translator.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the Qt Linguist of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 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 GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "translator.h"
#include <qplatformdefs.h>

#ifndef QT_NO_TRANSLATION

#include <QFileInfo>
#include <QString>
#include <QCoreApplication>
#include <QDataStream>
#include <QFile>
#include <QMap>
#include <QtAlgorithms>

#if defined(Q_OS_UNIX)
#define QT_USE_MMAP
#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>

/*
$ 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 char* found, const char* target)
{
    // 0 means anything, "" means empty
    return found == 0 || qstrcmp(found, target) == 0;
}

#if defined(Q_C_CALLBACKS)
extern "C" {
#endif

/*
  Yes, unfortunately, we have code here that depends on endianness.
  The candidate is big endian (it comes from a .qm file) whereas the
  target endianness depends on the system Qt is running on.
*/
#ifdef Q_OS_TEMP
static int __cdecl cmp_uint32_little(const void* target, const void* candidate)
#else
static int cmp_uint32_little(const void* target, const void* candidate)
#endif
{
    const uchar* t = (const uchar*) target;
    const uchar* c = (const uchar*) candidate;
    return t[3] != c[0] ? (int) t[3] - (int) c[0]
         : t[2] != c[1] ? (int) t[2] - (int) c[1]
         : t[1] != c[2] ? (int) t[1] - (int) c[2]
                   : (int) t[0] - (int) c[3];
}

#ifdef Q_OS_TEMP
static int __cdecl cmp_uint32_big(const void* target, const void* candidate)
#else
static int cmp_uint32_big(const void* target, const void* candidate)
#endif
{
    const uint* t = (const uint*) target;
    const uint* c = (const uint*) candidate;
    return (*t > *c ? 1 : (*t == *c ? 0 : -1));
}

#if defined(Q_C_CALLBACKS)
}
#endif

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;
}

extern bool qt_detectRTLLanguage();

class TranslatorPrivate
{
public:
    struct Offset {
        Offset()
            : h(0), o(0) { }
        Offset(const TranslatorMessage& m, int offset)
            : h(m.hash()), o(offset) { }

        bool operator<(const Offset &other) const {
            return (h != other.h) ? h < other.h : o < other.o;
        }
        bool operator==(const Offset &other) const {
            return h == other.h && o == other.o;
        }
        uint h;
        uint o;
    };

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

    TranslatorPrivate(Translator *qq) : q(qq), unmapPointer(0), unmapLength(0) {}
    // Translator must finalize this before deallocating it

    Translator *q;
    // for mmap'ed files, this is what needs to be unmapped.
    char *unmapPointer;
    unsigned int unmapLength;

    // for squeezed but non-file data, this is what needs to be deleted
    QByteArray messageArray;
    QByteArray offsetArray;
    QByteArray contextArray;

#ifndef QT_NO_TRANSLATION_BUILDER
    QMap<TranslatorMessage, void *> messages;
#endif

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

};


/*!
    \class Translator

    \brief The Translator class provides internationalization support for text
    output.

    \ingroup i18n
    \ingroup environment
    \mainclass

    An object of this class contains a set of TranslatorMessage
    objects, each of which specifies a translation from a source
    language to a target language. Translator provides functions to
    look up translations, add new ones, remove them, load and save
    them, etc.

    The most common use of Translator is to: load a translator file
    created with \l{Qt Linguist Manual}, install it using
    QApplication::installTranslator(), and use it via QObject::tr().
    For example:

    \code
    int main(int argc, char ** argv)
    {
        QApplication app(argc, argv);

        Translator translator(0);
        translator.load("french.qm", ".");
        app.installTranslator(&translator);

        MyWidget m;
        app.setMainWidget(&m);
        m.show();

        return app.exec();
    }
    \endcode
    Note that the translator must be created \e before the
    application's main window.

    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.

    We call a translation a "messsage". For this reason, translation
    files are sometimes referred to as "message files".

    It is possible to lookup a translation using findMessage() (as
    tr() and QApplication::translate() do) and contains(), to insert a
    new translation messsage using insert(), and to remove one using
    remove().

    Translation tools often need more information than the bare source
    text and translation, for example, context information to help
    the translator. But end-user programs that are using translations
    usually only need lookup. To cater for these different needs,
    Translator can use stripped translator files that use the minimum
    of memory and which support little more functionality than
    findMessage().

    Thus, load() may not load enough information to make anything more
    than findMessage() work. save() has an argument indicating
    whether to save just this minimum of information or to save
    everything.

    "Everything" means that for each translation item the following
    information is kept:

    \list
    \i The \e {translated text} - the return value from tr().
    \i The input key:
        \list
        \i The \e {source text} - usually the argument to tr().
        \i The \e context - usually the class name for the tr() caller.
        \i The \e comment - a comment that helps disambiguate different uses
           of the same text in the same context.
        \endlist
    \endlist

    The minimum for each item is just the information necessary for
    findMessage() to return the right text. This may include the
    source, context and comment, but usually it is just a hash value
    and the translated text.

    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 disambiguating comments such as
    "two-sided printing" for one and "binding" for the other. The
    comment enables the translator to choose the appropriate gender
    for the Spanish version, and enables Qt to distinguish between
    translations.

    Note that when Translator loads a stripped file, most functions
    do not work. The functions that do work with stripped files are
    explicitly documented as such.

    \sa TranslatorMessage QApplication::installTranslator()
    QApplication::removeTranslator() QObject::tr() QApplication::translate()
*/

/*!
    \enum Translator::SaveMode

    This enum type defines how Translator writes translation
    files. There are two modes:

    \value Everything  files are saved with all available information
    \value Stripped  files are saved with just enough information for
        end-user applications

    Note that when Translator loads a stripped file, most functions do
    not work. The functions that do work with stripped files are
    explicitly documented as such.
*/

/*!
    Constructs an empty message file object with parent \a parent that
    is not connected to any file.
*/

Translator::Translator(QObject * parent)
    : QTranslator(parent)
{
    d = new TranslatorPrivate(this);
}

/*!
    Destroys the object and frees any allocated resources.
*/

Translator::~Translator()
{
    if (QCoreApplication::instance())
        QCoreApplication::instance()->removeTranslator(this);
    clear();
    delete d;
}

/*!
    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. The previous contents of this translator object
    is discarded.

    If the file name does not exist, other file names are tried
    in the following order:

    \list 1
    \i File name without \a suffix appended.
    \i 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.
    \i File name stripped without \a suffix appended.
    \i 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
    \i /opt/foolib/foo.fr_ca.qm
    \i /opt/foolib/foo.fr_ca
    \i /opt/foolib/foo.fr.qm
    \i /opt/foolib/foo.fr
    \i /opt/foolib/foo.qm
    \i /opt/foolib/foo
    \endlist

    \sa save()
*/

bool Translator::load(const QString & filename, const QString & directory,
                       const QString & search_delimiters,
                       const QString & suffix)
{
    clear();

    QString prefix;

    if (filename[0] == QLatin1Char('/')
#ifdef Q_WS_WIN
         || (filename[0].isLetter() && filename[1] == QLatin1Char(':')) || filename[0] == QLatin1Char('\\')
#endif
        )
        prefix = QLatin1String("");
    else
        prefix = directory;

    if (prefix.length()) {
        if (prefix[int(prefix.length()-1)] != QLatin1Char('/'))
            prefix += QLatin1Char('/');
    }

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

    for (;;) {
        QFileInfo fi;

        realname = prefix + fname + (suffix.isNull() ? QString::fromLatin1(".qm") : suffix);
        fi.setFile(realname);
        if (fi.isReadable())
            break;

        realname = prefix + fname;
        fi.setFile(realname);
        if (fi.isReadable())
            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.

    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(QLatin1String(":")))
        fd = QT_OPEN(QFile::encodeName(realname), O_RDONLY,
#if defined(Q_OS_WIN)
                 _S_IREAD | _S_IWRITE
#else
                 0666
#endif
                );
    if (fd >= 0) {
        struct stat st;
        if (!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->unmapPointer = ptr;
                d->unmapLength = st.st_size;