2 * Copyright (C) 2011 Apple Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
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29 #include <wtf/Assertions.h>
30 #include <wtf/FastMalloc.h>
31 #include <wtf/Vector.h>
35 template <typename T> class BlockStack {
37 static const size_t blockSize = 4096;
38 static const size_t blockLength = blockSize / sizeof(T);
46 const Vector<T*>& blocks();
50 T* m_spareBlock; // Used to avoid thrash at block boundaries.
53 template <typename T> BlockStack<T>::BlockStack()
58 template <typename T> BlockStack<T>::~BlockStack()
61 fastFree(m_spareBlock);
62 for (size_t i = 0; i < m_blocks.size(); ++i)
63 fastFree(m_blocks[i]);
66 template <typename T> inline const Vector<T*>& BlockStack<T>::blocks()
71 template <typename T> T* BlockStack<T>::grow()
73 T* block = m_spareBlock ? m_spareBlock : static_cast<T*>(fastMalloc(blockSize));
76 m_blocks.append(block);
80 template <typename T> void BlockStack<T>::shrink(T* newEnd)
82 ASSERT(newEnd != m_blocks.last() + blockLength);
83 m_spareBlock = m_blocks.last();
84 m_blocks.removeLast();
86 while (m_blocks.last() + blockLength != newEnd) {
87 fastFree(m_blocks.last());
88 m_blocks.removeLast();
94 using WTF::BlockStack;