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         int cp;
 140         char buf[16];
 141         char *end;
 142
 143         ptr = qstring_get_str(val);
 144         qstring_append(str, "\"");
 145
 146         for (; *ptr; ptr = end) {
 147             cp = mod_utf8_codepoint(ptr, 6, &end);
 148             switch (cp) {
 149             case '\"':
 150                 qstring_append(str, "\\\"");
 151                 break;
 152             case '\\':
 153                 qstring_append(str, "\\\\");
 154                 break;
 155             case '\b':
 156                 qstring_append(str, "\\b");
 157                 break;
 158             case '\f':
 159                 qstring_append(str, "\\f");
 160                 break;
 161             case '\n':
 162                 qstring_append(str, "\\n");
 163                 break;
 164             case '\r':
 165                 qstring_append(str, "\\r");
 166                 break;
 167             case '\t':
 168                 qstring_append(str, "\\t");
 169                 break;
 170             default:
 171                 if (cp < 0) {
 172                     cp = 0xFFFD; /* replacement character */
 173                 }
 174                 if (cp > 0xFFFF) {
 175                     /* beyond BMP; need a surrogate pair */
 176                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
 177                              0xD800 + ((cp - 0x10000) >> 10),
 178                              0xDC00 + ((cp - 0x10000) & 0x3FF));
 179                 } else if (cp < 0x20 || cp >= 0x7F) {
 180                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
 181                 } else {
 182                     buf[0] = cp;
 183                     buf[1] = 0;
 184                 }
 185                 qstring_append(str, buf);
 186             }
 187         };
 188
 189         qstring_append(str, "\"");
 190         break;
 191     }
 192     case QTYPE_QDICT: {
 193         ToJsonIterState s;
 194         QDict *val = qobject_to_qdict(obj);
 195
 196         s.count = 0;
 197         s.str = str;
 198         s.indent = indent + 1;
 199         s.pretty = pretty;
 200         qstring_append(str, "{");
 201         qdict_iter(val, to_json_dict_iter, &s);
 202         if (pretty) {
 203             int j;
 204             qstring_append(str, "\n");
 205             for (j = 0 ; j < indent ; j++)
 206                 qstring_append(str, "    ");
 207         }
 208         qstring_append(str, "}");
 209         break;
 210     }
 211     case QTYPE_QLIST: {
 212         ToJsonIterState s;
 213         QList *val = qobject_to_qlist(obj);
 214
 215         s.count = 0;
 216         s.str = str;
 217         s.indent = indent + 1;
 218         s.pretty = pretty;
 219         qstring_append(str, "[");
 220         qlist_iter(val, (void *)to_json_list_iter, &s);
 221         if (pretty) {
 222             int j;
 223             qstring_append(str, "\n");
 224             for (j = 0 ; j < indent ; j++)
 225                 qstring_append(str, "    ");
 226         }
 227         qstring_append(str, "]");
 228         break;
 229     }
 230     case QTYPE_QFLOAT: {
 231         QFloat *val = qobject_to_qfloat(obj);
 232         char buffer[1024];
 233         int len;
 234
 235         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
 236         while (len > 0 && buffer[len - 1] == '0') {
 237             len--;
 238         }
 239
 240         if (len && buffer[len - 1] == '.') {
 241             buffer[len - 1] = 0;
 242         } else {
 243             buffer[len] = 0;
 244         }
 245
 246         qstring_append(str, buffer);
 247         break;
 248     }
 249     case QTYPE_QBOOL: {
 250         QBool *val = qobject_to_qbool(obj);
 251
 252         if (qbool_get_int(val)) {
 253             qstring_append(str, "true");
 254         } else {
 255             qstring_append(str, "false");
 256         }
 257         break;
 258     }
 259     case QTYPE_QERROR:
 260         /* XXX: should QError be emitted? */
 261     case QTYPE_NONE:
 262         break;
 263     case QTYPE_MAX:
 264         abort();
 265     }
 266 }
 267
 268 QString *qobject_to_json(const QObject *obj)
 269 {
 270     QString *str = qstring_new();
 271
 272     to_json(obj, str, 0, 0);
 273
 274     return str;
 275 }
 276
 277 QString *qobject_to_json_pretty(const QObject *obj)
 278 {
 279     QString *str = qstring_new();
 280
 281     to_json(obj, str, 1, 0);
 282
 283     return str;
 284 }