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