include/qapi/qobject-output-visitor.h

   1 /*
   2  * Output Visitor
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  10  * See the COPYING.LIB file in the top-level directory.
  11  *
  12  */
  13
  14 #ifndef QOBJECT_OUTPUT_VISITOR_H
  15 #define QOBJECT_OUTPUT_VISITOR_H
  16
  17 #include "qapi/visitor.h"
  18
  19 typedef struct QObjectOutputVisitor QObjectOutputVisitor;
  20
  21 /**
  22  * Create a QObject output visitor for @obj
  23  *
  24  * A QObject output visitor visit builds a QObject from QAPI Object.
  25  * This simultaneously walks the QAPI object and the QObject being
  26  * built.  The latter walk starts at @obj.
  27  *
  28  * visit_type_FOO() creates a QObject for QAPI type FOO.  It creates a
  29  * QDict for struct/union types, a QList for list types, QString for
  30  * type 'str' and enumeration types, QNum for integer and float
  31  * types, QBool for type 'bool'.  For type 'any', it increments the
  32  * QObject's reference count.  For QAPI alternate types, it creates
  33  * the QObject for the member that is in use.
  34  *
  35  * visit_start_struct() ... visit_end_struct() visits a QAPI
  36  * struct/union and creates a QDict.  Visits in between visit the
  37  * members.  visit_optional() is true when the struct/union has this
  38  * member.  visit_check_struct() does nothing.
  39  *
  40  * visit_start_list() ... visit_end_list() visits a QAPI list and
  41  * creates a QList.  Visits in between visit list members, one after
  42  * the other.  visit_next_list() returns NULL when all QAPI list
  43  * members have been visited.  visit_check_list() does nothing.
  44  *
  45  * visit_start_alternate() ... visit_end_alternate() visits a QAPI
  46  * alternate.  The visit in between creates the QObject for the
  47  * alternate member that is in use.
  48  *
  49  * Errors are not expected to happen.
  50  *
  51  * The caller is responsible for freeing the visitor with
  52  * visit_free().
  53  */
  54 Visitor *qobject_output_visitor_new(QObject **result);
  55
  56 #endif