xref: /qemu/include/qapi/qobject-input-visitor.h (revision 6402cbbb)
1 /*
2  * Input Visitor
3  *
4  * Copyright (C) 2017 Red Hat, Inc.
5  * Copyright IBM, Corp. 2011
6  *
7  * Authors:
8  *  Anthony Liguori   <aliguori@us.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
11  * See the COPYING.LIB file in the top-level directory.
12  *
13  */
14 
15 #ifndef QOBJECT_INPUT_VISITOR_H
16 #define QOBJECT_INPUT_VISITOR_H
17 
18 #include "qapi/visitor.h"
19 #include "qapi/qmp/qobject.h"
20 
21 typedef struct QObjectInputVisitor QObjectInputVisitor;
22 
23 /*
24  * Create a QObject input visitor for @obj
25  *
26  * A QObject input visitor visit builds a QAPI object from a QObject.
27  * This simultaneously walks the QAPI object being built and the
28  * QObject.  The latter walk starts at @obj.
29  *
30  * visit_type_FOO() creates an instance of QAPI type FOO.  The visited
31  * QObject must match FOO.  QDict matches struct/union types, QList
32  * matches list types, QString matches type 'str' and enumeration
33  * types, QNum matches integer and float types, QBool matches type
34  * 'bool'.  Type 'any' is matched by QObject.  A QAPI alternate type
35  * is matched when one of its member types is.
36  *
37  * visit_start_struct() ... visit_end_struct() visits a QDict and
38  * creates a QAPI struct/union.  Visits in between visit the
39  * dictionary members.  visit_optional() is true when the QDict has
40  * this member.  visit_check_struct() fails if unvisited members
41  * remain.
42  *
43  * visit_start_list() ... visit_end_list() visits a QList and creates
44  * a QAPI list.  Visits in between visit list members, one after the
45  * other.  visit_next_list() returns NULL when all QList members have
46  * been visited.  visit_check_list() fails if unvisited members
47  * remain.
48  *
49  * visit_start_alternate() ... visit_end_alternate() visits a QObject
50  * and creates a QAPI alternate.  The visit in between visits the same
51  * QObject and initializes the alternate member that is in use.
52  *
53  * Error messages refer to parts of @obj in JavaScript/Python syntax.
54  * For example, 'a.b[2]' refers to the second member of the QList
55  * member 'b' of the QDict member 'a' of QDict @obj.
56  *
57  * The caller is responsible for freeing the visitor with
58  * visit_free().
59  */
60 Visitor *qobject_input_visitor_new(QObject *obj);
61 
62 /*
63  * Create a QObject input visitor for @obj for use with keyval_parse()
64  *
65  * This is like qobject_input_visitor_new(), except scalars are all
66  * QString, and error messages refer to parts of @obj in the syntax
67  * keyval_parse() uses for KEYs.
68  */
69 Visitor *qobject_input_visitor_new_keyval(QObject *obj);
70 
71 /*
72  * Create a QObject input visitor for parsing @str.
73  *
74  * If @str looks like JSON, parse it as JSON, else as KEY=VALUE,...
75  * @implied_key applies to KEY=VALUE, and works as in keyval_parse().
76  * On failure, store an error through @errp and return NULL.
77  * On success, return a new QObject input visitor for the parse.
78  */
79 Visitor *qobject_input_visitor_new_str(const char *str,
80                                        const char *implied_key,
81                                        Error **errp);
82 
83 #endif
84