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, s->pretty ? "," : ", ");
  91     }
  92
  93     if (s->pretty) {
  94         qstring_append(s->str, "\n");
  95         for (j = 0 ; j < s->indent ; j++)
  96             qstring_append(s->str, "    ");
  97     }
  98
  99     qkey = qstring_from_str(key);
 100     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
 101     QDECREF(qkey);
 102
 103     qstring_append(s->str, ": ");
 104     to_json(obj, s->str, s->pretty, s->indent);
 105     s->count++;
 106 }
 107
 108 static void to_json_list_iter(QObject *obj, void *opaque)
 109 {
 110     ToJsonIterState *s = opaque;
 111     int j;
 112
 113     if (s->count) {
 114         qstring_append(s->str, s->pretty ? "," : ", ");
 115     }
 116
 117     if (s->pretty) {
 118         qstring_append(s->str, "\n");
 119         for (j = 0 ; j < s->indent ; j++)
 120             qstring_append(s->str, "    ");
 121     }
 122
 123     to_json(obj, s->str, s->pretty, s->indent);
 124     s->count++;
 125 }
 126
 127 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 128 {
 129     switch (qobject_type(obj)) {
 130     case QTYPE_QINT: {
 131         QInt *val = qobject_to_qint(obj);
 132         char buffer[1024];
 133
 134         snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
 135         qstring_append(str, buffer);
 136         break;
 137     }
 138     case QTYPE_QSTRING: {
 139         QString *val = qobject_to_qstring(obj);
 140         const char *ptr;
 141         int cp;
 142         char buf[16];
 143         char *end;
 144
 145         ptr = qstring_get_str(val);
 146         qstring_append(str, "\"");
 147
 148         for (; *ptr; ptr = end) {
 149             cp = mod_utf8_codepoint(ptr, 6, &end);
 150             switch (cp) {
 151             case '\"':
 152                 qstring_append(str, "\\\"");
 153                 break;
 154             case '\\':
 155                 qstring_append(str, "\\\\");
 156                 break;
 157             case '\b':
 158                 qstring_append(str, "\\b");
 159                 break;
 160             case '\f':
 161                 qstring_append(str, "\\f");
 162                 break;
 163             case '\n':
 164                 qstring_append(str, "\\n");
 165                 break;
 166             case '\r':
 167                 qstring_append(str, "\\r");
 168                 break;
 169             case '\t':
 170                 qstring_append(str, "\\t");
 171                 break;
 172             default:
 173                 if (cp < 0) {
 174                     cp = 0xFFFD; /* replacement character */
 175                 }
 176                 if (cp > 0xFFFF) {
 177                     /* beyond BMP; need a surrogate pair */
 178                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
 179                              0xD800 + ((cp - 0x10000) >> 10),
 180                              0xDC00 + ((cp - 0x10000) & 0x3FF));
 181                 } else if (cp < 0x20 || cp >= 0x7F) {
 182                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
 183                 } else {
 184                     buf[0] = cp;
 185                     buf[1] = 0;
 186                 }
 187                 qstring_append(str, buf);
 188             }
 189         };
 190
 191         qstring_append(str, "\"");
 192         break;
 193     }
 194     case QTYPE_QDICT: {
 195         ToJsonIterState s;
 196         QDict *val = qobject_to_qdict(obj);
 197
 198         s.count = 0;
 199         s.str = str;
 200         s.indent = indent + 1;
 201         s.pretty = pretty;
 202         qstring_append(str, "{");
 203         qdict_iter(val, to_json_dict_iter, &s);
 204         if (pretty) {
 205             int j;
 206             qstring_append(str, "\n");
 207             for (j = 0 ; j < indent ; j++)
 208                 qstring_append(str, "    ");
 209         }
 210         qstring_append(str, "}");
 211         break;
 212     }
 213     case QTYPE_QLIST: {
 214         ToJsonIterState s;
 215         QList *val = qobject_to_qlist(obj);
 216
 217         s.count = 0;
 218         s.str = str;
 219         s.indent = indent + 1;
 220         s.pretty = pretty;
 221         qstring_append(str, "[");
 222         qlist_iter(val, (void *)to_json_list_iter, &s);
 223         if (pretty) {
 224             int j;
 225             qstring_append(str, "\n");
 226             for (j = 0 ; j < indent ; j++)
 227                 qstring_append(str, "    ");
 228         }
 229         qstring_append(str, "]");
 230         break;
 231     }
 232     case QTYPE_QFLOAT: {
 233         QFloat *val = qobject_to_qfloat(obj);
 234         char buffer[1024];
 235         int len;
 236
 237         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
 238         while (len > 0 && buffer[len - 1] == '0') {
 239             len--;
 240         }
 241
 242         if (len && buffer[len - 1] == '.') {
 243             buffer[len - 1] = 0;
 244         } else {
 245             buffer[len] = 0;
 246         }
 247
 248         qstring_append(str, buffer);
 249         break;
 250     }
 251     case QTYPE_QBOOL: {
 252         QBool *val = qobject_to_qbool(obj);
 253
 254         if (qbool_get_int(val)) {
 255             qstring_append(str, "true");
 256         } else {
 257             qstring_append(str, "false");
 258         }
 259         break;
 260     }
 261     case QTYPE_QERROR:
 262         /* XXX: should QError be emitted? */
 263     case QTYPE_NONE:
 264         break;
 265     case QTYPE_MAX:
 266         abort();
 267     }
 268 }
 269
 270 QString *qobject_to_json(const QObject *obj)
 271 {
 272     QString *str = qstring_new();
 273
 274     to_json(obj, str, 0, 0);
 275
 276     return str;
 277 }
 278
 279 QString *qobject_to_json_pretty(const QObject *obj)
 280 {
 281     QString *str = qstring_new();
 282
 283     to_json(obj, str, 1, 0);
 284
 285     return str;
 286 }