diff options
Diffstat (limited to 'src/bus.py')
| -rw-r--r-- | src/bus.py | 132 |
1 files changed, 112 insertions, 20 deletions
@@ -156,32 +156,96 @@ class Bus: raise self.__oserror(e) + def write_timed(self, message : str, timeout : float, clock_id : int = None): + ''' + Broadcast a message a bus + + @param message:str The message to write, may not be longer than 2047 bytes + after UTF-8 encoding + @param timeout:float The time the function shall fail with `os.errno.EAGAIN`, + if it has not already completed + @param clock_id:int? The clock `timeout` is measured in, it must be a + predictable clock, if `None`, `timeout` is measured in + relative time instead of absolute time + ''' + from native_bus import bus_write_timed_wrapped + if clock_id is None: + import time + clock_id = time.CLOCK_MONOTONIC_RAW + timeout += timeout.clock_gettime(clock_id) + (r, e) = bus_write_timed_wrapped(self.bus, message, timeout, clock_id) + if r == -1: + raise self.__oserror(e) + + def read(self, callback : callable, user_data = None): ''' Listen (in a loop, forever) for new message on a bus - @param callback Function to call when a message is received, the - input parameters will be the read message and - `user_data` from the function's [`Bus.read`] parameter - with the same name. The message must have been parsed - or copied when `callback` returns as it may be over - overridden after that time. `callback` should - return either of the the values: - 0: stop listening - 1: continue listening - -1: an error has occurred - However, the function [`Bus.read`] will invoke - `callback` with `message` set to `None` one time - directly after it has started listening on the bus. - This is to the the program now it can safely continue - with any action that requires that the programs is - listening on the bus. - NB! The received message will not be decoded from UTF-8 - @param user_data See description of `callback` + @param callback:(message:str?, user_data:¿U?=user_data)→int + Function to call when a message is received, the + input parameters will be the read message and + `user_data` from the function's [`Bus.read`] parameter + with the same name. The message must have been parsed + or copied when `callback` returns as it may be over + overridden after that time. `callback` should + return either of the the values: + 0: stop listening + 1: continue listening + -1: an error has occurred + However, the function [`Bus.read`] will invoke + `callback` with `message` set to `None` one time + directly after it has started listening on the bus. + This is to the the program now it can safely continue + with any action that requires that the programs is + listening on the bus. + NB! The received message will not be decoded from UTF-8 + @param user_data:¿U? See description of `callback` ''' from native_bus import bus_read_wrapped - if bus_read_wrapped(self.bus, callback, user_data) == -1: - raise self.__oserror() + (r, e) = bus_read_wrapped(self.bus, callback, user_data) + if r == -1: + raise self.__oserror(e) + + + def read_timed(self, callback : callable, timeout : float, clock_id : int = None, user_data = None): + ''' + Listen (in a loop, forever) for new message on a bus + + @param callback:(message:str?, user_data:¿U?=user_data)→int + Function to call when a message is received, the + input parameters will be the read message and + `user_data` from the function's [`Bus.read`] parameter + with the same name. The message must have been parsed + or copied when `callback` returns as it may be over + overridden after that time. `callback` should + return either of the the values: + 0: stop listening + 1: continue listening + -1: an error has occurred + However, the function [`Bus.read`] will invoke + `callback` with `message` set to `None` one time + directly after it has started listening on the bus. + This is to the the program now it can safely continue + with any action that requires that the programs is + listening on the bus. + NB! The received message will not be decoded from UTF-8 + @param timeout:float The time the function shall fail with `os.errno.EAGAIN`, + if it has not already completed, note that the callback + function may or may not have been called + @param clock_id:int? The clock `timeout` is measured in, it must be a + predictable clock, if `None`, `timeout` is measured in + relative time instead of absolute time + @param user_data:¿U? See description of `callback` + ''' + from native_bus import bus_read_timed_wrapped + if clock_id is None: + import time + clock_id = time.CLOCK_MONOTONIC_RAW + timeout += timeout.clock_gettime(clock_id) + (r, e) = bus_read_timed_wrapped(self.bus, callback, user_data, timeout, clock_id) + if r == -1: + raise self.__oserror(e) def poll_start(self): @@ -232,6 +296,34 @@ class Bus: return message + def poll_timed(self, timeout : float, clock_id : int = None) -> bytes: + ''' + Wait for a message to be broadcasted on the bus. + The caller should make a copy of the received message, + without freeing the original copy, and parse it in a + separate thread. When the new thread has started be + started, the caller of this function should then + either call `Bus.poll_timed` again or `Bus.poll_stop`. + + @param timeout:float The time the function shall fail with `os.errno.EAGAIN`, + if it has not already completed + @param clock_id:int? The clock `timeout` is measured in, it must be a + predictable clock, if `None`, `timeout` is measured in + relative time instead of absolute time + @return :bytes The received message + NB! The received message will not be decoded from UTF-8 + ''' + from native_bus import bus_poll_timed_wrapped + if clock_id is None: + import time + clock_id = time.CLOCK_MONOTONIC_RAW + timeout += timeout.clock_gettime(clock_id) + (message, e) = bus_poll_timed_wrapped(self.bus, timeout, clock_id) + if message is None: + raise self.__oserror(e) + return message + + def chown(self, owner = None, group = None): ''' Change the ownership of a bus |