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 /*
  63  * IMPORTANT: This function aborts on error, thus it must not
  64  * be used with untrusted arguments.
  65  */
  66 QObject *qobject_from_jsonf(const char *string, ...)
  67 {
  68     QObject *obj;
  69     va_list ap;
  70
  71     va_start(ap, string);
  72     obj = qobject_from_jsonv(string, &ap, &error_abort);
  73     va_end(ap);
  74
  75     assert(obj != NULL);
  76     return obj;
  77 }
  78
  79 typedef struct ToJsonIterState
  80 {
  81     int indent;
  82     int pretty;
  83     int count;
  84     QString *str;
  85 } ToJsonIterState;
  86
  87 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
  88
  89 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
  90 {
  91     ToJsonIterState *s = opaque;
  92     QString *qkey;
  93     int j;
  94
  95     if (s->count) {
  96         qstring_append(s->str, s->pretty ? "," : ", ");
  97     }
  98
  99     if (s->pretty) {
 100         qstring_append(s->str, "\n");
 101         for (j = 0 ; j < s->indent ; j++)
 102             qstring_append(s->str, "    ");
 103     }
 104
 105     qkey = qstring_from_str(key);
 106     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
 107     QDECREF(qkey);
 108
 109     qstring_append(s->str, ": ");
 110     to_json(obj, s->str, s->pretty, s->indent);
 111     s->count++;
 112 }
 113
 114 static void to_json_list_iter(QObject *obj, void *opaque)
 115 {
 116     ToJsonIterState *s = opaque;
 117     int j;
 118
 119     if (s->count) {
 120         qstring_append(s->str, s->pretty ? "," : ", ");
 121     }
 122
 123     if (s->pretty) {
 124         qstring_append(s->str, "\n");
 125         for (j = 0 ; j < s->indent ; j++)
 126             qstring_append(s->str, "    ");
 127     }
 128
 129     to_json(obj, s->str, s->pretty, s->indent);
 130     s->count++;
 131 }
 132
 133 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 134 {
 135     switch (qobject_type(obj)) {
 136     case QTYPE_QNULL:
 137         qstring_append(str, "null");
 138         break;
 139     case QTYPE_QNUM: {
 140         QNum *val = qobject_to(QNum, obj);
 141         char *buffer = qnum_to_string(val);
 142         qstring_append(str, buffer);
 143         g_free(buffer);
 144         break;
 145     }
 146     case QTYPE_QSTRING: {
 147         QString *val = qobject_to(QString, obj);
 148         const char *ptr;
 149         int cp;
 150         char buf[16];
 151         char *end;
 152
 153         ptr = qstring_get_str(val);
 154         qstring_append(str, "\"");
 155
 156         for (; *ptr; ptr = end) {
 157             cp = mod_utf8_codepoint(ptr, 6, &end);
 158             switch (cp) {
 159             case '\"':
 160                 qstring_append(str, "\\\"");
 161                 break;
 162             case '\\':
 163                 qstring_append(str, "\\\\");
 164                 break;
 165             case '\b':
 166                 qstring_append(str, "\\b");
 167                 break;
 168             case '\f':
 169                 qstring_append(str, "\\f");
 170                 break;
 171             case '\n':
 172                 qstring_append(str, "\\n");
 173                 break;
 174             case '\r':
 175                 qstring_append(str, "\\r");
 176                 break;
 177             case '\t':
 178                 qstring_append(str, "\\t");
 179                 break;
 180             default:
 181                 if (cp < 0) {
 182                     cp = 0xFFFD; /* replacement character */
 183                 }
 184                 if (cp > 0xFFFF) {
 185                     /* beyond BMP; need a surrogate pair */
 186                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
 187                              0xD800 + ((cp - 0x10000) >> 10),
 188                              0xDC00 + ((cp - 0x10000) & 0x3FF));
 189                 } else if (cp < 0x20 || cp >= 0x7F) {
 190                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
 191                 } else {
 192                     buf[0] = cp;
 193                     buf[1] = 0;
 194                 }
 195                 qstring_append(str, buf);
 196             }
 197         };
 198
 199         qstring_append(str, "\"");
 200         break;
 201     }
 202     case QTYPE_QDICT: {
 203         ToJsonIterState s;
 204         QDict *val = qobject_to(QDict, obj);
 205
 206         s.count = 0;
 207         s.str = str;
 208         s.indent = indent + 1;
 209         s.pretty = pretty;
 210         qstring_append(str, "{");
 211         qdict_iter(val, to_json_dict_iter, &s);
 212         if (pretty) {
 213             int j;
 214             qstring_append(str, "\n");
 215             for (j = 0 ; j < indent ; j++)
 216                 qstring_append(str, "    ");
 217         }
 218         qstring_append(str, "}");
 219         break;
 220     }
 221     case QTYPE_QLIST: {
 222         ToJsonIterState s;
 223         QList *val = qobject_to(QList, obj);
 224
 225         s.count = 0;
 226         s.str = str;
 227         s.indent = indent + 1;
 228         s.pretty = pretty;
 229         qstring_append(str, "[");
 230         qlist_iter(val, (void *)to_json_list_iter, &s);
 231         if (pretty) {
 232             int j;
 233             qstring_append(str, "\n");
 234             for (j = 0 ; j < indent ; j++)
 235                 qstring_append(str, "    ");
 236         }
 237         qstring_append(str, "]");
 238         break;
 239     }
 240     case QTYPE_QBOOL: {
 241         QBool *val = qobject_to(QBool, obj);
 242
 243         if (qbool_get_bool(val)) {
 244             qstring_append(str, "true");
 245         } else {
 246             qstring_append(str, "false");
 247         }
 248         break;
 249     }
 250     default:
 251         abort();
 252     }
 253 }
 254
 255 QString *qobject_to_json(const QObject *obj)
 256 {
 257     QString *str = qstring_new();
 258
 259     to_json(obj, str, 0, 0);
 260
 261     return str;
 262 }
 263
 264 QString *qobject_to_json_pretty(const QObject *obj)
 265 {
 266     QString *str = qstring_new();
 267
 268     to_json(obj, str, 1, 0);
 269
 270     return str;
 271 }