include/qapi/qobject-input-visitor.h

   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
  20 typedef struct QObjectInputVisitor QObjectInputVisitor;
  21
  22 /*
  23  * Create a QObject input visitor for @obj
  24  *
  25  * A QObject input visitor visit builds a QAPI object from a QObject.
  26  * This simultaneously walks the QAPI object being built and the
  27  * QObject.  The latter walk starts at @obj.
  28  *
  29  * visit_type_FOO() creates an instance of QAPI type FOO.  The visited
  30  * QObject must match FOO.  QDict matches struct/union types, QList
  31  * matches list types, QString matches type 'str' and enumeration
  32  * types, QNum matches integer and float types, QBool matches type
  33  * 'bool'.  Type 'any' is matched by QObject.  A QAPI alternate type
  34  * is matched when one of its member types is.
  35  *
  36  * visit_start_struct() ... visit_end_struct() visits a QDict and
  37  * creates a QAPI struct/union.  Visits in between visit the
  38  * dictionary members.  visit_optional() is true when the QDict has
  39  * this member.  visit_check_struct() fails if unvisited members
  40  * remain.
  41  *
  42  * visit_start_list() ... visit_end_list() visits a QList and creates
  43  * a QAPI list.  Visits in between visit list members, one after the
  44  * other.  visit_next_list() returns NULL when all QList members have
  45  * been visited.  visit_check_list() fails if unvisited members
  46  * remain.
  47  *
  48  * visit_start_alternate() ... visit_end_alternate() visits a QObject
  49  * and creates a QAPI alternate.  The visit in between visits the same
  50  * QObject and initializes the alternate member that is in use.
  51  *
  52  * Error messages refer to parts of @obj in JavaScript/Python syntax.
  53  * For example, 'a.b[2]' refers to the second member of the QList
  54  * member 'b' of the QDict member 'a' of QDict @obj.
  55  *
  56  * The caller is responsible for freeing the visitor with
  57  * visit_free().
  58  */
  59 Visitor *qobject_input_visitor_new(QObject *obj);
  60
  61 /*
  62  * Create a QObject input visitor for @obj for use with keyval_parse()
  63  *
  64  * This is like qobject_input_visitor_new(), except scalars are all
  65  * QString, and error messages refer to parts of @obj in the syntax
  66  * keyval_parse() uses for KEYs.
  67  */
  68 Visitor *qobject_input_visitor_new_keyval(QObject *obj);
  69
  70 /*
  71  * Create a QObject input visitor for parsing @str.
  72  *
  73  * If @str looks like JSON, parse it as JSON, else as KEY=VALUE,...
  74  * @implied_key applies to KEY=VALUE, and works as in keyval_parse().
  75  * On failure, store an error through @errp and return NULL.
  76  * On success, return a new QObject input visitor for the parse.
  77  */
  78 GCC_FMT_ATTR(1, 0)
  79 Visitor *qobject_input_visitor_new_str(const char *str,
  80                                        const char *implied_key,
  81                                        Error **errp);
  82
  83 #endif