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      1 /*
      2  * QObject JSON integration
      3  *
      4  * Copyright IBM, Corp. 2009
      5  *
      6  * Authors:
      7  *  Anthony Liguori   <aliguori (at) 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, ", ");
     91 
     92     if (s->pretty) {
     93         qstring_append(s->str, "\n");
     94         for (j = 0 ; j < s->indent ; j++)
     95             qstring_append(s->str, "    ");
     96     }
     97 
     98     qkey = qstring_from_str(key);
     99     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
    100     QDECREF(qkey);
    101 
    102     qstring_append(s->str, ": ");
    103     to_json(obj, s->str, s->pretty, s->indent);
    104     s->count++;
    105 }
    106 
    107 static void to_json_list_iter(QObject *obj, void *opaque)
    108 {
    109     ToJsonIterState *s = opaque;
    110     int j;
    111 
    112     if (s->count)
    113         qstring_append(s->str, ", ");
    114 
    115     if (s->pretty) {
    116         qstring_append(s->str, "\n");
    117         for (j = 0 ; j < s->indent ; j++)
    118             qstring_append(s->str, "    ");
    119     }
    120 
    121     to_json(obj, s->str, s->pretty, s->indent);
    122     s->count++;
    123 }
    124 
    125 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
    126 {
    127     switch (qobject_type(obj)) {
    128     case QTYPE_QINT: {
    129         QInt *val = qobject_to_qint(obj);
    130         char buffer[1024];
    131 
    132         snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
    133         qstring_append(str, buffer);
    134         break;
    135     }
    136     case QTYPE_QSTRING: {
    137         QString *val = qobject_to_qstring(obj);
    138         const char *ptr;
    139         int cp;
    140         char buf[16];
    141         char *end;
    142 
    143         ptr = qstring_get_str(val);
    144         qstring_append(str, "\"");
    145 
    146         for (; *ptr; ptr = end) {
    147             cp = mod_utf8_codepoint(ptr, 6, &end);
    148             switch (cp) {
    149             case '\"':
    150                 qstring_append(str, "\\\"");
    151                 break;
    152             case '\\':
    153                 qstring_append(str, "\\\\");
    154                 break;
    155             case '\b':
    156                 qstring_append(str, "\\b");
    157                 break;
    158             case '\f':
    159                 qstring_append(str, "\\f");
    160                 break;
    161             case '\n':
    162                 qstring_append(str, "\\n");
    163                 break;
    164             case '\r':
    165                 qstring_append(str, "\\r");
    166                 break;
    167             case '\t':
    168                 qstring_append(str, "\\t");
    169                 break;
    170             default:
    171                 if (cp < 0) {
    172                     cp = 0xFFFD; /* replacement character */
    173                 }
    174                 if (cp > 0xFFFF) {
    175                     /* beyond BMP; need a surrogate pair */
    176                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
    177                              0xD800 + ((cp - 0x10000) >> 10),
    178                              0xDC00 + ((cp - 0x10000) & 0x3FF));
    179                 } else if (cp < 0x20 || cp >= 0x7F) {
    180                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
    181                 } else {
    182                     buf[0] = cp;
    183                     buf[1] = 0;
    184                 }
    185                 qstring_append(str, buf);
    186             }
    187         };
    188 
    189         qstring_append(str, "\"");
    190         break;
    191     }
    192     case QTYPE_QDICT: {
    193         ToJsonIterState s;
    194         QDict *val = qobject_to_qdict(obj);
    195 
    196         s.count = 0;
    197         s.str = str;
    198         s.indent = indent + 1;
    199         s.pretty = pretty;
    200         qstring_append(str, "{");
    201         qdict_iter(val, to_json_dict_iter, &s);
    202         if (pretty) {
    203             int j;
    204             qstring_append(str, "\n");
    205             for (j = 0 ; j < indent ; j++)
    206                 qstring_append(str, "    ");
    207         }
    208         qstring_append(str, "}");
    209         break;
    210     }
    211     case QTYPE_QLIST: {
    212         ToJsonIterState s;
    213         QList *val = qobject_to_qlist(obj);
    214 
    215         s.count = 0;
    216         s.str = str;
    217         s.indent = indent + 1;
    218         s.pretty = pretty;
    219         qstring_append(str, "[");
    220         qlist_iter(val, (void *)to_json_list_iter, &s);
    221         if (pretty) {
    222             int j;
    223             qstring_append(str, "\n");
    224             for (j = 0 ; j < indent ; j++)
    225                 qstring_append(str, "    ");
    226         }
    227         qstring_append(str, "]");
    228         break;
    229     }
    230     case QTYPE_QFLOAT: {
    231         QFloat *val = qobject_to_qfloat(obj);
    232         char buffer[1024];
    233         int len;
    234 
    235         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
    236         while (len > 0 && buffer[len - 1] == '0') {
    237             len--;
    238         }
    239 
    240         if (len && buffer[len - 1] == '.') {
    241             buffer[len - 1] = 0;
    242         } else {
    243             buffer[len] = 0;
    244         }
    245 
    246         qstring_append(str, buffer);
    247         break;
    248     }
    249     case QTYPE_QBOOL: {
    250         QBool *val = qobject_to_qbool(obj);
    251 
    252         if (qbool_get_int(val)) {
    253             qstring_append(str, "true");
    254         } else {
    255             qstring_append(str, "false");
    256         }
    257         break;
    258     }
    259     case QTYPE_QERROR:
    260         /* XXX: should QError be emitted? */
    261     case QTYPE_NONE:
    262         break;
    263     case QTYPE_MAX:
    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 }
    285