Source/WebCore/platform/graphics/android/utils/LinearAllocator.h

/*
 * Copyright 2012, The Android Open Source Project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef LinearAllocator_h
#define LinearAllocator_h

namespace WebCore {

class LinearAllocator
{
public:
    LinearAllocator();
    ~LinearAllocator();

    void* alloc(size_t size);
    void rewindIfLastAlloc(void* ptr, size_t allocSize);

    void dumpMemoryStats(const char* prefix = "");

private:
    LinearAllocator(const LinearAllocator& other);

    class Page;

    Page* newPage(size_t pageSize);
    bool fitsInCurrentPage(size_t size);
    void ensureNext(size_t size);
    void* start(Page *p);
    void* end(Page* p);

    size_t m_pageSize;
    size_t m_maxAllocSize;
    void* m_next;
    Page* m_currentPage;
    Page* m_pages;

    // Memory usage tracking
    size_t m_totalAllocated;
    size_t m_wastedSpace;
    size_t m_pageCount;
    size_t m_dedicatedPageCount;
};

} // namespace WebCore

#endif // LinearAllocator_h