From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53906) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ePkq8-0003by-Rq for qemu-devel@nongnu.org; Fri, 15 Dec 2017 02:55:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ePkq3-0006ge-VN for qemu-devel@nongnu.org; Fri, 15 Dec 2017 02:55:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33292) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ePkq3-0006eX-Kl for qemu-devel@nongnu.org; Fri, 15 Dec 2017 02:55:23 -0500 Date: Fri, 15 Dec 2017 15:55:06 +0800 From: Peter Xu Message-ID: <20171215075505.GK7780@xz-mi> References: <20171205055200.16305-1-peterx@redhat.com> <20171205055200.16305-6-peterx@redhat.com> <20171213153702.GF7173@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20171213153702.GF7173@stefanha-x1.localdomain> Subject: Re: [Qemu-devel] [RFC v5 05/26] qjson: add "opaque" field to JSONMessageParser List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Stefan Hajnoczi , "Daniel P . Berrange" , Paolo Bonzini , Fam Zheng , Juan Quintela , mdroth@linux.vnet.ibm.com, Eric Blake , Laurent Vivier , Markus Armbruster , marcandre.lureau@redhat.com, "Dr . David Alan Gilbert" On Wed, Dec 13, 2017 at 03:37:02PM +0000, Stefan Hajnoczi wrote: > On Tue, Dec 05, 2017 at 01:51:39PM +0800, Peter Xu wrote: > > diff --git a/qga/main.c b/qga/main.c > > index 62a62755bd..3b5ebbc1ee 100644 > > --- a/qga/main.c > > +++ b/qga/main.c > > @@ -593,7 +593,8 @@ static void process_command(GAState *s, QDict *req) > > } > > > > /* handle requests/control events coming in over the channel */ > > -static void process_event(JSONMessageParser *parser, GQueue *tokens) > > +static void process_event(JSONMessageParser *parser, GQueue *tokens, > > + void *opaque) > > { > > GAState *s = container_of(parser, GAState, parser); > > QDict *qdict; > > @@ -1320,7 +1321,7 @@ static int run_agent(GAState *s, GAConfig *config, int socket_activation) > > s->command_state = ga_command_state_new(); > > ga_command_state_init(s, s->command_state); > > ga_command_state_init_all(s->command_state); > > - json_message_parser_init(&s->parser, process_event); > > + json_message_parser_init(&s->parser, process_event, NULL); > > This patch leaves the code with 2 ways of getting at state from the > parser pointer: > 1. Use container_of() like existing users. > 2. Use the new (unused) opaque argument. > > Given that #1 exists, is this patch really necessary? I didn't really notice that. Thanks for pointing out. However even if so I would still prefer the opaque way to do it if asked. Existing #1 of course works but IMHO is less flexible and has dependency between structure layouts. How about I append another patch to convert existing users (or, I can post as separate patches after this series)? It's not really a lot, and the conversion would be obvious: *** qga/main.c: run_agent[1324] json_message_parser_init(&s->parser, process_event, NULL); *** qobject/qjson.c: qobject_from_jsonv[45] json_message_parser_init(&state.parser, parse_json, NULL); *** tests/libqtest.c: qmp_fd_receive[438] json_message_parser_init(&qmp.parser, qmp_response, NULL); Though, if you still insist, I can drop it too. > > Please explain in the commit description, don't make me look ahead in > the patch series. I will add some comments if this patch is still alive in next version. Thanks, -- Peter Xu