
+    capnp::MallocMessageBuilder hostIdMessage(8);
+    auto hostId = hostIdMessage.initRoot<capnp::rpc::twoparty::SturdyRefHostId>();
+    hostId.setSide(capnp::rpc::twoparty::Side::SERVER);
+    return client.bootstrap(hostId);
+}
+
 template <typename SturdyRefHostId, typename ProvisionId,
           typename RecipientId, typename ThirdPartyCapId, typename JoinAnswer>
 capnp::RpcSystem<SturdyRefHostId> makeRpcClientWithRestorer(

capnp/includes/capnp_cpp.pxd

@@ -345,6 +345,7 @@ cdef extern from "capnp/rpc-twoparty.h" namespace " ::capnp":
         VoidPromise onDisconnect()
         VoidPromise onDrained()
     RpcSystem makeRpcServer(TwoPartyVatNetwork&, PyRestorer&)
+    RpcSystem makeRpcServerBootstrap"makeRpcServer"(TwoPartyVatNetwork&, Capability.Client)
     RpcSystem makeRpcClient(TwoPartyVatNetwork&)
 
 cdef extern from "capnp/dynamic.h" namespace " ::capnp":

capnp/lib/capnp.pxd

@@ -1,6 +1,6 @@
 from capnp.includes cimport capnp_cpp as capnp
 from capnp.includes cimport schema_cpp
-from capnp.includes.capnp_cpp cimport Schema as C_Schema, StructSchema as C_StructSchema, InterfaceSchema as C_InterfaceSchema, EnumSchema as C_EnumSchema, ListSchema as C_ListSchema, DynamicStruct as C_DynamicStruct, DynamicValue as C_DynamicValue, Type as C_Type, DynamicList as C_DynamicList, SchemaParser as C_SchemaParser, ParsedSchema as C_ParsedSchema, VOID, ArrayPtr, StringPtr, String, StringTree, DynamicOrphan as C_DynamicOrphan, AnyPointer as C_DynamicObject, DynamicCapability as C_DynamicCapability, Request, Response, RemotePromise, PyPromise, VoidPromise, CallContext, PyRestorer, RpcSystem, makeRpcServer, makeRpcClient, Capability as C_Capability, TwoPartyVatNetwork as C_TwoPartyVatNetwork, Side, AsyncIoStream, Own, makeTwoPartyVatNetwork, PromiseFulfillerPair as C_PromiseFulfillerPair, copyPromiseFulfillerPair, newPromiseAndFulfiller, PyArray, DynamicStruct_Builder
+from capnp.includes.capnp_cpp cimport Schema as C_Schema, StructSchema as C_StructSchema, InterfaceSchema as C_InterfaceSchema, EnumSchema as C_EnumSchema, ListSchema as C_ListSchema, DynamicStruct as C_DynamicStruct, DynamicValue as C_DynamicValue, Type as C_Type, DynamicList as C_DynamicList, SchemaParser as C_SchemaParser, ParsedSchema as C_ParsedSchema, VOID, ArrayPtr, StringPtr, String, StringTree, DynamicOrphan as C_DynamicOrphan, AnyPointer as C_DynamicObject, DynamicCapability as C_DynamicCapability, Request, Response, RemotePromise, PyPromise, VoidPromise, CallContext, PyRestorer, RpcSystem, makeRpcServer, makeRpcServerBootstrap, makeRpcClient, Capability as C_Capability, TwoPartyVatNetwork as C_TwoPartyVatNetwork, Side, AsyncIoStream, Own, makeTwoPartyVatNetwork, PromiseFulfillerPair as C_PromiseFulfillerPair, copyPromiseFulfillerPair, newPromiseAndFulfiller, PyArray, DynamicStruct_Builder
 from capnp.includes.schema_cpp cimport Node as C_Node, EnumNode as C_EnumNode
 from capnp.includes.types cimport *
 from capnp.helpers.non_circular cimport reraise_kj_exception

capnp/lib/capnp.pyx

@@ -2253,6 +2253,9 @@ cdef class TwoPartyClient:
 
         return self.restore(ref)
 
+    cpdef bootstrap(self) except +reraise_kj_exception:
+        return _CapabilityClient()._init(helpers.bootstrapHelper(deref(self.thisptr)), self)
+
     cpdef on_disconnect(self) except +reraise_kj_exception:
         return _VoidPromise()._init(deref(self._network.thisptr).onDisconnect())
 
@@ -2263,12 +2266,18 @@ cdef class TwoPartyServer:
     cdef public _Restorer _restorer
     cdef public _AsyncIoStream _stream
     cdef object _port
-    cdef public object port_promise
+    cdef public object port_promise, _bootstrap
     cdef capnp.TaskSet * _task_set
     cdef capnp.ErrorHandler _error_handler
 
-    def __init__(self, socket, restorer, server_socket=None):
-        self._restorer = _convert_restorer(restorer)
+    def __init__(self, socket, restorer=None, server_socket=None, bootstrap=None):
+        if not restorer and not bootstrap:
+            raise KjException("You must provide either a bootstrap interface or a restorer (deperecated) to a server constructor.")
+
+        cdef _InterfaceSchema schema
+        self._restorer = None
+        self._bootstrap = None
+
         if isinstance(socket, basestring):
             self._connect(socket)
         else:
@@ -2277,11 +2286,19 @@ cdef class TwoPartyServer:
             self._server_socket = server_socket
             self._port = 0
             self._network = _TwoPartyVatNetwork()._init(self._stream, capnp.SERVER)
+
+            if bootstrap:
+                self._bootstrap = bootstrap
+                schema = bootstrap.schema
+                self.thisptr = new RpcSystem(makeRpcServerBootstrap(deref(self._network.thisptr), helpers.server_to_client(schema.thisptr, <PyObject *>bootstrap)))
+            elif restorer:
+                self._restorer = _convert_restorer(restorer)
                 self.thisptr = new RpcSystem(makeRpcServer(deref(self._network.thisptr), deref(self._restorer.thisptr)))
 
             Py_INCREF(self._orig_stream)
             Py_INCREF(self._stream)
             Py_INCREF(self._restorer)
+            Py_INCREF(self._bootstrap)
             Py_INCREF(self._network)
             self._disconnect_promise = self.on_disconnect().then(self._decref)
 
@@ -2292,6 +2309,7 @@ cdef class TwoPartyServer:
         self.port_promise = Promise()._init(helpers.connectServer(deref(self._task_set), deref(self._restorer.thisptr), loop.thisptr, temp_string))
 
     def _decref(self):
+        Py_DECREF(self._bootstrap)
         Py_DECREF(self._restorer)
         Py_DECREF(self._orig_stream)
         Py_DECREF(self._stream)
@@ -2318,8 +2336,6 @@ cdef class TwoPartyServer:
             else:
                 return self._port
 
-    # TODO: add restore functionality here?
-
 cdef class _AsyncIoStream:
     cdef Own[AsyncIoStream] thisptr
 

test/test_rpc.py

@@ -86,3 +86,17 @@ def test_ez_rpc():
 
     with pytest.raises(capnp.KjException):
         response = remote.wait()
+
+def test_simple_rpc_bootstrap():
+    read, write = socket.socketpair(socket.AF_UNIX)
+
+    server = capnp.TwoPartyServer(write, bootstrap=Server(100))
+    client = capnp.TwoPartyClient(read)
+
+    cap = client.bootstrap()
+    cap = cap.cast_as(test_capability_capnp.TestInterface)
+
+    remote = cap.foo(i=5)
+    response = remote.wait()
+
+    assert response.x == '125'