1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/*
* Core Definitions for QAPI Visitor implementations
*
* Copyright (C) 2012-2016 Red Hat, Inc.
*
* Author: Paolo Bonizni <pbonzini@redhat.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.
*
*/
#ifndef QAPI_VISITOR_IMPL_H
#define QAPI_VISITOR_IMPL_H
#include "qapi/visitor.h"
/*
* This file describes the callback interface for implementing a QAPI
* visitor. For the client interface, see visitor.h. When
* implementing the callbacks, it is easiest to declare a struct with
* 'Visitor visitor;' as the first member. A callback's contract
* matches the corresponding public functions' contract unless stated
* otherwise. In the comments below, some callbacks are marked "must
* be set for $TYPE visits to work"; if a visitor implementation omits
* that callback, it should also document that it is only useful for a
* subset of QAPI.
*/
/*
* There are four classes of visitors; setting the class determines
* how QAPI enums are visited, as well as what additional restrictions
* can be asserted. The values are intentionally chosen so as to
* permit some assertions based on whether a given bit is set (that
* is, some assertions apply to input and clone visitors, some
* assertions apply to output and clone visitors).
*/
typedef enum VisitorType {
VISITOR_INPUT = 1,
VISITOR_OUTPUT = 2,
VISITOR_CLONE = 3,
VISITOR_DEALLOC = 4,
} VisitorType;
struct Visitor
{
/*
* Only input visitors may fail!
*/
/* Must be set to visit structs */
bool (*start_struct)(Visitor *v, const char *name, void **obj,
size_t size, Error **errp);
/* Optional; intended for input visitors */
bool (*check_struct)(Visitor *v, Error **errp);
/* Must be set to visit structs */
void (*end_struct)(Visitor *v, void **obj);
/* Must be set; implementations may require @list to be non-null,
* but must document it. */
bool (*start_list)(Visitor *v, const char *name, GenericList **list,
size_t size, Error **errp);
/* Must be set */
GenericList *(*next_list)(Visitor *v, GenericList *tail, size_t size);
/* Optional; intended for input visitors */
bool (*check_list)(Visitor *v, Error **errp);
/* Must be set */
void (*end_list)(Visitor *v, void **list);
/* Must be set by input and clone visitors to visit alternates */
bool (*start_alternate)(Visitor *v, const char *name,
GenericAlternate **obj, size_t size,
Error **errp);
/* Optional */
void (*end_alternate)(Visitor *v, void **obj);
/* Must be set */
bool (*type_int64)(Visitor *v, const char *name, int64_t *obj,
Error **errp);
/* Must be set */
bool (*type_uint64)(Visitor *v, const char *name, uint64_t *obj,
Error **errp);
/* Optional; fallback is type_uint64() */
bool (*type_size)(Visitor *v, const char *name, uint64_t *obj,
Error **errp);
/* Must be set */
bool (*type_bool)(Visitor *v, const char *name, bool *obj, Error **errp);
/* Must be set */
bool (*type_str)(Visitor *v, const char *name, char **obj, Error **errp);
/* Must be set to visit numbers */
bool (*type_number)(Visitor *v, const char *name, double *obj,
Error **errp);
/* Must be set to visit arbitrary QTypes */
bool (*type_any)(Visitor *v, const char *name, QObject **obj,
Error **errp);
/* Must be set to visit explicit null values. */
bool (*type_null)(Visitor *v, const char *name, QNull **obj,
Error **errp);
/* Must be set for input visitors to visit structs, optional otherwise.
The core takes care of the return type in the public interface. */
void (*optional)(Visitor *v, const char *name, bool *present);
/* Optional */
bool (*deprecated_accept)(Visitor *v, const char *name, Error **errp);
/* Optional */
bool (*deprecated)(Visitor *v, const char *name);
/* Must be set */
VisitorType type;
/* Must be set for output visitors, optional otherwise. */
void (*complete)(Visitor *v, void *opaque);
/* Must be set */
void (*free)(Visitor *v);
};
#endif
|
