qtranslator.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

                     _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->used_mmap = true;
                d->unmapPointer = ptr;
                d->unmapLength = st.st_size;
                ok = true;
            }
        }
        ::close(fd);
    }
#endif // QT_USE_MMAP

    if (!ok) {
        QFile file(realname);
        if (!file.exists())
            return false;
        d->unmapLength = file.size();
        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);
}

/*!
  \overload
  \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 (len < MagicLength || memcmp(data, magic, MagicLength) != 0) {
        clear();
        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;
        }

        data += blockLen;
    }

    return ok;
}

/*!
    Empties this translator of all contents.

    This function works with stripped translator files.
*/

void QTranslatorPrivate::clear()
{
    if (unmapPointer && unmapLength) {
#if defined(QT_USE_MMAP)
        if(used_mmap)
            munmap(unmapPointer, unmapLength);
        else
#else
            delete [] unmapPointer;
#endif
        unmapPointer = 0;
        unmapLength = 0;
    }

    messageArray = 0;
    contextArray = 0;
    offsetArray = 0;
    messageLength = 0;
    contextLength = 0;
    offsetLength = 0;

    QCoreApplication * const application = QCoreApplication::instance();
    if (application) {
        QEvent * const event = new QEvent(QEvent::LanguageChange);
        QCoreApplication::postEvent(application, event);
    }
}


static QString getMessage(const uchar *m, const uchar *end, const char *context, const char *sourceText, const char *comment)
{
    const uchar *tn = 0;
    uint tn_length = 0;

    for (;;) {
        uchar tag = 0;
        if (m < end)
            tag = read8(m++);
        switch((Tag)tag) {
        case Tag_End:
            goto end;
        case Tag_Translation:
            tn_length = read32(m);
            if (tn_length % 1)
                return QString();
            m += 4;
            if (tn_length == 0xffffffff)
                return QString();
            tn = m;
            m += tn_length;
            break;
        case Tag_Hash:
            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 (*m && !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::fromUtf16((const ushort *)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;
}


/*!
    Returns the translation for the key (\a context, \a sourceText,
    \a comment). If none is found, also tries (\a context, \a
    sourceText, ""). If that still fails, returns an empty string.

    \sa load()
*/
QString QTranslator::translate(const char *context, const char *sourceText, const char *comment) const
{
    Q_D(const QTranslator);
    if (context == 0)
        context = "";
    if (sourceText == 0)
        sourceText = "";
    if (comment == 0)
        comment = "";

    if (!d->offsetLength)
        return QString();

    /*
        Check if the context belongs to this QTranslator. If many
        translators are installed, this step is necessary.
    */
    if (d->contextLength) {
        quint16 hTableSize = read16(d->contextArray);
        uint g = elfHash(context) % hTableSize;
        const uchar *c = d->contextArray + 2 + (g << 1);
        quint16 off = read16(c);
        c += 2;
        if (off == 0)
            return QString();
        c = d->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 = d->offsetLength / (2 * sizeof(quint32));
    if (!numItems)
        return QString();

    for (;;) {
        quint32 h = elfHash(QByteArray(sourceText) + comment);

        const uchar *start = d->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 != d->offsetArray && read32(start) == read32(start-8))
                start -= 8;

            while (start < d->offsetArray + d->offsetLength) {
                quint32 rh = read32(start);
                start += 4;
                if (rh != h)
                    break;
                quint32 ro = read32(start);
                start += 4;
                QString tn = getMessage(d->messageArray + ro, d->messageArray + d->messageLength, context, sourceText, comment);
                if (!tn.isNull())
                    return tn;
            }
        }
        if (!comment[0])
            break;
        comment = "";
    }
    return QString();
}

/*!
    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.
*/

#endif // QT_NO_TRANSLATION