qbytearray.cpp

奇趣公司比较新的qt/emd版本

        QByteArray x("ship");
        QByteArray y("air");
        x.prepend(y);
        // x == "airship"
    \endcode

    This is the same as insert(0, \a ba).

    \sa append(), insert()
*/

QByteArray &QByteArray::prepend(const QByteArray &ba)
{
    if (d == &shared_null || d == &shared_empty) {
        *this = ba;
    } else if (ba.d != &shared_null) {
        QByteArray tmp = *this;
        *this = ba;
        append(tmp);
    }
    return *this;
}

/*!
    \overload

    Prepends the string \a str to this byte array.
*/

QByteArray &QByteArray::prepend(const char *str)
{
    if (str) {
        int len = qstrlen(str);
        if (d->ref != 1 || d->size + len > d->alloc)
            realloc(qAllocMore(d->size + len, sizeof(Data)));
        memmove(d->data+len, d->data, d->size);
        memcpy(d->data, str, len);
        d->size += len;
        d->data[d->size] = '\0';
    }
    return *this;
}

/*!
    \overload

    Prepends the character \a ch to this byte array.
*/

QByteArray &QByteArray::prepend(char ch)
{
    if (d->ref != 1 || d->size + 1 > d->alloc)
        realloc(qAllocMore(d->size + 1, sizeof(Data)));
    memmove(d->data+1, d->data, d->size);
    d->data[0] = ch;
    ++d->size;
    d->data[d->size] = '\0';
    return *this;
}

/*!
    Appends the byte array \a ba onto the end of this byte array.

    Example:
    \code
        QByteArray x("free");
        QByteArray y("dom");
        x.append(y);
        // x == "freedom"
    \endcode

    This is the same as insert(size(), \a ba).

    This operation is typically very fast (\l{constant time}),
    because QByteArray preallocates extra space at the end of the
    character data so it can grow without reallocating the entire
    data each time.

    \sa operator+=(), prepend(), insert()
*/

QByteArray &QByteArray::append(const QByteArray &ba)
{
    if (d == &shared_null || d == &shared_empty) {
        *this = ba;
    } else if (ba.d != &shared_null) {
        if (d->ref != 1 || d->size + ba.d->size > d->alloc)
            realloc(qAllocMore(d->size + ba.d->size, sizeof(Data)));
        memcpy(d->data + d->size, ba.d->data, ba.d->size);
        d->size += ba.d->size;
        d->data[d->size] = '\0';
    }
    return *this;
}

/*! \fn QByteArray &QByteArray::append(const QString &str)

    \overload

    Appends the string \a str to this byte array. The Unicode data is
    converted into 8-bit characters using QString::toAscii().

    If the QString contains non-ASCII Unicode characters, using this
    function can lead to loss of information. You can disable this
    function by defining \c QT_NO_CAST_TO_ASCII when you compile your
    applications. You then need to call QString::toAscii() (or
    QString::toLatin1() or QString::toUtf8() or QString::toLocal8Bit())
    explicitly if you want to convert the data to \c{const char *}.
*/

/*!
    \overload

    Appends the string \a str to this byte array.
*/

QByteArray& QByteArray::append(const char *str)
{
    if (str) {
        int len = qstrlen(str);
        if (d->ref != 1 || d->size + len > d->alloc)
            realloc(qAllocMore(d->size + len, sizeof(Data)));
        memcpy(d->data + d->size, str, len + 1); // include null terminator
        d->size += len;
    }
    return *this;
}

/*!
    \overload

    Appends the character \a ch to this byte array.
*/

QByteArray& QByteArray::append(char ch)
{
    if (d->ref != 1 || d->size + 1 > d->alloc)
        realloc(qAllocMore(d->size + 1, sizeof(Data)));
    d->data[d->size++] = ch;
    d->data[d->size] = '\0';
    return *this;
}

/*!
  \internal
  Inserts \a len bytes from the array \a arr at position \a pos and returns a
  reference the modified byte array.
*/
static inline QByteArray &qbytearray_insert(QByteArray *ba,
                                            int pos, const char *arr, int len)
{
    Q_ASSERT(pos >= 0);

    if (pos < 0 || len <= 0 || arr == 0)
        return *ba;

    int oldsize = ba->size();
    ba->resize(qMax(pos, oldsize) + len);
    char *dst = ba->data();
    if (pos > oldsize)
        ::memset(dst + oldsize, 0x20, pos - oldsize);
    else
        ::memmove(dst + pos + len, dst + pos, oldsize - pos);
    memcpy(dst + pos, arr, len);
    return *ba;
}

/*!
    Inserts the byte array \a ba at index position \a i and returns a
    reference to this byte array.

    Example:
    \code
        QByteArray ba("Meal");
        ba.insert(1, QByteArray("ontr"));
        // ba == "Montreal"
    \endcode

    \sa append(), prepend(), replace(), remove()
*/

QByteArray &QByteArray::insert(int i, const QByteArray &ba)
{
    QByteArray copy(ba);
    return qbytearray_insert(this, i, copy.d->data, copy.d->size);
}

/*!
    \fn QByteArray &QByteArray::insert(int i, const QString &str)

    \overload

    Inserts the string \a str at index position \a i in the byte
    array. The Unicode data is converted into 8-bit characters using
    QString::toAscii().

    If \a i is greater than size(), the array is first extended using
    resize().

    If the QString contains non-ASCII Unicode characters, using this
    function can lead to loss of information. You can disable this
    function by defining \c QT_NO_CAST_TO_ASCII when you compile your
    applications. You then need to call QString::toAscii() (or
    QString::toLatin1() or QString::toUtf8() or QString::toLocal8Bit())
    explicitly if you want to convert the data to \c{const char *}.
*/

/*!
    \overload

    Inserts the string \a str at position \a i in the byte array.

    If \a i is greater than size(), the array is first extended using
    resize().
*/

QByteArray &QByteArray::insert(int i, const char *str)
{
    return qbytearray_insert(this, i, str, qstrlen(str));
}

/*!
    \overload

    Inserts character \a ch at index position \a i in the byte array.
    If \a i is greater than size(), the array is first extended using
    resize().
*/

QByteArray &QByteArray::insert(int i, char ch)
{
    return qbytearray_insert(this, i, &ch, 1);
}

/*!
    Removes \a len bytes from the array, starting at index position \a
    pos, and returns a reference to the array.

    If \a pos is out of range, nothing happens. If \a pos is valid,
    but \a pos + \a len is larger than the size of the array, the
    array is truncated at position \a pos.

    Example:
    \code
        QByteArray ba("Montreal");
        ba.remove(1, 4);
        // ba == "Meal"
    \endcode

    \sa insert(), replace()
*/

QByteArray &QByteArray::remove(int pos, int len)
{
    if (len <= 0  || pos >= d->size || pos < 0)
        return *this;
    detach();
    if (pos + len >= d->size) {
        resize(pos);
    } else {
        memmove(d->data + pos, d->data + pos + len, d->size - pos - len);
        resize(d->size - len);
    }
    return *this;
}

/*!
    Replaces \a len bytes from index position \a pos with the byte
    array \a after, and returns a reference to this byte array.

    Example:
    \code
        QByteArray x("Say yes!");
        QByteArray y("no");
        x.replace(4, 3, y);
        // x == "Say no!"
    \endcode

    \sa insert(), remove()
*/

QByteArray &QByteArray::replace(int pos, int len, const QByteArray &after)
{
    QByteArray copy(after);
    remove(pos, len);
    return insert(pos, copy);
}

/*! \fn QByteArray &QByteArray::replace(int pos, int len, const char *after)

    \overload
*/

/*!
    \overload

    Replaces every occurrence of the byte array \a before with the
    byte array \a after.

    Example:
    \code
        QByteArray ba("colour behaviour flavour neighbour");
        ba.replace(QByteArray("ou"), QByteArray("o"));
        // ba == "color behavior flavor neighbor"
    \endcode
*/

QByteArray &QByteArray::replace(const QByteArray &before, const QByteArray &after)
{
    if (isNull() || before == after)
        return *this;

    QByteArray aft = after;
    if (after.d == d)
        aft.detach();

    QByteArrayMatcher matcher(before);
    int index = 0;
    const int bl = before.d->size;
    const int al = aft.d->size;
    int len = d->size;
    char *d = data();

    if (bl == al) {
        if (bl) {
            while ((index = matcher.indexIn(*this, index)) != -1) {
                memcpy(d + index, aft.constData(), al);
                index += bl;
            }
        }
    } else if (al < bl) {
        uint to = 0;
        uint movestart = 0;
        uint num = 0;
        while ((index = matcher.indexIn(*this, index)) != -1) {
            if (num) {
                int msize = index - movestart;
                if (msize > 0) {
                    memmove(d + to, d + movestart, msize);
                    to += msize;
                }
            } else {
                to = index;
            }
            if (al) {
                memcpy(d + to, aft.constData(), al);
                to += al;
            }
            index += bl;
            movestart = index;
            num++;
        }
        if (num) {
            int msize = len - movestart;
            if (msize > 0)
                memmove(d + to, d + movestart, msize);
            resize(len - num*(bl-al));
        }
    } else {
        // the most complex case. We don't want to lose performance by doing repeated
        // copies and reallocs of the string.
        while (index != -1) {
            uint indices[4096];
            uint pos = 0;
            while(pos < 4095) {
                index = matcher.indexIn(*this, index);
                if (index == -1)
                    break;
                indices[pos++] = index;
                index += bl;
                // avoid infinite loop
                if (!bl)
                    index++;
            }
            if (!pos)
                break;

            // we have a table of replacement positions, use them for fast replacing
            int adjust = pos*(al-bl);
            // index has to be adjusted in case we get back into the loop above.
            if (index != -1)
                index += adjust;
            int newlen = len + adjust;
            int moveend = len;
            if (newlen > len) {
                resize(newlen);
                len = newlen;
            }
            d = this->d->data;

            while(pos) {
                pos--;
                int movestart = indices[pos] + bl;
                int insertstart = indices[pos] + pos*(al-bl);
                int moveto = insertstart + al;
                memmove(d + moveto, d + movestart, (moveend - movestart));
                if (aft.size())
                    memcpy(d + insertstart, aft.constData(), al);
                moveend = movestart - bl;
            }
        }
    }
    return *this;
}


/*! \fn QByteArray &QByteArray::replace(const char *before, const QByteArray &after)
    \overload

    Replaces every occurrence of the string \a before with the
    byte array \a after.
*/


/*! \fn QByteArray &QByteArray::replace(const QByteArray &before, const char *after)
    \overload

    Replaces every occurrence of the byte array \a before with the
    string \a after.
*/

/*! \fn QByteArray &QByteArray::replace(const QString &before, const QByteArray &after)

    \overload

    Replaces every occurrence of the string \a before with the byte
    array \a after. The Unicode data is converted into 8-bit
    characters using QString::toAscii().

    If the QString contains non-ASCII Unicode characters, using this
    function can lead to loss of information. You can disable this
    function by defining \c QT_NO_CAST_TO_ASCII when you compile your
    applications. You then need to call QString::toAscii() (or
    QString::toLatin1() or QString::toUtf8() or QString::toLocal8Bit())
    explicitly if you want to convert the data to \c{const char *}.
*/

/*! \fn QByteArray &QByteArray::replace(const QString &before, const char *after)
    \overload

    Replaces every occurrence of the string \a before with the string
    \a after.
*/

/*! \fn QByteArray &QByteArray::replace(const char *before, const char *after)

    \overload

    Replaces every occurrence of the string \a before with the string
    \a after.
*/

/*!
    \overload

    Replaces every occurrence of the character \a before with the
    byte array \a after.
*/

QByteArray &QByteArray::replace(char before, const QByteArray &after)
{
    char b[2] = { before, '\0' };
    QByteArray cb = fromRawData(b, 1);
    return replace(cb, after);
}

/*! \fn QByteArray &QByteArray::replace(char before, const QString &after)

    \overload