From ef5d474472426eda6abf8128cdb1d026af94862b Mon Sep 17 00:00:00 2001 From: John Snow Date: Fri, 10 Jul 2020 01:22:08 -0400 Subject: [PATCH] python/qmp.py: Do not return None from cmd_obj MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This makes typing the qmp library difficult, as it necessitates wrapping Optional[] around the type for every return type up the stack. At some point, it becomes difficult to discern or remember why it's None instead of the expected object. Use the python exception system to tell us exactly why we didn't get an object. Remove this special-cased return. Signed-off-by: John Snow Reviewed-by: Kevin Wolf Message-Id: <20200710052220.3306-5-jsnow@redhat.com> Signed-off-by: Philippe Mathieu-Daudé --- python/qemu/qmp.py | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py index aa8a666b8a..ef3c919b76 100644 --- a/python/qemu/qmp.py +++ b/python/qemu/qmp.py @@ -225,22 +225,18 @@ class QEMUMonitorProtocol: self.__sockfile = self.__sock.makefile(mode='r') return self.__negotiate_capabilities() - def cmd_obj(self, qmp_cmd): + def cmd_obj(self, qmp_cmd: QMPMessage) -> QMPMessage: """ Send a QMP command to the QMP Monitor. @param qmp_cmd: QMP command to be sent as a Python dict - @return QMP response as a Python dict or None if the connection has - been closed + @return QMP response as a Python dict """ self.logger.debug(">>> %s", qmp_cmd) - try: - self.__sock.sendall(json.dumps(qmp_cmd).encode('utf-8')) - except OSError as err: - if err.errno == errno.EPIPE: - return None - raise err + self.__sock.sendall(json.dumps(qmp_cmd).encode('utf-8')) resp = self.__json_read() + if resp is None: + raise QMPConnectError("Unexpected empty reply from server") self.logger.debug("<<< %s", resp) return resp