containers/test_stack.cpp

This is an example of how to use stxxl::STACK_GENERATOR class to generate an external stack type with stxxl::grow_shrink_stack implementation, four blocks per page, block size 4096 bytes

/***************************************************************************
 *  containers/test_stack.cpp
 *
 *  Part of the STXXL. See http://stxxl.sourceforge.net
 *
 *  Copyright (C) 2003 Roman Dementiev <dementiev@mpi-sb.mpg.de>
 *
 *  Distributed under the Boost Software License, Version 1.0.
 *  (See accompanying file LICENSE_1_0.txt or copy at
 *  http://www.boost.org/LICENSE_1_0.txt)
 **************************************************************************/


#include <stxxl/stack>


int main(int argc, char * argv[])
{
    typedef stxxl::STACK_GENERATOR<int, stxxl::external, stxxl::grow_shrink, 4, 4096>::result ext_stack_type;
    typedef stxxl::STACK_GENERATOR<int, stxxl::external, stxxl::grow_shrink2, 1, 4096>::result ext_stack_type2;

    if (argc < 2)
    {
        STXXL_MSG("Usage: " << argv[0] << " test_size_in_pages");
        return -1;
    }
    {
        ext_stack_type my_stack;
        int test_size = atoi(argv[1]) * 4 * 4096 / sizeof(int), i;

        for (i = 0; i < test_size; i++)
        {
            my_stack.push(i);
            assert(my_stack.top() == i);
            assert(my_stack.size() == i + 1);
        }

        for (i = test_size - 1; i >= 0; i--)
        {
            assert(my_stack.top() == i);
            my_stack.pop();
            assert(my_stack.size() == i);
        }

        for (i = 0; i < test_size; i++)
        {
            my_stack.push(i);
            assert(my_stack.top() == i);
            assert(my_stack.size() == i + 1);
        }

        // test swap
        ext_stack_type s2;
        std::swap(s2, my_stack);
        std::swap(s2, my_stack);

        for (i = test_size - 1; i >= 0; i--)
        {
            assert(my_stack.top() == i);
            my_stack.pop();
            assert(my_stack.size() == i);
        }

        std::stack<int> int_stack;

        for (i = 0; i < test_size; i++)
        {
            int_stack.push(i);
            assert(int_stack.top() == i);
            assert(int(int_stack.size()) == i + 1);
        }

        ext_stack_type my_stack1(int_stack);

        for (i = test_size - 1; i >= 0; i--)
        {
            assert(my_stack1.top() == i);
            my_stack1.pop();
            assert(my_stack1.size() == i);
        }

        STXXL_MSG("Test 1 passed.");
    }
    {
        // prefetch pool with 10 blocks (> D is recommended)
        stxxl::prefetch_pool<ext_stack_type2::block_type> p_pool(10);
        // write pool with 10 blocks (> D is recommended)
        stxxl::write_pool<ext_stack_type2::block_type> w_pool(10);
        // create a stack that does not prefetch (level of prefetch aggressiveness 0)
        ext_stack_type2 my_stack(p_pool, w_pool, 0);
        int test_size = atoi(argv[1]) * 4 * 4096 / sizeof(int), i;

        for (i = 0; i < test_size; i++)
        {
            my_stack.push(i);
            assert(my_stack.top() == i);
            assert(my_stack.size() == i + 1);
        }
        my_stack.set_prefetch_aggr(10);
        for (i = test_size - 1; i >= 0; i--)
        {
            assert(my_stack.top() == i);
            my_stack.pop();
            assert(my_stack.size() == i);
        }

        for (i = 0; i < test_size; i++)
        {
            my_stack.push(i);
            assert(my_stack.top() == i);
            assert(my_stack.size() == i + 1);
        }

        // test swap
        ext_stack_type2 s2(p_pool, w_pool, 0);
        std::swap(s2, my_stack);
        std::swap(s2, my_stack);

        for (i = test_size - 1; i >= 0; i--)
        {
            assert(my_stack.top() == i);
            my_stack.pop();
            assert(my_stack.size() == i);
        }

        STXXL_MSG("Test 2 passed.");
    }

    return 0;
}

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