From patchwork Tue Mar 27 12:20:51 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Capitulino X-Patchwork-Id: 148934 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 333BFB6EEF for ; Tue, 27 Mar 2012 23:22:57 +1100 (EST) Received: from localhost ([::1]:40732 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCVQN-0005XI-1e for incoming@patchwork.ozlabs.org; Tue, 27 Mar 2012 08:22:55 -0400 Received: from eggs.gnu.org ([208.118.235.92]:50230) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCVOk-0001g9-Db for qemu-devel@nongnu.org; Tue, 27 Mar 2012 08:21:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SCVOe-0000Mh-6C for qemu-devel@nongnu.org; Tue, 27 Mar 2012 08:21:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41310) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCVOd-0000MK-Ua for qemu-devel@nongnu.org; Tue, 27 Mar 2012 08:21:08 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q2RCL6UY020065 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 27 Mar 2012 08:21:06 -0400 Received: from localhost (ovpn-113-71.phx2.redhat.com [10.3.113.71]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q2RCL5eC025975; Tue, 27 Mar 2012 08:21:06 -0400 From: Luiz Capitulino To: aliguori@us.ibm.com Date: Tue, 27 Mar 2012 09:20:51 -0300 Message-Id: <1332850851-4059-14-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1332850851-4059-1-git-send-email-lcapitulino@redhat.com> References: <1332850851-4059-1-git-send-email-lcapitulino@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: Paolo Bonzini , qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 13/13] qmp: document strict parsing X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Paolo Bonzini Signed-off-by: Paolo Bonzini Signed-off-by: Luiz Capitulino --- QMP/qmp-spec.txt | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/QMP/qmp-spec.txt b/QMP/qmp-spec.txt index 9d30a8c..1ba916c 100644 --- a/QMP/qmp-spec.txt +++ b/QMP/qmp-spec.txt @@ -209,13 +209,27 @@ incompatible way are disabled by default and will be advertised by the capabilities array (section '2.2 Server Greeting'). Thus, Clients can check that array and enable the capabilities they support. -Additionally, Clients must not assume any particular: - -- Size of json-objects or length of json-arrays +The QMP Server performs a type check on the arguments to a command. It +generates an error if a value does not have the expected type for its +key, or if it does not understand a key that the Client included. The +strictness of the Server catches wrong assumptions of Clients about +the Server's schema. Clients can assume that, when such validation +errors occur, they will be reported before the command generated any +side effect. + +However, Clients must not assume any particular: + +- Length of json-arrays +- Size of json-objects; in particular, future versions of QEMU may add + new keys and Clients should be able to ignore them. - Order of json-object members or json-array elements - Amount of errors generated by a command, that is, new errors can be added to any existing command in newer versions of the Server +Of course, the Server does guarantee to send valid JSON. But apart from +this, a Client should be "conservative in what they send, and liberal in +what they accept". + 6. Downstream extension of QMP ------------------------------