]>
git.proxmox.com Git - mirror_qemu.git/blob - include/qapi/visitor-impl.h
2 * Core Definitions for QAPI Visitor implementations
4 * Copyright (C) 2012-2016 Red Hat, Inc.
6 * Author: Paolo Bonizni <pbonzini@redhat.com>
8 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
9 * See the COPYING.LIB file in the top-level directory.
12 #ifndef QAPI_VISITOR_IMPL_H
13 #define QAPI_VISITOR_IMPL_H
15 #include "qapi/visitor.h"
18 * This file describes the callback interface for implementing a QAPI
19 * visitor. For the client interface, see visitor.h. When
20 * implementing the callbacks, it is easiest to declare a struct with
21 * 'Visitor visitor;' as the first member. A callback's contract
22 * matches the corresponding public functions' contract unless stated
23 * otherwise. In the comments below, some callbacks are marked "must
24 * be set for $TYPE visits to work"; if a visitor implementation omits
25 * that callback, it should also document that it is only useful for a
30 * There are three classes of visitors; setting the class determines
31 * how QAPI enums are visited, as well as what additional restrictions
34 typedef enum VisitorType
{
42 /* Must be set to visit structs */
43 void (*start_struct
)(Visitor
*v
, const char *name
, void **obj
,
44 size_t size
, Error
**errp
);
46 /* Optional; intended for input visitors */
47 void (*check_struct
)(Visitor
*v
, Error
**errp
);
49 /* Must be set to visit structs */
50 void (*end_struct
)(Visitor
*v
, void **obj
);
52 /* Must be set; implementations may require @list to be non-null,
53 * but must document it. */
54 void (*start_list
)(Visitor
*v
, const char *name
, GenericList
**list
,
55 size_t size
, Error
**errp
);
58 GenericList
*(*next_list
)(Visitor
*v
, GenericList
*tail
, size_t size
);
61 void (*end_list
)(Visitor
*v
, void **list
);
63 /* Must be set by input and dealloc visitors to visit alternates;
64 * optional for output visitors. */
65 void (*start_alternate
)(Visitor
*v
, const char *name
,
66 GenericAlternate
**obj
, size_t size
,
67 bool promote_int
, Error
**errp
);
69 /* Optional, needed for dealloc visitor */
70 void (*end_alternate
)(Visitor
*v
, void **obj
);
73 void (*type_int64
)(Visitor
*v
, const char *name
, int64_t *obj
,
77 void (*type_uint64
)(Visitor
*v
, const char *name
, uint64_t *obj
,
80 /* Optional; fallback is type_uint64() */
81 void (*type_size
)(Visitor
*v
, const char *name
, uint64_t *obj
,
85 void (*type_bool
)(Visitor
*v
, const char *name
, bool *obj
, Error
**errp
);
88 void (*type_str
)(Visitor
*v
, const char *name
, char **obj
, Error
**errp
);
90 /* Must be set to visit numbers */
91 void (*type_number
)(Visitor
*v
, const char *name
, double *obj
,
94 /* Must be set to visit arbitrary QTypes */
95 void (*type_any
)(Visitor
*v
, const char *name
, QObject
**obj
,
98 /* Must be set to visit explicit null values. */
99 void (*type_null
)(Visitor
*v
, const char *name
, Error
**errp
);
101 /* Must be set for input visitors, optional otherwise. The core
102 * takes care of the return type in the public interface. */
103 void (*optional
)(Visitor
*v
, const char *name
, bool *present
);
109 void (*free
)(Visitor
*v
);