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