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