Add errcheck functions to opus foreign functions

discord/opus.py

@@ -42,17 +42,36 @@ class EncoderStruct(ctypes.Structure):
 
 EncoderStructPtr = ctypes.POINTER(EncoderStruct)
 
+def _err_lt(result, func, args):
+    if result < 0:
+        log.info('error has happened in {0.__name__}'.format(func))
+        raise OpusError(result)
+    return result
+
+def _err_ne(result, func, args):
+    if result.value != 0:
+        log.info('error has happened in {0.__name__}'.format(func))
+        raise OpusError(result.value)
+    return result
+
 # A list of exported functions.
 # The first argument is obviously the name.
 # The second one are the types of arguments it takes.
 # The third is the result type.
+# The fourth is the error handler.
 exported_functions = [
-    ('opus_strerror', [ctypes.c_int], ctypes.c_char_p),
-    ('opus_encoder_get_size', [ctypes.c_int], ctypes.c_int),
-    ('opus_encoder_create', [ctypes.c_int, ctypes.c_int, ctypes.c_int, c_int_ptr], EncoderStructPtr),
-    ('opus_encode', [EncoderStructPtr, c_int16_ptr, ctypes.c_int, ctypes.c_char_p, ctypes.c_int32], ctypes.c_int32),
-    ('opus_encoder_ctl', None, ctypes.c_int32),
-    ('opus_encoder_destroy', [EncoderStructPtr], None)
+    ('opus_strerror',
+        [ctypes.c_int], ctypes.c_char_p, None),
+    ('opus_encoder_get_size',
+        [ctypes.c_int], ctypes.c_int, None),
+    ('opus_encoder_create',
+        [ctypes.c_int, ctypes.c_int, ctypes.c_int, c_int_ptr], EncoderStructPtr, _err_ne),
+    ('opus_encode',
+        [EncoderStructPtr, c_int16_ptr, ctypes.c_int, ctypes.c_char_p, ctypes.c_int32], ctypes.c_int32, _err_lt),
+    ('opus_encoder_ctl',
+        None, ctypes.c_int32, _err_lt),
+    ('opus_encoder_destroy',
+        [EncoderStructPtr], None, None),
 ]
 
 def libopus_loader(name):
@@ -74,6 +93,12 @@ def libopus_loader(name):
         except KeyError:
             pass
 
+        try:
+            if item[3]:
+                func.errcheck = item[3]
+        except KeyError:
+            log.exception("Error assigning check function to %s", func)
+
     return lib
 
 try:
@@ -211,22 +236,12 @@ class Encoder:
 
     def _create_state(self):
         ret = ctypes.c_int()
-        result = _lib.opus_encoder_create(self.SAMPLING_RATE, self.CHANNELS, self.application, ctypes.byref(ret))
-
-        if ret.value != 0:
-            log.info('error has happened in state creation')
-            raise OpusError(ret.value)
-
-        return result
+        return _lib.opus_encoder_create(self.SAMPLING_RATE, self.CHANNELS, self.application, ctypes.byref(ret))
 
     def set_bitrate(self, kbps):
         kbps = min(128, max(16, int(kbps)))
 
-        ret = _lib.opus_encoder_ctl(self._state, CTL_SET_BITRATE, kbps * 1024)
-        if ret < 0:
-            log.info('error has happened in set_bitrate')
-            raise OpusError(ret)
-
+        _lib.opus_encoder_ctl(self._state, CTL_SET_BITRATE, kbps * 1024)
         return kbps
 
     def set_bandwidth(self, req):
@@ -234,36 +249,20 @@ class Encoder:
             raise KeyError('%r is not a valid bandwidth setting. Try one of: %s' % (req, ','.join(band_ctl)))
 
         k = band_ctl[req]
-        ret = _lib.opus_encoder_ctl(self._state, CTL_SET_BANDWIDTH, k)
-
-        if ret < 0:
-            log.info('error has happened in set_bandwidth')
-            raise OpusError(ret)
+        _lib.opus_encoder_ctl(self._state, CTL_SET_BANDWIDTH, k)
 
     def set_signal_type(self, req):
         if req not in signal_ctl:
             raise KeyError('%r is not a valid signal setting. Try one of: %s' % (req, ','.join(signal_ctl)))
 
         k = signal_ctl[req]
-        ret = _lib.opus_encoder_ctl(self._state, CTL_SET_SIGNAL, k)
-
-        if ret < 0:
-            log.info('error has happened in set_signal_type')
-            raise OpusError(ret)
+        _lib.opus_encoder_ctl(self._state, CTL_SET_SIGNAL, k)
 
     def set_fec(self, enabled=True):
-        ret = _lib.opus_encoder_ctl(self._state, CTL_SET_FEC, 1 if enabled else 0)
-
-        if ret < 0:
-            log.info('error has happened in set_fec')
-            raise OpusError(ret)
+        _lib.opus_encoder_ctl(self._state, CTL_SET_FEC, 1 if enabled else 0)
 
     def set_expected_packet_loss_percent(self, percentage):
-        ret = _lib.opus_encoder_ctl(self._state, CTL_SET_PLP, min(100, max(0, int(percentage * 100))))
-
-        if ret < 0:
-            log.info('error has happened in set_expected_packet_loss_percent')
-            raise OpusError(ret)
+        _lib.opus_encoder_ctl(self._state, CTL_SET_PLP, min(100, max(0, int(percentage * 100))))
 
     def encode(self, pcm, frame_size):
         max_data_bytes = len(pcm)
@@ -271,8 +270,5 @@ class Encoder:
         data = (ctypes.c_char * max_data_bytes)()
 
         ret = _lib.opus_encode(self._state, pcm, frame_size, data, max_data_bytes)
-        if ret < 0:
-            log.info('error has happened in encode')
-            raise OpusError(ret)
 
         return array.array('b', data[:ret]).tobytes()