qemu/qobject/qjson.c
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   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
  24typedef struct JSONParsingState
  25{
  26    JSONMessageParser parser;
  27    va_list *ap;
  28    QObject *result;
  29} JSONParsingState;
  30
  31static 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
  37QObject *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
  51QObject *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 */
  60QObject *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
  73typedef struct ToJsonIterState
  74{
  75    int indent;
  76    int pretty;
  77    int count;
  78    QString *str;
  79} ToJsonIterState;
  80
  81static void to_json(const QObject *obj, QString *str, int pretty, int indent);
  82
  83static 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
 107static 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
 125static 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
 140        ptr = qstring_get_str(val);
 141        qstring_append(str, "\"");
 142        while (*ptr) {
 143            if ((ptr[0] & 0xE0) == 0xE0 &&
 144                (ptr[1] & 0x80) && (ptr[2] & 0x80)) {
 145                uint16_t wchar;
 146                char escape[7];
 147
 148                wchar  = (ptr[0] & 0x0F) << 12;
 149                wchar |= (ptr[1] & 0x3F) << 6;
 150                wchar |= (ptr[2] & 0x3F);
 151                ptr += 2;
 152
 153                snprintf(escape, sizeof(escape), "\\u%04X", wchar);
 154                qstring_append(str, escape);
 155            } else if ((ptr[0] & 0xE0) == 0xC0 && (ptr[1] & 0x80)) {
 156                uint16_t wchar;
 157                char escape[7];
 158
 159                wchar  = (ptr[0] & 0x1F) << 6;
 160                wchar |= (ptr[1] & 0x3F);
 161                ptr++;
 162
 163                snprintf(escape, sizeof(escape), "\\u%04X", wchar);
 164                qstring_append(str, escape);
 165            } else switch (ptr[0]) {
 166                case '\"':
 167                    qstring_append(str, "\\\"");
 168                    break;
 169                case '\\':
 170                    qstring_append(str, "\\\\");
 171                    break;
 172                case '\b':
 173                    qstring_append(str, "\\b");
 174                    break;
 175                case '\f':
 176                    qstring_append(str, "\\f");
 177                    break;
 178                case '\n':
 179                    qstring_append(str, "\\n");
 180                    break;
 181                case '\r':
 182                    qstring_append(str, "\\r");
 183                    break;
 184                case '\t':
 185                    qstring_append(str, "\\t");
 186                    break;
 187                default: {
 188                    if (ptr[0] <= 0x1F) {
 189                        char escape[7];
 190                        snprintf(escape, sizeof(escape), "\\u%04X", ptr[0]);
 191                        qstring_append(str, escape);
 192                    } else {
 193                        char buf[2] = { ptr[0], 0 };
 194                        qstring_append(str, buf);
 195                    }
 196                    break;
 197                }
 198                }
 199            ptr++;
 200        }
 201        qstring_append(str, "\"");
 202        break;
 203    }
 204    case QTYPE_QDICT: {
 205        ToJsonIterState s;
 206        QDict *val = qobject_to_qdict(obj);
 207
 208        s.count = 0;
 209        s.str = str;
 210        s.indent = indent + 1;
 211        s.pretty = pretty;
 212        qstring_append(str, "{");
 213        qdict_iter(val, to_json_dict_iter, &s);
 214        if (pretty) {
 215            int j;
 216            qstring_append(str, "\n");
 217            for (j = 0 ; j < indent ; j++)
 218                qstring_append(str, "    ");
 219        }
 220        qstring_append(str, "}");
 221        break;
 222    }
 223    case QTYPE_QLIST: {
 224        ToJsonIterState s;
 225        QList *val = qobject_to_qlist(obj);
 226
 227        s.count = 0;
 228        s.str = str;
 229        s.indent = indent + 1;
 230        s.pretty = pretty;
 231        qstring_append(str, "[");
 232        qlist_iter(val, (void *)to_json_list_iter, &s);
 233        if (pretty) {
 234            int j;
 235            qstring_append(str, "\n");
 236            for (j = 0 ; j < indent ; j++)
 237                qstring_append(str, "    ");
 238        }
 239        qstring_append(str, "]");
 240        break;
 241    }
 242    case QTYPE_QFLOAT: {
 243        QFloat *val = qobject_to_qfloat(obj);
 244        char buffer[1024];
 245        int len;
 246
 247        len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
 248        while (len > 0 && buffer[len - 1] == '0') {
 249            len--;
 250        }
 251
 252        if (len && buffer[len - 1] == '.') {
 253            buffer[len - 1] = 0;
 254        } else {
 255            buffer[len] = 0;
 256        }
 257        
 258        qstring_append(str, buffer);
 259        break;
 260    }
 261    case QTYPE_QBOOL: {
 262        QBool *val = qobject_to_qbool(obj);
 263
 264        if (qbool_get_int(val)) {
 265            qstring_append(str, "true");
 266        } else {
 267            qstring_append(str, "false");
 268        }
 269        break;
 270    }
 271    case QTYPE_QERROR:
 272        /* XXX: should QError be emitted? */
 273    case QTYPE_NONE:
 274        break;
 275    }
 276}
 277
 278QString *qobject_to_json(const QObject *obj)
 279{
 280    QString *str = qstring_new();
 281
 282    to_json(obj, str, 0, 0);
 283
 284    return str;
 285}
 286
 287QString *qobject_to_json_pretty(const QObject *obj)
 288{
 289    QString *str = qstring_new();
 290
 291    to_json(obj, str, 1, 0);
 292
 293    return str;
 294}
 295