bt2: make _ListenerHandle not hold a strong reference on the target object

[babeltrace.git] / src / bindings / python / bt2 / bt2 / utils.py

diff --git a/src/bindings/python/bt2/bt2/utils.py b/src/bindings/python/bt2/bt2/utils.py
index 6d80fea283b59a45814233e7bfb335bee5885020..67017cd021aa637d2df664919220471b5ab70962 100644 (file)
--- a/src/bindings/python/bt2/bt2/utils.py
+++ b/src/bindings/python/bt2/bt2/utils.py
@@ -21,7 +21,7 @@
 # THE SOFTWARE.
 
 import bt2
-import bt2.logging
+from bt2 import logging as bt2_logging
 from bt2 import native_bt
 
 
@@ -47,13 +47,14 @@ def _check_str(o):
 
 def _check_type(o, expected_type):
     if not isinstance(o, expected_type):
-        raise TypeError("'{}' is not a '{}' object".format(o.__class__.__name__,
-                                                           expected_type))
+        raise TypeError(
+            "'{}' is not a '{}' object".format(o.__class__.__name__, expected_type)
+        )
 
 
 def _is_in_int64_range(v):
-    assert(isinstance(v, int))
-    return v >= -(2**63) and v <= (2**63 - 1)
+    assert isinstance(v, int)
+    return v >= -(2 ** 63) and v <= (2 ** 63 - 1)
 
 
 def _is_int64(v):
@@ -64,8 +65,8 @@ def _is_int64(v):
 
 
 def _is_in_uint64_range(v):
-    assert(isinstance(v, int))
-    return v >= 0 and v <= (2**64 - 1)
+    assert isinstance(v, int)
+    return v >= 0 and v <= (2 ** 64 - 1)
 
 
 def _is_uint64(v):
@@ -112,29 +113,17 @@ def _check_alignment(a):
         raise ValueError('{} is not a power of two'.format(a))
 
 
-def _raise_bt2_error(msg):
-    if msg is None:
-        raise bt2.Error
-    else:
-        raise bt2.Error(msg)
-
-
-def _handle_ptr(ptr, msg=None):
-    if ptr is None:
-        _raise_bt2_error(msg)
-
-
 def _check_log_level(log_level):
     _check_int(log_level)
 
     log_levels = (
-        bt2.logging.LoggingLevel.TRACE,
-        bt2.logging.LoggingLevel.DEBUG,
-        bt2.logging.LoggingLevel.INFO,
-        bt2.logging.LoggingLevel.WARNING,
-        bt2.logging.LoggingLevel.ERROR,
-        bt2.logging.LoggingLevel.FATAL,
-        bt2.logging.LoggingLevel.NONE,
+        bt2_logging.LoggingLevel.TRACE,
+        bt2_logging.LoggingLevel.DEBUG,
+        bt2_logging.LoggingLevel.INFO,
+        bt2_logging.LoggingLevel.WARNING,
+        bt2_logging.LoggingLevel.ERROR,
+        bt2_logging.LoggingLevel.FATAL,
+        bt2_logging.LoggingLevel.NONE,
     )
 
     if log_level not in log_levels:
@@ -146,11 +135,12 @@ def _handle_func_status(status, msg=None):
         # no error
         return
 
-    if status == native_bt.__BT_FUNC_STATUS_ERROR or status == native_bt.__BT_FUNC_STATUS_MEMORY_ERROR:
-        if msg is None:
-            raise bt2.Error
-        else:
-            raise bt2.Error(msg)
+    if status == native_bt.__BT_FUNC_STATUS_ERROR:
+        assert msg is not None
+        raise bt2._Error(msg)
+    elif status == native_bt.__BT_FUNC_STATUS_MEMORY_ERROR:
+        assert msg is not None
+        raise bt2._MemoryError(msg)
     elif status == native_bt.__BT_FUNC_STATUS_END:
         if msg is None:
             raise bt2.Stop
@@ -161,35 +151,27 @@ def _handle_func_status(status, msg=None):
             raise bt2.TryAgain
         else:
             raise bt2.TryAgain(msg)
-    elif status == native_bt.__BT_FUNC_STATUS_CANCELED:
+    elif status == native_bt.__BT_FUNC_STATUS_OVERFLOW_ERROR:
         if msg is None:
-            raise bt2.Canceled
+            raise bt2._OverflowError
         else:
-            raise bt2.Canceled(msg)
-    elif status == native_bt.__BT_FUNC_STATUS_LOADING_ERROR:
+            raise bt2._OverflowError(msg)
+    elif status == native_bt.__BT_FUNC_STATUS_UNKNOWN_OBJECT:
         if msg is None:
-            raise bt2.LoadingError
+            raise bt2.UnknownObject
         else:
-            raise bt2.LoadingError(msg)
-    elif status == native_bt.__BT_FUNC_STATUS_OVERFLOW:
-        if msg is None:
-            raise bt2.OverflowError
-        else:
-            raise bt2.OverflowError(msg)
-    elif status == native_bt.__BT_FUNC_STATUS_INVALID_OBJECT:
-        if msg is None:
-            raise bt2.InvalidObject
-        else:
-            raise bt2.InvalidObject(msg)
-    elif status == native_bt.__BT_FUNC_STATUS_INVALID_PARAMS:
-        if msg is None:
-            raise bt2.InvalidParams
-        else:
-            raise bt2.InvalidParams(msg)
-    elif status == native_bt.__BT_FUNC_STATUS_UNSUPPORTED:
-        if msg is None:
-            raise bt2.Unsupported
-        else:
-            raise bt2.Unsupported(msg)
+            raise bt2.UnknownObject(msg)
     else:
         assert False
+
+
+class _ListenerHandle:
+    def __init__(self, addr):
+        self._addr = addr
+        self._listener_id = None
+
+    def _set_listener_id(self, listener_id):
+        self._listener_id = listener_id
+
+    def _invalidate(self):
+        self._listener_id = None