Implement GATT client included service discovery

This commit is contained in:
Josh Wu
2023-05-05 17:48:10 +08:00
parent f9f694dfcf
commit e9bf5757c4

View File

@@ -63,6 +63,7 @@ from .gatt import (
GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
GATT_REQUEST_TIMEOUT,
GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
GATT_INCLUDE_ATTRIBUTE_TYPE,
Characteristic,
ClientCharacteristicConfigurationBits,
)
@@ -109,6 +110,7 @@ class AttributeProxy(EventEmitter):
class ServiceProxy(AttributeProxy):
uuid: UUID
characteristics: List[CharacteristicProxy]
included_services: List[ServiceProxy]
@staticmethod
def from_client(service_class, client, service_uuid):
@@ -502,12 +504,69 @@ class Client:
return services
async def discover_included_services(self, _service):
async def discover_included_services(
self, service: ServiceProxy
) -> List[ServiceProxy]:
'''
See Vol 3, Part G - 4.5.1 Find Included Services
'''
# TODO
return []
starting_handle = service.handle
ending_handle = service.end_group_handle
included_services: List[ServiceProxy] = []
while starting_handle <= ending_handle:
response = await self.send_request(
ATT_Read_By_Type_Request(
starting_handle=starting_handle,
ending_handle=ending_handle,
attribute_type=GATT_INCLUDE_ATTRIBUTE_TYPE,
)
)
if response is None:
# TODO raise appropriate exception
return []
# Check if we reached the end of the iteration
if response.op_code == ATT_ERROR_RESPONSE:
if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
# Unexpected end
logger.warning(
'!!! unexpected error while discovering included services: '
f'{HCI_Constant.error_name(response.error_code)}'
)
raise ATT_Error(
error_code=response.error_code,
message='Unexpected error while discovering included services',
)
break
# Stop if for some reason the list was empty
if not response.attributes:
break
# Process all included services returned in this iteration
for attribute_handle, attribute_value in response.attributes:
if attribute_handle < starting_handle:
# Something's not right
logger.warning(f'bogus handle value: {attribute_handle}')
return []
group_starting_handle, group_ending_handle = struct.unpack_from(
'<HH', attribute_value
)
service_uuid = UUID.from_bytes(attribute_value[4:])
included_service = ServiceProxy(
self, group_starting_handle, group_ending_handle, service_uuid, True
)
included_services.append(included_service)
# Move on to the next included services
starting_handle = response.attributes[-1][0] + 1
service.included_services = included_services
return included_services
async def discover_characteristics(
self, uuids, service: Optional[ServiceProxy]