py/stream: Switch stream close operation from method to ioctl.

This patch moves the implementation of stream closure from a dedicated
method to the ioctl of the stream protocol, for each type that implements
closing.  The benefits of this are:

1. Rounds out the stream ioctl function, which already includes flush,
   seek and poll (among other things).

2. Makes calling mp_stream_close() on an object slightly more efficient
   because it now no longer needs to lookup the close method and call it,
   rather it just delegates straight to the ioctl function (if it exists).

3. Reduces code size and allows future types that implement the stream
   protocol to be smaller because they don't need a dedicated close method.

Code size reduction is around 200 bytes smaller for x86 archs and around
30 bytes smaller for the bare-metal archs.

1 files changed, 6 insertions, 9 deletions

diff --git a/extmod/modwebsocket.c b/extmod/modwebsocket.c
index a651164b2..5a826ec64 100644
--- a/extmod/modwebsocket.c
+++ b/extmod/modwebsocket.c
@@ -256,6 +256,11 @@ STATIC mp_uint_t websocket_write(mp_obj_t self_in, const void *buf, mp_uint_t si
 STATIC mp_uint_t websocket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *errcode) {
     mp_obj_websocket_t *self = MP_OBJ_TO_PTR(self_in);
     switch (request) {
+        case MP_STREAM_CLOSE:
+            // TODO: Send close signaling to the other side, otherwise it's
+            // abrupt close (connection abort).
+            mp_stream_close(self->sock);
+            return 0;
         case MP_STREAM_GET_DATA_OPTS:
             return self->ws_flags & FRAME_OPCODE_MASK;
         case MP_STREAM_SET_DATA_OPTS: {
@@ -269,21 +274,13 @@ STATIC mp_uint_t websocket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t
     }
 }
 
-STATIC mp_obj_t websocket_close(mp_obj_t self_in) {
-    mp_obj_websocket_t *self = MP_OBJ_TO_PTR(self_in);
-    // TODO: Send close signaling to the other side, otherwise it's
-    // abrupt close (connection abort).
-    return mp_stream_close(self->sock);
-}
-STATIC MP_DEFINE_CONST_FUN_OBJ_1(websocket_close_obj, websocket_close);
-
 STATIC const mp_rom_map_elem_t websocket_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
     { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
     { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
     { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
     { MP_ROM_QSTR(MP_QSTR_ioctl), MP_ROM_PTR(&mp_stream_ioctl_obj) },
-    { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&websocket_close_obj) },
+    { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&mp_stream_close_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(websocket_locals_dict, websocket_locals_dict_table);