diff options
Diffstat (limited to 'decoders/ir_irmp/irmp_library.py')
| -rw-r--r-- | decoders/ir_irmp/irmp_library.py | 40 |
1 files changed, 33 insertions, 7 deletions
diff --git a/decoders/ir_irmp/irmp_library.py b/decoders/ir_irmp/irmp_library.py index d542a1d..5ec6522 100644 --- a/decoders/ir_irmp/irmp_library.py +++ b/decoders/ir_irmp/irmp_library.py @@ -29,6 +29,8 @@ class IrmpLibrary: Library instance for an infrared protocol detector. ''' + __usable_instance = None + class ResultData(ctypes.Structure): _fields_ = [ ( 'protocol', ctypes.c_uint32, ), @@ -54,14 +56,13 @@ class IrmpLibrary: return 'libirmp.dylib' return 'irmp.dll' - def __init__(self): + def _library_setup_api(self): ''' - Create a library instance. + Lookup the C library's API routines. Declare their prototypes. ''' - # Load the library. Lookup routines, declare their prototypes. - filename = self._library_filename() - self._lib = ctypes.cdll.LoadLibrary(filename) + if not self._lib: + return False self._lib.irmp_get_sample_rate.restype = ctypes.c_uint32 self._lib.irmp_get_sample_rate.argtypes = [] @@ -85,20 +86,46 @@ class IrmpLibrary: # Create a result buffer that's local to the library instance. self._data = self.ResultData() + return True + + def __init__(self): + ''' + Create a library instance. + ''' + + # Only create a working instance for the first invocation. + # Degrade all other instances, make them fail "late" during + # execution, so that users will see the errors. + self._lib = None + self._data = None + if IrmpLibrary.__usable_instance is None: + filename = self._library_filename() + self._lib = ctypes.cdll.LoadLibrary(filename) + self._library_setup_api() + IrmpLibrary.__usable_instance = self + def get_sample_rate(self): + if not self._lib: + return None return self._lib.irmp_get_sample_rate() def reset_state(self): + if not self._lib: + return None self._lib.irmp_reset_state() def add_one_sample(self, level): + if not self._lib: + raise Exception("IRMP library limited to a single instance.") if not self._lib.irmp_add_one_sample(int(level)): return False self._lib.irmp_get_result_data(ctypes.byref(self._data)) return True def get_result_data(self): - data = { + if not self._data: + return None + return { 'proto_nr': self._data.protocol, 'proto_name': self._data.protocol_name.decode('UTF-8', 'ignore'), 'address': self._data.address, @@ -108,4 +135,3 @@ class IrmpLibrary: 'start': self._data.start_sample, 'end': self._data.end_sample, } - return data |