From 1829851cfee10e196abec50325d828de182fd356 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 22 Mar 2012 22:39:39 +0100 Subject: [PATCH] qmp: document strict parsing 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 ------------------------------ -- 2.7.4