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[Qemu-devel] [PULL 03/10] qdict: Make qdict_flatten() shallow-clone-frie
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PULL 03/10] qdict: Make qdict_flatten() shallow-clone-friendly |
Date: |
Fri, 22 Jun 2018 17:32:21 +0200 |
From: Max Reitz <address@hidden>
In its current form, qdict_flatten() removes all entries from nested
QDicts that are moved to the root QDict. It is completely sufficient to
remove all old entries from the root QDict, however. If the nested
dicts have a refcount of 1, this will automatically delete them, too.
And if they have a greater refcount, we probably do not want to modify
them in the first place.
The latter observation means that it was currently (in general)
impossible to qdict_flatten() a shallowly cloned dict because that would
empty nested QDicts in the original dict as well. This patch changes
this, so you can now use qdict_flatten(qdict_shallow_clone(dict)) to get
a flattened copy without disturbing the original.
Signed-off-by: Max Reitz <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>
Signed-off-by: Markus Armbruster <address@hidden>
---
qobject/block-qdict.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/qobject/block-qdict.c b/qobject/block-qdict.c
index df833083a7..36129e7379 100644
--- a/qobject/block-qdict.c
+++ b/qobject/block-qdict.c
@@ -114,19 +114,30 @@ static void qdict_flatten_qdict(QDict *qdict, QDict
*target, const char *prefix)
/*
* Flatten non-empty QDict and QList recursively into @target,
- * copy other objects to @target
+ * copy other objects to @target.
+ * On the root level (if @qdict == @target), remove flattened
+ * nested QDicts and QLists from @qdict.
+ *
+ * (Note that we do not need to remove entries from nested
+ * dicts or lists. Their reference count is decremented on
+ * the root level, so there are no leaks. In fact, if they
+ * have a reference count greater than one, we are probably
+ * well advised not to modify them altogether.)
*/
if (dict_val && qdict_size(dict_val)) {
qdict_flatten_qdict(dict_val, target,
new_key ? new_key : entry->key);
- qdict_del(qdict, entry->key);
+ if (target == qdict) {
+ qdict_del(qdict, entry->key);
+ }
} else if (list_val && !qlist_empty(list_val)) {
qdict_flatten_qlist(list_val, target,
new_key ? new_key : entry->key);
- qdict_del(qdict, entry->key);
+ if (target == qdict) {
+ qdict_del(qdict, entry->key);
+ }
} else if (target != qdict) {
qdict_put_obj(target, new_key, qobject_ref(value));
- qdict_del(qdict, entry->key);
}
g_free(new_key);
--
2.17.1
- [Qemu-devel] [PULL 00/10] QAPI patches for 2018-06-22, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 02/10] qapi/events: generate event enum in main module, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 08/10] Revert commit d4e5ec877ca, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 03/10] qdict: Make qdict_flatten() shallow-clone-friendly,
Markus Armbruster <=
- [Qemu-devel] [PULL 04/10] tests: Add QDict clone-flatten test, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 05/10] qapi: allow empty branches in flat unions, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 07/10] qapi: Open files with encoding='utf-8', Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 06/10] qapi: remove empty flat union branches and types, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 01/10] qapi/visit: remove useless prefix argument, Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 09/10] qapi/introspect: Eliminate pointless variable in .visit_end(), Markus Armbruster, 2018/06/22
- [Qemu-devel] [PULL 10/10] MAINTAINERS: Update QAPI stanza for commit fb0bc835e56, Markus Armbruster, 2018/06/22
- Re: [Qemu-devel] [PULL 00/10] QAPI patches for 2018-06-22, Peter Maydell, 2018/06/22