/****************************************************************************

**

** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** GNU Lesser General Public License Usage

** 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, Nokia gives you certain additional

** rights. These rights are described in the Nokia 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.

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** Other Usage

** Alternatively, this file may be used in accordance with the terms and

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** $QT_END_LICENSE$

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****************************************************************************/

#include "qplatformdefs.h"

#include "qtranslator.h"

#ifndef QT_NO_TRANSLATION

#include "qfileinfo.h"

#include "qstring.h"

#include "qstringlist.h"

#include "qcoreapplication.h"

#include "qcoreapplication_p.h"

#include "qdatastream.h"

#include "qdir.h"

#include "qfile.h"

#include "qmap.h"

#include "qalgorithms.h"

#include "qhash.h"

#include "qtranslator_p.h"

#include "qlocale.h"

#if defined(Q_OS_UNIX) && !defined(Q_OS_SYMBIAN) && !defined(Q_OS_INTEGRITY)

#define QT_USE_MMAP

#include "private/qcore_unix_p.h"

#endif

#ifdef Q_OS_SYMBIAN

#include "private/qcore_symbian_p.h"

#endif

// most of the headers below are already included in qplatformdefs.h

// also this lacks Large File support but that's probably irrelevant

#if defined(QT_USE_MMAP)

// for mmap

#include <sys/mman.h>

#include <errno.h>

#endif

#include <stdlib.h>

#include "qobject_p.h"

QT_BEGIN_NAMESPACE

enum Tag { Tag_End = 1, Tag_SourceText16, Tag_Translation, Tag_Context16, Tag_Obsolete1,

           Tag_SourceText, Tag_Context, Tag_Comment, Tag_Obsolete2 };

/*

$ mcookie

3cb86418caef9c95cd211cbf60a1bddd

$

*/

// magic number for the file

static const int MagicLength = 16;

static const uchar magic[MagicLength] = {

    0x3c, 0xb8, 0x64, 0x18, 0xca, 0xef, 0x9c, 0x95,

    0xcd, 0x21, 0x1c, 0xbf, 0x60, 0xa1, 0xbd, 0xdd

};

static bool match(const uchar* found, const char* target, uint len)

{

    // catch the case if \a found has a zero-terminating symbol and \a len includes it.

    // (normalize it to be without the zero-terminating symbol)

    if (len > 0 && found[len-1] == '\0')

        --len;

    return (memcmp(found, target, len) == 0 && target[len] == '\0');

}

static uint elfHash(const char *name)

{

    const uchar *k;

    uint h = 0;

    uint g;

    if (name) {

        k = (const uchar *) name;

        while (*k) {

            h = (h << 4) + *k++;

            if ((g = (h & 0xf0000000)) != 0)

                h ^= g >> 24;

            h &= ~g;

        }

    }

    if (!h)

        h = 1;

    return h;

}

static int numerusHelper(int n, const uchar *rules, int rulesSize)

{

#define CHECK_RANGE \

    do { \

        if (i >= rulesSize) \

            return -1; \

    } while (0)

    int result = 0;

    int i = 0;

    if (rulesSize == 0)

        return 0;

    for (;;) {

        bool orExprTruthValue = false;

        for (;;) {

            bool andExprTruthValue = true;

            for (;;) {

                bool truthValue = true;

                CHECK_RANGE;

                int opcode = rules[i++];

                int leftOperand = n;

                if (opcode & Q_MOD_10) {

                    leftOperand %= 10;

                } else if (opcode & Q_MOD_100) {

                    leftOperand %= 100;

                } else if (opcode & Q_LEAD_1000) {

                    while (leftOperand >= 1000)

                        leftOperand /= 1000;

                }

                int op = opcode & Q_OP_MASK;

                CHECK_RANGE;

                int rightOperand = rules[i++];

                switch (op) {

                default:

                    return -1;

                case Q_EQ:

                    truthValue = (leftOperand == rightOperand);

                    break;

                case Q_LT:

                    truthValue = (leftOperand < rightOperand);

                    break;

                case Q_LEQ:

                    truthValue = (leftOperand <= rightOperand);

                    break;

		case Q_BETWEEN:

                    int bottom = rightOperand;

                    CHECK_RANGE;

                    int top = rules[i++];

                    truthValue = (leftOperand >= bottom && leftOperand <= top);

                }

                if (opcode & Q_NOT)

                    truthValue = !truthValue;

                andExprTruthValue = andExprTruthValue && truthValue;

                if (i == rulesSize || rules[i] != Q_AND)

                    break;

                ++i;

            }

            orExprTruthValue = orExprTruthValue || andExprTruthValue;

            if (i == rulesSize || rules[i] != Q_OR)

                break;

            ++i;

        }

        if (orExprTruthValue)

            return result;

        ++result;

        if (i == rulesSize)

            return result;

        if (rules[i++] != Q_NEWRULE)

            break;

    }

    return -1;

}

class QTranslatorPrivate : public QObjectPrivate

{

    Q_DECLARE_PUBLIC(QTranslator)

public:

    enum { Contexts = 0x2f, Hashes = 0x42, Messages = 0x69, NumerusRules = 0x88 };

    QTranslatorPrivate()

        : used_mmap(0), unmapPointer(0), unmapLength(0),

          messageArray(0), offsetArray(0), contextArray(0), numerusRulesArray(0),

          messageLength(0), offsetLength(0), contextLength(0), numerusRulesLength(0) {}

    // for mmap'ed files, this is what needs to be unmapped.

    bool used_mmap : 1;

    char *unmapPointer;

    unsigned int unmapLength;

    // for squeezed but non-file data, this is what needs to be deleted

    const uchar *messageArray;

    const uchar *offsetArray;

    const uchar *contextArray;

    const uchar *numerusRulesArray;

    uint messageLength;

    uint offsetLength;

    uint contextLength;

    uint numerusRulesLength;

    bool do_load(const QString &filename);

    bool do_load(const uchar *data, int len);

    QString do_translate(const char *context, const char *sourceText, const char *comment,

                         int n) const;

    void clear();

};

/*!

    \class QTranslator

    \brief The QTranslator class provides internationalization support for text

    output.

    \ingroup i18n

    An object of this class contains a set of translations from a

    source language to a target language. QTranslator provides

    functions to look up translations in a translation file.

    Translation files are created using \l{Qt Linguist}.

    The most common use of QTranslator is to: load a translation

    file, install it using QApplication::installTranslator(), and use

    it via QObject::tr(). Here's the \c main() function from the

    \l{linguist/hellotr}{Hello tr()} example:

    \snippet examples/linguist/hellotr/main.cpp 2

    Note that the translator must be created \e before the

    application's widgets.

    Most applications will never need to do anything else with this

    class. The other functions provided by this class are useful for

    applications that work on translator files.

    \section1 Looking up Translations

    It is possible to look up a translation using translate() (as tr()

    and QApplication::translate() do). The translate() function takes

    up to three parameters:

    \list

    \o The \e context - usually the class name for the tr() caller.

    \o The \e {source text} - usually the argument to tr().

    \o The \e disambiguation - an optional string that helps disambiguate

       different uses of the same text in the same context.

    \endlist

    For example, the "Cancel" in a dialog might have "Anuluj" when the

    program runs in Polish (in this case the source text would be

    "Cancel"). The context would (normally) be the dialog's class

    name; there would normally be no comment, and the translated text

    would be "Anuluj".

    But it's not always so simple. The Spanish version of a printer

    dialog with settings for two-sided printing and binding would

    probably require both "Activado" and "Activada" as translations

    for "Enabled". In this case the source text would be "Enabled" in

    both cases, and the context would be the dialog's class name, but

    the two items would have disambiguations such as "two-sided printing"

    for one and "binding" for the other. The disambiguation enables the

    translator to choose the appropriate gender for the Spanish version,

    and enables Qt to distinguish between translations.

    \section1 Using Multiple Translations

    Multiple translation files can be installed in an application.

    Translations are searched for in the reverse order in which they were

    installed, so the most recently installed translation file is searched

    for translations first and the earliest translation file is searched

    last. The search stops as soon as a translation containing a matching

    string is found.

    This mechanism makes it possible for a specific translation to be

    "selected" or given priority over the others; simply uninstall the

    translator from the application by passing it to the

    QApplication::removeTranslator() function and reinstall it with

    QApplication::installTranslator(). It will then be the first

    translation to be searched for matching strings.

    \sa QApplication::installTranslator(), QApplication::removeTranslator(),

        QObject::tr(), QApplication::translate(), {I18N Example},

        {Hello tr() Example}, {Arrow Pad Example}, {Troll Print Example}

*/

/*!

    Constructs an empty message file object with parent \a parent that

    is not connected to any file.

*/

QTranslator::QTranslator(QObject * parent)

    : QObject(*new QTranslatorPrivate, parent)

{

}

#ifdef QT3_SUPPORT

/*!

    \overload QTranslator()

    \obsolete

 */

QTranslator::QTranslator(QObject * parent, const char * name)

    : QObject(*new QTranslatorPrivate, parent)

{

    setObjectName(QString::fromAscii(name));

}

#endif

/*!

    Destroys the object and frees any allocated resources.

*/

QTranslator::~QTranslator()

{

    if (QCoreApplication::instance())

        QCoreApplication::removeTranslator(this);

    Q_D(QTranslator);

    d->clear();

}

/*!

    Loads \a filename + \a suffix (".qm" if the \a suffix is not

    specified), which may be an absolute file name or relative to \a

    directory. Returns true if the translation is successfully loaded;

    otherwise returns false.

    If \a directory is not specified, the directory of the

    application's executable is used (i.e., as

    \l{QCoreApplication::}{applicationDirPath()}). 

    The previous contents of this translator object are discarded.

    If the file name does not exist, other file names are tried

    in the following order:

    \list 1

    \o File name without \a suffix appended.

    \o File name with text after a character in \a search_delimiters

       stripped ("_." is the default for \a search_delimiters if it is

       an empty string) and \a suffix.

    \o File name stripped without \a suffix appended.

    \o File name stripped further, etc.

    \endlist

    For example, an application running in the fr_CA locale

    (French-speaking Canada) might call load("foo.fr_ca",

    "/opt/foolib"). load() would then try to open the first existing

    readable file from this list:

    \list 1

    \o \c /opt/foolib/foo.fr_ca.qm

    \o \c /opt/foolib/foo.fr_ca

    \o \c /opt/foolib/foo.fr.qm

    \o \c /opt/foolib/foo.fr

    \o \c /opt/foolib/foo.qm

    \o \c /opt/foolib/foo

    \endlist

*/

bool QTranslator::load(const QString & filename, const QString & directory,

                       const QString & search_delimiters,

                       const QString & suffix)

{

    Q_D(QTranslator);

    d->clear();

    QString fname = filename;

    QString prefix;

    if (QFileInfo(filename).isRelative()) {

#ifdef Q_OS_SYMBIAN

        //TFindFile doesn't like path in the filename

        QString dir(directory);

        int slash = filename.lastIndexOf(QLatin1Char('/'));

        slash = qMax(slash, filename.lastIndexOf(QLatin1Char('\\')));

        if (slash >=0) {

            //so move the path component into the directory prefix

            if (dir.isEmpty())

                dir = filename.left(slash + 1);

            else

                dir = dir + QLatin1Char('/') + filename.left(slash + 1);

            fname = fname.mid(slash + 1);

        }

        if (dir.isEmpty())

            prefix = QCoreApplication::applicationDirPath();

        else

            prefix = QFileInfo(dir).absoluteFilePath(); //TFindFile doesn't like dirty paths

        if (prefix.length() > 2 && prefix.at(1) == QLatin1Char(':') && prefix.at(0).isLetter())

            prefix[0] = QLatin1Char('Y');

#else

        prefix = directory;

#endif

        if (prefix.length() && !prefix.endsWith(QLatin1Char('/')))

            prefix += QLatin1Char('/');

    }

#ifdef Q_OS_SYMBIAN

    QString nativePrefix = QDir::toNativeSeparators(prefix);

#endif

    QString realname;

    QString delims;

    delims = search_delimiters.isNull() ? QString::fromLatin1("_.") : search_delimiters;

    for (;;) {

        QFileInfo fi;

#ifdef Q_OS_SYMBIAN

        //search for translations on other drives, e.g. Qt may be in Z, while app is in C

        //note this uses symbian search rules, i.e. y:->a:, followed by z:

        TFindFile finder(qt_s60GetRFs());

        QString fname2 = fname + (suffix.isNull() ? QString::fromLatin1(".qm") : suffix);

        TInt err = finder.FindByDir(

            qt_QString2TPtrC(fname2),

            qt_QString2TPtrC(nativePrefix));

        if (err != KErrNone)

            err = finder.FindByDir(qt_QString2TPtrC(fname), qt_QString2TPtrC(nativePrefix));

        if (err == KErrNone) {

            fi.setFile(qt_TDesC2QString(finder.File()));

            realname = fi.canonicalFilePath();

            if (fi.isReadable() && fi.isFile())

                break;

        }

#endif

        realname = prefix + fname + (suffix.isNull() ? QString::fromLatin1(".qm") : suffix);

        fi.setFile(realname);

        if (fi.isReadable() && fi.isFile())

            break;

        realname = prefix + fname;

        fi.setFile(realname);

        if (fi.isReadable() && fi.isFile())

            break;

        int rightmost = 0;

        for (int i = 0; i < (int)delims.length(); i++) {

            int k = fname.lastIndexOf(delims[i]);

            if (k > rightmost)

                rightmost = k;

        }

        // no truncations? fail

        if (rightmost == 0)

            return false;

        fname.truncate(rightmost);

    }

    // realname is now the fully qualified name of a readable file.

    return d->do_load(realname);

}

bool QTranslatorPrivate::do_load(const QString &realname)

{

    QTranslatorPrivate *d = this;

    bool ok = false;

#ifdef QT_USE_MMAP

#ifndef MAP_FILE

#define MAP_FILE 0

#endif

#ifndef MAP_FAILED

#define MAP_FAILED -1

#endif

    int fd = -1;

    if (!realname.startsWith(QLatin1Char(':')))

        fd = QT_OPEN(QFile::encodeName(realname), O_RDONLY,

#if defined(Q_OS_WIN)

                     _S_IREAD | _S_IWRITE

#else

                     0666

#endif

            );

    if (fd >= 0) {

        QT_STATBUF st;

        if (!QT_FSTAT(fd, &st)) {

            char *ptr;

            ptr = reinterpret_cast<char *>(

                mmap(0, st.st_size,             // any address, whole file

                     PROT_READ,                 // read-only memory

                     MAP_FILE | MAP_PRIVATE,    // swap-backed map from file

                     fd, 0));                   // from offset 0 of fd

            if (ptr && ptr != reinterpret_cast<char *>(MAP_FAILED)) {

                d->used_mmap = true;

                d->unmapPointer = ptr;

                d->unmapLength = st.st_size;

                ok = true;

            }

        }

        ::close(fd);

    }

#endif // QT_USE_MMAP

    if (!ok) {

        QFile file(realname);

        d->unmapLength = file.size();

        if (!d->unmapLength)

            return false;

        d->unmapPointer = new char[d->unmapLength];

        if (file.open(QIODevice::ReadOnly))

            ok = (d->unmapLength == (uint)file.read(d->unmapPointer, d->unmapLength));

        if (!ok) {

            delete [] d->unmapPointer;

            d->unmapPointer = 0;

            d->unmapLength = 0;

            return false;

        }

    }

    return d->do_load(reinterpret_cast<const uchar *>(d->unmapPointer), d->unmapLength);

}

static QString find_translation(const QLocale & locale,

                                const QString & filename,

                                const QString & prefix,

                                const QString & directory,

                                const QString & suffix)

{

    QString path;

    if (QFileInfo(filename).isRelative()) {

        path = directory;

        if (!path.isEmpty() && !path.endsWith(QLatin1Char('/')))

            path += QLatin1Char('/');

    }

    QFileInfo fi;

    QString realname;

    QStringList fuzzyLocales;

    // see http://www.unicode.org/reports/tr35/#LanguageMatching for inspiration

    QStringList languages = locale.uiLanguages();

#if defined(Q_OS_UNIX) && !defined(Q_OS_SYMBIAN)

    for (int i = languages.size()-1; i >= 0; --i) {

        QString lang = languages.at(i);

        QString lowerLang = lang.toLower();

        if (lang != lowerLang)

            languages.insert(i+1, lowerLang);

    }

#endif

    // try explicit locales names first

    foreach (QString localeName, languages) {

        localeName.replace(QLatin1Char('-'), QLatin1Char('_'));

        realname = path + filename + prefix + localeName + (suffix.isNull() ? QLatin1String(".qm") : suffix);

        fi.setFile(realname);

        if (fi.isReadable() && fi.isFile())

            return realname;

        realname = path + filename + prefix + localeName;

        fi.setFile(realname);

        if (fi.isReadable() && fi.isFile())

            return realname;

        fuzzyLocales.append(localeName);

    }

    // start guessing

    foreach (QString localeName, fuzzyLocales) {

        for (;;) {

            int rightmost = localeName.lastIndexOf(QLatin1Char('_'));

            // no truncations? fail

            if (rightmost <= 0)

                break;

            localeName.truncate(rightmost);

            realname = path + filename + prefix + localeName + (suffix.isNull() ? QLatin1String(".qm") : suffix);

            fi.setFile(realname);

            if (fi.isReadable() && fi.isFile())

                return realname;

            realname = path + filename + prefix + localeName;

            fi.setFile(realname);

            if (fi.isReadable() && fi.isFile())

                return realname;

        }

    }

    if (!suffix.isNull()) {

        realname = path + filename + suffix;

        fi.setFile(realname);

        if (fi.isReadable() && fi.isFile())

            return realname;

    }

    realname = path + filename + prefix;

    fi.setFile(realname);

    if (fi.isReadable() && fi.isFile())

        return realname;

    realname = path + filename;

    fi.setFile(realname);

    if (fi.isReadable() && fi.isFile())

        return realname;

    return QString();

}

/*!

    \since 4.8

    Loads \a filename + \a prefix + \l{QLocale::uiLanguages()}{ui language

    name} + \a suffix (".qm" if the \a suffix is not specified), which may be

    an absolute file name or relative to \a directory. Returns true if the

    translation is successfully loaded; otherwise returns false.

    The previous contents of this translator object are discarded.

    If the file name does not exist, other file names are tried

    in the following order:

    \list 1

    \o File name without \a suffix appended.

    \o File name with ui language part after a "_" character stripped and \a suffix.

    \o File name with ui language part stripped without \a suffix appended.

    \o File name with ui language part stripped further, etc.

    \endlist

    For example, an application running in the locale with the following

    \l{QLocale::uiLanguages()}{ui languages} - "es", "fr-CA", "de" might call

    load(QLocale::system(), "foo", ".", "/opt/foolib", ".qm"). load() would

    replace '-' (dash) with '_' (underscore) in the ui language and then try to

    open the first existing readable file from this list:

    \list 1

    \o \c /opt/foolib/foo.es.qm

    \o \c /opt/foolib/foo.es

    \o \c /opt/foolib/foo.fr_CA.qm

    \o \c /opt/foolib/foo.fr_CA

    \o \c /opt/foolib/foo.de.qm

    \o \c /opt/foolib/foo.de

    \o \c /opt/foolib/foo.fr.qm

    \o \c /opt/foolib/foo.fr

    \o \c /opt/foolib/foo.qm

    \o \c /opt/foolib/foo.

    \o \c /opt/foolib/foo

    \endlist

    On operating systems where file system is case sensitive, QTranslator also

    tries to load a lower-cased version of the locale name.

*/

bool QTranslator::load(const QLocale & locale,

                       const QString & filename,

                       const QString & prefix,

                       const QString & directory,

                       const QString & suffix)

{

    Q_D(QTranslator);

    d->clear();

    QString fname = find_translation(locale, filename, prefix, directory, suffix);

    return !fname.isEmpty() && d->do_load(fname);

}

/*!

  \overload load()

  \fn bool QTranslator::load(const uchar *data, int len)

  Loads the QM file data \a data of length \a len into the

  translator.

  The data is not copied. The caller must be able to guarantee that \a data

  will not be deleted or modified.

*/

bool QTranslator::load(const uchar *data, int len)

{

    Q_D(QTranslator);

    d->clear();

    return d->do_load(data, len);

}

static quint8 read8(const uchar *data)

{

    return *data;

}

static quint16 read16(const uchar *data)

{

    return (data[0] << 8) | (data[1]);

}

static quint32 read32(const uchar *data)

{

    return (data[0] << 24)

        | (data[1] << 16)

        | (data[2] << 8)

        | (data[3]);

}

bool QTranslatorPrivate::do_load(const uchar *data, int len)

{

    if (!data || len < MagicLength || memcmp(data, magic, MagicLength))

        return false;

    bool ok = true;

    const uchar *end = data + len;

    data += MagicLength;

    while (data < end - 4) {

        quint8 tag = read8(data++);

        quint32 blockLen = read32(data);

        data += 4;

        if (!tag || !blockLen)

            break;

        if (data + blockLen > end) {

            ok = false;

            break;

        }

        if (tag == QTranslatorPrivate::Contexts) {

            contextArray = data;

            contextLength = blockLen;

        } else if (tag == QTranslatorPrivate::Hashes) {

            offsetArray = data;

            offsetLength = blockLen;

        } else if (tag == QTranslatorPrivate::Messages) {

            messageArray = data;

            messageLength = blockLen;

        } else if (tag == QTranslatorPrivate::NumerusRules) {

            numerusRulesArray = data;

            numerusRulesLength = blockLen;

        }

        data += blockLen;

    }

    return ok;

}

static QString getMessage(const uchar *m, const uchar *end, const char *context,

                          const char *sourceText, const char *comment, int numerus)

{

    const uchar *tn = 0;

    uint tn_length = 0;

    int currentNumerus = -1;

    for (;;) {

        uchar tag = 0;

        if (m < end)

            tag = read8(m++);

        switch((Tag)tag) {

        case Tag_End:

            goto end;

        case Tag_Translation: {

            int len = read32(m);

            if (len % 1)

                return QString();

            m += 4;

            if (++currentNumerus == numerus) {

                tn_length = len;

                tn = m;

            }

            m += len;

            break;

        }

        case Tag_Obsolete1:

            m += 4;

            break;

        case Tag_SourceText: {

            quint32 len = read32(m);

            m += 4;

            if (!match(m, sourceText, len))

                return QString();

            m += len;

        }

            break;

        case Tag_Context: {

            quint32 len = read32(m);

            m += 4;

            if (!match(m, context, len))

                return QString();

            m += len;

        }

            break;

        case Tag_Comment: {

            quint32 len = read32(m);

            m += 4;

            if (*m && !match(m, comment, len))

                return QString();

            m += len;

        }

            break;

        default:

            return QString();

        }

    }

end:

    if (!tn)

        return QString();

    QString str = QString((const QChar *)tn, tn_length/2);

    if (QSysInfo::ByteOrder == QSysInfo::LittleEndian) {

        for (int i = 0; i < str.length(); ++i)

            str[i] = QChar((str.at(i).unicode() >> 8) + ((str.at(i).unicode() << 8) & 0xff00));

    }

    return str;

}

QString QTranslatorPrivate::do_translate(const char *context, const char *sourceText,

                                         const char *comment, int n) const

{

    if (context == 0)

        context = "";

    if (sourceText == 0)

        sourceText = "";

    if (comment == 0)

        comment = "";

    if (!offsetLength)

        return QString();

    /*

        Check if the context belongs to this QTranslator. If many

        translators are installed, this step is necessary.

    */

    if (contextLength) {

        quint16 hTableSize = read16(contextArray);

        uint g = elfHash(context) % hTableSize;

        const uchar *c = contextArray + 2 + (g << 1);

        quint16 off = read16(c);

        c += 2;

        if (off == 0)

            return QString();

        c = contextArray + (2 + (hTableSize << 1) + (off << 1));

        for (;;) {

            quint8 len = read8(c++);

            if (len == 0)

                return QString();

            if (match(c, context, len))

                break;

            c += len;

        }

    }

    size_t numItems = offsetLength / (2 * sizeof(quint32));

    if (!numItems)

        return QString();

    int numerus = 0;

    if (n >= 0)

        numerus = numerusHelper(n, numerusRulesArray, numerusRulesLength);

    for (;;) {

        quint32 h = elfHash(QByteArray(QByteArray(sourceText) + comment).constData());

        const uchar *start = offsetArray;

        const uchar *end = start + ((numItems-1) << 3);

        while (start <= end) {

            const uchar *middle = start + (((end - start) >> 4) << 3);

            uint hash = read32(middle);

            if (h == hash) {

                start = middle;

                break;

            } else if (hash < h) {

                start = middle + 8;

            } else {

                end = middle - 8;

            }

        }

        if (start <= end) {

            // go back on equal key

            while (start != offsetArray && read32(start) == read32(start-8))

                start -= 8;

            while (start < offsetArray + offsetLength) {

                quint32 rh = read32(start);

                start += 4;

                if (rh != h)

                    break;

                quint32 ro = read32(start);

                start += 4;

                QString tn = getMessage(messageArray + ro, messageArray + messageLength, context,

                                        sourceText, comment, numerus);

                if (!tn.isNull())

                    return tn;

            }

        }

        if (!comment[0])

            break;

        comment = "";

    }

    return QString();

}

/*!

    Empties this translator of all contents.

    This function works with stripped translator files.

*/

void QTranslatorPrivate::clear()

{

    Q_Q(QTranslator);

    if (unmapPointer && unmapLength) {

#if defined(QT_USE_MMAP)

        if (used_mmap)

            munmap(unmapPointer, unmapLength);

        else

#endif

            delete [] unmapPointer;

    }

    unmapPointer = 0;

    unmapLength = 0;

    messageArray = 0;

    contextArray = 0;

    offsetArray = 0;

    numerusRulesArray = 0;

    messageLength = 0;

    contextLength = 0;

    offsetLength = 0;

    numerusRulesLength = 0;

    if (QCoreApplicationPrivate::isTranslatorInstalled(q))

        QCoreApplication::postEvent(QCoreApplication::instance(),

                                    new QEvent(QEvent::LanguageChange));

}

/*!

    Returns the translation for the key (\a context, \a sourceText,

    \a disambiguation). If none is found, also tries (\a context, \a

    sourceText, ""). If that still fails, returns an empty string.

    If you need to programatically insert translations in to a

    QTranslator, this function can be reimplemented.

    \sa load()

*/

QString QTranslator::translate(const char *context, const char *sourceText, const char *disambiguation) const

{

    Q_D(const QTranslator);

    return d->do_translate(context, sourceText, disambiguation, -1);

}

/*!

    \overload translate()

    Returns the translation for the key (\a context, \a sourceText,

    \a disambiguation). If none is found, also tries (\a context, \a

    sourceText, ""). If that still fails, returns an empty string.

    If \a n is not -1, it is used to choose an appropriate form for

    the translation (e.g. "%n file found" vs. "%n files found").

    \sa load()

*/

QString QTranslator::translate(const char *context, const char *sourceText, const char *disambiguation,

                               int n) const

{

    Q_D(const QTranslator);

    // this step is necessary because the 3-parameter translate() overload is virtual

    if (n == -1)

        return translate(context, sourceText, disambiguation);

    return d->do_translate(context, sourceText, disambiguation, n);

}

/*!

    Returns true if this translator is empty, otherwise returns false.

    This function works with stripped and unstripped translation files.

*/

bool QTranslator::isEmpty() const

{

    Q_D(const QTranslator);

    return !d->unmapPointer && !d->unmapLength && !d->messageArray &&

           !d->offsetArray && !d->contextArray;

}

/*!

    \fn QString QTranslator::find(const char *context, const char *sourceText, const char * comment = 0) const

    Use translate(\a context, \a sourceText, \a comment) instead.

*/

QT_END_NAMESPACE

#endif // QT_NO_TRANSLATION