Experiment with Bleak changes (#55)

* Introduce driver that works with Bleak, enables to use BLE devices in windows without a need of external BLE dongle.

* Fix issues in auto review.

* Add method description and UT.

* Fix docstring to comply with pep257

* Experiment

* Make test only work in 3.7+

* Fix versions

* One more try

* Kick it

* Kick

* cmon

* Dummm

* yeah yeah

* Add

* Fix version

Co-authored-by: mgr <tomekmgr@gmail.com>

.travis.yml

@@ -1,14 +1,8 @@
 sudo: false
 language: python
-virtualenv:
-  system_site_packages: true
-
-matrix:
-  include:
-    - os: linux
-      python: 2.7
-    - os: linux
-      python: 3.5
+python:
+  - 3.6
+  - 3.8
 
 addons:
   apt:
@@ -21,16 +15,17 @@ addons:
       - libdbus-1-dev
       - libdbus-glib-1-dev
       - libgirepository-1.0-1
+      - libgirepository1.0-dev
 
-      - python-dbus
-      - python-gi
-      - python3-dbus
-      - python3-gi
+      - bluez
 install:
   - wget https://github.com/labapart/gattlib/releases/download/dev/gattlib_dbus_0.2-dev_x86_64.deb
   - sudo dpkg -i gattlib_dbus_0.2-dev_x86_64.deb
-  - pip install codecov codacy-coverage nose-exclude pygatt gatt pexpect bluepy
+  - pip install codecov codacy-coverage nose-exclude pygatt gatt pexpect bluepy bleak packaging dbus-python pygobject
+  - pip install --upgrade attrs
 
+env:
+  - READTHEDOCS=True
 
 script:
   - coverage run --omit="examples/*" --source=. -m nose tests -v --exclude-dir=examples

pylgbst/__init__.py

@@ -37,6 +37,20 @@ def get_connection_bluepy(controller='hci0', hub_mac=None):
     return BluepyConnection(controller).connect(hub_mac)
 
 
+def get_connection_bleak(controller='hci0', hub_mac=None):
+    """
+    Return connection based with Bleak API as an endpoint.
+
+    :param controller: Not used, kept for compatibility with others.
+    :param hub_mac: Optional Lego HUB MAC to connect to.
+    :return: Driver object.
+    """
+    del controller  # to prevent code analysis warning
+    from pylgbst.comms.cbleak import BleakDriver
+
+    return BleakDriver(hub_mac)
+
+
 def get_connection_auto(controller='hci0', hub_mac=None):
     fns = [
         get_connection_bluepy,
@@ -44,6 +58,7 @@ def get_connection_auto(controller='hci0', hub_mac=None):
         get_connection_gatt,
         get_connection_gattool,
         get_connection_gattlib,
+        get_connection_bleak,
     ]
 
     conn = None

pylgbst/comms/cbleak.py

@@ -0,0 +1,204 @@
+import asyncio
+import logging
+import queue
+import threading
+import time
+
+from bleak import BleakClient, discover
+
+from pylgbst.comms import Connection, MOVE_HUB_HW_UUID_CHAR
+
+log = logging.getLogger('comms-bleak')
+
+# Queues to handle request / responses. Acts as a buffer between API and async BLE driver
+resp_queue = queue.Queue()
+req_queue = queue.Queue()
+
+
+class BleakDriver(object):
+    """Driver that provides interface between API and Bleak."""
+
+    def __init__(self, hub_mac=None):
+        """
+        Initialize new object of Bleak Driver class.
+
+        :param hub_mac: Optional Lego HUB MAC to connect to.
+        """
+        self.hub_mac = hub_mac
+        self._handler = None
+        self._abort = False
+        self._connection_thread = None
+        self._processing_thread = None
+
+    def set_notify_handler(self, handler):
+        """
+        Set handler function used to communicate with an API.
+
+        :param handler: Handler function called by driver when received data
+        :return: None
+        """
+        self._handler = handler
+
+    def enable_notifications(self):
+        """
+        Enable notifications, in our cases starts communication threads.
+
+        We cannot do this earlier, because API need to fist set notification handler.
+        :return: None
+        """
+        self._connection_thread = threading.Thread(target=lambda: asyncio.run(self._bleak_thread()))
+        self._connection_thread.daemon = True
+        self._connection_thread.start()
+
+        self._processing_thread = threading.Thread(target=self._processing)
+        self._processing_thread.daemon = True
+        self._processing_thread.start()
+
+    async def _bleak_thread(self):
+        bleak = BleakConnection()
+        await bleak.connect(self.hub_mac)
+        await bleak.set_notify_handler(self._safe_handler)
+        # After connecting, need to send any data or hub will drop the connection,
+        # below command is Advertising name request update
+        await bleak.write_char(MOVE_HUB_HW_UUID_CHAR, bytearray([0x05, 0x00, 0x01, 0x01, 0x05]))
+        while not self._abort:
+            await asyncio.sleep(0.1)
+            if req_queue.qsize() != 0:
+                data = req_queue.get()
+                await bleak.write(data[0], data[1])
+
+    @staticmethod
+    def _safe_handler(handler, data):
+        resp_queue.put((handler, data))
+
+    def _processing(self):
+        while not self._abort:
+            if resp_queue.qsize() != 0:
+                msg = resp_queue.get()
+                self._handler(msg[0], msg[1])
+
+            time.sleep(0.1)
+
+    def write(self, handle, data):
+        """
+        Send data to given handle number.
+
+        :param handle: Handle number that will be translated into characteristic uuid
+        :param data: data to send
+        :raises ConnectionError" When internal threads are not working
+        :return: None
+        """
+        if not self._connection_thread.is_alive() or not self._processing_thread.is_alive():
+            raise ConnectionError('Something went wrong, communication threads not functioning.')
+
+        req_queue.put((handle, data))
+
+    def disconnect(self):
+        """
+        Disconnect and stops communication threads.
+
+        :return: None
+        """
+        self._abort = True
+
+    def is_alive(self):
+        """
+        Indicate whether driver is functioning or not.
+
+        :return: True if driver is functioning; False otherwise.
+        """
+        if self._connection_thread is not None and self._processing_thread is not None:
+            return self._connection_thread.is_alive() and self._processing_thread.is_alive()
+        else:
+            return False
+
+
+class BleakConnection(Connection):
+    """Bleak driver for communicating with BLE device."""
+
+    def __init__(self):
+        """Initialize new instance of BleakConnection class."""
+        Connection.__init__(self)
+        self.loop = asyncio.get_event_loop()
+
+        self._device = None
+        self._client = None
+        logging.getLogger('bleak.backends.dotnet.client').setLevel(logging.getLogger().level)
+
+    async def connect(self, hub_mac=None):
+        """
+        Connect to device.
+
+        :param hub_mac: Optional Lego HUB MAC to connect to.
+        :raises ConnectionError: When cannot connect to given MAC or name matching fails.
+        :return: None
+        """
+        log.info("Discovering devices... Press Green button on lego MoveHub")
+        devices = await discover()
+        log.debug("Devices: %s", devices)
+
+        for dev in devices:
+            log.debug(dev)
+            address = dev.address
+            name = dev.name
+            if self._is_device_matched(address, name, hub_mac):
+                log.info('Device matched')
+                self._device = dev
+                break
+
+        if not self._device:
+            raise ConnectionError('Device not found.')
+
+        self._client = BleakClient(self._device.address, self.loop)
+        status = await self._client.connect()
+        log.debug('Connection status: {status}'.format(status=status))
+
+    async def write(self, handle, data):
+        """
+        Send data to given handle number.
+
+        If handle cannot be found in service description, hardcoded LEGO uuid will be used.
+        :param handle: Handle number that will be translated into characteristic uuid
+        :param data: data to send
+        :return: None
+        """
+        log.debug('Request: {handle} {payload}'.format(handle=handle, payload=[hex(x) for x in data]))
+        desc = self._client.services.get_descriptor(handle)
+        if desc is None:
+            # dedicated handle not found, try to send by using LEGO Move Hub default characteristic
+            await self._client.write_gatt_char(MOVE_HUB_HW_UUID_CHAR, data)
+        else:
+            await self._client.write_gatt_char(desc.characteristic_uuid, data)
+
+    async def write_char(self, characteristic_uuid, data):
+        """
+        Send data to given handle number.
+
+        :param characteristic_uuid: Characteristic uuid used to send data
+        :param data: data to send
+        :return: None
+        """
+        await self._client.write_gatt_char(characteristic_uuid, data)
+
+    async def set_notify_handler(self, handler):
+        """
+        Set notification handler.
+
+        :param handler: Handle function to be called when receive any data.
+        :return: None
+        """
+
+        def c(handle, data):
+            log.debug('Response: {handle} {payload}'.format(handle=handle, payload=[hex(x) for x in data]))
+            handler(handle, data)
+
+        await self._client.start_notify(MOVE_HUB_HW_UUID_CHAR, c)
+
+    def is_alive(self):
+        """
+        To keep compatibility with the driver interface.
+
+        This method does nothing.
+        :return: None.
+        """
+        pass

setup.py

@@ -19,5 +19,6 @@ setup(
         "gattlib": ["gattlib"],
         "pygatt": ["pygatt", "pexpect"],
         "bluepy": ["bluepy"],
+        "bleak": ["bleak"],
     },
 )

tests/test_cbleak.py

@@ -0,0 +1,61 @@
+import sys
+import time
+import unittest
+
+import bleak
+from packaging import version
+
+import pylgbst
+import pylgbst.comms.cbleak as cbleak
+
+bleak.BleakClient = object()
+bleak.discover = object()
+
+last_response = None
+lt37 = version.parse(sys.version.split(' ')[0]) < version.parse("3.7")
+
+
+class BleakDriverTest(unittest.TestCase):
+    def test_driver_creation(self):
+        connection = pylgbst.get_connection_bleak()
+        self.assertIsInstance(connection, cbleak.BleakDriver)
+        self.assertFalse(connection.is_alive(), 'Checking that factory returns not started driver')
+
+    @unittest.skipIf(lt37, "Python version is too low")
+    def test_communication(self):
+        driver = cbleak.BleakDriver()
+
+        async def fake_thread():
+            print('Fake thread initialized')
+            while not driver._abort:
+                time.sleep(0.1)
+                if cbleak.req_queue.qsize() != 0:
+                    print('Received data, sending back')
+                    data = cbleak.req_queue.get()
+                    cbleak.resp_queue.put(data)
+
+        driver._bleak_thread = fake_thread
+        driver.set_notify_handler(BleakDriverTest.validation_handler)
+        driver.enable_notifications()
+
+        time.sleep(0.5)  # time for driver initialization
+        self.assertTrue(driver.is_alive(), 'Checking that driver starts')
+        handle = 0x32
+        data = [0xD, 0xE, 0xA, 0xD, 0xB, 0xE, 0xE, 0xF]
+        driver.write(handle, data)
+        time.sleep(0.5)  # processing time
+        self.assertEqual(handle, last_response[0], 'Verifying response handle')
+        self.assertEqual(data, last_response[1], 'Verifying response data')
+
+        driver.disconnect()
+        time.sleep(0.5)  # processing time
+        self.assertFalse(driver.is_alive())
+
+    @staticmethod
+    def validation_handler(handle, data):
+        global last_response
+        last_response = (handle, data)
+
+
+if __name__ == '__main__':
+    unittest.main()