[Qemu-devel] [PATCH v6 04/22] qapi: extend qdict_flatten() for QLists

[Max Reitz <mreitz@redhat.com>]

Reversing qdict_array_split(), qdict_flatten() should flatten QLists as
well by interpreting them as QDicts where every entry's key is its
index.

This allows bringing QDicts with QLists from QMP commands to the same
form as they would be given as command-line options, thereby allowing
them to be parsed the same way.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 qobject/qdict.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 51 insertions(+), 6 deletions(-)

diff --git a/qobject/qdict.c b/qobject/qdict.c
index fca1902..7b6b08a 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -477,7 +477,46 @@ static void qdict_destroy_obj(QObject *obj)
     g_free(qdict);
 }
 
-static void qdict_do_flatten(QDict *qdict, QDict *target, const char *prefix)
+static void qdict_flatten_qdict(QDict *qdict, QDict *target,
+                                const char *prefix);
+
+static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix)
+{
+    QObject *value;
+    const QListEntry *entry;
+    char *new_key;
+    int i;
+
+    /* This function is never called with prefix == NULL, i.e., it is always
+     * called from within qdict_flatten_q(list|dict)(). Therefore, it does not
+     * need to remove list entries during the iteration (the whole list will be
+     * deleted eventually anyway from qdict_flatten_qdict()). */
+    assert(prefix);
+
+    entry = qlist_first(qlist);
+
+    for (i = 0; entry; entry = qlist_next(entry), i++) {
+        value = qlist_entry_obj(entry);
+
+        qobject_incref(value);
+        new_key = g_strdup_printf("%s.%i", prefix, i);
+        qdict_put_obj(target, new_key, value);
+
+        if (qobject_type(value) == QTYPE_QDICT) {
+            qdict_flatten_qdict(qobject_to_qdict(value), target, new_key);
+        } else if (qobject_type(value) == QTYPE_QLIST) {
+            qdict_flatten_qlist(qobject_to_qlist(value), target, new_key);
+        } else {
+            /* All other types are moved to the target unchanged. */
+            qobject_incref(value);
+            qdict_put_obj(target, new_key, value);
+        }
+
+        g_free(new_key);
+    }
+}
+
+static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix)
 {
     QObject *value;
     const QDictEntry *entry, *next;
@@ -500,8 +539,12 @@ static void qdict_do_flatten(QDict *qdict, QDict *target, const char *prefix)
         if (qobject_type(value) == QTYPE_QDICT) {
             /* Entries of QDicts are processed recursively, the QDict object
              * itself disappears. */
-            qdict_do_flatten(qobject_to_qdict(value), target,
-                             new_key ? new_key : entry->key);
+            qdict_flatten_qdict(qobject_to_qdict(value), target,
+                                new_key ? new_key : entry->key);
+            delete = true;
+        } else if (qobject_type(value) == QTYPE_QLIST) {
+            qdict_flatten_qlist(qobject_to_qlist(value), target,
+                                new_key ? new_key : entry->key);
             delete = true;
         } else if (prefix) {
             /* All other objects are moved to the target unchanged. */
@@ -526,12 +569,14 @@ static void qdict_do_flatten(QDict *qdict, QDict *target, const char *prefix)
 
 /**
  * qdict_flatten(): For each nested QDict with key x, all fields with key y
- * are moved to this QDict and their key is renamed to "x.y". This operation
- * is applied recursively for nested QDicts.
+ * are moved to this QDict and their key is renamed to "x.y". For each nested
+ * QList with key x, the field at index y is moved to this QDict with the key
+ * "x.y" (i.e., the reverse of what qdict_array_split() does).
+ * This operation is applied recursively for nested QDicts and QLists.
  */
 void qdict_flatten(QDict *qdict)
 {
-    qdict_do_flatten(qdict, qdict, NULL);
+    qdict_flatten_qdict(qdict, qdict, NULL);
 }
 
 /* extract all the src QDict entries starting by start into dst */
-- 
1.8.5.1