translator.cpp

QT 开发环境里面一个很重要的文件

/****************************************************************************
**
** 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>

#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 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, NumerusRules = 0x88 };

    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

    QByteArray numerusRules;

#if 0
    bool do_load(const uchar *data, int len);
#endif

};


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

Translator::~Translator()
{
    clear();
    delete d;
}

bool Translator::save(const QString & filename, SaveMode mode)
{
    QFile file(filename);
    if (!file.open(QIODevice::WriteOnly)) return false;
    return save(&file, mode);
}

bool Translator::save(QIODevice *iod, SaveMode mode)
{
    squeeze(mode);

    QDataStream s(iod);
    s.writeRawData((const char *)magic, MagicLength);
    quint8 tag;

    if (!d->offsetArray.isEmpty()) {
        tag = (quint8)TranslatorPrivate::Hashes;
        quint32 oas = (quint32)d->offsetArray.size();
        s << tag << oas;
        s.writeRawData(d->offsetArray, oas);
    }
    if (!d->messageArray.isEmpty()) {
        tag = (quint8)TranslatorPrivate::Messages;
        quint32 mas = (quint32)d->messageArray.size();
        s << tag << mas;
        s.writeRawData(d->messageArray, mas);
    }
    if (!d->contextArray.isEmpty()) {
        tag = (quint8)TranslatorPrivate::Contexts;
        quint32 cas = (quint32)d->contextArray.size();
        s << tag << cas;
        s.writeRawData(d->contextArray, cas);
    }
    if (!d->numerusRules.isEmpty()) {
        quint32 nrs = d->numerusRules.size();
        s << quint8(TranslatorPrivate::NumerusRules) << nrs;
        s.writeRawData(d->numerusRules.constData(), nrs);
    }
    return true;
}

void Translator::clear()
{
    if (d->unmapPointer && d->unmapLength) {
        delete [] d->unmapPointer;
        d->unmapPointer = 0;
        d->unmapLength = 0;
    }

    d->messageArray.clear();
    d->offsetArray.clear();
    d->contextArray.clear();
    d->messages.clear();

    QEvent ev(QEvent::LanguageChange);
    QCoreApplication::sendEvent(QCoreApplication::instance(), &ev);
}

void Translator::squeeze(SaveMode mode)
{
    if (d->messages.isEmpty()) {
        if (mode == Stripped)
            unsqueeze();
        else
            return;
    }

    QMap<TranslatorMessage, void *> messages = d->messages;
    clear();

    QMap<TranslatorPrivate::Offset, void *> offsets;

    QDataStream ms(&d->messageArray, QIODevice::WriteOnly);
    QMap<TranslatorMessage, void *>::const_iterator it, next;
    int cpPrev = 0, cpNext = 0;
    for (it = messages.constBegin(); it != messages.constEnd(); ++it) {
        cpPrev = cpNext;
        next = it;
        ++next;
        if (next == messages.constEnd())
            cpNext = 0;
        else
            cpNext = (int) it.key().commonPrefix(next.key());
        offsets.insert(TranslatorPrivate::Offset(it.key(), ms.device()->pos()), (void *)0);
        it.key().write(ms, mode == Stripped, (TranslatorMessage::Prefix)qMax(cpPrev, cpNext + 1));
    }

    QMap<TranslatorPrivate::Offset, void *>::Iterator offset;
    offset = offsets.begin();
    QDataStream ds(&d->offsetArray, QIODevice::WriteOnly);
    while (offset != offsets.end()) {
        TranslatorPrivate::Offset k = offset.key();
        ++offset;
        ds << (quint32)k.h << (quint32)k.o;
    }

    if (mode == Stripped) {
        QMap<QByteArray, int> contextSet;
        for (it = messages.constBegin(); it != messages.constEnd(); ++it)
            ++contextSet[it.key().context()];

        quint16 hTableSize;
        if (contextSet.size() < 200)
            hTableSize = (contextSet.size() < 60) ? 151 : 503;
        else if (contextSet.size() < 2500)
            hTableSize = (contextSet.size() < 750) ? 1511 : 5003;
        else
            hTableSize = (contextSet.size() < 10000) ? 15013 : 3 * contextSet.size() / 2;

        QMultiMap<int, const char *> hashMap;
        QMap<QByteArray, int>::const_iterator c;
        for (c = contextSet.constBegin(); c != contextSet.constEnd(); ++c)
            hashMap.insert(elfHash(c.key()) % hTableSize, c.key());

        /*
          The contexts found in this translator are stored in a hash
          table to provide fast lookup. The context array has the
          following format:

              quint16 hTableSize;
              quint16 hTable[hTableSize];
              quint8  contextPool[...];

          The context pool stores the contexts as Pascal strings:

              quint8  len;
              quint8  data[len];

          Let's consider the look-up of context "FunnyDialog".  A
          hash value between 0 and hTableSize - 1 is computed, say h.
          If hTable[h] is 0, "FunnyDialog" is not covered by this
          translator. Else, we check in the contextPool at offset
          2 * hTable[h] to see if "FunnyDialog" is one of the
          contexts stored there, until we find it or we meet the
          empty string.
        */
        d->contextArray.resize(2 + (hTableSize << 1));
        QDataStream t(&d->contextArray, QIODevice::WriteOnly);