1 files changed, 98 insertions, 0 deletions
diff --git a/sleekxmpp/xmlstream/handler/waiter.py b/sleekxmpp/xmlstream/handler/waiter.py
new file mode 100644
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+++ b/sleekxmpp/xmlstream/handler/waiter.py
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+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2010  Nathanael C. Fritz
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permission.
+"""
+
+import logging
+try:
+    import queue
+except ImportError:
+    import Queue as queue
+
+from sleekxmpp.xmlstream import StanzaBase, RESPONSE_TIMEOUT
+from sleekxmpp.xmlstream.handler.base import BaseHandler
+
+
+class Waiter(BaseHandler):
+
+    """
+    The Waiter handler allows an event handler to block
+    until a particular stanza has been received. The handler
+    will either be given the matched stanza, or False if the
+    waiter has timed out.
+
+    Methods:
+        check_delete -- Overrides BaseHandler.check_delete
+        prerun       -- Overrides BaseHandler.prerun
+        run          -- Overrides BaseHandler.run
+        wait         -- Wait for a stanza to arrive and return it to
+                        an event handler.
+    """
+
+    def __init__(self, name, matcher, stream=None):
+        """
+        Create a new Waiter.
+
+        Arguments:
+            name    -- The name of the waiter.
+            matcher -- A matcher object to detect the desired stanza.
+            stream  -- Optional XMLStream instance to monitor.
+        """
+        BaseHandler.__init__(self, name, matcher, stream=stream)
+        self._payload = queue.Queue()
+
+    def prerun(self, payload):
+        """
+        Store the matched stanza.
+
+        Overrides BaseHandler.prerun
+
+        Arguments:
+            payload -- The matched stanza object.
+        """
+        self._payload.put(payload)
+
+    def run(self, payload):
+        """
+        Do not process this handler during the main event loop.
+
+        Overrides BaseHandler.run
+
+        Arguments:
+            payload -- The matched stanza object.
+        """
+        pass
+
+    def wait(self, timeout=RESPONSE_TIMEOUT):
+        """
+        Block an event handler while waiting for a stanza to arrive.
+
+        Be aware that this will impact performance if called from a
+        non-threaded event handler.
+
+        Will return either the received stanza, or False if the waiter
+        timed out.
+
+        Arguments:
+            timeout -- The number of seconds to wait for the stanza to
+                       arrive. Defaults to the global default timeout
+                       value sleekxmpp.xmlstream.RESPONSE_TIMEOUT.
+        """
+        try:
+            stanza = self._payload.get(True, timeout)
+        except queue.Empty:
+            stanza = False
+            logging.warning("Timed out waiting for %s" % self.name)
+        self.stream.removeHandler(self.name)
+        return stanza
+
+    def check_delete(self):
+        """
+        Always remove waiters after use.
+
+        Overrides BaseHandler.check_delete
+        """
+        return True