qbytearray.cpp

奇趣公司比较新的qt/emd版本

    Replaces every occurrence of the character \a before with the
    string \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(char before, const char *after)

    \overload

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

/*!
    \overload

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

QByteArray &QByteArray::replace(char before, char after)
{
    if (d->size) {
        char *i = data();
        char *e = i + d->size;
        for (; i != e; ++i)
            if (*i == before)
                * i = after;
    }
    return *this;
}

/*!
    Splits the byte array into subarrays wherever \a sep occurs, and
    returns the list of those arrays. If \a sep does not match
    anywhere in the byte array, split() returns a single-element list
    containing this byte array.
*/

QList<QByteArray> QByteArray::split(char sep) const
{
    QList<QByteArray> list;
    int start = 0;
    int end;
    while ((end = indexOf(sep, start)) != -1) {
        list.append(mid(start, end - start));
        start = end + 1;
    }
    list.append(mid(start));
    return list;
}

#define REHASH(a) \
    if (ol_minus_1 < sizeof(uint) * CHAR_BIT) \
        hashHaystack -= (a) << ol_minus_1; \
    hashHaystack <<= 1

/*!
    Returns the index position of the first occurrence of the byte
    array \a ba in this byte array, searching forward from index
    position \a from. Returns -1 if \a ba could not be found.

    Example:
    \code
        QByteArray x("sticky question");
        QByteArray y("sti");
        x.indexOf(y);               // returns 0
        x.indexOf(y, 1);            // returns 10
        x.indexOf(y, 10);           // returns 10
        x.indexOf(y, 11);           // returns -1
    \endcode

    \sa lastIndexOf(), contains(), count()
*/

int QByteArray::indexOf(const QByteArray &ba, int from) const
{
    const int l = d->size;
    const int ol = ba.d->size;
    if (from > d->size || ol + from > l)
        return -1;
    if (ol == 0)
        return from;
    if (ol == 1)
        return indexOf(*ba.d->data, from);

    if (l > 500 && ol > 5)
        return QByteArrayMatcher(ba).indexIn(*this, from);

    const char *needle = ba.d->data;
    const char *haystack = d->data + from;
    const char *end = d->data + (l - ol);
    const uint ol_minus_1 = ol - 1;
    uint hashNeedle = 0, hashHaystack = 0;
    int idx;
    for (idx = 0; idx < ol; ++idx) {
        hashNeedle = ((hashNeedle<<1) + needle[idx]);
        hashHaystack = ((hashHaystack<<1) + haystack[idx]);
    }
    hashHaystack -= *(haystack + ol_minus_1);

    while (haystack <= end) {
        hashHaystack += *(haystack + ol_minus_1);
        if (hashHaystack == hashNeedle  && *needle == *haystack
             && strncmp(needle, haystack, ol) == 0)
            return haystack - d->data;

        REHASH(*haystack);
        ++haystack;
    }
    return -1;
}

/*! \fn int QByteArray::indexOf(const QString &str, int from) const

    \overload

    Returns the index position of the first occurrence of the string
    \a str in the byte array, searching forward from index position
    \a from. Returns -1 if \a str could not be found.

    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 int QByteArray::indexOf(const char *str, int from) const

    \overload

    Returns the index position of the first occurrence of the string
    \a str in the byte array, searching forward from index position \a
    from. Returns -1 if \a str could not be found.
*/

/*!
    \overload

    Returns the index position of the first occurrence of the
    character \a ch in the byte array, searching forward from index
    position \a from. Returns -1 if \a ch could not be found.

    Example:
    \code
        QByteArray ba("ABCBA");
        ba.indexOf("B");            // returns 1
        ba.indexOf("B", 1);         // returns 1
        ba.indexOf("B", 2);         // returns 3
        ba.indexOf("X");            // returns -1
    \endcode

    \sa lastIndexOf(), contains()
*/

int QByteArray::indexOf(char ch, int from) const
{
    if (from < 0)
        from = qMax(from + d->size, 0);
    if (from < d->size) {
        const char *n = d->data + from - 1;
        const char *e = d->data + d->size;
        while (++n != e)
        if (*n == ch)
            return  n - d->data;
    }
    return -1;
}

/*!
    Returns the index position of the last occurrence of the byte
    array \a ba in this byte array, searching backward from index
    position \a from. If \a from is -1 (the default), the search
    starts at the last byte. Returns -1 if \a ba could not be found.

    Example:
    \code
        QByteArray x("crazy azimuths");
        QByteArray y("azy");
        x.lastIndexOf(y);           // returns 6
        x.lastIndexOf(y, 6);        // returns 6
        x.lastIndexOf(y, 5);        // returns 2
        x.lastIndexOf(y, 1);        // returns -1
    \endcode

    \sa indexOf(), contains(), count()
*/

int QByteArray::lastIndexOf(const QByteArray &ba, int from) const
{
    const int ol = ba.d->size;
    const int l = d->size;
    int delta = l - ol;
    if (from < 0)
        from = delta;
    if (from < 0 || from > l)
        return -1;
    if (from > delta)
        from = delta;
    if (ol == 1)
        return lastIndexOf(*ba.d->data, from);

    const char *needle = ba.d->data;
    const char *haystack = d->data + from;
    const char *end = d->data;
    const uint ol_minus_1 = ol - 1;
    const char *n = needle + ol_minus_1;
    const char *h = haystack + ol_minus_1;
    uint hashNeedle = 0, hashHaystack = 0;
    int idx;
    for (idx = 0; idx < ol; ++idx) {
        hashNeedle = ((hashNeedle<<1) + *(n-idx));
        hashHaystack = ((hashHaystack<<1) + *(h-idx));
    }
    hashHaystack -= *haystack;
    while (haystack >= end) {
        hashHaystack += *haystack;
        if (hashHaystack == hashNeedle  && strncmp(needle, haystack, ol) == 0)
            return haystack-d->data;
        --haystack;
        REHASH(*(haystack + ol));
    }
    return -1;

}

/*! \fn int QByteArray::lastIndexOf(const QString &str, int from) const

    \overload

    Returns the index position of the last occurrence of the string \a
    str in the byte array, searching backward from index position \a
    from. If \a from is -1 (the default), the search starts at the
    last (size() - 1) byte. Returns -1 if \a str could not be found.

    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 int QByteArray::lastIndexOf(const char *str, int from) const
    \overload

    Returns the index position of the last occurrence of the string \a
    str in the byte array, searching backward from index position \a
    from. If \a from is -1 (the default), the search starts at the
    last (size() - 1) byte. Returns -1 if \a str could not be found.
*/

/*!
    \overload

    Returns the index position of the last occurrence of character \a
    ch in the byte array, searching backward from index position \a
    from. If \a from is -1 (the default), the search starts at the
    last (size() - 1) byte. Returns -1 if \a ch could not be found.

    Example:
    \code
        QByteArray ba("ABCBA");
        ba.lastIndexOf("B");        // returns 3
        ba.lastIndexOf("B", 3);     // returns 3
        ba.lastIndexOf("B", 2);     // returns 1
        ba.lastIndexOf("X");        // returns -1
    \endcode

    \sa indexOf(), contains()
*/

int QByteArray::lastIndexOf(char ch, int from) const
{
    if (from < 0)
        from += d->size;
    else if (from > d->size)
        from = d->size-1;
    if (from >= 0) {
        const char *b = d->data;
        const char *n = d->data + from + 1;
        while (n-- != b)
            if (*n == ch)
                return  n - b;
    }
    return -1;
}

/*!
    Returns the number of (potentially overlapping) occurrences of
    byte array \a ba in this byte array.

    \sa contains(), indexOf()
*/

int QByteArray::count(const QByteArray &ba) const
{
    int num = 0;
    int i = -1;
    if (d->size > 500 && ba.d->size > 5) {
        QByteArrayMatcher matcher(ba);
        while ((i = matcher.indexIn(*this, i + 1)) != -1)
            ++num;
    } else {
        while ((i = indexOf(ba, i + 1)) != -1)
            ++num;
    }
    return num;
}

/*!
    \overload

    Returns the number of (potentially overlapping) occurrences of
    string \a str in the byte array.
*/

int QByteArray::count(const char *str) const
{
    int num = 0;
    int i = -1;
    while ((i = indexOf(str, i + 1)) != -1)
        ++num;
    return num;
}

/*!
    \overload

    Returns the number of occurrences of character \a ch in the byte
    array.

    \sa contains(), indexOf()
*/

int QByteArray::count(char ch) const
{
    int num = 0;
    const char *i = d->data + d->size;
    const char *b = d->data;
    while (i != b)
        if (*--i == ch)
            ++num;
    return num;
}

/*! \fn int QByteArray::count() const

    \overload

    Same as size().
*/

/*!
    Returns true if this byte array starts with byte array \a ba;
    otherwise returns false.

    Example:
    \code
        QByteArray url("ftp://ftp.trolltech.com/");
        if (url.startsWith("ftp:"))
            ...
    \endcode

    \sa endsWith(), left()
*/
bool QByteArray::startsWith(const QByteArray &ba) const
{
    if (d == ba.d || ba.d->size == 0)
        return true;
    if (d->size < ba.d->size)
        return false;
    return memcmp(d->data, ba.d->data, ba.d->size) == 0;
}

/*! \overload

    Returns true if this byte array starts with string \a str;
    otherwise returns false.
*/
bool QByteArray::startsWith(const char *str) const
{
    if (!str || !*str)
        return true;
    int len = qstrlen(str);
    if (d->size < len)
        return false;
    return qstrncmp(d->data, str, len) == 0;
}

/*! \overload

    Returns true if this byte array starts with character \a ch;
    otherwise returns false.
*/
bool QByteArray::startsWith(char ch) const
{
    if (d->size == 0)
        return false;
    return d->data[0] == ch;
}

/*!
    Returns true if this byte array ends with byte array \a ba;
    otherwise returns false.

    Example:
    \code
        QByteArray url("http://www.trolltech.com/index.html");
        if (url.endsWith(".html"))
            ...
    \endcode

    \sa startsWith(), right()
*/
bool QByteArray::endsWith(const QByteArray &ba) const
{
    if (d == ba.d || ba.d->size == 0)
        return true;
    if (d->size < ba.d->size)
        return false;
    return memcmp(d->data + d->size - ba.d->size, ba.d->data, ba.d->size) == 0;
}

/*! \overload

    Returns true if this byte array ends with string \a str; otherwise
    returns false.
*/
bool QByteArray::endsWith(const char *str) const
{
    if (!str || !*str)
        return true;
    int len = qstrlen(str);
    if (d->size < len)
        return false;
    return qstrncmp(d->data + d->size - len, str, len) == 0;
}

/*! \overload

    Returns true if this byte array ends with character \a ch;
    otherwise returns false.
*/
bool QByteArray::endsWith(char ch) const
{
    if (d->size == 0)
        return false;
    return d->data[d->size - 1] == ch;
}

/*!
    Returns a byte array that contains the leftmost \a