Connecting via BleakClient with address does an additional discovery.

• bleak version: latest
• Python version: 3.8
• Operating System: macOS
• BlueZ version (bluetoothctl -v) in case of Linux:

Description

I noticed it was taking about 5 seconds to discover devices and then connect to a discovered device (another 5 seconds)… After looking at the code it appears that the client implementation does a second discovery which is painfully slow. Is there any way we can just pass in a populated device or just connect to the uuid directly instead of rediscovering?

https://github.com/hbldh/bleak/blob/08f4fc4cfb9b8c334b31d1e0ee76b6088684ec44/bleak/backends/corebluetooth/client.py#L63

What I Did

async def discoverDevice() -> BLEDevice:
    devices = await discover()
    for d in devices:
        name = d.details.name()
        if name is not None and "TEST" in name:
            return d

    return None


async def run(loop):
    device = await discoverDevice()
    if device is None:
        return int(-1)

    # this does another discovery..
    async with BleakClient(device.address, loop=loop) as client:

loop = asyncio.get_event_loop()
loop.run_until_complete(run(loop))

[dhalbert]

A discover has to have been called before maing any connect, that is why it is in connect to ensure that the native OS backend actually has the BLE device in its’ caches.

I encountered the same thing just today. As @niemyjski mentioned, if BleakClient() alternatively took a device instead of an address, it could assume the device had been recently discovered. The constructor could take either, and do a discover() only if an address were passed.

[hbldh]

This is fixed in release 0.8.0. Closing.