/*

 * Copyright (C) 2003 Apple Computer, Inc.

 * Copyright (C) Research In Motion Limited 2010. All rights reserved.

 *

 * Portions are Copyright (C) 1998 Netscape Communications Corporation.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * Alternatively, the contents of this file may be used under the terms

 * of either the Mozilla Public License Version 1.1, found at

 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public

 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html

 * (the "GPL"), in which case the provisions of the MPL or the GPL are

 * applicable instead of those above.  If you wish to allow use of your

 * version of this file only under the terms of one of those two

 * licenses (the MPL or the GPL) and not to allow others to use your

 * version of this file under the LGPL, indicate your decision by

 * deletingthe provisions above and replace them with the notice and

 * other provisions required by the MPL or the GPL, as the case may be.

 * If you do not delete the provisions above, a recipient may use your

 * version of this file under any of the LGPL, the MPL or the GPL.

 */

#include "config.h"

#include "RenderArena.h"

#include <stdlib.h>

#include <string.h>

#include <wtf/Assertions.h>

#define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y))

namespace WebCore {

#ifndef NDEBUG

const int signature = 0xDBA00AEA;

const int signatureDead = 0xDBA00AED;

typedef struct {

    RenderArena* arena;

    size_t size;

    int signature;

} RenderArenaDebugHeader;

static const size_t debugHeaderSize = ARENA_ALIGN(sizeof(RenderArenaDebugHeader));

#endif

RenderArena::RenderArena(unsigned arenaSize)

{

    // Initialize the arena pool

    INIT_ARENA_POOL(&m_pool, "RenderArena", arenaSize);

    // Zero out the recyclers array

    memset(m_recyclers, 0, sizeof(m_recyclers));

}

RenderArena::~RenderArena()

{

    FinishArenaPool(&m_pool);

}

void* RenderArena::allocate(size_t size)

{

#ifndef NDEBUG

    // Use standard malloc so that memory debugging tools work.

    ASSERT(this);

    void* block = ::malloc(debugHeaderSize + size);

    RenderArenaDebugHeader* header = static_cast<RenderArenaDebugHeader*>(block);

    header->arena = this;

    header->size = size;

    header->signature = signature;

    return static_cast<char*>(block) + debugHeaderSize;

#else

    void* result = 0;

    // Ensure we have correct alignment for pointers.  Important for Tru64

    size = ROUNDUP(size, sizeof(void*));

    // Check recyclers first

    if (size < gMaxRecycledSize) {

        const int index = size >> 2;

        result = m_recyclers[index];

        if (result) {

            // Need to move to the next object

            void* next = *((void**)result);

            m_recyclers[index] = next;

        }

    }

    if (!result) {

        // Allocate a new chunk from the arena

        ARENA_ALLOCATE(result, &m_pool, size);

    }

    return result;

#endif

}

void RenderArena::free(size_t size, void* ptr)

{

#ifndef NDEBUG

    // Use standard free so that memory debugging tools work.

    void* block = static_cast<char*>(ptr) - debugHeaderSize;

    RenderArenaDebugHeader* header = static_cast<RenderArenaDebugHeader*>(block);

    ASSERT(header->signature == signature);

    ASSERT_UNUSED(size, header->size == size);

    ASSERT(header->arena == this);

    header->signature = signatureDead;

    ::free(block);

#else

    // Ensure we have correct alignment for pointers.  Important for Tru64

    size = ROUNDUP(size, sizeof(void*));

    // See if it's a size that we recycle

    if (size < gMaxRecycledSize) {

        const int index = size >> 2;

        void* currentTop = m_recyclers[index];

        m_recyclers[index] = ptr;

        *((void**)ptr) = currentTop;

    }

#endif

}

} // namespace WebCore