| Message ID | 1345471297-21459-1-git-send-email-berrange@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 20 Aug 2012 15:01:37 +0100 "Daniel P. Berrange" <berrange@redhat.com> wrote: > From: "Daniel P. Berrange" <berrange@redhat.com> > > The qmp-shell code assumes the JSON response is only on a single > line. If the QEMU monitor is configured in "pretty print" mode > the JSON response can be multi-line. The basic Python JSON APIs > do not appear to support a streaming mode, so the simple hack > here is to try parsing a line, and if it fails, then read another > line, append it, and try parsing again. Keep reading lines until > we can successfully parse > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > QMP/qmp.py | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/QMP/qmp.py b/QMP/qmp.py > index 36ecc1d..464a01a 100644 > --- a/QMP/qmp.py > +++ b/QMP/qmp.py > @@ -61,10 +61,18 @@ class QEMUMonitorProtocol: > > def __json_read(self, only_event=False): > while True: > - data = self.__sockfile.readline() > - if not data: > - return > - resp = json.loads(data) > + data = "" > + while True: > + moredata = self.__sockfile.readline() > + if not moredata: > + return > + data = data + moredata > + try: > + resp = json.loads(data) > + break > + except ValueError: > + pass > + I'm reluctant about this, because it makes it impossible to detect bad json from qemu (not that qmp-shell handles this gracefully today). At the same time I can't think of anything simpler than your hack. What about calling json.loads() when closing } matches the number of opening ones? QMP responses are always dictionaries. > if 'event' in resp: > self.__events.append(resp) > if not only_event:
On Mon, Aug 20, 2012 at 03:03:11PM -0300, Luiz Capitulino wrote: > On Mon, 20 Aug 2012 15:01:37 +0100 > "Daniel P. Berrange" <berrange@redhat.com> wrote: > > > From: "Daniel P. Berrange" <berrange@redhat.com> > > > > The qmp-shell code assumes the JSON response is only on a single > > line. If the QEMU monitor is configured in "pretty print" mode > > the JSON response can be multi-line. The basic Python JSON APIs > > do not appear to support a streaming mode, so the simple hack > > here is to try parsing a line, and if it fails, then read another > > line, append it, and try parsing again. Keep reading lines until > > we can successfully parse > > > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > > --- > > QMP/qmp.py | 16 ++++++++++++---- > > 1 file changed, 12 insertions(+), 4 deletions(-) > > > > diff --git a/QMP/qmp.py b/QMP/qmp.py > > index 36ecc1d..464a01a 100644 > > --- a/QMP/qmp.py > > +++ b/QMP/qmp.py > > @@ -61,10 +61,18 @@ class QEMUMonitorProtocol: > > > > def __json_read(self, only_event=False): > > while True: > > - data = self.__sockfile.readline() > > - if not data: > > - return > > - resp = json.loads(data) > > + data = "" > > + while True: > > + moredata = self.__sockfile.readline() > > + if not moredata: > > + return > > + data = data + moredata > > + try: > > + resp = json.loads(data) > > + break > > + except ValueError: > > + pass > > + > > I'm reluctant about this, because it makes it impossible to detect bad > json from qemu (not that qmp-shell handles this gracefully today). Yeah, it is slightly unpleasant. > At the same time I can't think of anything simpler than your hack. What > about calling json.loads() when closing } matches the number of opening ones? > QMP responses are always dictionaries. How about making multi-line processing an optional feature, by adding a '-m' flag to qmp-shell. That way we still get error checking by default Daniel
On Mon, 20 Aug 2012 19:25:02 +0100 "Daniel P. Berrange" <berrange@redhat.com> wrote: > On Mon, Aug 20, 2012 at 03:03:11PM -0300, Luiz Capitulino wrote: > > On Mon, 20 Aug 2012 15:01:37 +0100 > > "Daniel P. Berrange" <berrange@redhat.com> wrote: > > > > > From: "Daniel P. Berrange" <berrange@redhat.com> > > > > > > The qmp-shell code assumes the JSON response is only on a single > > > line. If the QEMU monitor is configured in "pretty print" mode > > > the JSON response can be multi-line. The basic Python JSON APIs > > > do not appear to support a streaming mode, so the simple hack > > > here is to try parsing a line, and if it fails, then read another > > > line, append it, and try parsing again. Keep reading lines until > > > we can successfully parse > > > > > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > > > --- > > > QMP/qmp.py | 16 ++++++++++++---- > > > 1 file changed, 12 insertions(+), 4 deletions(-) > > > > > > diff --git a/QMP/qmp.py b/QMP/qmp.py > > > index 36ecc1d..464a01a 100644 > > > --- a/QMP/qmp.py > > > +++ b/QMP/qmp.py > > > @@ -61,10 +61,18 @@ class QEMUMonitorProtocol: > > > > > > def __json_read(self, only_event=False): > > > while True: > > > - data = self.__sockfile.readline() > > > - if not data: > > > - return > > > - resp = json.loads(data) > > > + data = "" > > > + while True: > > > + moredata = self.__sockfile.readline() > > > + if not moredata: > > > + return > > > + data = data + moredata > > > + try: > > > + resp = json.loads(data) > > > + break > > > + except ValueError: > > > + pass > > > + > > > > I'm reluctant about this, because it makes it impossible to detect bad > > json from qemu (not that qmp-shell handles this gracefully today). > > Yeah, it is slightly unpleasant. > > > At the same time I can't think of anything simpler than your hack. What > > about calling json.loads() when closing } matches the number of opening ones? > > QMP responses are always dictionaries. > > How about making multi-line processing an optional feature, by adding > a '-m' flag to qmp-shell. That way we still get error checking by > default Good idea. > > > Daniel
diff --git a/QMP/qmp.py b/QMP/qmp.py index 36ecc1d..464a01a 100644 --- a/QMP/qmp.py +++ b/QMP/qmp.py @@ -61,10 +61,18 @@ class QEMUMonitorProtocol: def __json_read(self, only_event=False): while True: - data = self.__sockfile.readline() - if not data: - return - resp = json.loads(data) + data = "" + while True: + moredata = self.__sockfile.readline() + if not moredata: + return + data = data + moredata + try: + resp = json.loads(data) + break + except ValueError: + pass + if 'event' in resp: self.__events.append(resp) if not only_event: