qjson.c

   1 /*
   2  * QEMU JSON writer
   3  *
   4  * Copyright Alexander Graf
   5  *
   6  * Authors:
   7  *  Alexander Graf <agraf@suse.de>
   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 #include <qapi/qmp/qstring.h>
  15 #include <stdbool.h>
  16 #include <glib.h>
  17 #include <qjson.h>
  18 #include <qemu/module.h>
  19 #include <qom/object.h>
  20
  21 struct QJSON {
  22     Object obj;
  23     QString *str;
  24     bool omit_comma;
  25 };
  26
  27 static void json_emit_element(QJSON *json, const char *name)
  28 {
  29     /* Check whether we need to print a , before an element */
  30     if (json->omit_comma) {
  31         json->omit_comma = false;
  32     } else {
  33         qstring_append(json->str, ", ");
  34     }
  35
  36     if (name) {
  37         qstring_append(json->str, "\"");
  38         qstring_append(json->str, name);
  39         qstring_append(json->str, "\" : ");
  40     }
  41 }
  42
  43 void json_start_object(QJSON *json, const char *name)
  44 {
  45     json_emit_element(json, name);
  46     qstring_append(json->str, "{ ");
  47     json->omit_comma = true;
  48 }
  49
  50 void json_end_object(QJSON *json)
  51 {
  52     qstring_append(json->str, " }");
  53     json->omit_comma = false;
  54 }
  55
  56 void json_start_array(QJSON *json, const char *name)
  57 {
  58     json_emit_element(json, name);
  59     qstring_append(json->str, "[ ");
  60     json->omit_comma = true;
  61 }
  62
  63 void json_end_array(QJSON *json)
  64 {
  65     qstring_append(json->str, " ]");
  66     json->omit_comma = false;
  67 }
  68
  69 void json_prop_int(QJSON *json, const char *name, int64_t val)
  70 {
  71     json_emit_element(json, name);
  72     qstring_append_int(json->str, val);
  73 }
  74
  75 void json_prop_str(QJSON *json, const char *name, const char *str)
  76 {
  77     json_emit_element(json, name);
  78     qstring_append_chr(json->str, '"');
  79     qstring_append(json->str, str);
  80     qstring_append_chr(json->str, '"');
  81 }
  82
  83 const char *qjson_get_str(QJSON *json)
  84 {
  85     return qstring_get_str(json->str);
  86 }
  87
  88 QJSON *qjson_new(void)
  89 {
  90     QJSON *json = (QJSON *)object_new(TYPE_QJSON);
  91     return json;
  92 }
  93
  94 void qjson_finish(QJSON *json)
  95 {
  96     json_end_object(json);
  97 }
  98
  99 static void qjson_initfn(Object *obj)
 100 {
 101     QJSON *json = (QJSON *)object_dynamic_cast(obj, TYPE_QJSON);
 102     assert(json);
 103
 104     json->str = qstring_from_str("{ ");
 105     json->omit_comma = true;
 106 }
 107
 108 static void qjson_finalizefn(Object *obj)
 109 {
 110     QJSON *json = (QJSON *)object_dynamic_cast(obj, TYPE_QJSON);
 111
 112     assert(json);
 113     qobject_decref(QOBJECT(json->str));
 114 }
 115
 116 static const TypeInfo qjson_type_info = {
 117     .name = TYPE_QJSON,
 118     .parent = TYPE_OBJECT,
 119     .instance_size = sizeof(QJSON),
 120     .instance_init = qjson_initfn,
 121     .instance_finalize = qjson_finalizefn,
 122 };
 123
 124 static void qjson_register_types(void)
 125 {
 126     type_register_static(&qjson_type_info);
 127 }
 128
 129 type_init(qjson_register_types)