summaryrefslogtreecommitdiffstats
path: root/src/corelib/json/qjsondocument.cpp
blob: 097e665b68bfb9ee90057815b519fa60322d0383 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include <qjsondocument.h>
#include <qjsonobject.h>
#include <qjsonvalue.h>
#include <qjsonarray.h>
#include <qstringlist.h>
#include <qvariant.h>
#include <qdebug.h>
#include "qjsonwriter_p.h"
#include "qjsonparser_p.h"
#include "qjson_p.h"

QT_BEGIN_NAMESPACE

/*! \class QJsonDocument
    \inmodule QtCore
    \ingroup json
    \reentrant
    \since 5.0

    \brief The QJsonDocument class provides a way to read and write JSON documents.

    QJsonDocument is a class that wraps a complete JSON document and can read and
    write this document both from a UTF-8 encoded text based representation as well
    as Qt's own binary format.

    A JSON document can be converted from its text-based representation to a QJsonDocument
    using QJsonDocument::fromJson(). toJson() converts it back to text. The parser is very
    fast and efficient and converts the JSON to the binary representation used by Qt.

    Validity of the parsed document can be queried with !isNull()

    A document can be queried as to whether it contains an array or an object using isArray()
    and isObject(). The array or object contained in the document can be retrieved using
    array() or object() and then read or manipulated.

    A document can also be created from a stored binary representation using fromBinaryData() or
    fromRawData().

    \sa {JSON Support in Qt}, {JSON Save Game Example}
*/

/*!
 * Constructs an empty and invalid document.
 */
QJsonDocument::QJsonDocument()
    : d(0)
{
}

/*!
 * Creates a QJsonDocument from \a object.
 */
QJsonDocument::QJsonDocument(const QJsonObject &object)
    : d(0)
{
    setObject(object);
}

/*!
 * Constructs a QJsonDocument from \a array.
 */
QJsonDocument::QJsonDocument(const QJsonArray &array)
    : d(0)
{
    setArray(array);
}

/*!
    \internal
 */
QJsonDocument::QJsonDocument(QJsonPrivate::Data *data)
    : d(data)
{
    Q_ASSERT(d);
    d->ref.ref();
}

/*!
 Deletes the document.

 Binary data set with fromRawData is not freed.
 */
QJsonDocument::~QJsonDocument()
{
    if (d && !d->ref.deref())
        delete d;
}

/*!
 * Creates a copy of the \a other document.
 */
QJsonDocument::QJsonDocument(const QJsonDocument &other)
{
    d = other.d;
    if (d)
        d->ref.ref();
}

/*!
 * Assigns the \a other document to this QJsonDocument.
 * Returns a reference to this object.
 */
QJsonDocument &QJsonDocument::operator =(const QJsonDocument &other)
{
    if (d != other.d) {
        if (d && !d->ref.deref())
            delete d;
        d = other.d;
        if (d)
            d->ref.ref();
    }

    return *this;
}

/*! \enum QJsonDocument::DataValidation

  This value is used to tell QJsonDocument whether to validate the binary data
  when converting to a QJsonDocument using fromBinaryData() or fromRawData().

  \value Validate Validate the data before using it. This is the default.
  \value BypassValidation Bypasses data validation. Only use if you received the
  data from a trusted place and know it's valid, as using of invalid data can crash
  the application.
  */

/*!
 Creates a QJsonDocument that uses the first \a size bytes from
 \a data. It assumes \a data contains a binary encoded JSON document.
 The created document does not take ownership of \a data and the caller
 has to guarantee that \a data will not be deleted or modified as long as
 any QJsonDocument, QJsonObject or QJsonArray still references the data.

 \a data has to be aligned to a 4 byte boundary.

 \a validation decides whether the data is checked for validity before being used.
 By default the data is validated. If the \a data is not valid, the method returns
 a null document.

 Returns a QJsonDocument representing the data.

 \sa rawData(), fromBinaryData(), isNull(), DataValidation
 */
QJsonDocument QJsonDocument::fromRawData(const char *data, int size, DataValidation validation)
{
    if (quintptr(data) & 3) {
        qWarning() <<"QJsonDocument::fromRawData: data has to have 4 byte alignment";
        return QJsonDocument();
    }

    QJsonPrivate::Data *d = new QJsonPrivate::Data((char *)data, size);
    d->ownsData = false;

    if (validation != BypassValidation && !d->valid()) {
        delete d;
        return QJsonDocument();
    }

    return QJsonDocument(d);
}

/*!
  Returns the raw binary representation of the data
  \a size will contain the size of the returned data.

  This method is useful to e.g. stream the JSON document
  in it's binary form to a file.
 */
const char *QJsonDocument::rawData(int *size) const
{
    if (!d) {
        *size = 0;
        return 0;
    }
    *size = d->alloc;
    return d->rawData;
}

/*!
 Creates a QJsonDocument from \a data.

 \a validation decides whether the data is checked for validity before being used.
 By default the data is validated. If the \a data is not valid, the method returns
 a null document.

 \sa toBinaryData(), fromRawData(), isNull(), DataValidation
 */
QJsonDocument QJsonDocument::fromBinaryData(const QByteArray &data, DataValidation validation)
{
    if (data.size() < (int)(sizeof(QJsonPrivate::Header) + sizeof(QJsonPrivate::Base)))
        return QJsonDocument();

    QJsonPrivate::Header h;
    memcpy(&h, data.constData(), sizeof(QJsonPrivate::Header));
    QJsonPrivate::Base root;
    memcpy(&root, data.constData() + sizeof(QJsonPrivate::Header), sizeof(QJsonPrivate::Base));

    // do basic checks here, so we don't try to allocate more memory than we can.
    if (h.tag != QJsonDocument::BinaryFormatTag || h.version != 1u ||
        sizeof(QJsonPrivate::Header) + root.size > (uint)data.size())
        return QJsonDocument();

    const uint size = sizeof(QJsonPrivate::Header) + root.size;
    char *raw = (char *)malloc(size);
    if (!raw)
        return QJsonDocument();

    memcpy(raw, data.constData(), size);
    QJsonPrivate::Data *d = new QJsonPrivate::Data(raw, size);

    if (validation != BypassValidation && !d->valid()) {
        delete d;
        return QJsonDocument();
    }

    return QJsonDocument(d);
}

/*!
 Creates a QJsonDocument from the QVariant \a variant.

 If the \a variant contains any other type than a QVariantMap,
 QVariantList or QStringList, the returned document
 document is invalid.

 \sa toVariant()
 */
QJsonDocument QJsonDocument::fromVariant(const QVariant &variant)
{
    QJsonDocument doc;
    if (variant.type() == QVariant::Map) {
        doc.setObject(QJsonObject::fromVariantMap(variant.toMap()));
    } else if (variant.type() == QVariant::List) {
        doc.setArray(QJsonArray::fromVariantList(variant.toList()));
    } else if (variant.type() == QVariant::StringList) {
        doc.setArray(QJsonArray::fromStringList(variant.toStringList()));
    }
    return doc;
}

/*!
 Returns a QVariant representing the Json document.

 The returned variant will be a QVariantList if the document is
 a QJsonArray and a QVariantMap if the document is a QJsonObject.

 \sa fromVariant(), QJsonValue::toVariant()
 */
QVariant QJsonDocument::toVariant() const
{
    if (!d)
        return QVariant();

    if (d->header->root()->isArray())
        return QJsonArray(d, static_cast<QJsonPrivate::Array *>(d->header->root())).toVariantList();
    else
        return QJsonObject(d, static_cast<QJsonPrivate::Object *>(d->header->root())).toVariantMap();
}

/*!
 Converts the QJsonDocument to a UTF-8 encoded JSON document.

 \sa fromJson()
 */
#ifndef QT_JSON_READONLY
QByteArray QJsonDocument::toJson() const
{
    return toJson(Indented);
}
#endif

/*!
    \enum QJsonDocument::JsonFormat

    This value defines the format of the JSON byte array produced
    when converting to a QJsonDocument using toJson().

    \value Indented Defines human readable output as follows:
        \code
        {
            "Array": [
                true,
                999,
                "string"
            ],
            "Key": "Value",
            "null": null
        }
        \endcode

    \value Compact Defines a compact output as follows:
        \code
        {"Array":[true,999,"string"],"Key":"Value","null":null}
        \endcode
  */

/*!
    Converts the QJsonDocument to a UTF-8 encoded JSON document in the provided \a format.

    \sa fromJson(), JsonFormat
 */
#ifndef QT_JSON_READONLY
QByteArray QJsonDocument::toJson(JsonFormat format) const
{
    if (!d)
        return QByteArray();

    QByteArray json;

    if (d->header->root()->isArray())
        QJsonPrivate::Writer::arrayToJson(static_cast<QJsonPrivate::Array *>(d->header->root()), json, 0, (format == Compact));
    else
        QJsonPrivate::Writer::objectToJson(static_cast<QJsonPrivate::Object *>(d->header->root()), json, 0, (format == Compact));

    return json;
}
#endif

/*!
 Parses a UTF-8 encoded JSON document and creates a QJsonDocument
 from it.

 \a json contains the json document to be parsed.

 The optional \a error variable can be used to pass in a QJsonParseError data
 structure that will contain information about possible errors encountered during
 parsing.

 \sa toJson(), QJsonParseError
 */
QJsonDocument QJsonDocument::fromJson(const QByteArray &json, QJsonParseError *error)
{
    QJsonPrivate::Parser parser(json.constData(), json.length());
    return parser.parse(error);
}

/*!
    Returns \c true if the document doesn't contain any data.
 */
bool QJsonDocument::isEmpty() const
{
    if (!d)
        return true;

    return false;
}

/*!
 Returns a binary representation of the document.

 The binary representation is also the native format used internally in Qt,
 and is very efficient and fast to convert to and from.

 The binary format can be stored on disk and interchanged with other applications
 or computers. fromBinaryData() can be used to convert it back into a
 JSON document.

 \sa fromBinaryData()
 */
QByteArray QJsonDocument::toBinaryData() const
{
    if (!d || !d->rawData)
        return QByteArray();

    return QByteArray(d->rawData, d->header->root()->size + sizeof(QJsonPrivate::Header));
}

/*!
    Returns \c true if the document contains an array.

    \sa array(), isObject()
 */
bool QJsonDocument::isArray() const
{
    if (!d)
        return false;

    QJsonPrivate::Header *h = (QJsonPrivate::Header *)d->rawData;
    return h->root()->isArray();
}

/*!
    Returns \c true if the document contains an object.

    \sa object(), isArray()
 */
bool QJsonDocument::isObject() const
{
    if (!d)
        return false;

    QJsonPrivate::Header *h = (QJsonPrivate::Header *)d->rawData;
    return h->root()->isObject();
}

/*!
    Returns the QJsonObject contained in the document.

    Returns an empty object if the document contains an
    array.

    \sa isObject(), array(), setObject()
 */
QJsonObject QJsonDocument::object() const
{
    if (d) {
        QJsonPrivate::Base *b = d->header->root();
        if (b->isObject())
            return QJsonObject(d, static_cast<QJsonPrivate::Object *>(b));
    }
    return QJsonObject();
}

/*!
    Returns the QJsonArray contained in the document.

    Returns an empty array if the document contains an
    object.

    \sa isArray(), object(), setArray()
 */
QJsonArray QJsonDocument::array() const
{
    if (d) {
        QJsonPrivate::Base *b = d->header->root();
        if (b->isArray())
            return QJsonArray(d, static_cast<QJsonPrivate::Array *>(b));
    }
    return QJsonArray();
}

/*!
    Sets \a object as the main object of this document.

    \sa setArray(), object()
 */
void QJsonDocument::setObject(const QJsonObject &object)
{
    if (d && !d->ref.deref())
        delete d;

    d = object.d;

    if (!d) {
        d = new QJsonPrivate::Data(0, QJsonValue::Object);
    } else if (d->compactionCounter || object.o != d->header->root()) {
        QJsonObject o(object);
        if (d->compactionCounter)
            o.compact();
        else
            o.detach();
        d = o.d;
        d->ref.ref();
        return;
    }
    d->ref.ref();
}

/*!
    Sets \a array as the main object of this document.

    \sa setObject(), array()
 */
void QJsonDocument::setArray(const QJsonArray &array)
{
    if (d && !d->ref.deref())
        delete d;

    d = array.d;

    if (!d) {
        d = new QJsonPrivate::Data(0, QJsonValue::Array);
    } else if (d->compactionCounter || array.a != d->header->root()) {
        QJsonArray a(array);
        if (d->compactionCounter)
            a.compact();
        else
            a.detach();
        d = a.d;
        d->ref.ref();
        return;
    }
    d->ref.ref();
}

/*!
    Returns \c true if the \a other document is equal to this document.
 */
bool QJsonDocument::operator==(const QJsonDocument &other) const
{
    if (d == other.d)
        return true;

    if (!d || !other.d)
        return false;

    if (d->header->root()->isArray() != other.d->header->root()->isArray())
        return false;

    if (d->header->root()->isObject())
        return QJsonObject(d, static_cast<QJsonPrivate::Object *>(d->header->root()))
                == QJsonObject(other.d, static_cast<QJsonPrivate::Object *>(other.d->header->root()));
    else
        return QJsonArray(d, static_cast<QJsonPrivate::Array *>(d->header->root()))
                == QJsonArray(other.d, static_cast<QJsonPrivate::Array *>(other.d->header->root()));
}

/*!
 \fn bool QJsonDocument::operator!=(const QJsonDocument &other) const

    returns \c true if \a other is not equal to this document
 */

/*!
    returns \c true if this document is null.

    Null documents are documents created through the default constructor.

    Documents created from UTF-8 encoded text or the binary format are
    validated during parsing. If validation fails, the returned document
    will also be null.
 */
bool QJsonDocument::isNull() const
{
    return (d == 0);
}

#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
QDebug operator<<(QDebug dbg, const QJsonDocument &o)
{
    if (!o.d) {
        dbg << "QJsonDocument()";
        return dbg;
    }
    QByteArray json;
    if (o.d->header->root()->isArray())
        QJsonPrivate::Writer::arrayToJson(static_cast<QJsonPrivate::Array *>(o.d->header->root()), json, 0, true);
    else
        QJsonPrivate::Writer::objectToJson(static_cast<QJsonPrivate::Object *>(o.d->header->root()), json, 0, true);
    dbg.nospace() << "QJsonDocument("
                  << json.constData() // print as utf-8 string without extra quotation marks
                  << ")";
    return dbg.space();
}
#endif

QT_END_NAMESPACE