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 "qapi/qmp/qstring.h"
  25 #include "qemu/unicode.h"
  26
  27 typedef struct JSONParsingState
  28 {
  29     JSONMessageParser parser;
  30     va_list *ap;
  31     QObject *result;
  32     Error *err;
  33 } JSONParsingState;
  34
  35 static void parse_json(JSONMessageParser *parser, GQueue *tokens)
  36 {
  37     JSONParsingState *s = container_of(parser, JSONParsingState, parser);
  38
  39     s->result = json_parser_parse_err(tokens, s->ap, &s->err);
  40 }
  41
  42 QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp)
  43 {
  44     JSONParsingState state = {};
  45
  46     state.ap = ap;
  47
  48     json_message_parser_init(&state.parser, parse_json);
  49     json_message_parser_feed(&state.parser, string, strlen(string));
  50     json_message_parser_flush(&state.parser);
  51     json_message_parser_destroy(&state.parser);
  52
  53     error_propagate(errp, state.err);
  54     return state.result;
  55 }
  56
  57 QObject *qobject_from_json(const char *string, Error **errp)
  58 {
  59     return qobject_from_jsonv(string, NULL, errp);
  60 }
  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     return obj;
  72 }
  73
  74 /*
  75  * Parse @string as JSON object with %-escapes interpolated.
  76  * Abort on error.  Do not use with untrusted @string.
  77  * Return the resulting QDict.  It is never null.
  78  */
  79 QDict *qdict_from_jsonf_nofail(const char *string, ...)
  80 {
  81     QDict *obj;
  82     va_list ap;
  83
  84     va_start(ap, string);
  85     obj = qobject_to(QDict, qobject_from_jsonv(string, &ap, &error_abort));
  86     va_end(ap);
  87
  88     assert(obj);
  89     return obj;
  90 }
  91
  92 typedef struct ToJsonIterState
  93 {
  94     int indent;
  95     int pretty;
  96     int count;
  97     QString *str;
  98 } ToJsonIterState;
  99
 100 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
 101
 102 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
 103 {
 104     ToJsonIterState *s = opaque;
 105     QString *qkey;
 106     int j;
 107
 108     if (s->count) {
 109         qstring_append(s->str, s->pretty ? "," : ", ");
 110     }
 111
 112     if (s->pretty) {
 113         qstring_append(s->str, "\n");
 114         for (j = 0 ; j < s->indent ; j++)
 115             qstring_append(s->str, "    ");
 116     }
 117
 118     qkey = qstring_from_str(key);
 119     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
 120     qobject_unref(qkey);
 121
 122     qstring_append(s->str, ": ");
 123     to_json(obj, s->str, s->pretty, s->indent);
 124     s->count++;
 125 }
 126
 127 static void to_json_list_iter(QObject *obj, void *opaque)
 128 {
 129     ToJsonIterState *s = opaque;
 130     int j;
 131
 132     if (s->count) {
 133         qstring_append(s->str, s->pretty ? "," : ", ");
 134     }
 135
 136     if (s->pretty) {
 137         qstring_append(s->str, "\n");
 138         for (j = 0 ; j < s->indent ; j++)
 139             qstring_append(s->str, "    ");
 140     }
 141
 142     to_json(obj, s->str, s->pretty, s->indent);
 143     s->count++;
 144 }
 145
 146 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 147 {
 148     switch (qobject_type(obj)) {
 149     case QTYPE_QNULL:
 150         qstring_append(str, "null");
 151         break;
 152     case QTYPE_QNUM: {
 153         QNum *val = qobject_to(QNum, obj);
 154         char *buffer = qnum_to_string(val);
 155         qstring_append(str, buffer);
 156         g_free(buffer);
 157         break;
 158     }
 159     case QTYPE_QSTRING: {
 160         QString *val = qobject_to(QString, obj);
 161         const char *ptr;
 162         int cp;
 163         char buf[16];
 164         char *end;
 165
 166         ptr = qstring_get_str(val);
 167         qstring_append(str, "\"");
 168
 169         for (; *ptr; ptr = end) {
 170             cp = mod_utf8_codepoint(ptr, 6, &end);
 171             switch (cp) {
 172             case '\"':
 173                 qstring_append(str, "\\\"");
 174                 break;
 175             case '\\':
 176                 qstring_append(str, "\\\\");
 177                 break;
 178             case '\b':
 179                 qstring_append(str, "\\b");
 180                 break;
 181             case '\f':
 182                 qstring_append(str, "\\f");
 183                 break;
 184             case '\n':
 185                 qstring_append(str, "\\n");
 186                 break;
 187             case '\r':
 188                 qstring_append(str, "\\r");
 189                 break;
 190             case '\t':
 191                 qstring_append(str, "\\t");
 192                 break;
 193             default:
 194                 if (cp < 0) {
 195                     cp = 0xFFFD; /* replacement character */
 196                 }
 197                 if (cp > 0xFFFF) {
 198                     /* beyond BMP; need a surrogate pair */
 199                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
 200                              0xD800 + ((cp - 0x10000) >> 10),
 201                              0xDC00 + ((cp - 0x10000) & 0x3FF));
 202                 } else if (cp < 0x20 || cp >= 0x7F) {
 203                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
 204                 } else {
 205                     buf[0] = cp;
 206                     buf[1] = 0;
 207                 }
 208                 qstring_append(str, buf);
 209             }
 210         };
 211
 212         qstring_append(str, "\"");
 213         break;
 214     }
 215     case QTYPE_QDICT: {
 216         ToJsonIterState s;
 217         QDict *val = qobject_to(QDict, obj);
 218
 219         s.count = 0;
 220         s.str = str;
 221         s.indent = indent + 1;
 222         s.pretty = pretty;
 223         qstring_append(str, "{");
 224         qdict_iter(val, to_json_dict_iter, &s);
 225         if (pretty) {
 226             int j;
 227             qstring_append(str, "\n");
 228             for (j = 0 ; j < indent ; j++)
 229                 qstring_append(str, "    ");
 230         }
 231         qstring_append(str, "}");
 232         break;
 233     }
 234     case QTYPE_QLIST: {
 235         ToJsonIterState s;
 236         QList *val = qobject_to(QList, obj);
 237
 238         s.count = 0;
 239         s.str = str;
 240         s.indent = indent + 1;
 241         s.pretty = pretty;
 242         qstring_append(str, "[");
 243         qlist_iter(val, (void *)to_json_list_iter, &s);
 244         if (pretty) {
 245             int j;
 246             qstring_append(str, "\n");
 247             for (j = 0 ; j < indent ; j++)
 248                 qstring_append(str, "    ");
 249         }
 250         qstring_append(str, "]");
 251         break;
 252     }
 253     case QTYPE_QBOOL: {
 254         QBool *val = qobject_to(QBool, obj);
 255
 256         if (qbool_get_bool(val)) {
 257             qstring_append(str, "true");
 258         } else {
 259             qstring_append(str, "false");
 260         }
 261         break;
 262     }
 263     default:
 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 }