initial commit

env/lib/python3.10/site-packages/jeepney/io/common.py

@@ -0,0 +1,88 @@
+from contextlib import contextmanager
+from itertools import count
+
+from jeepney import HeaderFields, Message, MessageFlag, MessageType
+
+class MessageFilters:
+    def __init__(self):
+        self.filters = {}
+        self.filter_ids = count()
+
+    def matches(self, message):
+        for handle in self.filters.values():
+            if handle.rule.matches(message):
+                yield handle
+
+
+class FilterHandle:
+    def __init__(self, filters: MessageFilters, rule, queue):
+        self._filters = filters
+        self._filter_id = next(filters.filter_ids)
+        self.rule = rule
+        self.queue = queue
+
+        self._filters.filters[self._filter_id] = self
+
+    def close(self):
+        del self._filters.filters[self._filter_id]
+
+    def __enter__(self):
+        return self.queue
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+        return False
+
+
+class ReplyMatcher:
+    def __init__(self):
+        self._futures = {}
+
+    @contextmanager
+    def catch(self, serial, future):
+        """Context manager to capture a reply for the given serial number"""
+        self._futures[serial] = future
+
+        try:
+            yield future
+        finally:
+            del self._futures[serial]
+
+    def dispatch(self, msg):
+        """Dispatch an incoming message which may be a reply
+
+        Returns True if a task was waiting for it, otherwise False.
+        """
+        rep_serial = msg.header.fields.get(HeaderFields.reply_serial, -1)
+        if rep_serial in self._futures:
+            self._futures[rep_serial].set_result(msg)
+            return True
+        else:
+            return False
+
+    def drop_all(self, exc: Exception = None):
+        """Throw an error in any task still waiting for a reply"""
+        if exc is None:
+            exc = RouterClosed("D-Bus router closed before reply arrived")
+        futures, self._futures = self._futures, {}
+        for fut in futures.values():
+            fut.set_exception(exc)
+
+
+class RouterClosed(Exception):
+    """Raised in tasks waiting for a reply when the router is closed
+
+    This will also be raised if the receiver task crashes, so tasks are not
+    stuck waiting for a reply that can never come. The router object will not
+    be usable after this is raised.
+    """
+    pass
+
+
+def check_replyable(msg: Message):
+    """Raise an error if we wouldn't expect a reply for msg"""
+    if msg.header.message_type != MessageType.method_call:
+        raise TypeError("Only method call messages have replies "
+                        f"(not {msg.header.message_type})")
+    if MessageFlag.no_reply_expected & msg.header.flags:
+        raise ValueError("This message has the no_reply_expected flag set")