util_vector.h

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/*
 * Copyright 2011, Blender Foundation.
 *
 * 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.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#ifndef __UTIL_VECTOR_H__
#define __UTIL_VECTOR_H__

/* Vector */

#include <string.h>
#include <vector>

CCL_NAMESPACE_BEGIN

using std::vector;

/* Array
 *
 * Simplified version of vector, serving two purposes:
 * - somewhat faster in that it does not clear memory on resize/alloc,
 *   this was actually showing up in profiles quite significantly
 * - if this is used, we are not tempted to use inefficient operations */

template<typename T>
class array
{
public:
    array()
    {
        data = NULL;
        datasize = 0;
    }

    array(size_t newsize)
    {
        if(newsize == 0) {
            data = NULL;
            datasize = 0;
        }
        else {
            data = new T[newsize];
            datasize = newsize;
        }
    }

    array(const array& from)
    {
        *this = from;
    }

    array& operator=(const array& from)
    {
        if(from.datasize == 0) {
            data = NULL;
            datasize = 0;
        }
        else {
            data = new T[from.datasize];
            memcpy(data, from.data, from.datasize*sizeof(T));
            datasize = from.datasize;
        }

        return *this;
    }

    array& operator=(const vector<T>& from)
    {
        datasize = from.size();
        data = NULL;

        if(datasize > 0) {
            data = new T[datasize];
            memcpy(data, &from[0], datasize*sizeof(T));
        }

        return *this;
    }

    ~array()
    {
        delete [] data;
    }

    void resize(size_t newsize)
    {
        if(newsize == 0) {
            clear();
        }
        else {
            T *newdata = new T[newsize];
            memcpy(newdata, data, ((datasize < newsize)? datasize: newsize)*sizeof(T));
            delete [] data;

            data = newdata;
            datasize = newsize;
        }
    }

    void clear()
    {
        delete [] data;
        data = NULL;
        datasize = 0;
    }

    size_t size() const
    {
        return datasize;
    }

    T& operator[](size_t i) const
    {
        return data[i];
    }

protected:
    T *data;
    size_t datasize;
};

CCL_NAMESPACE_END

#endif /* __UTIL_VECTOR_H__ */