Merge pull request #2448 from tannewt/packet_buffer

Add PacketBuffer and MTU negotiation support.

3 files changed, 248 insertions, 1 deletions

diff --git a/shared-bindings/_bleio/PacketBuffer.c b/shared-bindings/_bleio/PacketBuffer.c
new file mode 100644
index 000000000..f9f171870
--- /dev/null
+++ b/shared-bindings/_bleio/PacketBuffer.c
@@ -0,0 +1,201 @@
+/*
+ * 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), whichever is smaller. The MTU can change so check `packet_size` 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 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 int 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);
+
+    return MP_OBJ_NEW_SMALL_INT(common_hal_bleio_packet_buffer_readinto(self, bufinfo.buf, bufinfo.len));
+}
+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.
+//|
+// 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);
+    }
+
+    common_hal_bleio_packet_buffer_write(self, data_bufinfo.buf, data_bufinfo.len,
+                                         header_bufinfo.buf, header_bufinfo.len);
+    return mp_const_none;
+}
+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
+//|
+//|     Maximum size of each packet in bytes. This is the minimum of the Characterstic length and
+//|     the negotiated Maximum Transfer Unit (MTU).
+//|
+STATIC mp_obj_t bleio_packet_buffer_get_packet_size(mp_obj_t self_in) {
+    bleio_packet_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
+
+    return mp_obj_new_bool(common_hal_bleio_packet_buffer_get_packet_size(self));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(bleio_packet_buffer_get_packet_size_obj, bleio_packet_buffer_get_packet_size);
+
+const mp_obj_property_t bleio_packet_buffer_packet_size_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&bleio_packet_buffer_get_packet_size_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) },
+
+    { MP_OBJ_NEW_QSTR(MP_QSTR_packet_size),    MP_ROM_PTR(&bleio_packet_buffer_packet_size_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
+};
diff --git a/shared-bindings/_bleio/PacketBuffer.h b/shared-bindings/_bleio/PacketBuffer.h
new file mode 100644
index 000000000..990a2f8bb
--- /dev/null
+++ b/shared-bindings/_bleio/PacketBuffer.h
@@ -0,0 +1,43 @@
+/*
+ * 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.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_PACKETBUFFER_H
+#define MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_PACKETBUFFER_H
+
+#include "common-hal/_bleio/PacketBuffer.h"
+
+extern const mp_obj_type_t bleio_packet_buffer_type;
+
+extern void common_hal_bleio_packet_buffer_construct(
+    bleio_packet_buffer_obj_t *self, bleio_characteristic_obj_t *characteristic,
+    size_t buffer_size);
+void common_hal_bleio_packet_buffer_write(bleio_packet_buffer_obj_t *self, uint8_t *data, size_t len, uint8_t* header, size_t header_len);
+int common_hal_bleio_packet_buffer_readinto(bleio_packet_buffer_obj_t *self, uint8_t *data, size_t len);
+uint16_t common_hal_bleio_packet_buffer_get_packet_size(bleio_packet_buffer_obj_t *self);
+bool common_hal_bleio_packet_buffer_deinited(bleio_packet_buffer_obj_t *self);
+void common_hal_bleio_packet_buffer_deinit(bleio_packet_buffer_obj_t *self);
+
+#endif // MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_PACKETBUFFER_H
diff --git a/shared-bindings/_bleio/__init__.c b/shared-bindings/_bleio/__init__.c
index ba2454da4..5d26862a6 100644
--- a/shared-bindings/_bleio/__init__.c
+++ b/shared-bindings/_bleio/__init__.c
@@ -35,6 +35,7 @@
 #include "shared-bindings/_bleio/CharacteristicBuffer.h"
 #include "shared-bindings/_bleio/Connection.h"
 #include "shared-bindings/_bleio/Descriptor.h"
+#include "shared-bindings/_bleio/PacketBuffer.h"
 #include "shared-bindings/_bleio/ScanEntry.h"
 #include "shared-bindings/_bleio/ScanResults.h"
 #include "shared-bindings/_bleio/Service.h"
@@ -69,6 +70,7 @@
 //|     CharacteristicBuffer
 //|     Connection
 //|     Descriptor
+//|     PacketBuffer
 //|     ScanEntry
 //|     ScanResults
 //|     Service
@@ -140,8 +142,9 @@ STATIC const mp_rom_map_elem_t bleio_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_Characteristic),       MP_ROM_PTR(&bleio_characteristic_type) },
     { MP_ROM_QSTR(MP_QSTR_CharacteristicBuffer), MP_ROM_PTR(&bleio_characteristic_buffer_type) },
     { MP_ROM_QSTR(MP_QSTR_Descriptor),           MP_ROM_PTR(&bleio_descriptor_type) },
+    { MP_ROM_QSTR(MP_QSTR_PacketBuffer),         MP_ROM_PTR(&bleio_packet_buffer_type) },
     { MP_ROM_QSTR(MP_QSTR_ScanEntry),            MP_ROM_PTR(&bleio_scanentry_type) },
-    { MP_ROM_QSTR(MP_QSTR_ScanResults),            MP_ROM_PTR(&bleio_scanresults_type) },
+    { MP_ROM_QSTR(MP_QSTR_ScanResults),          MP_ROM_PTR(&bleio_scanresults_type) },
     { MP_ROM_QSTR(MP_QSTR_Service),              MP_ROM_PTR(&bleio_service_type) },
     { MP_ROM_QSTR(MP_QSTR_UUID),                 MP_ROM_PTR(&bleio_uuid_type) },