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。

/**********************************************************************
** Copyright (C) 2000-2005 Trolltech AS.  All rights reserved.
**
** This file is part of the Qtopia Environment.
** 
** This program is free software; you can redistribute it and/or modify it
** under the terms of the GNU General Public License as published by the
** Free Software Foundation; either version 2 of the License, or (at your
** option) any later version.
** 
** A copy of the GNU GPL license version 2 is included in this package as 
** LICENSE.GPL.
**
** This program is distributed in the hope that it will be useful, but
** WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
** See the GNU General Public License for more details.
**
** In addition, as a special exception Trolltech gives permission to link
** the code of this program with Qtopia applications copyrighted, developed
** and distributed by Trolltech under the terms of the Qtopia Personal Use
** License Agreement. You must comply with the GNU General Public License
** in all respects for all of the code used other than the applications
** licensed under the Qtopia Personal Use License Agreement. If you modify
** this file, you may extend this exception to your version of the file,
** but you are not obligated to do so. If you do not wish to do so, delete
** this exception statement from your version.
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** See http://www.trolltech.com/gpl/ for GPL licensing information.
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**********************************************************************/

#include "qglobal.h"
#if defined(Q_CC_BOR)
    // needed for qsort() because of a std namespace problem on Borland
#   include "qplatformdefs.h"
#elif defined(Q_WS_WIN)
    // needed for bsearch on some platforms
#   include "qt_windows.h"
#endif

#define	 QGARRAY_CPP
#include "qgarray.h"
#include <stdlib.h>
#include <string.h>

#ifdef QT_THREAD_SUPPORT
#  include <private/qmutexpool_p.h>
#endif // QT_THREAD_SUPPORT

/*
  If USE_MALLOC isn't defined, we use new[] and delete[] to allocate
  memory. The documentation for QMemArray<T>::assign() explicitly
  mentions that the array is freed using free(), so don't mess around
  with USE_MALLOC unless you know what you're doing.
*/
#define USE_MALLOC

#undef NEW
#undef DELETE

#if defined(USE_MALLOC)
#define NEW(type,size)	((type*)malloc(size*sizeof(type)))
#define DELETE(array)	(free((char*)array))
#else
#define NEW(type,size)	(new type[size])
#define DELETE(array)	(delete[] array)
#define DONT_USE_REALLOC			// comment to use realloc()
#endif

/*!
  \class QShared qshared.h
  \reentrant
  \ingroup shared
  \brief The QShared class is used internally for implementing shared classes.

  \internal

  It only contains a reference count and member functions to increment and
  decrement it.

  Shared classes normally have internal classes that inherit QShared and
  add the shared data.

  \sa \link shclass.html Shared Classes\endlink
*/

/*!
  \class QGArray qgarray.h
  \reentrant
  \ingroup shared
  \ingroup collection
  \brief The QGArray class is an internal class for implementing the QMemArray class.

  \internal

  QGArray is a strictly internal class that acts as base class for the
  QMemArray template array.

  It contains an array of bytes and has no notion of an array element.
*/


/*!
  Constructs a null array.
*/

QGArray::QGArray()
{
    shd = newData();
    Q_CHECK_PTR( shd );
}

/*!
  Dummy constructor; does not allocate any data.

  This constructor does not initialize any array data so subclasses
  must do it. The intention is to make the code more efficient.
*/

QGArray::QGArray( int, int )
{
}

/*!
  Constructs an array with room for \a size bytes.
*/

QGArray::QGArray( int size )
{
    if ( size < 0 ) {
#if defined(QT_CHECK_RANGE)
	qWarning( "QGArray: Cannot allocate array with negative length" );
#endif
	size = 0;
    }
    shd = newData();
    Q_CHECK_PTR( shd );
    if ( size == 0 )				// zero length
	return;
    shd->data = NEW(char,size);
    Q_CHECK_PTR( shd->data );
    shd->len =
#ifdef QT_QGARRAY_SPEED_OPTIM
	shd->maxl =
#endif
	size;
}

/*!
  Constructs a shallow copy of \a a.
*/

QGArray::QGArray( const QGArray &a )
{
    shd = a.shd;
    shd->ref();
}

/*!
  Dereferences the array data and deletes it if this was the last
  reference.
*/

QGArray::~QGArray()
{
    if ( shd && shd->deref() ) {		// delete when last reference
	if ( shd->data )			// is lost
	    DELETE(shd->data);
	deleteData( shd );
	shd = 0;
    }
}


/*!
  \fn QGArray &QGArray::operator=( const QGArray &a )

  Assigns a shallow copy of \a a to this array and returns a reference to
  this array.  Equivalent to assign().
*/

/*!
  \fn void QGArray::detach()

  Detaches this array from shared array data.
*/

/*!
  \fn char *QGArray::data() const

  Returns a pointer to the actual array data.
*/

/*!
  \fn uint QGArray::nrefs() const

  Returns the reference count.
*/

/*!
  \fn uint QGArray::size() const

  Returns the size of the array, in bytes.
*/


/*!
  Returns TRUE if this array is equal to \a a, otherwise FALSE.
  The comparison is bitwise, of course.
*/

bool QGArray::isEqual( const QGArray &a ) const
{
    if ( size() != a.size() )			// different size
	return FALSE;
    if ( data() == a.data() )			// has same data
	return TRUE;
    return (size() ? memcmp( data(), a.data(), size() ) : 0) == 0;
}


/*!
  Resizes the array to \a newsize bytes. \a optim is either
  MemOptim (the default) or SpeedOptim.
*/
bool QGArray::resize( uint newsize, Optimization optim )
{
#ifndef QT_QGARRAY_SPEED_OPTIM
    Q_UNUSED(optim);
#endif

    if ( newsize == shd->len
#ifdef QT_QGARRAY_SPEED_OPTIM
	 && newsize == shd->maxl
#endif
	) // nothing to do
	return TRUE;
    if ( newsize == 0 ) {			// remove array
	if ( shd->data )
	    DELETE(shd->data);
	shd->data = 0;
	shd->len = 0;
#ifdef QT_QGARRAY_SPEED_OPTIM
	shd->maxl = 0;
#endif
	return TRUE;
    }

    uint newmaxl = newsize;
#ifdef QT_QGARRAY_SPEED_OPTIM
    if ( optim == SpeedOptim ) {
	if ( newsize <= shd->maxl &&
	     ( newsize * 4 > shd->maxl || shd->maxl <= 4 ) ) {
	    shd->len = newsize;
	    return TRUE;
	}
	newmaxl = 4;
	while ( newmaxl < newsize )
	    newmaxl *= 2;
	// try to spare some memory
	if ( newmaxl >= 1024 * 1024 && newsize <= newmaxl - (newmaxl >> 2) )
	    newmaxl -= newmaxl >> 2;
    }
    shd->maxl = newmaxl;
#endif

    if ( shd->data ) {				// existing data
#if defined(DONT_USE_REALLOC)
	char *newdata = NEW(char,newsize);	// manual realloc
	memcpy( newdata, shd->data, QMIN(shd->len,newmaxl) );
	DELETE(shd->data);
	shd->data = newdata;
#else
	shd->data = (char *)realloc( shd->data, newmaxl );
#endif
    } else {
	shd->data = NEW(char,newmaxl);
    }
    if ( !shd->data )				// no memory
	return FALSE;
    shd->len = newsize;
    return TRUE;
}

/*!\overload
*/
bool QGArray::resize( uint newsize )
{
    return resize( newsize, MemOptim );
}


/*!
  Fills the array with the repeated occurrences of \a d, which is
  \a sz bytes long.
  If \a len is specified as different from -1, then the array will be
  resized to \a len*sz before it is filled.

  Returns TRUE if successful, or FALSE if the memory cannot be allocated
  (only when \a len != -1).

  \sa resize()
*/

bool QGArray::fill( const char *d, int len, uint sz )
{
    if ( len < 0 )
	len = shd->len/sz;			// default: use array length
    else if ( !resize( len*sz ) )
	return FALSE;
    if ( sz == 1 )				// 8 bit elements
	memset( data(), *d, len );
    else if ( sz == 4 ) {			// 32 bit elements
	register Q_INT32 *x = (Q_INT32*)data();
	Q_INT32 v = *((Q_INT32*)d);
	while ( len-- )
	    *x++ = v;
    } else if ( sz == 2 ) {			// 16 bit elements
	register Q_INT16 *x = (Q_INT16*)data();
	Q_INT16 v = *((Q_INT16*)d);
	while ( len-- )
	    *x++ = v;
    } else {					// any other size elements
	register char *x = data();
	while ( len-- ) {			// more complicated
	    memcpy( x, d, sz );
	    x += sz;
	}
    }
    return TRUE;
}

/*!
    \overload
  Shallow copy. Dereference the current array and references the data
  contained in \a a instead. Returns a reference to this array.
  \sa operator=()
*/

QGArray &QGArray::assign( const QGArray &a )
{
    a.shd->ref();				// avoid 'a = a'
    if ( shd->deref() ) {			// delete when last reference
	if ( shd->data )			// is lost
	    DELETE(shd->data);
	deleteData( shd );
    }
    shd = a.shd;
    return *this;
}

/*!
  Shallow copy. Dereference the current array and references the
  array data \a d, which contains \a len bytes.
  Returns a reference to this array.

  Do not delete \a d later, because QGArray takes care of that.
*/

QGArray &QGArray::assign( const char *d, uint len )
{
    if ( shd->count > 1 ) {			// disconnect this
	shd->count--;
	shd = newData();
	Q_CHECK_PTR( shd );
    } else {
	if ( shd->data )
	    DELETE(shd->data);
    }
    shd->data = (char *)d;
    shd->len =
#ifdef QT_QGARRAY_SPEED_OPTIM
	shd->maxl =
#endif
	len;
    return *this;
}

/*!
  Deep copy. Dereference the current array and obtains a copy of the data
  contained in \a a instead. Returns a reference to this array.
  \sa assign(), operator=()
*/

QGArray &QGArray::duplicate( const QGArray &a )
{
    if ( a.shd == shd ) {			// a.duplicate(a) !
	if ( shd->count > 1 ) {
	    shd->count--;
	    register array_data *n = newData();
	    Q_CHECK_PTR( n );
	    if ( (n->len=shd->len) ) {
		n->data = NEW(char,n->len);
		Q_CHECK_PTR( n->data );
		if ( n->data )
		    memcpy( n->data, shd->data, n->len );
	    } else {
		n->data = 0;
	    }
	    shd = n;
	}
	return *this;
    }
    char *oldptr = 0;
    if ( shd->count > 1 ) {			// disconnect this
	shd->count--;
	shd = newData();