qemu/qobject/qjson.c

   1 /*
   2  * QObject JSON integration
   3  *
   4  * Copyright IBM, Corp. 2009
   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 #include "qapi/qmp/json-lexer.h"
  15 #include "qapi/qmp/json-parser.h"
  16 #include "qapi/qmp/json-streamer.h"
  17 #include "qapi/qmp/qjson.h"
  18 #include "qapi/qmp/qint.h"
  19 #include "qapi/qmp/qlist.h"
  20 #include "qapi/qmp/qbool.h"
  21 #include "qapi/qmp/qfloat.h"
  22 #include "qapi/qmp/qdict.h"
  23
  24 typedef struct JSONParsingState
  25 {
  26     JSONMessageParser parser;
  27     va_list *ap;
  28     QObject *result;
  29 } JSONParsingState;
  30
  31 static void parse_json(JSONMessageParser *parser, QList *tokens)
  32 {
  33     JSONParsingState *s = container_of(parser, JSONParsingState, parser);
  34     s->result = json_parser_parse(tokens, s->ap);
  35 }
  36
  37 QObject *qobject_from_jsonv(const char *string, va_list *ap)
  38 {
  39     JSONParsingState state = {};
  40
  41     state.ap = ap;
  42
  43     json_message_parser_init(&state.parser, parse_json);
  44     json_message_parser_feed(&state.parser, string, strlen(string));
  45     json_message_parser_flush(&state.parser);
  46     json_message_parser_destroy(&state.parser);
  47
  48     return state.result;
  49 }
  50
  51 QObject *qobject_from_json(const char *string)
  52 {
  53     return qobject_from_jsonv(string, NULL);
  54 }
  55
  56 /*
  57  * IMPORTANT: This function aborts on error, thus it must not
  58  * be used with untrusted arguments.
  59  */
  60 QObject *qobject_from_jsonf(const char *string, ...)
  61 {
  62     QObject *obj;
  63     va_list ap;
  64
  65     va_start(ap, string);
  66     obj = qobject_from_jsonv(string, &ap);
  67     va_end(ap);
  68
  69     assert(obj != NULL);
  70     return obj;
  71 }
  72
  73 typedef struct ToJsonIterState
  74 {
  75     int indent;
  76     int pretty;
  77     int count;
  78     QString *str;
  79 } ToJsonIterState;
  80
  81 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
  82
  83 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
  84 {
  85     ToJsonIterState *s = opaque;
  86     QString *qkey;
  87     int j;
  88
  89     if (s->count) {
  90         qstring_append(s->str, s->pretty ? "," : ", ");
  91     }
  92
  93     if (s->pretty) {
  94         qstring_append(s->str, "\n");
  95         for (j = 0 ; j < s->indent ; j++)
  96             qstring_append(s->str, "    ");
  97     }
  98
  99     qkey = qstring_from_str(key);
 100     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
 101     QDECREF(qkey);
 102
 103     qstring_append(s->str, ": ");
 104     to_json(obj, s->str, s->pretty, s->indent);
 105     s->count++;
 106 }
 107
 108 static void to_json_list_iter(QObject *obj, void *opaque)
 109 {
 110     ToJsonIterState *s = opaque;
 111     int j;
 112
 113     if (s->count) {
 114         qstring_append(s->str, s->pretty ? "," : ", ");
 115     }
 116
 117     if (s->pretty) {
 118         qstring_append(s->str, "\n");
 119         for (j = 0 ; j < s->indent ; j++)
 120             qstring_append(s->str, "    ");
 121     }
 122
 123     to_json(obj, s->str, s->pretty, s->indent);
 124     s->count++;
 125 }
 126
 127 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 128 {
 129     switch (qobject_type(obj)) {
 130     case QTYPE_QNULL:
 131         qstring_append(str, "null");
 132         break;
 133     case QTYPE_QINT: {
 134         QInt *val = qobject_to_qint(obj);
 135         char buffer[1024];
 136
 137         snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
 138         qstring_append(str, buffer);
 139         break;
 140     }
 141     case QTYPE_QSTRING: {
 142         QString *val = qobject_to_qstring(obj);
 143         const char *ptr;
 144         int cp;
 145         char buf[16];
 146         char *end;
 147
 148         ptr = qstring_get_str(val);
 149         qstring_append(str, "\"");
 150
 151         for (; *ptr; ptr = end) {
 152             cp = mod_utf8_codepoint(ptr, 6, &end);
 153             switch (cp) {
 154             case '\"':
 155                 qstring_append(str, "\\\"");
 156                 break;
 157             case '\\':
 158                 qstring_append(str, "\\\\");
 159                 break;
 160             case '\b':
 161                 qstring_append(str, "\\b");
 162                 break;
 163             case '\f':
 164                 qstring_append(str, "\\f");
 165                 break;
 166             case '\n':
 167                 qstring_append(str, "\\n");
 168                 break;
 169             case '\r':
 170                 qstring_append(str, "\\r");
 171                 break;
 172             case '\t':
 173                 qstring_append(str, "\\t");
 174                 break;
 175             default:
 176                 if (cp < 0) {
 177                     cp = 0xFFFD; /* replacement character */
 178                 }
 179                 if (cp > 0xFFFF) {
 180                     /* beyond BMP; need a surrogate pair */
 181                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
 182                              0xD800 + ((cp - 0x10000) >> 10),
 183                              0xDC00 + ((cp - 0x10000) & 0x3FF));
 184                 } else if (cp < 0x20 || cp >= 0x7F) {
 185                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
 186                 } else {
 187                     buf[0] = cp;
 188                     buf[1] = 0;
 189                 }
 190                 qstring_append(str, buf);
 191             }
 192         };
 193
 194         qstring_append(str, "\"");
 195         break;
 196     }
 197     case QTYPE_QDICT: {
 198         ToJsonIterState s;
 199         QDict *val = qobject_to_qdict(obj);
 200
 201         s.count = 0;
 202         s.str = str;
 203         s.indent = indent + 1;
 204         s.pretty = pretty;
 205         qstring_append(str, "{");
 206         qdict_iter(val, to_json_dict_iter, &s);
 207         if (pretty) {
 208             int j;
 209             qstring_append(str, "\n");
 210             for (j = 0 ; j < indent ; j++)
 211                 qstring_append(str, "    ");
 212         }
 213         qstring_append(str, "}");
 214         break;
 215     }
 216     case QTYPE_QLIST: {
 217         ToJsonIterState s;
 218         QList *val = qobject_to_qlist(obj);
 219
 220         s.count = 0;
 221         s.str = str;
 222         s.indent = indent + 1;
 223         s.pretty = pretty;
 224         qstring_append(str, "[");
 225         qlist_iter(val, (void *)to_json_list_iter, &s);
 226         if (pretty) {
 227             int j;
 228             qstring_append(str, "\n");
 229             for (j = 0 ; j < indent ; j++)
 230                 qstring_append(str, "    ");
 231         }
 232         qstring_append(str, "]");
 233         break;
 234     }
 235     case QTYPE_QFLOAT: {
 236         QFloat *val = qobject_to_qfloat(obj);
 237         char buffer[1024];
 238         int len;
 239
 240         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
 241         while (len > 0 && buffer[len - 1] == '0') {
 242             len--;
 243         }
 244
 245         if (len && buffer[len - 1] == '.') {
 246             buffer[len - 1] = 0;
 247         } else {
 248             buffer[len] = 0;
 249         }
 250
 251         qstring_append(str, buffer);
 252         break;
 253     }
 254     case QTYPE_QBOOL: {
 255         QBool *val = qobject_to_qbool(obj);
 256
 257         if (qbool_get_bool(val)) {
 258             qstring_append(str, "true");
 259         } else {
 260             qstring_append(str, "false");
 261         }
 262         break;
 263     }
 264     default:
 265         abort();
 266     }
 267 }
 268
 269 QString *qobject_to_json(const QObject *obj)
 270 {
 271     QString *str = qstring_new();
 272
 273     to_json(obj, str, 0, 0);
 274
 275     return str;
 276 }
 277
 278 QString *qobject_to_json_pretty(const QObject *obj)
 279 {
 280     QString *str = qstring_new();
 281
 282     to_json(obj, str, 1, 0);
 283
 284     return str;
 285 }