nsresult PyG_Base::HandleNativeGatewayError(const char *szMethodName)
{
nsresult rc = NS_OK;
if (PyErr_Occurred()) {
// The error handling - fairly involved, but worth it as
// good error reporting is critical for users to know WTF
// is going on - especially with TypeErrors etc in their
// return values (ie, after the Python code has successfully
// exited, but we encountered errors unpacking their
// result values for the COM caller - there is literally no
// way to catch these exceptions from Python code, as their
// is no Python function directly on the call-stack)
// First line of attack in an error is to call-back on the policy.
// If the callback of the error handler succeeds and returns an
// integer (for the nsresult), we take no further action.
// If this callback fails, we log _2_ exceptions - the error
// handler error, and the original error.
PRBool bProcessMainError = PR_TRUE; // set to false if our exception handler does its thing!
PyObject *exc_typ, *exc_val, *exc_tb;
PyErr_Fetch(&exc_typ, &exc_val, &exc_tb);
PyObject *err_result = PyObject_CallMethod(m_pPyObject,
(char*)"_GatewayException_",
(char*)"z(OOO)",
szMethodName,
exc_typ ? exc_typ : Py_None, // should never be NULL, but defensive programming...
exc_val ? exc_val : Py_None, // may well be NULL.
exc_tb ? exc_tb : Py_None); // may well be NULL.
if (err_result == NULL) {
PyXPCOM_LogError("The exception handler _CallMethodException_ failed!\n");
} else if (err_result == Py_None) {
// The exception handler has chosen not to do anything with
// this error, so we still need to print it!
;
} else if (PyInt_Check(err_result)) {
// The exception handler has given us the nresult.
rc = PyInt_AsLong(err_result);
bProcessMainError = PR_FALSE;
} else {
// The exception handler succeeded, but returned other than
// int or None.
PyXPCOM_LogError("The _CallMethodException_ handler returned object of type '%s' - None or an integer expected\n", err_result->ob_type->tp_name);
}
Py_XDECREF(err_result);
PyErr_Restore(exc_typ, exc_val, exc_tb);
if (bProcessMainError) {
PyXPCOM_LogError("The function '%s' failed\n", szMethodName);
rc = PyXPCOM_SetCOMErrorFromPyException();
}
PyErr_Clear();
}
return rc;
}
// nsIArray impl
NS_IMETHODIMP nsPyArgArray::GetLength(PRUint32 *aLength)
{
CEnterLeavePython _celp;
int size = PySequence_Length(mObject);
if (size==-1) {
return PyXPCOM_SetCOMErrorFromPyException();
}
*aLength = (PRUint32) size;
return NS_OK;
}
/* void queryElementAt (in unsigned long index, in nsIIDRef uuid, [iid_is (uuid), retval] out nsQIResult result); */
NS_IMETHODIMP nsPyArgArray::QueryElementAt(PRUint32 index, const nsIID & uuid, void * *result)
{
*result = nsnull;
// for now let Python check index validity. Probably won't get the correct
// hresult, but its not even clear what that is :)
if (uuid.Equals(NS_GET_IID(nsIVariant)) || uuid.Equals(NS_GET_IID(nsISupports))) {
CEnterLeavePython _celp;
PyObject *sub = PySequence_GetItem(mObject, index);
if (sub==NULL) {
return PyXPCOM_SetCOMErrorFromPyException();
}
nsresult rv = PyObject_AsVariant(sub, (nsIVariant **)result);
Py_DECREF(sub);
return rv;
}
NS_WARNING("nsPyArgArray only handles nsIVariant");
return NS_ERROR_NO_INTERFACE;
}