buffer.cpp

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

/* ***** BEGIN LICENSE BLOCK ***** 
 * Version: RCSL 1.0/RPSL 1.0 
 *  
 * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
 *      
 * The contents of this file, and the files included with this file, are 
 * subject to the current version of the RealNetworks Public Source License 
 * Version 1.0 (the "RPSL") available at 
 * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 * the file under the RealNetworks Community Source License Version 1.0 
 * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, 
 * in which case the RCSL will apply. You may also obtain the license terms 
 * directly from RealNetworks.  You may not use this file except in 
 * compliance with the RPSL or, if you have a valid RCSL with RealNetworks 
 * applicable to this file, the RCSL.  Please see the applicable RPSL or 
 * RCSL for the rights, obligations and limitations governing use of the 
 * contents of the file.  
 *  
 * This file is part of the Helix DNA Technology. RealNetworks is the 
 * developer of the Original Code and owns the copyrights in the portions 
 * it created. 
 *  
 * This file, and the files included with this file, is distributed and made 
 * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS 
 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * 
 * Technology Compatibility Kit Test Suite(s) Location: 
 *    http://www.helixcommunity.org/content/tck 
 * 
 * Contributor(s): 
 *  
 * ***** END LICENSE BLOCK ***** */ 

#include "hlxclib/stdio.h"
#include "hlxclib/stdlib.h"
#include "hlxclib/string.h"
#include "hxtypes.h"

#include "hxassert.h"
#include "buffer.h"

#include "hxheap.h"
#ifdef _DEBUG
#undef HX_THIS_FILE		
static const char HX_THIS_FILE[] = __FILE__;
#endif


Buffer::Buffer() {
    refcount = 0;
}

Buffer::~Buffer() 
{
    if (base) delete[] base;
    HX_ASSERT(refcount == 0);
}

/*
 * Ensure that required number of contiguous bytes is
 * available (in preparation for storing a large object,
 * part of which may have already been buffered).
 */

void
WrapBuffer::ensure(int required) {
    int count;

    if (limit - data >= required)
	return;
    count = space - data;
    if (limit < base + required) {
	Byte* newbase = new Byte[required];
	memmove(newbase, data, count);
	delete[] base;
	base = newbase;
	limit = base + required;
    } else {
	memmove(base, data, count);
    }
    data = base;
    space = data + count;
}

void
WrapBuffer::ensure_space(int required) {
    if (limit - space >= required)
	return;
    ensure(required + count());
}

void
GrowBuffer::grow(int s) {
    Byte* newbase;
    int count;

    count = used();
    newbase = new Byte[s];
    memcpy(newbase, base, (count <= s ? count : s)); /* Flawfinder: ignore */
    delete[] base;
    base = newbase;
    limit = base + s;
    data = base;
    space = base + count;
} 

void
GrowBuffer::ensure_space(int required) {
    if (limit - space >= required)
	return;

    int s = used() + required;

    /*
     * Try to reduce the amount of copying required
     */

    grow(s*2);
}