source: trunk/tools/porting/src/smallobject.h@ 769

/****************************************************************************
**
** Copyright (C) 2001-2004 Roberto Raggi
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the qt3to4 porting application of the Qt Toolkit.
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** Foundation and appearing in the file LICENSE.LGPL included in the
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#ifndef SMALLOBJECT_H
#define SMALLOBJECT_H

#include <QList>

#include <assert.h>
#include <stdlib.h>
#include <string.h>

QT_BEGIN_NAMESPACE

struct block_t
{
    static int N;

    block_t *chain;
    char *data;
    char *ptr;
    char *end;

    inline void init(int block_size = 256)
    {
        ++N;
        chain = 0;
        data = (char*) malloc(block_size);
        ptr = data;
        end = data + block_size;
    }

    inline void init0(int block_size)
    {
        init();
        memset(data, '0', block_size);
    }

    inline void destroy()
    {
        --N;
        if (chain) {
            chain->destroy();
            free(chain);
        }

        free(data);
    }

    inline void *allocate(size_t size, block_t **right_most)
    {
        const unsigned int block_size = 1 << 16;
        if (end < ptr + size) {
            assert( size < block_size );

            if (!chain) {
                chain = (block_t*) malloc(sizeof(block_t));
                Q_ASSERT(chain);
                chain->init(block_size);
            }

            return chain->allocate(size, right_most);
        }

        char *r = ptr;
        ptr += size;