From 08ab287975f409e420863a8d39e3b3add8ca6088 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones@redhat.com>
Date: Tue, 2 Jun 2015 09:46:36 +0200
Subject: [PATCH 2/4] qdict: Add qdict_join()

Message-id: <1433238397-2500-2-git-send-email-rjones@redhat.com>
Patchwork-id: 65278
O-Subject: [RHEL-7.2 qemu-kvm PATCH 1/2] qdict: Add qdict_join()
Bugzilla: 1226697
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

From: Max Reitz <mreitz@redhat.com>

This function joins two QDicts by absorbing one into the other.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 include/qapi/qmp/qdict.h |  3 +++
 qobject/qdict.c          | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h
index d6855d1..fc6e2f2 100644
--- a/include/qapi/qmp/qdict.h
+++ b/include/qapi/qmp/qdict.h
@@ -16,6 +16,7 @@
 #include "qapi/qmp/qobject.h"
 #include "qapi/qmp/qlist.h"
 #include "qemu/queue.h"
+#include <stdbool.h>
 #include <stdint.h>
 
 #define QDICT_BUCKET_MAX 512
@@ -67,4 +68,6 @@ const char *qdict_get_try_str(const QDict *qdict, const char *key);
 QDict *qdict_clone_shallow(const QDict *src);
 void qdict_flatten(QDict *qdict);
 
+void qdict_join(QDict *dest, QDict *src, bool overwrite);
+
 #endif /* QDICT_H */
diff --git a/qobject/qdict.c b/qobject/qdict.c
index 472f106..c7e35ae 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -527,3 +527,35 @@ void qdict_flatten(QDict *qdict)
 {
     qdict_do_flatten(qdict, qdict, NULL);
 }
+
+/**
+ * qdict_join(): Absorb the src QDict into the dest QDict, that is, move all
+ * elements from src to dest.
+ *
+ * If an element from src has a key already present in dest, it will not be
+ * moved unless overwrite is true.
+ *
+ * If overwrite is true, the conflicting values in dest will be discarded and
+ * replaced by the corresponding values from src.
+ *
+ * Therefore, with overwrite being true, the src QDict will always be empty when
+ * this function returns. If overwrite is false, the src QDict will be empty
+ * iff there were no conflicts.
+ */
+void qdict_join(QDict *dest, QDict *src, bool overwrite)
+{
+    const QDictEntry *entry, *next;
+
+    entry = qdict_first(src);
+    while (entry) {
+        next = qdict_next(src, entry);
+
+        if (overwrite || !qdict_haskey(dest, entry->key)) {
+            qobject_incref(entry->value);
+            qdict_put_obj(dest, entry->key, entry->value);
+            qdict_del(src, entry->key);
+        }
+
+        entry = next;
+    }
+}
-- 
1.8.3.1