qgarray.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

	Q_CHECK_PTR( shd );
    } else {					// delete after copy was made
	oldptr = shd->data;
    }
    if ( a.shd->len ) {				// duplicate data
	shd->data = NEW(char,a.shd->len);
	Q_CHECK_PTR( shd->data );
	if ( shd->data )
	    memcpy( shd->data, a.shd->data, a.shd->len );
    } else {
	shd->data = 0;
    }
    shd->len =
#ifdef QT_QGARRAY_SPEED_OPTIM
	shd->maxl =
#endif
	a.shd->len;
    if ( oldptr )
	DELETE(oldptr);
    return *this;
}

/*!
    \overload
  Deep copy. Dereferences the current array and obtains a copy of
  \a len characters from array data \a d instead.  Returns a reference
  to this array.
  \sa assign(), operator=()
*/

QGArray &QGArray::duplicate( const char *d, uint len )
{
    char *data;
    if ( d == 0 || len == 0 ) {
	data = 0;
	len  = 0;
    } else {
	if ( shd->count == 1 && shd->len == len ) {
	    if ( shd->data != d )		// avoid self-assignment
		memcpy( shd->data, d, len );	// use same buffer
	    return *this;
	}
	data = NEW(char,len);
	Q_CHECK_PTR( data );
	memcpy( data, d, len );
    }
    if ( shd->count > 1 ) {			// detach
	shd->count--;
	shd = newData();
	Q_CHECK_PTR( shd );
    } else {					// just a single reference
	if ( shd->data )
	    DELETE(shd->data);
    }
    shd->data = data;
    shd->len =
#ifdef QT_QGARRAY_SPEED_OPTIM
	shd->maxl =
#endif
	len;
    return *this;
}

/*!
  Resizes this array to \a len bytes and copies the \a len bytes at
  address \a d into it.

  \warning This function disregards the reference count mechanism.  If
  other QGArrays reference the same data as this, all will be updated.
*/

void QGArray::store( const char *d, uint len )
{						// store, but not deref
    resize( len );
    memcpy( shd->data, d, len );
}


/*!
  \fn array_data *QGArray::sharedBlock() const

  Returns a pointer to the shared array block.

  \warning

  Do not use this function.  Using it is begging for trouble.  We dare
  not remove it, for fear of breaking code, but we \e strongly
  discourage new use of it.
*/

/*!
  \fn void QGArray::setSharedBlock( array_data *p )

  Sets the shared array block to \a p.

  \warning

  Do not use this function.  Using it is begging for trouble.  We dare
  not remove it, for fear of breaking code, but we \e strongly
  discourage new use of it.
*/


/*!
  Sets raw data and returns a reference to the array.

  Dereferences the current array and sets the new array data to \a d and
  the new array size to \a len.	 Do not attempt to resize or re-assign the
  array data when raw data has been set.
  Call resetRawData(d,len) to reset the array.

  Setting raw data is useful because it sets QMemArray data without
  allocating memory or copying data.

  Example of intended use:
  \code
    static uchar bindata[] = { 231, 1, 44, ... };
    QByteArray	a;
    a.setRawData( bindata, sizeof(bindata) );	// a points to bindata
    QDataStream s( a, IO_ReadOnly );		// open on a's data
    s >> <something>;				// read raw bindata
    s.close();
    a.resetRawData( bindata, sizeof(bindata) ); // finished
  \endcode

  Example of misuse (do not do this):
  \code
    static uchar bindata[] = { 231, 1, 44, ... };
    QByteArray	a, b;
    a.setRawData( bindata, sizeof(bindata) );	// a points to bindata
    a.resize( 8 );				// will crash
    b = a;					// will crash
    a[2] = 123;					// might crash
      // forget to resetRawData - will crash
  \endcode

  \warning If you do not call resetRawData(), QGArray will attempt to
  deallocate or reallocate the raw data, which might not be too good.
  Be careful.
*/

QGArray &QGArray::setRawData( const char *d, uint len )
{
    duplicate( 0, 0 );				// set null data
    shd->data = (char *)d;
    shd->len  = len;
    return *this;
}

/*!
  Resets raw data.

  The arguments must be the data, \a d, and length \a len, that were
  passed to setRawData().  This is for consistency checking.
*/

void QGArray::resetRawData( const char *d, uint len )
{
    if ( d != shd->data || len != shd->len ) {
#if defined(QT_CHECK_STATE)
	qWarning( "QGArray::resetRawData: Inconsistent arguments" );
#endif
	return;
    }
    shd->data = 0;
    shd->len  = 0;
}


/*!
  Finds the first occurrence of \a d in the array from position \a index,
  where \a sz is the size of the \a d element.

  Note that \a index is given in units of \a sz, not bytes.

  This function only compares whole cells, not bytes.
*/

int QGArray::find( const char *d, uint index, uint sz ) const
{
    index *= sz;
    if ( index >= shd->len ) {
#if defined(QT_CHECK_RANGE)
	qWarning( "QGArray::find: Index %d out of range", index/sz );
#endif
	return -1;
    }
    register uint i;
    uint ii;
    switch ( sz ) {
	case 1: {				// 8 bit elements
	    register char *x = data() + index;
	    char v = *d;
	    for ( i=index; i<shd->len; i++ ) {
		if ( *x++ == v )
		    break;
	    }
	    ii = i;
	    }
	    break;
	case 2: {				// 16 bit elements
	    register Q_INT16 *x = (Q_INT16*)(data() + index);
	    Q_INT16 v = *((Q_INT16*)d);
	    for ( i=index; i<shd->len; i+=2 ) {
		if ( *x++ == v )
		    break;
	    }
	    ii = i/2;
	    }
	    break;
	case 4: {				// 32 bit elements
	    register Q_INT32 *x = (Q_INT32*)(data() + index);
	    Q_INT32 v = *((Q_INT32*)d);
	    for ( i=index; i<shd->len; i+=4 ) {
		if ( *x++ == v )
		    break;
	    }
	    ii = i/4;
	    }
	    break;
	default: {				// any size elements
	    for ( i=index; i<shd->len; i+=sz ) {
		if ( memcmp( d, &shd->data[i], sz ) == 0 )
		    break;
	    }
	    ii = i/sz;
	    }
	    break;
    }
    return i<shd->len ? (int)ii : -1;
}

/*!
  Returns the number of occurrences of \a d in the array, where \a sz is
  the size of the \a d element.

  This function only compares whole cells, not bytes.
*/

int QGArray::contains( const char *d, uint sz ) const
{
    register uint i = shd->len;
    int count = 0;
    switch ( sz ) {
	case 1: {				// 8 bit elements
	    register char *x = data();
	    char v = *d;
	    while ( i-- ) {
		if ( *x++ == v )
		    count++;
	    }
	    }
	    break;
	case 2: {				// 16 bit elements
	    register Q_INT16 *x = (Q_INT16*)data();
	    Q_INT16 v = *((Q_INT16*)d);
	    i /= 2;
	    while ( i-- ) {
		if ( *x++ == v )
		    count++;
	    }
	    }
	    break;
	case 4: {				// 32 bit elements
	    register Q_INT32 *x = (Q_INT32*)data();
	    Q_INT32 v = *((Q_INT32*)d);
	    i /= 4;
	    while ( i-- ) {
		if ( *x++ == v )
		    count++;
	    }
	    }
	    break;
	default: {				// any size elements
	    for ( i=0; i<shd->len; i+=sz ) {
		if ( memcmp(d, &shd->data[i], sz) == 0 )
		    count++;
	    }
	    }
	    break;
    }
    return count;
}

static int cmp_item_size = 0;

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

#ifdef Q_OS_TEMP
static int __cdecl cmp_arr( const void *n1, const void *n2 )
#else
static int cmp_arr( const void *n1, const void *n2 )
#endif
{
    return ( n1 && n2 ) ? memcmp( n1, n2, cmp_item_size )
			: ( n1 ? 1 : ( n2 ? -1 : 0 ) );
    // ### Qt 3.0: Add a virtual compareItems() method and call that instead
}

#if defined(Q_C_CALLBACKS)
}
#endif

/*!
  Sorts the first \a sz items of the array.
*/

void QGArray::sort( uint sz )
{
    int numItems = size() / sz;
    if ( numItems < 2 )
	return;

#ifdef QT_THREAD_SUPPORT
    QMutexLocker locker( qt_global_mutexpool ?
			 qt_global_mutexpool->get( &cmp_item_size ) : 0 );
#endif // QT_THREAD_SUPPORT

    cmp_item_size = sz;
    qsort( shd->data, numItems, sz, cmp_arr );
}

/*!
  Binary search; assumes that \a d is a sorted array of size \a sz.
*/

int QGArray::bsearch( const char *d, uint sz ) const
{
    int numItems = size() / sz;
    if ( !numItems )
	return -1;

#ifdef QT_THREAD_SUPPORT
    QMutexLocker locker( qt_global_mutexpool ?
			 qt_global_mutexpool->get( &cmp_item_size ) : 0 );
#endif // QT_THREAD_SUPPORT

    cmp_item_size = sz;
    char* r = (char*)::bsearch( d, shd->data, numItems, sz, cmp_arr );
    if ( !r )
	return -1;
    while( (r >= shd->data + sz) && (cmp_arr( r - sz, d ) == 0) )
	r -= sz;	// search to first of equal elements; bsearch is undef
    return (int)(( r - shd->data ) / sz);
}


/*!
  \fn char *QGArray::at( uint index ) const

  Returns a pointer to the byte at offset \a index in the array.
*/

/*!
  Expand the array if necessary, and copies (the first part of) its
  contents from the \a index * \a sz bytes at \a d.

  Returns TRUE if the operation succeeds, FALSE if it runs out of
  memory.

  \warning This function disregards the reference count mechanism.  If
  other QGArrays reference the same data as this, all will be changed.
*/

bool QGArray::setExpand( uint index, const char *d, uint sz )
{
    index *= sz;
    if ( index >= shd->len ) {
	if ( !resize( index+sz ) )		// no memory
	    return FALSE;
    }
    memcpy( data() + index, d, sz );
    return TRUE;
}


/*!
  Prints a warning message if at() or [] is given a bad index.
*/

void QGArray::msg_index( uint index )
{
#if defined(QT_CHECK_RANGE)
    qWarning( "QGArray::at: Absolute index %d out of range", index );
#else
    Q_UNUSED( index )
#endif
}


/*!
  Returns a new shared array block.
*/

QGArray::array_data * QGArray::newData()
{
    return new array_data;
}


/*!
  Deletes the shared array block \a p.
*/

void QGArray::deleteData( array_data *p )
{
    delete p;
}