Initial commit

1 files changed, 93 insertions, 0 deletions

diff --git a/olpcgames/dbusproxy.py b/olpcgames/dbusproxy.py
new file mode 100755
index 0000000..a103e28
--- /dev/null
+++ b/olpcgames/dbusproxy.py
@@ -0,0 +1,93 @@
+"""Spike test for a safer networking system for DBUS-based objects"""
+from olpcgames import eventwrap, util
+from dbus import proxies
+import logging 
+log = logging.getLogger( 'dbus' )
+log.setLevel( logging.DEBUG )
+
+def wrap( value, tube=None,path=None ):
+    """Wrap object with any required pygame-side proxies"""
+    if isinstance( value,proxies._ProxyMethod ):
+        return DBUSMethod( value, tube=tube, path=path )
+    elif isinstance( value, proxies._DeferredMethod ):
+        value._proxy_method = DBUSMethod( value._proxy_method, tube=tube, path=path )
+        return value 
+    elif isinstance( value, proxies.ProxyObject ):
+        return DBUSProxy( value, tube=tube, path=path )
+    else:
+        return value 
+
+class DBUSProxy( object ):
+    """Proxy for the DBUS Proxy object"""
+    def __init__( self, proxy, tube=None, path=None ):
+        log.info( 'Creating Pygame-side proxy for %s (%s)', proxy,path )
+        self.__proxy = proxy
+        self.__tube = tube
+        self.__path = path
+    def __getattr__( self, key ):
+        """Retrieve attribute of given key"""
+        from dbus import proxies
+        return wrap( getattr( self.__proxy, key ) )
+    def add_signal_receiver( self, callback, eventName, interface, path=None, sender_keyword='sender'):
+        """Add a new signal handler (which will be called many times) for given signal 
+        """
+        log.info( """Setting signal receiver %s for event %s on interface %s (object path %s) with sender_keyword = %r""",
+            callback, eventName, interface, path, sender_keyword,
+        )
+        log.debug( """proxy: %s proxy.tube: %s""", self.__proxy, self.__proxy.tube )
+        self.__tube.add_signal_receiver(
+            Callback( callback ),
+            eventName,
+            interface,
+            path = path or self.__path, 
+            sender_keyword = sender_keyword,
+        )
+
+class DBUSMethod( object ):
+    """DBUS method which does callbacks in the Pygame (eventwrapper) thread"""
+    def __init__( self, proxy, tube,path ):
+        log.info( 'Creating Pygame-side method proxy for %s', proxy )
+        self.__proxy = proxy
+        self.__tube = tube 
+        self.__path = path
+    def __call__( self, *args, **named ):
+        """Perform the asynchronous call"""
+        log.info( 'Calling proxy for %s with *%s, **%s', self.__proxy, args, named )
+        callback, errback = named.get( 'reply_handler'), named.get( 'error_handler' )
+        if not callback:
+            raise TypeError( """Require a reply_handler named argument to do any asynchronous call""" )
+        else:
+            callback = Callback( callback )
+        if not errback:
+            errback = defaultErrback
+        else:
+            errback = Callback( errback )
+        named['reply_handler'] = callback
+        named['error_handler'] = errback
+        return self.__proxy( *args, **named )
+
+def defaultErrback( error ):
+    """Log the error to stderr/log"""
+    log.error( """Failure in DBUS call: %s""", error )
+
+class Callback( object ):
+    """PyGTK-side callback which generates a CallbackResult to process on the Pygame side"""
+    def __init__( self, callable, callContext = None):
+        """Initialize the callback to process results"""
+        self.callable = callable
+        if callContext is None:
+            callContext = util.get_traceback( None )
+        self.callContext = callContext
+    def __call__( self, *args, **named ):
+        """PyGTK-side callback operation"""
+        log.info( 'Callback %s return value *%s, **%s', self.callable, args, named )
+        from olpcgames import eventwrap
+        args = [wrap(a) for a in args]
+        named = dict([
+            (k,wrap(v)) for k,v in named.items()
+        ])
+        eventwrap.post( 
+            eventwrap.CallbackResult( 
+                self.callable, args, named, callContext = self.callContext 
+            )
+        )