1 files changed, 256 insertions, 0 deletions
diff --git a/qapi/qobject-output-visitor.c b/qapi/qobject-output-visitor.c
new file mode 100644
index 0000000000..92c5b5b7bb
--- /dev/null
+++ b/qapi/qobject-output-visitor.c
@@ -0,0 +1,256 @@
+/*
+ * Core Definitions for QAPI/QMP Command Registry
+ *
+ * Copyright (C) 2012-2016 Red Hat, Inc.
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/qobject-output-visitor.h"
+#include "qapi/visitor-impl.h"
+#include "qemu/queue.h"
+#include "qemu-common.h"
+#include "qapi/qmp/types.h"
+
+typedef struct QStackEntry
+{
+    QObject *value;
+    void *qapi; /* sanity check that caller uses same pointer */
+    QSLIST_ENTRY(QStackEntry) node;
+} QStackEntry;
+
+struct QmpOutputVisitor
+{
+    Visitor visitor;
+    QSLIST_HEAD(, QStackEntry) stack; /* Stack of unfinished containers */
+    QObject *root; /* Root of the output visit */
+    QObject **result; /* User's storage location for result */
+};
+
+#define qmp_output_add(qov, name, value) \
+    qmp_output_add_obj(qov, name, QOBJECT(value))
+#define qmp_output_push(qov, value, qapi) \
+    qmp_output_push_obj(qov, QOBJECT(value), qapi)
+
+static QmpOutputVisitor *to_qov(Visitor *v)
+{
+    return container_of(v, QmpOutputVisitor, visitor);
+}
+
+/* Push @value onto the stack of current QObjects being built */
+static void qmp_output_push_obj(QmpOutputVisitor *qov, QObject *value,
+                                void *qapi)
+{
+    QStackEntry *e = g_malloc0(sizeof(*e));
+
+    assert(qov->root);
+    assert(value);
+    e->value = value;
+    e->qapi = qapi;
+    QSLIST_INSERT_HEAD(&qov->stack, e, node);
+}
+
+/* Pop a value off the stack of QObjects being built, and return it. */
+static QObject *qmp_output_pop(QmpOutputVisitor *qov, void *qapi)
+{
+    QStackEntry *e = QSLIST_FIRST(&qov->stack);
+    QObject *value;
+
+    assert(e);
+    assert(e->qapi == qapi);
+    QSLIST_REMOVE_HEAD(&qov->stack, node);
+    value = e->value;
+    assert(value);
+    g_free(e);
+    return value;
+}
+
+/* Add @value to the current QObject being built.
+ * If the stack is visiting a dictionary or list, @value is now owned
+ * by that container. Otherwise, @value is now the root.  */
+static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name,
+                               QObject *value)
+{
+    QStackEntry *e = QSLIST_FIRST(&qov->stack);
+    QObject *cur = e ? e->value : NULL;
+
+    if (!cur) {
+        /* Don't allow reuse of visitor on more than one root */
+        assert(!qov->root);
+        qov->root = value;
+    } else {
+        switch (qobject_type(cur)) {
+        case QTYPE_QDICT:
+            assert(name);
+            qdict_put_obj(qobject_to_qdict(cur), name, value);
+            break;
+        case QTYPE_QLIST:
+            assert(!name);
+            qlist_append_obj(qobject_to_qlist(cur), value);
+            break;
+        default:
+            g_assert_not_reached();
+        }
+    }
+}
+
+static void qmp_output_start_struct(Visitor *v, const char *name, void **obj,
+                                    size_t unused, Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QDict *dict = qdict_new();
+
+    qmp_output_add(qov, name, dict);
+    qmp_output_push(qov, dict, obj);
+}
+
+static void qmp_output_end_struct(Visitor *v, void **obj)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QObject *value = qmp_output_pop(qov, obj);
+    assert(qobject_type(value) == QTYPE_QDICT);
+}
+
+static void qmp_output_start_list(Visitor *v, const char *name,
+                                  GenericList **listp, size_t size,
+                                  Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QList *list = qlist_new();
+
+    qmp_output_add(qov, name, list);
+    qmp_output_push(qov, list, listp);
+}
+
+static GenericList *qmp_output_next_list(Visitor *v, GenericList *tail,
+                                         size_t size)
+{
+    return tail->next;
+}
+
+static void qmp_output_end_list(Visitor *v, void **obj)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QObject *value = qmp_output_pop(qov, obj);
+    assert(qobject_type(value) == QTYPE_QLIST);
+}
+
+static void qmp_output_type_int64(Visitor *v, const char *name, int64_t *obj,
+                                  Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qint_from_int(*obj));
+}
+
+static void qmp_output_type_uint64(Visitor *v, const char *name, uint64_t *obj,
+                                   Error **errp)
+{
+    /* FIXME values larger than INT64_MAX become negative */
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qint_from_int(*obj));
+}
+
+static void qmp_output_type_bool(Visitor *v, const char *name, bool *obj,
+                                 Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qbool_from_bool(*obj));
+}
+
+static void qmp_output_type_str(Visitor *v, const char *name, char **obj,
+                                Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    if (*obj) {
+        qmp_output_add(qov, name, qstring_from_str(*obj));
+    } else {
+        qmp_output_add(qov, name, qstring_from_str(""));
+    }
+}
+
+static void qmp_output_type_number(Visitor *v, const char *name, double *obj,
+                                   Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qfloat_from_double(*obj));
+}
+
+static void qmp_output_type_any(Visitor *v, const char *name, QObject **obj,
+                                Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qobject_incref(*obj);
+    qmp_output_add_obj(qov, name, *obj);
+}
+
+static void qmp_output_type_null(Visitor *v, const char *name, Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add_obj(qov, name, qnull());
+}
+
+/* Finish building, and return the root object.
+ * The root object is never null. The caller becomes the object's
+ * owner, and should use qobject_decref() when done with it.  */
+static void qmp_output_complete(Visitor *v, void *opaque)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+
+    /* A visit must have occurred, with each start paired with end.  */
+    assert(qov->root && QSLIST_EMPTY(&qov->stack));
+    assert(opaque == qov->result);
+
+    qobject_incref(qov->root);
+    *qov->result = qov->root;
+    qov->result = NULL;
+}
+
+static void qmp_output_free(Visitor *v)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QStackEntry *e;
+
+    while (!QSLIST_EMPTY(&qov->stack)) {
+        e = QSLIST_FIRST(&qov->stack);
+        QSLIST_REMOVE_HEAD(&qov->stack, node);
+        g_free(e);
+    }
+
+    qobject_decref(qov->root);
+    g_free(qov);
+}
+
+Visitor *qmp_output_visitor_new(QObject **result)
+{
+    QmpOutputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.type = VISITOR_OUTPUT;
+    v->visitor.start_struct = qmp_output_start_struct;
+    v->visitor.end_struct = qmp_output_end_struct;
+    v->visitor.start_list = qmp_output_start_list;
+    v->visitor.next_list = qmp_output_next_list;
+    v->visitor.end_list = qmp_output_end_list;
+    v->visitor.type_int64 = qmp_output_type_int64;
+    v->visitor.type_uint64 = qmp_output_type_uint64;
+    v->visitor.type_bool = qmp_output_type_bool;
+    v->visitor.type_str = qmp_output_type_str;
+    v->visitor.type_number = qmp_output_type_number;
+    v->visitor.type_any = qmp_output_type_any;
+    v->visitor.type_null = qmp_output_type_null;
+    v->visitor.complete = qmp_output_complete;
+    v->visitor.free = qmp_output_free;
+
+    *result = NULL;
+    v->result = result;
+
+    return &v->visitor;
+}