Hi
On Fri, Aug 24, 2018 at 10:05 AM Markus Armbruster <arm...@redhat.com> wrote:
>
> Marc-André Lureau <marcandre.lur...@redhat.com> writes:
>
> > Add a new function qdict_steal(), that deletes a key from a dict, and
> > returns the associated value, if any. Simplify related code.
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > ---
> > include/qapi/qmp/qdict.h | 1 +
> > monitor.c | 3 +--
> > qobject/block-qdict.c | 7 ++-----
> > qobject/qdict.c | 22 ++++++++++++++++++++++
> > 4 files changed, 26 insertions(+), 7 deletions(-)
>
> Missing: tests/check-qdict.c update.
ok
>
> > diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h
> > index 7f3ec10a10..84644bfba6 100644
> > --- a/include/qapi/qmp/qdict.h
> > +++ b/include/qapi/qmp/qdict.h
> > @@ -37,6 +37,7 @@ QObject *qdict_entry_value(const QDictEntry *entry);
> > size_t qdict_size(const QDict *qdict);
> > void qdict_put_obj(QDict *qdict, const char *key, QObject *value);
> > void qdict_del(QDict *qdict, const char *key);
> > +QObject *qdict_steal(QDict *qdict, const char *key);
> > int qdict_haskey(const QDict *qdict, const char *key);
> > QObject *qdict_get(const QDict *qdict, const char *key);
> > bool qdict_is_equal(const QObject *x, const QObject *y);
> > diff --git a/monitor.c b/monitor.c
> > index a1999e396c..eab2dc7b7b 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -4262,8 +4262,7 @@ static void handle_qmp_command(JSONMessageParser
> > *parser, GQueue *tokens)
> >
> > qdict = qobject_to(QDict, req);
> > if (qdict) {
> > - id = qobject_ref(qdict_get(qdict, "id"));
> > - qdict_del(qdict, "id");
> > + id = qdict_steal(qdict, "id");
> > } /* else will fail qmp_dispatch() */
> >
> > if (req && trace_event_get_state_backends(TRACE_HANDLE_QMP_COMMAND)) {
> > diff --git a/qobject/block-qdict.c b/qobject/block-qdict.c
> > index 42054cc274..a07664ee6a 100644
> > --- a/qobject/block-qdict.c
> > +++ b/qobject/block-qdict.c
> > @@ -692,8 +692,6 @@ void qdict_join(QDict *dest, QDict *src, bool overwrite)
> > */
> > bool qdict_rename_keys(QDict *qdict, const QDictRenames *renames, Error
> > **errp)
> > {
> > - QObject *qobj;
> > -
> > while (renames->from) {
> > if (qdict_haskey(qdict, renames->from)) {
> > if (qdict_haskey(qdict, renames->to)) {
> > @@ -702,9 +700,8 @@ bool qdict_rename_keys(QDict *qdict, const QDictRenames
> > *renames, Error **errp)
> > return false;
> > }
> >
> > - qobj = qdict_get(qdict, renames->from);
> > - qdict_put_obj(qdict, renames->to, qobject_ref(qobj));
> > - qdict_del(qdict, renames->from);
> > + qdict_put_obj(qdict, renames->to,
> > + qdict_steal(qdict, renames->from));
> > }
> >
> > renames++;
>
> How did you find possible uses for qdict_steal()?
manual review
>
> > diff --git a/qobject/qdict.c b/qobject/qdict.c
> > index 3d8c2f7bbc..322f23f094 100644
> > --- a/qobject/qdict.c
> > +++ b/qobject/qdict.c
> > @@ -406,6 +406,28 @@ void qdict_del(QDict *qdict, const char *key)
> > }
> > }
> >
> > +/**
> > + * qdict_steal(): Steal a 'key:value' pair from the dictionary
>
> "Steal" is cute, but perhaps qdict_get_and_del() would be clearer.
"steal" is common in glib. I don't mind renaming.
>
> > + *
> > + * Return the associated entry value and remove it, or NULL.
>
> Suggest
>
> * If @qdict has @key, return its value, and delete it from @qdict.
> * Else, return NULL.
>
> > + */
> > +QObject *qdict_steal(QDict *qdict, const char *key)
> > +{
> > + QDictEntry *entry;
> > + QObject *val = NULL;
> > +
> > + entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
> > + if (entry) {
> > + QLIST_REMOVE(entry, next);
> > + val = qobject_ref(entry->value);
> > + qentry_destroy(entry);
> > + qdict->size--;
> > + }
> > +
> > + return val;
> > +}
>
> This is a slightly extended qdict_del().
>
> void qdict_del(QDict *qdict, const char *key)
> {
> QDictEntry *entry;
>
> entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
> if (entry) {
> QLIST_REMOVE(entry, next);
> qentry_destroy(entry);
> qdict->size--;
> }
> }
>
> Heavy-handed de-duplication:
>
> QObject *qdict_get_and_del(QDict *qdict, const char *key)
> {
> QDictEntry *entry;
> QObject *val;
>
> entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_BUCKET_MAX);
> if (!entry) {
> return NULL;
> }
>
> QLIST_REMOVE(entry, next);
> val = qobject_ref(entry->value);
> qentry_destroy(entry);
> qdict->size--;
> return val;
> }
>
> void qdict_del(QDict *qdict, const char *key)
> {
> qobject_unref(qdict_get_and_del(qdict, key));
> }
>
> Makes qdict_del() execute an additional qobject_ref() / qobject_unref(),
> but that shouldn't matter.
ok
>
> > +
> > +
>
> Just one blank line, please.
ok
>
> > /**
> > * qdict_is_equal(): Test whether the two QDicts are equal
> > *
>
thanks
--
Marc-André Lureau
