circuitpython/shared-bindings/_bleio/PacketBuffer.c
2020-05-04 23:05:47 -04:00

257 lines
11 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019 Scott Shawcroft for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "py/mperrno.h"
#include "py/ioctl.h"
#include "py/objproperty.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "shared-bindings/_bleio/__init__.h"
#include "shared-bindings/_bleio/PacketBuffer.h"
#include "shared-bindings/_bleio/UUID.h"
#include "shared-bindings/util.h"
//| .. currentmodule:: _bleio
//|
//| :class:`PacketBuffer` -- Packet-oriented characteristic usage.
//| =====================================================================
//|
//| Accumulates a Characteristic's incoming packets in a FIFO buffer and facilitates packet aware
//| outgoing writes. A packet's size is either the characteristic length or the maximum transmission
//| unit (MTU) minus overhead, whichever is smaller. The MTU can change so check `incoming_packet_length`
//| and `outgoing_packet_length` before creating a buffer to store data.
//|
//| When we're the server, we ignore all connections besides the first to subscribe to
//| notifications.
//|
//| .. class:: PacketBuffer(characteristic, *, buffer_size)
//|
//| Monitor the given Characteristic. Each time a new value is written to the Characteristic
//| add the newly-written packet of bytes to a FIFO buffer.
//|
//| :param Characteristic characteristic: The Characteristic to monitor.
//| It may be a local Characteristic provided by a Peripheral Service, or a remote Characteristic
//| in a remote Service that a Central has connected to.
//| :param int buffer_size: Size of ring buffer (in packets of the Characteristic's maximum
//| length) that stores incoming packets coming from the peer.
//|
STATIC mp_obj_t bleio_packet_buffer_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_characteristic, ARG_buffer_size };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_characteristic, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_buffer_size, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
const mp_obj_t characteristic = args[ARG_characteristic].u_obj;
const mp_int_t buffer_size = args[ARG_buffer_size].u_int;
if (buffer_size < 1) {
mp_raise_ValueError_varg(translate("%q must be >= 1"), MP_QSTR_buffer_size);
}
if (!MP_OBJ_IS_TYPE(characteristic, &bleio_characteristic_type)) {
mp_raise_TypeError(translate("Expected a Characteristic"));
}
bleio_packet_buffer_obj_t *self = m_new_obj(bleio_packet_buffer_obj_t);
self->base.type = &bleio_packet_buffer_type;
common_hal_bleio_packet_buffer_construct(self, MP_OBJ_TO_PTR(characteristic), buffer_size);
return MP_OBJ_FROM_PTR(self);
}
STATIC void check_for_deinit(bleio_packet_buffer_obj_t *self) {
if (common_hal_bleio_packet_buffer_deinited(self)) {
raise_deinited_error();
}
}
//| .. method:: readinto(buf)
//|
//| Reads a single BLE packet into the ``buf``. Raises an exception if the next packet is longer
//| than the given buffer. Use `packet_size` to read the maximum length of a single packet.
//|
//| :return: number of bytes read and stored into ``buf``
//| :rtype: int
//|
STATIC mp_obj_t bleio_packet_buffer_readinto(mp_obj_t self_in, mp_obj_t buffer_obj) {
bleio_packet_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(buffer_obj, &bufinfo, MP_BUFFER_WRITE);
mp_int_t size = common_hal_bleio_packet_buffer_readinto(self, bufinfo.buf, bufinfo.len);
if (size < 0) {
mp_raise_ValueError_varg(translate("Buffer too short by %d bytes"), size * -1);
}
return MP_OBJ_NEW_SMALL_INT(size);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(bleio_packet_buffer_readinto_obj, bleio_packet_buffer_readinto);
//| .. method:: write(data, *, header=None)
//|
//| Writes all bytes from data into the same outgoing packet. The bytes from header are included
//| before data when the pending packet is currently empty.
//|
//| This does not block until the data is sent. It only blocks until the data is pending.
//|
//| :return: number of bytes written. May include header bytes when packet is empty.
//| :rtype: int
//|
// TODO: Add a kwarg `merge=False` to dictate whether subsequent writes are merged into a pending
// one.
STATIC mp_obj_t bleio_packet_buffer_write(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_data, ARG_header };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_header, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
bleio_packet_buffer_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_for_deinit(self);
mp_buffer_info_t data_bufinfo;
mp_get_buffer_raise(args[ARG_data].u_obj, &data_bufinfo, MP_BUFFER_READ);
mp_buffer_info_t header_bufinfo;
header_bufinfo.len = 0;
if (args[ARG_header].u_obj != MP_OBJ_NULL) {
mp_get_buffer_raise(args[ARG_header].u_obj, &header_bufinfo, MP_BUFFER_READ);
}
mp_int_t num_bytes_written = common_hal_bleio_packet_buffer_write(
self, data_bufinfo.buf, data_bufinfo.len, header_bufinfo.buf, header_bufinfo.len);
if (num_bytes_written < 0) {
// TODO: Raise an error if not connected. Right now the not-connected error
// is unreliable, because common_hal_bleio_packet_buffer_write()
// checks for conn_handle being set, but setting that
// can be delayed because conn_handle is discovered by spying on
// gatts write events, which may not have been sent yet.
//
// IDEAL:
// mp_raise_bleio_ConnectionError(translate("Not connected"));
// TEMPORARY:
num_bytes_written = 0;
}
return MP_OBJ_NEW_SMALL_INT(num_bytes_written);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(bleio_packet_buffer_write_obj, 1, bleio_packet_buffer_write);
//| .. method:: deinit()
//|
//| Disable permanently.
//|
STATIC mp_obj_t bleio_packet_buffer_deinit(mp_obj_t self_in) {
bleio_packet_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
common_hal_bleio_packet_buffer_deinit(self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(bleio_packet_buffer_deinit_obj, bleio_packet_buffer_deinit);
//| .. attribute:: packet_size
//|
//| `packet_size` is the same as `incoming_packet_length`.
//| The name `packet_size` is deprecated and
//| will be removed in CircuitPython 6.0.0.
//|
//| .. attribute:: incoming_packet_length
//|
//| Maximum length in bytes of a packet we are reading.
//|
STATIC mp_obj_t bleio_packet_buffer_get_incoming_packet_length(mp_obj_t self_in) {
bleio_packet_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_int_t size = common_hal_bleio_packet_buffer_get_incoming_packet_length(self);
if (size < 0) {
mp_raise_ValueError(translate("No connection: length cannot be determined"));
}
return MP_OBJ_NEW_SMALL_INT(size);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(bleio_packet_buffer_get_incoming_packet_length_obj, bleio_packet_buffer_get_incoming_packet_length);
const mp_obj_property_t bleio_packet_buffer_incoming_packet_length_obj = {
.base.type = &mp_type_property,
.proxy = { (mp_obj_t)&bleio_packet_buffer_get_incoming_packet_length_obj,
(mp_obj_t)&mp_const_none_obj,
(mp_obj_t)&mp_const_none_obj },
};
//| .. attribute:: outgoing_packet_length
//|
//| Maximum length in bytes of a packet we are writing.
//|
STATIC mp_obj_t bleio_packet_buffer_get_outgoing_packet_length(mp_obj_t self_in) {
bleio_packet_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_int_t size = common_hal_bleio_packet_buffer_get_outgoing_packet_length(self);
if (size < 0) {
mp_raise_ValueError(translate("No connection: length cannot be determined"));
}
return MP_OBJ_NEW_SMALL_INT(size);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(bleio_packet_buffer_get_outgoing_packet_length_obj, bleio_packet_buffer_get_outgoing_packet_length);
const mp_obj_property_t bleio_packet_buffer_outgoing_packet_length_obj = {
.base.type = &mp_type_property,
.proxy = { (mp_obj_t)&bleio_packet_buffer_get_outgoing_packet_length_obj,
(mp_obj_t)&mp_const_none_obj,
(mp_obj_t)&mp_const_none_obj },
};
STATIC const mp_rom_map_elem_t bleio_packet_buffer_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&bleio_packet_buffer_deinit_obj) },
// Standard stream methods.
{ MP_OBJ_NEW_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&bleio_packet_buffer_readinto_obj) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_write), MP_ROM_PTR(&bleio_packet_buffer_write_obj) },
// .packet_size is now an alias for .incoming_packet_length
// TODO: Remove in 6.0.0.
{ MP_OBJ_NEW_QSTR(MP_QSTR_packet_size), MP_ROM_PTR(&bleio_packet_buffer_incoming_packet_length_obj) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_incoming_packet_length), MP_ROM_PTR(&bleio_packet_buffer_incoming_packet_length_obj) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_outgoing_packet_length), MP_ROM_PTR(&bleio_packet_buffer_outgoing_packet_length_obj) },
};
STATIC MP_DEFINE_CONST_DICT(bleio_packet_buffer_locals_dict, bleio_packet_buffer_locals_dict_table);
const mp_obj_type_t bleio_packet_buffer_type = {
{ &mp_type_type },
.name = MP_QSTR_PacketBuffer,
.make_new = bleio_packet_buffer_make_new,
.locals_dict = (mp_obj_dict_t*)&bleio_packet_buffer_locals_dict
};