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 "json-lexer.h"
  15 #include "json-parser.h"
  16 #include "json-streamer.h"
  17 #include "qjson.h"
  18 #include "qint.h"
  19 #include "qlist.h"
  20 #include "qbool.h"
  21 #include "qfloat.h"
  22 #include "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 count;
  76     QString *str;
  77 } ToJsonIterState;
  78
  79 static void to_json(const QObject *obj, QString *str);
  80
  81 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
  82 {
  83     ToJsonIterState *s = opaque;
  84     QString *qkey;
  85
  86     if (s->count) {
  87         qstring_append(s->str, ", ");
  88     }
  89
  90     qkey = qstring_from_str(key);
  91     to_json(QOBJECT(qkey), s->str);
  92     QDECREF(qkey);
  93
  94     qstring_append(s->str, ": ");
  95     to_json(obj, s->str);
  96     s->count++;
  97 }
  98
  99 static void to_json_list_iter(QObject *obj, void *opaque)
 100 {
 101     ToJsonIterState *s = opaque;
 102
 103     if (s->count) {
 104         qstring_append(s->str, ", ");
 105     }
 106
 107     to_json(obj, s->str);
 108     s->count++;
 109 }
 110
 111 static void to_json(const QObject *obj, QString *str)
 112 {
 113     switch (qobject_type(obj)) {
 114     case QTYPE_QINT: {
 115         QInt *val = qobject_to_qint(obj);
 116         char buffer[1024];
 117
 118         snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
 119         qstring_append(str, buffer);
 120         break;
 121     }
 122     case QTYPE_QSTRING: {
 123         QString *val = qobject_to_qstring(obj);
 124         const char *ptr;
 125
 126         ptr = qstring_get_str(val);
 127         qstring_append(str, "\"");
 128         while (*ptr) {
 129             if ((ptr[0] & 0xE0) == 0xE0 &&
 130                 (ptr[1] & 0x80) && (ptr[2] & 0x80)) {
 131                 uint16_t wchar;
 132                 char escape[7];
 133
 134                 wchar  = (ptr[0] & 0x0F) << 12;
 135                 wchar |= (ptr[1] & 0x3F) << 6;
 136                 wchar |= (ptr[2] & 0x3F);
 137                 ptr += 2;
 138
 139                 snprintf(escape, sizeof(escape), "\\u%04X", wchar);
 140                 qstring_append(str, escape);
 141             } else if ((ptr[0] & 0xE0) == 0xC0 && (ptr[1] & 0x80)) {
 142                 uint16_t wchar;
 143                 char escape[7];
 144
 145                 wchar  = (ptr[0] & 0x1F) << 6;
 146                 wchar |= (ptr[1] & 0x3F);
 147                 ptr++;
 148
 149                 snprintf(escape, sizeof(escape), "\\u%04X", wchar);
 150                 qstring_append(str, escape);
 151             } else switch (ptr[0]) {
 152                 case '\"':
 153                     qstring_append(str, "\\\"");
 154                     break;
 155                 case '\\':
 156                     qstring_append(str, "\\\\");
 157                     break;
 158                 case '\b':
 159                     qstring_append(str, "\\b");
 160                     break;
 161                 case '\f':
 162                     qstring_append(str, "\\f");
 163                     break;
 164                 case '\n':
 165                     qstring_append(str, "\\n");
 166                     break;
 167                 case '\r':
 168                     qstring_append(str, "\\r");
 169                     break;
 170                 case '\t':
 171                     qstring_append(str, "\\t");
 172                     break;
 173                 default: {
 174                     if (ptr[0] <= 0x1F) {
 175                         char escape[7];
 176                         snprintf(escape, sizeof(escape), "\\u%04X", ptr[0]);
 177                         qstring_append(str, escape);
 178                     } else {
 179                         char buf[2] = { ptr[0], 0 };
 180                         qstring_append(str, buf);
 181                     }
 182                     break;
 183                 }
 184                 }
 185             ptr++;
 186         }
 187         qstring_append(str, "\"");
 188         break;
 189     }
 190     case QTYPE_QDICT: {
 191         ToJsonIterState s;
 192         QDict *val = qobject_to_qdict(obj);
 193
 194         s.count = 0;
 195         s.str = str;
 196         qstring_append(str, "{");
 197         qdict_iter(val, to_json_dict_iter, &s);
 198         qstring_append(str, "}");
 199         break;
 200     }
 201     case QTYPE_QLIST: {
 202         ToJsonIterState s;
 203         QList *val = qobject_to_qlist(obj);
 204
 205         s.count = 0;
 206         s.str = str;
 207         qstring_append(str, "[");
 208         qlist_iter(val, (void *)to_json_list_iter, &s);
 209         qstring_append(str, "]");
 210         break;
 211     }
 212     case QTYPE_QFLOAT: {
 213         QFloat *val = qobject_to_qfloat(obj);
 214         char buffer[1024];
 215         int len;
 216
 217         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
 218         while (len > 0 && buffer[len - 1] == '0') {
 219             len--;
 220         }
 221
 222         if (len && buffer[len - 1] == '.') {
 223             buffer[len - 1] = 0;
 224         } else {
 225             buffer[len] = 0;
 226         }
 227
 228         qstring_append(str, buffer);
 229         break;
 230     }
 231     case QTYPE_QBOOL: {
 232         QBool *val = qobject_to_qbool(obj);
 233
 234         if (qbool_get_int(val)) {
 235             qstring_append(str, "true");
 236         } else {
 237             qstring_append(str, "false");
 238         }
 239         break;
 240     }
 241     case QTYPE_QERROR:
 242         /* XXX: should QError be emitted? */
 243     case QTYPE_NONE:
 244         break;
 245     }
 246 }
 247
 248 QString *qobject_to_json(const QObject *obj)
 249 {
 250     QString *str = qstring_new();
 251
 252     to_json(obj, str);
 253
 254     return str;
 255 }