NS_IMETHODIMP
PyG_Base::QueryInterface(REFNSIID iid, void** ppv)
{
#ifdef PYXPCOM_DEBUG_FULL
{
char *sziid = iid.ToString();
LogF("PyGatewayBase::QueryInterface: %s", sziid);
Allocator::Free(sziid);
}
#endif
NS_PRECONDITION(ppv, "NULL pointer");
if (ppv==nsnull)
return NS_ERROR_NULL_POINTER;
*ppv = nsnull;
// If one of our native interfaces (but NOT nsISupports if we have a base)
// return this.
// It is important is that nsISupports come from the base object
// to ensure that we live by XPCOM identity rules (other interfaces need
// not abide by this rule - only nsISupports.)
if ( (m_pBaseObject==NULL || !iid.Equals(NS_GET_IID(nsISupports)))
&& (*ppv=ThisAsIID(iid)) != NULL ) {
AddRef();
return NS_OK;
}
// If we have a "base object", then we need to delegate _every_ remaining
// QI to it.
if (m_pBaseObject != NULL)
return m_pBaseObject->QueryInterface(iid, ppv);
// Call the Python policy to see if it (says it) supports the interface
PRBool supports = PR_FALSE;
{ // temp scope for Python lock
CEnterLeavePython celp;
PyObject * ob = Py_nsIID::PyObjectFromIID(iid);
// must say this is an 'internal' call, else we recurse QI into
// oblivion.
PyObject * this_interface_ob = Py_nsISupports::PyObjectFromInterface(
(nsXPTCStubBase *)this,
iid, PR_FALSE, PR_TRUE);
if ( !ob || !this_interface_ob) {
Py_XDECREF(ob);
Py_XDECREF(this_interface_ob);
return NS_ERROR_OUT_OF_MEMORY;
}
PyObject *result = PyObject_CallMethod(m_pPyObject, (char*)"_QueryInterface_",
(char*)"OO",
this_interface_ob, ob);
Py_DECREF(ob);
Py_DECREF(this_interface_ob);
if ( result ) {
if (Py_nsISupports::InterfaceFromPyObject(result, iid, (nsISupports **)ppv, PR_TRUE)) {
// If OK, but NULL, _QI_ returned None, which simply means
// "no such interface"
supports = (*ppv!=NULL);
// result has been QI'd and AddRef'd all ready for return.
} else {
// Dump this message and any Python exception before
// reporting the fact that QI failed - this error
// may provide clues!
PyXPCOM_LogError("The _QueryInterface_ method returned an object of type '%s', but an interface was expected\n", result->ob_type->tp_name);
// supports remains false
}
Py_DECREF(result);
} else {
NS_ABORT_IF_FALSE(PyErr_Occurred(), "Got NULL result, but no Python error flagged!");
NS_WARN_IF_FALSE(!supports, "Have failure with success flag set!");
PyXPCOM_LogError("The _QueryInterface_ processing failed.\n");
// supports remains false.
// We have reported the error, and are returning to COM,
// so we should clear it.
PyErr_Clear();
}
} // end of temp scope for Python lock - lock released here!
if ( !supports )
return NS_ERROR_NO_INTERFACE;
return NS_OK;
}
