Commit 55e1819c authored by Eric Blake's avatar Eric Blake Committed by Markus Armbruster
Browse files

qobject: Simplify QObject 



The QObject hierarchy is small enough, and unlikely to grow further
(since we only use it to map to JSON and already cover all JSON
types), that we can simplify things by not tracking a separate
vtable, but just inline the code element of the vtable QType
directly into QObject (renamed to type), and track a separate array
of destroy functions.  We can drop qnull_destroy_obj() in the
process.

The remaining QObject subclasses must export their destructor.

This also has the nice benefit of moving the typename 'QType'
out of the way, so that the next patch can repurpose it for a
nicer name for 'qtype_code'.

The various objects are still the same size (so no change in cache
line pressure), but now have less indirection (although I didn't
bother benchmarking to see if there is a noticeable speedup, as
we don't have hard evidence that this was in a performance hotspot
in the first place).

A future patch could drop the refcnt size to 32 bits for a smaller
struct on 64-bit architectures, if desired (we have limits on the
largest JSON that we are willing to parse, and will probably never
need to take full advantage of a 64-bit refcnt).

Suggested-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-2-git-send-email-eblake@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent d20a580b

include/qapi/qmp/qbool.h

+1 −0
Original line number Diff line number Diff line
@@ -25,5 +25,6 @@ typedef struct QBool { 
QBool *qbool_from_bool(bool value);

bool qbool_get_bool(const QBool *qb);

QBool *qobject_to_qbool(const QObject *obj);

void qbool_destroy_obj(QObject *obj);



#endif /* QBOOL_H */

include/qapi/qmp/qdict.h

+1 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ void qdict_iter(const QDict *qdict, 
                void *opaque);

const QDictEntry *qdict_first(const QDict *qdict);

const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry);

void qdict_destroy_obj(QObject *obj);



/* Helper to qdict_put_obj(), accepts any object */

#define qdict_put(qdict, key, obj) \

include/qapi/qmp/qfloat.h

+1 −0
Original line number Diff line number Diff line
@@ -25,5 +25,6 @@ typedef struct QFloat { 
QFloat *qfloat_from_double(double value);

double qfloat_get_double(const QFloat *qi);

QFloat *qobject_to_qfloat(const QObject *obj);

void qfloat_destroy_obj(QObject *obj);



#endif /* QFLOAT_H */

include/qapi/qmp/qint.h

+1 −0
Original line number Diff line number Diff line
@@ -24,5 +24,6 @@ typedef struct QInt { 
QInt *qint_from_int(int64_t value);

int64_t qint_get_int(const QInt *qi);

QInt *qobject_to_qint(const QObject *obj);

void qint_destroy_obj(QObject *obj);



#endif /* QINT_H */

include/qapi/qmp/qlist.h

+1 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ QObject *qlist_peek(QList *qlist); 
int qlist_empty(const QList *qlist);

size_t qlist_size(const QList *qlist);

QList *qobject_to_qlist(const QObject *obj);

void qlist_destroy_obj(QObject *obj);



static inline const QListEntry *qlist_first(const QList *qlist)

{