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