summaryrefslogtreecommitdiff
path: root/kdecore/sycoca/ksycoca.cpp
blob: 24099d18b9de89e1df46df23bf0f4d58341543af (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
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
/*  This file is part of the KDE libraries
 *  Copyright (C) 1999-2000 Waldo Bastian <bastian@kde.org>
 *  Copyright (C) 2005-2009 David Faure <faure@kde.org>
 *  Copyright (C) 2008 Hamish Rodda <rodda@kde.org>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License version 2 as published by the Free Software Foundation;
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 **/

#include "ksycoca.h"
#include "ksycoca_p.h"
#include "ksycocatype.h"
#include "ksycocafactory.h"
#include "ktoolinvocation.h"
#include "kglobal.h"
#include "kmemfile.h"
#include "kde_file.h"
#include "kconfiggroup.h"
#include "ksharedconfig.h"

#include "kdebug.h"
#include "kstandarddirs.h"

#include <QtCore/QDataStream>
#include <QtCore/QCoreApplication>
#include <QtCore/QFile>
#include <QtCore/QBuffer>
#include <QProcess>
#include <QtDBus/QtDBus>

// #include <config.h>

#include <stdlib.h>
#include <fcntl.h>

#include "ksycocadevices_p.h"

// TODO: remove mmap() from kdewin32 and use QFile::mmap() when needed
#ifdef Q_WS_WIN
#undef HAVE_MMAP
#endif
/**
 * Sycoca file version number.
 * If the existing file is outdated, it will not get read
 * but instead we'll ask kded to regenerate a new one...
 */
#define KSYCOCA_VERSION 205

/**
 * Sycoca file name, used internally (by kbuildsycoca)
 */
#define KSYCOCA_FILENAME "ksycoca4"

#if HAVE_MADVISE
#include <sys/mman.h> // This #include was checked when looking for posix_madvise
#endif

#ifndef MAP_FAILED
#define MAP_FAILED ((void *) -1)
#endif

static bool s_autoRebuild = true;

// The following limitations are in place:
// Maximum length of a single string: 8192 bytes
// Maximum length of a string list: 1024 strings
// Maximum number of entries: 8192
//
// The purpose of these limitations is to limit the impact
// of database corruption.


Q_DECLARE_OPERATORS_FOR_FLAGS(KSycocaPrivate::BehaviorsIfNotFound)

KSycocaPrivate::KSycocaPrivate()
    : databaseStatus( DatabaseNotOpen ),
      readError( false ),
      timeStamp( 0 ),
      m_databasePath(),
      updateSig( 0 ),
      sycoca_size(0),
      sycoca_mmap(0),
      m_mmapFile(0),
      m_device(0)
{
#ifdef Q_OS_WIN
    /*
      on windows we use KMemFile (QSharedMemory) to avoid problems
      with mmap (can't delete a mmap'd file)
    */
    m_sycocaStrategy = StrategyMemFile;
#else
    m_sycocaStrategy = StrategyMmap;
#endif
    KConfigGroup config(KGlobal::config(), "KSycoca");
    setStrategyFromString(config.readEntry("strategy"));
}

void KSycocaPrivate::setStrategyFromString(const QString& strategy) {
    if (strategy == QLatin1String("mmap"))
        m_sycocaStrategy = StrategyMmap;
    else if (strategy == QLatin1String("file"))
        m_sycocaStrategy = StrategyFile;
    else if (strategy == QLatin1String("sharedmem"))
        m_sycocaStrategy = StrategyMemFile;
    else if (!strategy.isEmpty())
        kWarning(7011) << "Unknown sycoca strategy:" << strategy;
}

bool KSycocaPrivate::tryMmap()
{
#ifdef HAVE_MMAP
    Q_ASSERT(!m_databasePath.isEmpty());
    m_mmapFile = new QFile(m_databasePath);
    const bool canRead = m_mmapFile->open(QIODevice::ReadOnly);
    Q_ASSERT(canRead);
    Q_UNUSED(canRead); // no compiler warning in release builds.
    fcntl(m_mmapFile->handle(), F_SETFD, FD_CLOEXEC);
    sycoca_size = m_mmapFile->size();
    sycoca_mmap = (const char *) mmap(0, sycoca_size,
                                      PROT_READ, MAP_SHARED,
                                      m_mmapFile->handle(), 0);
    /* POSIX mandates only MAP_FAILED, but we are paranoid so check for
       null pointer too.  */
    if (sycoca_mmap == (const char*) MAP_FAILED || sycoca_mmap == 0) {
        kDebug(7011) << "mmap failed. (length = " << sycoca_size << ")";
        sycoca_mmap = 0;
        return false;
    } else {
#ifdef HAVE_MADVISE
        (void) posix_madvise((void*)sycoca_mmap, sycoca_size, POSIX_MADV_WILLNEED);
#endif // HAVE_MADVISE
        return true;
    }
#endif // HAVE_MMAP
    return false;
}

int KSycoca::version()
{
   return KSYCOCA_VERSION;
}

class KSycocaSingleton
{
public:
    KSycocaSingleton() { }
    ~KSycocaSingleton() { }

    bool hasSycoca() const {
        return m_threadSycocas.hasLocalData();
    }
    KSycoca* sycoca() {
        if (!m_threadSycocas.hasLocalData())
            m_threadSycocas.setLocalData(new KSycoca);
        return m_threadSycocas.localData();
    }
    void setSycoca(KSycoca* s) {
        m_threadSycocas.setLocalData(s);
    }

private:
    QThreadStorage<KSycoca*> m_threadSycocas;
};

K_GLOBAL_STATIC(KSycocaSingleton, ksycocaInstance)

// Read-only constructor
KSycoca::KSycoca()
  : d(new KSycocaPrivate)
{
    QDBusConnection::sessionBus().connect(QString(), QString(),
                                          QString::fromLatin1("org.kde.KSycoca"),
                                          QString::fromLatin1("notifyDatabaseChanged"),
                                          this, SLOT(notifyDatabaseChanged(QStringList)));
}

bool KSycocaPrivate::openDatabase(bool openDummyIfNotFound)
{
    Q_ASSERT(databaseStatus == DatabaseNotOpen);

    delete m_device; m_device = 0;
    QString path = KSycoca::absoluteFilePath();

    bool canRead = KDE::access(path, R_OK) == 0;
    kDebug(7011) << "Trying to open ksycoca from" << path;
    if (!canRead) {
        path = KSycoca::absoluteFilePath(KSycoca::GlobalDatabase);
        if (!path.isEmpty()) {
            kDebug(7011) << "Trying to open global ksycoca from " << path;
            canRead = KDE::access(path, R_OK) == 0;
        }
    }

    bool result = true;
    if (canRead) {
        m_databasePath = path;
        checkVersion();
    } else { // No database file
        kDebug(7011) << "Could not open ksycoca";
        m_databasePath.clear();
        databaseStatus = NoDatabase;
        if (openDummyIfNotFound) {
            // We open a dummy database instead.
            //kDebug(7011) << "No database, opening a dummy one.";

            m_sycocaStrategy = StrategyDummyBuffer;
            QDataStream* str = stream();
            *str << qint32(KSYCOCA_VERSION);
            *str << qint32(0);
        } else {
            result = false;
        }
    }
    return result;
}

KSycocaAbstractDevice* KSycocaPrivate::device()
{
    if (m_device)
        return m_device;

    Q_ASSERT(!m_databasePath.isEmpty());

    KSycocaAbstractDevice* device = m_device;
    if (m_sycocaStrategy == StrategyDummyBuffer) {
        device = new KSycocaBufferDevice;
        device->device()->open(QIODevice::ReadOnly); // can't fail
    } else {
#ifdef HAVE_MMAP
        if (m_sycocaStrategy == StrategyMmap && tryMmap()) {
            device = new KSycocaMmapDevice(sycoca_mmap,
                                           sycoca_size);
            if (!device->device()->open(QIODevice::ReadOnly)) {
                delete device; device = 0;
            }
        }
#endif
#ifndef QT_NO_SHAREDMEMORY
        if (!device && m_sycocaStrategy == StrategyMemFile) {
            device = new KSycocaMemFileDevice(m_databasePath);
            if (!device->device()->open(QIODevice::ReadOnly)) {
                delete device; device = 0;
            }
        }
#endif
        if (!device) {
            device = new KSycocaFileDevice(m_databasePath);
            if (!device->device()->open(QIODevice::ReadOnly)) {
                kError(7011) << "Couldn't open" << m_databasePath << "even though it is readable? Impossible.";
                //delete device; device = 0; // this would crash in the return statement...
            }
        }
    }
    if (device) {
        m_device = device;
    }
    return m_device;
}

QDataStream*& KSycocaPrivate::stream()
{
    if (!m_device) {
        if (databaseStatus == DatabaseNotOpen) {
            checkDatabase(KSycocaPrivate::IfNotFoundRecreate | KSycocaPrivate::IfNotFoundOpenDummy);
        }

        device(); // create m_device
    }

    return m_device->stream();
}

// Read-write constructor - only for KBuildSycoca
KSycoca::KSycoca( bool /* dummy */ )
  : d(new KSycocaPrivate)
{
    // This instance was not created by the singleton, but by a direct call to new!
    ksycocaInstance->setSycoca(this);
}

KSycoca * KSycoca::self()
{
    KSycoca* s = ksycocaInstance->sycoca();
    Q_ASSERT(s);
    return s;
}

KSycoca::~KSycoca()
{
    d->closeDatabase();
    delete d;
    //if (ksycocaInstance.exists()
    //    && ksycocaInstance->self == this)
    //    ksycocaInstance->self = 0;
}

bool KSycoca::isAvailable()
{
    return self()->d->checkDatabase(KSycocaPrivate::IfNotFoundDoNothing/* don't open dummy db if not found */);
}

void KSycocaPrivate::closeDatabase()
{
    delete m_device;
    m_device = 0;

    // It is very important to delete all factories here
    // since they cache information about the database file
    // But other threads might be using them, so this class is
    // refcounted, and deleted when the last thread is done with them
    qDeleteAll(m_factories);
    m_factories.clear();
#ifdef HAVE_MMAP
    if (sycoca_mmap) {
        //QBuffer *buf = static_cast<QBuffer*>(device);
        //buf->buffer().clear();
        // Solaris has munmap(char*, size_t) and everything else should
        // be happy with a char* for munmap(void*, size_t)
        munmap(const_cast<char*>(sycoca_mmap), sycoca_size);
        sycoca_mmap = 0;
    }
    delete m_mmapFile; m_mmapFile = 0;
#endif

    databaseStatus = DatabaseNotOpen;
    timeStamp = 0;
}

void KSycoca::addFactory( KSycocaFactory *factory )
{
    d->addFactory(factory);
}

#ifndef KDE_NO_DEPRECATED
bool KSycoca::isChanged(const char *type)
{
    return self()->d->changeList.contains(QString::fromLatin1(type));
}
#endif

void KSycoca::notifyDatabaseChanged(const QStringList &changeList)
{
    d->changeList = changeList;
    //kDebug(7011) << QThread::currentThread() << "got a notifyDatabaseChanged signal" << changeList;
    // kbuildsycoca tells us the database file changed
    // Close the database and forget all about what we knew
    // The next call to any public method will recreate
    // everything that's needed.
    d->closeDatabase();

    // Now notify applications
#ifndef KDE_NO_DEPRECATED
    emit databaseChanged();
#endif
    emit databaseChanged(changeList);
}

QDataStream * KSycoca::findEntry(int offset, KSycocaType &type)
{
   QDataStream* str = stream();
   Q_ASSERT(str);
   //kDebug(7011) << QString("KSycoca::_findEntry(offset=%1)").arg(offset,8,16);
   str->device()->seek(offset);
   qint32 aType;
   *str >> aType;
   type = KSycocaType(aType);
   //kDebug(7011) << QString("KSycoca::found type %1").arg(aType);
   return str;
}

KSycocaFactoryList* KSycoca::factories()
{
    return d->factories();
}

// Warning, checkVersion rewinds to the beginning of stream().
bool KSycocaPrivate::checkVersion()
{
    QDataStream *m_str = device()->stream();
    Q_ASSERT(m_str);
    m_str->device()->seek(0);
    qint32 aVersion;
    *m_str >> aVersion;
    if ( aVersion < KSYCOCA_VERSION ) {
        kWarning(7011) << "Found version" << aVersion << ", expecting version" << KSYCOCA_VERSION << "or higher.";
        databaseStatus = BadVersion;
        return false;
    } else {
        databaseStatus = DatabaseOK;
        return true;
    }
}

// If it returns true, we have a valid database and the stream has rewinded to the beginning
// and past the version number.
bool KSycocaPrivate::checkDatabase(BehaviorsIfNotFound ifNotFound)
{
    if (databaseStatus == DatabaseOK) {
        if (checkVersion()) // we know the version is ok, but we must rewind the stream anyway
            return true;
    }

    closeDatabase(); // close the dummy one

    // We can only use the installed ksycoca file if kdeinit+klauncher+kded are running,
    // since kded is what keeps the file uptodate.
    const bool kdeinitRunning = QDBusConnection::sessionBus().interface()->isServiceRegistered(QString::fromLatin1("org.kde.klauncher"));

    // Check if new database already available
    if (kdeinitRunning && openDatabase(ifNotFound & IfNotFoundOpenDummy)) {
        if (checkVersion()) {
            // Database exists, and version is ok.
            return true;
        }
    }

    if (ifNotFound & IfNotFoundRecreate) {
        // Well, if kdeinit is not running we need to launch it,
        // but otherwise we simply need to run kbuildsycoca to recreate the sycoca file.
        if (!kdeinitRunning) {
            kDebug(7011) << "We have no database.... launching kdeinit";
            KToolInvocation::klauncher(); // this calls startKdeinit, and blocks until it returns
            // and since kdeinit4 only returns after kbuildsycoca4 is done, we can proceed.
        } else {
            kDebug(7011) << QThread::currentThread() << "We have no database.... launching" << KBUILDSYCOCA_EXENAME;
            if (QProcess::execute(KStandardDirs::findExe(QString::fromLatin1(KBUILDSYCOCA_EXENAME))) != 0)
                qWarning("ERROR: Running KSycoca failed.");
        }

        closeDatabase(); // close the dummy one

        // Ok, the new database should be here now, open it.
        if (!openDatabase(ifNotFound & IfNotFoundOpenDummy)) {
            kDebug(7011) << "Still no database...";
            return false; // Still no database - uh oh
        }
        if (!checkVersion()) {
            kDebug(7011) << "Still outdated...";
            return false; // Still outdated - uh oh
        }
        return true;
    }

    return false;
}

QDataStream * KSycoca::findFactory(KSycocaFactoryId id)
{
    // Ensure we have a valid database (right version, and rewinded to beginning)
    if (!d->checkDatabase(KSycocaPrivate::IfNotFoundRecreate)) {
        return 0;
    }

    QDataStream* str = stream();
    Q_ASSERT(str);

    qint32 aId;
    qint32 aOffset;
    while(true) {
        *str >> aId;
        if (aId == 0) {
            kError(7011) << "Error, KSycocaFactory (id =" << int(id) << ") not found!";
            break;
        }
        *str >> aOffset;
        if (aId == id) {
            //kDebug(7011) << "KSycoca::findFactory(" << id << ") offset " << aOffset;
            str->device()->seek(aOffset);
            return str;
        }
    }
    return 0;
}

QString KSycoca::kfsstnd_prefixes()
{
    // do not try to launch kbuildsycoca from here; this code is also called by kbuildsycoca.
   if (!d->checkDatabase(KSycocaPrivate::IfNotFoundDoNothing))
       return QString();
   QDataStream* str = stream();
   Q_ASSERT(str);
   qint32 aId;
   qint32 aOffset;
   // skip factories offsets
   while(true)
   {
      *str >> aId;
      if ( aId )
        *str >> aOffset;
      else
        break; // just read 0
   }
   // We now point to the header
   QString prefixes;
   KSycocaEntry::read(*str, prefixes);
   *str >> d->timeStamp;
   KSycocaEntry::read(*str, d->language);
   *str >> d->updateSig;
   KSycocaEntry::read(*str, d->allResourceDirs);
   return prefixes;
}

quint32 KSycoca::timeStamp()
{
   if (!d->timeStamp)
      (void) kfsstnd_prefixes();
   return d->timeStamp;
}

quint32 KSycoca::updateSignature()
{
   if (!d->timeStamp)
      (void) kfsstnd_prefixes();
   return d->updateSig;
}

QString KSycoca::absoluteFilePath(DatabaseType type)
{
    if (type == GlobalDatabase) {
        QString path = KGlobal::dirs()->findResource("services", QString::fromLatin1(KSYCOCA_FILENAME));
        if (path.isEmpty())
            return KGlobal::dirs()->saveLocation("services") + QString::fromLatin1(KSYCOCA_FILENAME);
        return path;
    }

    const QByteArray ksycoca_env = qgetenv("KDESYCOCA");
    if (ksycoca_env.isEmpty())
        return KGlobal::dirs()->saveLocation("cache") + QString::fromLatin1(KSYCOCA_FILENAME);
    else
        return QFile::decodeName(ksycoca_env);
}

QString KSycoca::language()
{
   if (d->language.isEmpty())
      (void) kfsstnd_prefixes();
   return d->language;
}

QStringList KSycoca::allResourceDirs()
{
   if (!d->timeStamp)
      (void) kfsstnd_prefixes();
   return d->allResourceDirs;
}

void KSycoca::flagError()
{
    kWarning(7011) << "ERROR: KSycoca database corruption!";
    KSycocaPrivate* d = ksycocaInstance->sycoca()->d;
    if (d->readError)
        return;
    d->readError = true;
    if (s_autoRebuild) {
        // Rebuild the damned thing.
        if (QProcess::execute(KStandardDirs::findExe(QString::fromLatin1(KBUILDSYCOCA_EXENAME))) != 0)
            qWarning("ERROR: Running %s failed", KBUILDSYCOCA_EXENAME);
        // Old comment, maybe not true anymore:
        // Do not wait until the DBUS signal from kbuildsycoca here.
        // It deletes m_str which is a problem when flagError is called during the KSycocaFactory ctor...
    }
}

#ifndef KDE_NO_DEPRECATED
bool KSycoca::readError() // KDE5: remove
{
    return false;
}
#endif

bool KSycoca::isBuilding()
{
    return false;
}

void KSycoca::disableAutoRebuild()
{
   s_autoRebuild = false;
}

QDataStream*& KSycoca::stream()
{
    return d->stream();
}

void KSycoca::clearCaches()
{
    if (ksycocaInstance.exists() && ksycocaInstance->hasSycoca())
        ksycocaInstance->sycoca()->d->closeDatabase();
}

#include "../../ksycoca.moc"