| Message ID | 1373363617-4723-6-git-send-email-kwolf@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 07/09/2013 03:53 AM, Kevin Wolf wrote: > These can be used when an embedded struct is parsed and members not > belonging to the struct may be present in the input (parsing flat > namespect QMP union with discriminator) namespect? Not sure if you meant 'namespaced'? Again, a comment demonstrating in sample QMP on what this is attempting would be helpful in the commit message. Without looking at later patches yet, I'm guessing from your description that your intent is to reach a point where: { 'type': 'Extra1', 'data': { 'foo': 'str' } } { 'type': 'Extra2', 'data': { 'bar': 'str' } } { 'union': 'Type', 'data': { 'variant1': 'Extra1', 'variant2': 'Extra2' } } { 'command': 'test', 'data': { 'arg': 'Type' } } which currently requires this over the wire: { "execute": "test", "arguments": { "arg": { "type": "variant1", "data": { "foo": "hello" } } } } can be shortened to: { "execute": "test", "arguments": { "arg": { "type": "variant1", "foo": "hello" } } } by allowing the struct passed as "arg" to inline the contents of the union rather than require another nesting level through "data". This patch sets up the entry points so that a future patch can parse the struct of arg as an implicit struct, and not choke over the key "foo", instead of the current visitor of a union type that expects exactly the two keys "type" and "data". > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > include/qapi/visitor-impl.h | 4 ++++ > include/qapi/visitor.h | 3 +++ > qapi/qapi-visit-core.c | 16 ++++++++++++++++ > qapi/qmp-input-visitor.c | 14 ++++++++++++++ > 4 files changed, 37 insertions(+) Although the commit message left me floundering, the code itself seems reasonable - you are just adding two new entry points to allow a new type of parse. It remains to later patches to see how the new parsers are useful, but that doesn't stop me from giving: Reviewed-by: Eric Blake <eblake@redhat.com>
On 07/11/2013 06:41 AM, Eric Blake wrote: > On 07/09/2013 03:53 AM, Kevin Wolf wrote: >> These can be used when an embedded struct is parsed and members not >> belonging to the struct may be present in the input (parsing flat >> namespect QMP union with discriminator) > > namespect? Not sure if you meant 'namespaced'? > > Again, a comment demonstrating in sample QMP on what this is attempting > would be helpful in the commit message. Without looking at later > patches yet, Now that I've read the commit message of patch 6/11, may I suggest something along the lines of this wording: Add a new visitor that allows parsing of an implicit struct, which is created by inlining the namespace of the nested union 'data' struct into the top-level struct of the union itself.
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h index 5159964..5c1297f 100644 --- a/include/qapi/visitor-impl.h +++ b/include/qapi/visitor-impl.h @@ -22,6 +22,10 @@ struct Visitor const char *name, size_t size, Error **errp); void (*end_struct)(Visitor *v, Error **errp); + void (*start_implicit_struct)(Visitor *v, void **obj, size_t size, + Error **errp); + void (*end_implicit_struct)(Visitor *v, Error **errp); + void (*start_list)(Visitor *v, const char *name, Error **errp); GenericList *(*next_list)(Visitor *v, GenericList **list, Error **errp); void (*end_list)(Visitor *v, Error **errp); diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h index 28c21d8..bd24f85 100644 --- a/include/qapi/visitor.h +++ b/include/qapi/visitor.h @@ -33,6 +33,9 @@ void visit_end_handle(Visitor *v, Error **errp); void visit_start_struct(Visitor *v, void **obj, const char *kind, const char *name, size_t size, Error **errp); void visit_end_struct(Visitor *v, Error **errp); +void visit_start_implicit_struct(Visitor *v, void **obj, size_t size, + Error **errp); +void visit_end_implicit_struct(Visitor *v, Error **errp); void visit_start_list(Visitor *v, const char *name, Error **errp); GenericList *visit_next_list(Visitor *v, GenericList **list, Error **errp); void visit_end_list(Visitor *v, Error **errp); diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c index 401ee6e..9b4d51b 100644 --- a/qapi/qapi-visit-core.c +++ b/qapi/qapi-visit-core.c @@ -45,6 +45,22 @@ void visit_end_struct(Visitor *v, Error **errp) v->end_struct(v, errp); } +void visit_start_implicit_struct(Visitor *v, void **obj, size_t size, + Error **errp) +{ + if (!error_is_set(errp) && v->start_implicit_struct) { + v->start_implicit_struct(v, obj, size, errp); + } +} + +void visit_end_implicit_struct(Visitor *v, Error **errp) +{ + assert(!error_is_set(errp)); + if (v->end_implicit_struct) { + v->end_implicit_struct(v, errp); + } +} + void visit_start_list(Visitor *v, const char *name, Error **errp) { if (!error_is_set(errp)) { diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index 67fb127..59c5cac 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -144,6 +144,18 @@ static void qmp_input_end_struct(Visitor *v, Error **errp) qmp_input_pop(qiv, errp); } +static void qmp_input_start_implicit_struct(Visitor *v, void **obj, + size_t size, Error **errp) +{ + if (obj) { + *obj = g_malloc0(size); + } +} + +static void qmp_input_end_implicit_struct(Visitor *v, Error **errp) +{ +} + static void qmp_input_start_list(Visitor *v, const char *name, Error **errp) { QmpInputVisitor *qiv = to_qiv(v); @@ -293,6 +305,8 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj) v->visitor.start_struct = qmp_input_start_struct; v->visitor.end_struct = qmp_input_end_struct; + v->visitor.start_implicit_struct = qmp_input_start_implicit_struct; + v->visitor.end_implicit_struct = qmp_input_end_implicit_struct; v->visitor.start_list = qmp_input_start_list; v->visitor.next_list = qmp_input_next_list; v->visitor.end_list = qmp_input_end_list;
These can be used when an embedded struct is parsed and members not belonging to the struct may be present in the input (parsing flat namespect QMP union with discriminator) Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- include/qapi/visitor-impl.h | 4 ++++ include/qapi/visitor.h | 3 +++ qapi/qapi-visit-core.c | 16 ++++++++++++++++ qapi/qmp-input-visitor.c | 14 ++++++++++++++ 4 files changed, 37 insertions(+)