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 #define QJSON(obj) OBJECT_CHECK(QJSON, (obj), TYPE_QJSON)
  28
  29 static void json_emit_element(QJSON *json, const char *name)
  30 {
  31     /* Check whether we need to print a , before an element */
  32     if (json->omit_comma) {
  33         json->omit_comma = false;
  34     } else {
  35         qstring_append(json->str, ", ");
  36     }
  37
  38     if (name) {
  39         qstring_append(json->str, "\"");
  40         qstring_append(json->str, name);
  41         qstring_append(json->str, "\" : ");
  42     }
  43 }
  44
  45 void json_start_object(QJSON *json, const char *name)
  46 {
  47     json_emit_element(json, name);
  48     qstring_append(json->str, "{ ");
  49     json->omit_comma = true;
  50 }
  51
  52 void json_end_object(QJSON *json)
  53 {
  54     qstring_append(json->str, " }");
  55     json->omit_comma = false;
  56 }
  57
  58 void json_start_array(QJSON *json, const char *name)
  59 {
  60     json_emit_element(json, name);
  61     qstring_append(json->str, "[ ");
  62     json->omit_comma = true;
  63 }
  64
  65 void json_end_array(QJSON *json)
  66 {
  67     qstring_append(json->str, " ]");
  68     json->omit_comma = false;
  69 }
  70
  71 void json_prop_int(QJSON *json, const char *name, int64_t val)
  72 {
  73     json_emit_element(json, name);
  74     qstring_append_int(json->str, val);
  75 }
  76
  77 void json_prop_str(QJSON *json, const char *name, const char *str)
  78 {
  79     json_emit_element(json, name);
  80     qstring_append_chr(json->str, '"');
  81     qstring_append(json->str, str);
  82     qstring_append_chr(json->str, '"');
  83 }
  84
  85 const char *qjson_get_str(QJSON *json)
  86 {
  87     return qstring_get_str(json->str);
  88 }
  89
  90 QJSON *qjson_new(void)
  91 {
  92     QJSON *json = QJSON(object_new(TYPE_QJSON));
  93     return json;
  94 }
  95
  96 void qjson_finish(QJSON *json)
  97 {
  98     json_end_object(json);
  99 }
 100
 101 static void qjson_initfn(Object *obj)
 102 {
 103     QJSON *json = QJSON(obj);
 104
 105     json->str = qstring_from_str("{ ");
 106     json->omit_comma = true;
 107 }
 108
 109 static void qjson_finalizefn(Object *obj)
 110 {
 111     QJSON *json = QJSON(obj);
 112
 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)