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, ", ");
  91
  92     if (s->pretty) {
  93         qstring_append(s->str, "\n");
  94         for (j = 0 ; j < s->indent ; j++)
  95             qstring_append(s->str, "    ");
  96     }
  97
  98     qkey = qstring_from_str(key);
  99     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
 100     QDECREF(qkey);
 101
 102     qstring_append(s->str, ": ");
 103     to_json(obj, s->str, s->pretty, s->indent);
 104     s->count++;
 105 }
 106
 107 static void to_json_list_iter(QObject *obj, void *opaque)
 108 {
 109     ToJsonIterState *s = opaque;
 110     int j;
 111
 112     if (s->count)
 113         qstring_append(s->str, ", ");
 114
 115     if (s->pretty) {
 116         qstring_append(s->str, "\n");
 117         for (j = 0 ; j < s->indent ; j++)
 118             qstring_append(s->str, "    ");
 119     }
 120
 121     to_json(obj, s->str, s->pretty, s->indent);
 122     s->count++;
 123 }
 124
 125 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 126 {
 127     switch (qobject_type(obj)) {
 128     case QTYPE_QINT: {
 129         QInt *val = qobject_to_qint(obj);
 130         char buffer[1024];
 131
 132         snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
 133         qstring_append(str, buffer);
 134         break;
 135     }
 136     case QTYPE_QSTRING: {
 137         QString *val = qobject_to_qstring(obj);
 138         const char *ptr;
 139
 140         ptr = qstring_get_str(val);
 141         qstring_append(str, "\"");
 142         while (*ptr) {
 143             if ((ptr[0] & 0xE0) == 0xE0 &&
 144                 (ptr[1] & 0x80) && (ptr[2] & 0x80)) {
 145                 uint16_t wchar;
 146                 char escape[7];
 147
 148                 wchar  = (ptr[0] & 0x0F) << 12;
 149                 wchar |= (ptr[1] & 0x3F) << 6;
 150                 wchar |= (ptr[2] & 0x3F);
 151                 ptr += 2;
 152
 153                 snprintf(escape, sizeof(escape), "\\u%04X", wchar);
 154                 qstring_append(str, escape);
 155             } else if ((ptr[0] & 0xE0) == 0xC0 && (ptr[1] & 0x80)) {
 156                 uint16_t wchar;
 157                 char escape[7];
 158
 159                 wchar  = (ptr[0] & 0x1F) << 6;
 160                 wchar |= (ptr[1] & 0x3F);
 161                 ptr++;
 162
 163                 snprintf(escape, sizeof(escape), "\\u%04X", wchar);
 164                 qstring_append(str, escape);
 165             } else switch (ptr[0]) {
 166                 case '\"':
 167                     qstring_append(str, "\\\"");
 168                     break;
 169                 case '\\':
 170                     qstring_append(str, "\\\\");
 171                     break;
 172                 case '\b':
 173                     qstring_append(str, "\\b");
 174                     break;
 175                 case '\f':
 176                     qstring_append(str, "\\f");
 177                     break;
 178                 case '\n':
 179                     qstring_append(str, "\\n");
 180                     break;
 181                 case '\r':
 182                     qstring_append(str, "\\r");
 183                     break;
 184                 case '\t':
 185                     qstring_append(str, "\\t");
 186                     break;
 187                 default: {
 188                     if (ptr[0] <= 0x1F) {
 189                         char escape[7];
 190                         snprintf(escape, sizeof(escape), "\\u%04X", ptr[0]);
 191                         qstring_append(str, escape);
 192                     } else {
 193                         char buf[2] = { ptr[0], 0 };
 194                         qstring_append(str, buf);
 195                     }
 196                     break;
 197                 }
 198                 }
 199             ptr++;
 200         }
 201         qstring_append(str, "\"");
 202         break;
 203     }
 204     case QTYPE_QDICT: {
 205         ToJsonIterState s;
 206         QDict *val = qobject_to_qdict(obj);
 207
 208         s.count = 0;
 209         s.str = str;
 210         s.indent = indent + 1;
 211         s.pretty = pretty;
 212         qstring_append(str, "{");
 213         qdict_iter(val, to_json_dict_iter, &s);
 214         if (pretty) {
 215             int j;
 216             qstring_append(str, "\n");
 217             for (j = 0 ; j < indent ; j++)
 218                 qstring_append(str, "    ");
 219         }
 220         qstring_append(str, "}");
 221         break;
 222     }
 223     case QTYPE_QLIST: {
 224         ToJsonIterState s;
 225         QList *val = qobject_to_qlist(obj);
 226
 227         s.count = 0;
 228         s.str = str;
 229         s.indent = indent + 1;
 230         s.pretty = pretty;
 231         qstring_append(str, "[");
 232         qlist_iter(val, (void *)to_json_list_iter, &s);
 233         if (pretty) {
 234             int j;
 235             qstring_append(str, "\n");
 236             for (j = 0 ; j < indent ; j++)
 237                 qstring_append(str, "    ");
 238         }
 239         qstring_append(str, "]");
 240         break;
 241     }
 242     case QTYPE_QFLOAT: {
 243         QFloat *val = qobject_to_qfloat(obj);
 244         char buffer[1024];
 245         int len;
 246
 247         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
 248         while (len > 0 && buffer[len - 1] == '0') {
 249             len--;
 250         }
 251
 252         if (len && buffer[len - 1] == '.') {
 253             buffer[len - 1] = 0;
 254         } else {
 255             buffer[len] = 0;
 256         }
 257
 258         qstring_append(str, buffer);
 259         break;
 260     }
 261     case QTYPE_QBOOL: {
 262         QBool *val = qobject_to_qbool(obj);
 263
 264         if (qbool_get_int(val)) {
 265             qstring_append(str, "true");
 266         } else {
 267             qstring_append(str, "false");
 268         }
 269         break;
 270     }
 271     case QTYPE_QERROR:
 272         /* XXX: should QError be emitted? */
 273     case QTYPE_NONE:
 274         break;
 275     }
 276 }
 277
 278 QString *qobject_to_json(const QObject *obj)
 279 {
 280     QString *str = qstring_new();
 281
 282     to_json(obj, str, 0, 0);
 283
 284     return str;
 285 }
 286
 287 QString *qobject_to_json_pretty(const QObject *obj)
 288 {
 289     QString *str = qstring_new();
 290
 291     to_json(obj, str, 1, 0);
 292
 293     return str;
 294 }