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-rw-r--r--src/qapi/qmp-output-visitor.c280
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diff --git a/src/qapi/qmp-output-visitor.c b/src/qapi/qmp-output-visitor.c
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+++ b/src/qapi/qmp-output-visitor.c
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+/*
+ * Core Definitions for QAPI/QMP Command Registry
+ *
+ * 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 "qapi/qmp-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;
+ bool is_list_head;
+ QTAILQ_ENTRY(QStackEntry) node;
+} QStackEntry;
+
+typedef QTAILQ_HEAD(QStack, QStackEntry) QStack;
+
+struct QmpOutputVisitor
+{
+ Visitor visitor;
+ /* FIXME: we are abusing stack to hold two separate pieces of
+ * information: the current root object in slot 0, and the stack
+ * of N objects still being built in slots 1 through N (for N+1
+ * slots in use). Worse, our behavior is inconsistent:
+ * qmp_output_add_obj() visiting two top-level scalars in a row
+ * discards the first in favor of the second, but visiting two
+ * top-level objects in a row tries to append the second object
+ * into the first (since the first object was placed in the stack
+ * in both slot 0 and 1, but only popped from slot 1). */
+ QStack stack;
+};
+
+#define qmp_output_add(qov, name, value) \
+ qmp_output_add_obj(qov, name, QOBJECT(value))
+#define qmp_output_push(qov, value) qmp_output_push_obj(qov, QOBJECT(value))
+
+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)
+{
+ QStackEntry *e = g_malloc0(sizeof(*e));
+
+ assert(value);
+ e->value = value;
+ if (qobject_type(e->value) == QTYPE_QLIST) {
+ e->is_list_head = true;
+ }
+ QTAILQ_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)
+{
+ QStackEntry *e = QTAILQ_FIRST(&qov->stack);
+ QObject *value;
+
+ assert(e);
+ QTAILQ_REMOVE(&qov->stack, e, node);
+ value = e->value;
+ assert(value);
+ g_free(e);
+ return value;
+}
+
+/* Grab the root QObject, if any */
+static QObject *qmp_output_first(QmpOutputVisitor *qov)
+{
+ QStackEntry *e = QTAILQ_LAST(&qov->stack, QStack);
+
+ if (!e) {
+ /* No root */
+ return NULL;
+ }
+ assert(e->value);
+ return e->value;
+}
+
+/* Peek at the top of the stack of QObjects being built.
+ * The stack must not be empty. */
+static QObject *qmp_output_last(QmpOutputVisitor *qov)
+{
+ QStackEntry *e = QTAILQ_FIRST(&qov->stack);
+
+ assert(e && e->value);
+ return e->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)
+{
+ QObject *cur;
+
+ if (QTAILQ_EMPTY(&qov->stack)) {
+ /* Stack was empty, track this object as root */
+ qmp_output_push_obj(qov, value);
+ return;
+ }
+
+ cur = qmp_output_last(qov);
+
+ switch (qobject_type(cur)) {
+ case QTYPE_QDICT:
+ assert(name);
+ qdict_put_obj(qobject_to_qdict(cur), name, value);
+ break;
+ case QTYPE_QLIST:
+ qlist_append_obj(qobject_to_qlist(cur), value);
+ break;
+ default:
+ /* The previous root was a scalar, replace it with a new root */
+ /* FIXME this is abusing the stack; see comment above */
+ qobject_decref(qmp_output_pop(qov));
+ assert(QTAILQ_EMPTY(&qov->stack));
+ qmp_output_push_obj(qov, value);
+ break;
+ }
+}
+
+static void qmp_output_start_struct(Visitor *v, void **obj, const char *kind,
+ const char *name, 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);
+}
+
+static void qmp_output_end_struct(Visitor *v, Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qmp_output_pop(qov);
+}
+
+static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ QList *list = qlist_new();
+
+ qmp_output_add(qov, name, list);
+ qmp_output_push(qov, list);
+}
+
+static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp,
+ Error **errp)
+{
+ GenericList *list = *listp;
+ QmpOutputVisitor *qov = to_qov(v);
+ QStackEntry *e = QTAILQ_FIRST(&qov->stack);
+
+ assert(e);
+ if (e->is_list_head) {
+ e->is_list_head = false;
+ return list;
+ }
+
+ return list ? list->next : NULL;
+}
+
+static void qmp_output_end_list(Visitor *v, Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qmp_output_pop(qov);
+}
+
+static void qmp_output_type_int(Visitor *v, int64_t *obj, const char *name,
+ Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qmp_output_add(qov, name, qint_from_int(*obj));
+}
+
+static void qmp_output_type_bool(Visitor *v, bool *obj, const char *name,
+ Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qmp_output_add(qov, name, qbool_from_bool(*obj));
+}
+
+static void qmp_output_type_str(Visitor *v, char **obj, const char *name,
+ 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, double *obj, const char *name,
+ Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qmp_output_add(qov, name, qfloat_from_double(*obj));
+}
+
+static void qmp_output_type_any(Visitor *v, QObject **obj, const char *name,
+ Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qobject_incref(*obj);
+ qmp_output_add_obj(qov, name, *obj);
+}
+
+/* Finish building, and return the root object. Will not be NULL. */
+QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
+{
+ QObject *obj = qmp_output_first(qov);
+ if (obj) {
+ qobject_incref(obj);
+ } else {
+ obj = qnull();
+ }
+ return obj;
+}
+
+Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
+{
+ return &v->visitor;
+}
+
+void qmp_output_visitor_cleanup(QmpOutputVisitor *v)
+{
+ QStackEntry *e, *tmp;
+
+ /* The bottom QStackEntry, if any, owns the root QObject. See the
+ * qmp_output_push_obj() invocations in qmp_output_add_obj(). */
+ QObject *root = QTAILQ_EMPTY(&v->stack) ? NULL : qmp_output_first(v);
+
+ QTAILQ_FOREACH_SAFE(e, &v->stack, node, tmp) {
+ QTAILQ_REMOVE(&v->stack, e, node);
+ g_free(e);
+ }
+
+ qobject_decref(root);
+ g_free(v);
+}
+
+QmpOutputVisitor *qmp_output_visitor_new(void)
+{
+ QmpOutputVisitor *v;
+
+ v = g_malloc0(sizeof(*v));
+
+ 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_enum = output_type_enum;
+ v->visitor.type_int = qmp_output_type_int;
+ 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;
+
+ QTAILQ_INIT(&v->stack);
+
+ return v;
+}
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