/* Copyright (C) 2011 Kwan Ting Chan
 * 
 * Use, modification and distribution is subject to the 
 * Boost Software License, Version 1.0. (See accompanying
 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
 */

#include "test_simple_seg_storage.hpp"
#include "track_allocator.hpp"
#include "random_shuffle.hpp"

#include <boost/pool/simple_segregated_storage.hpp>
#include <boost/assert.hpp>
#include <boost/integer/common_factor_ct.hpp>
#if defined(BOOST_MSVC) && (BOOST_MSVC <= 1600)
#pragma warning(push)
#pragma warning(disable: 4244)
// ..\..\boost/random/uniform_int_distribution.hpp(171) :
//   warning C4127: conditional expression is constant
#pragma warning(disable: 4127)
#endif
#include <boost/random/mersenne_twister.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/random/variate_generator.hpp>
#if defined(BOOST_MSVC) && (BOOST_MSVC <= 1600)
#pragma warning(pop)
#endif

#include <boost/core/lightweight_test.hpp>

#include <algorithm>
#include <functional>
#include <set>
#include <vector>

#include <cstddef>
#include <cstdlib>
#include <ctime>

#ifdef BOOST_MSVC
#pragma warning(disable:4267)
#endif

// "A free list is ordered if repeated calls to malloc() will result in a
//  constantly-increasing sequence of values, as determined by std::less<void*>"
// Return: true if in constantly-increasing order, false otherwise
bool check_is_order(const std::vector<void*>& vs)
{
    if(vs.size() < 2) { return true; }

    void *lower, *higher;
    std::vector<void*>::const_iterator ci = vs.begin();
    lower = *(ci++);
    while(ci != vs.end())
    {
        higher = *(ci++);
        if(!std::less<void*>()(lower, higher)) { return false; }
    }

    return true;
}

// Return: number of chunks malloc'd from store
std::size_t test_is_order(test_simp_seg_store& store)
{
    std::vector<void*> vpv;
    std::size_t nchunk = 0;
    // Pre: !empty()
    while(!store.empty())
    {
        void* const first = store.get_first();
        void* const pv = store.malloc();
        // "Takes the first available chunk from the free list
        //  and returns it"
        BOOST_TEST(first == pv);

        vpv.push_back(pv);
        ++nchunk;
    }
    BOOST_TEST(check_is_order(vpv));

    return nchunk;
}

boost::mt19937 gen;

int main()
{
    std::srand(static_cast<unsigned>(std::time(0)));
    gen.seed(static_cast<boost::uint32_t>(std::time(0)));

    /* Store::segregate(block, sz, partition_sz, end) */
    std::size_t partition_sz
        = boost::integer::static_lcm<sizeof(void*), sizeof(int)>::value;
    boost::uniform_int<> dist(partition_sz, 10000);
    boost::variate_generator<boost::mt19937&,
        boost::uniform_int<> > die(gen, dist);
    std::size_t block_size = die();
    // Pre: npartition_sz >= sizeof(void*)
    //      npartition_sz = sizeof(void*) * i, for some integer i
    //      nsz >= npartition_sz
    //      block is properly aligned for an array of object of
    //        size npartition_sz and array of void *
    BOOST_ASSERT(partition_sz >= sizeof(void*));
    BOOST_ASSERT(partition_sz % sizeof(void*) == 0);
    BOOST_ASSERT(block_size >= partition_sz);
    {
        char* const pc = track_allocator::malloc(block_size);
        // (Test) Pre: block of memory is valid
        BOOST_ASSERT(pc);
        int endadd = 0;
        void* const pvret = test_simp_seg_store::segregate(pc, block_size,
            partition_sz, &endadd);

        // The first chunk "is always equal to block"
        BOOST_TEST(pvret == pc);

        void* cur = test_simp_seg_store::get_nextof(static_cast<int*>(pvret));
        void* last = pvret;
        std::size_t nchunk = 1;
        while(cur != &endadd)
        {
            ++nchunk;

            // Memory of each chunk does not overlap
            // The free list constructed is actually from the given block
            // The "interleaved free list is ordered"
            BOOST_TEST(std::less_equal<void*>()(static_cast<char*>(last)
                + partition_sz, cur));
            BOOST_TEST(std::less_equal<void*>()(static_cast<char*>(cur)
                + partition_sz, pc + block_size));

            last = cur;
            cur = test_simp_seg_store::get_nextof(static_cast<int*>(cur));
        }
        // "The last chunk is set to point to end"
        // "Partitioning into as many partition_sz-sized chunks as possible"
        BOOST_TEST(nchunk == block_size/partition_sz);
    }

    /* t.add_block(block, sz, partition_sz), t.malloc() */
    {
        // Default constructor of simple_segregated_storage do nothing
        test_simp_seg_store tstore;
        // Post: empty()
        BOOST_TEST(tstore.empty());

        char* const pc = track_allocator::malloc(block_size);
        tstore.add_block(pc, block_size, partition_sz);

        // The first chunk "is always equal to block"
        BOOST_TEST(tstore.get_first() == pc);

        // Empty before add_block() => "is ordered after"
        std::size_t nchunk = test_is_order(tstore);
        // "Partitioning into as many partition_sz-sized chunks as possible"
        BOOST_TEST(nchunk == block_size/partition_sz);

        BOOST_ASSERT(partition_sz <= 23);
        test_simp_seg_store tstore2;
        char* const pc2 = track_allocator::malloc(88);
        tstore2.add_block(pc2, 24, partition_sz);
        tstore2.add_block(pc2 + 64, 24, partition_sz);
        tstore2.add_block(pc2 + 32, 24, partition_sz);
        tstore2.add_block(track_allocator::malloc(23), 23, partition_sz);
        std::size_t nchunk_ref = (3*(24/partition_sz)) + (23/partition_sz);
        for(nchunk = 0; !tstore2.empty(); tstore2.malloc(), ++nchunk) {}
        // add_block() merges new free list to existing
        BOOST_TEST(nchunk == nchunk_ref);
    }

    /* t.free(chunk) */
    {
        test_simp_seg_store tstore;
        char* const pc = track_allocator::malloc(partition_sz);
        tstore.add_block(pc, partition_sz, partition_sz);
        void* pv = tstore.malloc();
        BOOST_TEST(tstore.empty());
        tstore.free(pv);
    }

    /* t.add_ordered_block(block, sz, partition_sz) */
    {
        {
            char* const pc = track_allocator::malloc(6 * partition_sz);
            std::vector<void*> vpv;
            vpv.push_back(pc);
            vpv.push_back(pc + (2 * partition_sz));
            vpv.push_back(pc + (4 * partition_sz));

            do
            {
                test_simp_seg_store tstore;
                tstore.add_ordered_block(vpv[0], 2*partition_sz, partition_sz);
                tstore.add_ordered_block(vpv[1], 2*partition_sz, partition_sz);
                tstore.add_ordered_block(vpv[2], 2*partition_sz, partition_sz);
                // "Order-preserving"
                test_is_order(tstore);
            } while(std::next_permutation(vpv.begin(), vpv.end()));
        }

        {
            test_simp_seg_store tstore;
            char* const pc = track_allocator::malloc(6 * partition_sz);
            tstore.add_ordered_block(pc, 2 * partition_sz, partition_sz);
            tstore.add_ordered_block(pc + (4 * partition_sz),
                (2 * partition_sz), partition_sz);
            // "Order-preserving"
            test_is_order(tstore);
        }

        {
            test_simp_seg_store tstore;
            char* const pc = track_allocator::malloc(6 * partition_sz);
            tstore.add_ordered_block(pc + (4 * partition_sz),
                (2 * partition_sz), partition_sz);
            tstore.add_ordered_block(pc, 2 * partition_sz, partition_sz);
            // "Order-preserving"
            test_is_order(tstore);
        }
    }

    /* t.ordered_free(chunk) */
    {
        char* const pc = track_allocator::malloc(6 * partition_sz);

        test_simp_seg_store tstore;
        tstore.add_block(pc, 6 * partition_sz, partition_sz);

        std::vector<void*> vpv;
        for(std::size_t i=0; i < 6; ++i) { vpv.push_back(tstore.malloc()); }
        BOOST_ASSERT(tstore.empty());
        pool_test_random_shuffle(vpv.begin(), vpv.end());

        for(std::size_t i=0; i < 6; ++i)
        {
            tstore.ordered_free(vpv[i]);
        }
        // "Order-preserving"
        test_is_order(tstore);
    }

    /* t.malloc_n(n, partition_sz) */
    {
        {
            char* const pc = track_allocator::malloc(12 * partition_sz);
            test_simp_seg_store tstore;
            tstore.add_ordered_block(pc, 2 * partition_sz, partition_sz);
            tstore.add_ordered_block(pc + (3 * partition_sz),
                3 * partition_sz, partition_sz);
            tstore.add_ordered_block(pc + (7 * partition_sz),
                5 * partition_sz, partition_sz);

            void* pvret = tstore.malloc_n(6, partition_sz);
            BOOST_TEST(pvret == 0);

            pvret = tstore.malloc_n(0, partition_sz);
            // There's no prohibition against asking for zero elements
            BOOST_TEST(pvret == 0);

            pvret = tstore.malloc_n(3, partition_sz);
            // Implicit assumption that contiguous sequence found is the first
            //  available while traversing from the start of the free list
            BOOST_TEST(pvret == pc + (3 * partition_sz));

            pvret = tstore.malloc_n(4, partition_sz);
            BOOST_TEST(pvret == pc + (7 * partition_sz));

            // There should still be two contiguous
            //  and one non-contiguous chunk left
            std::size_t nchunks = 0;
            while(!tstore.empty())
            {
                tstore.malloc();
                ++nchunks;
            }
            BOOST_TEST(nchunks == 3);
        }

        {
            char* const pc = track_allocator::malloc(12 * partition_sz);
            test_simp_seg_store tstore;
            tstore.add_ordered_block(pc, 2 * partition_sz, partition_sz);
            tstore.add_ordered_block(pc + (3 * partition_sz),
                3 * partition_sz, partition_sz);
            tstore.add_ordered_block(pc + (7 * partition_sz),
                5 * partition_sz, partition_sz);

            tstore.malloc_n(3, partition_sz);
            // "Order-preserving"
            test_is_order(tstore);
        }
    }

    for(std::set<char*>::iterator itr
            = track_allocator::allocated_blocks.begin();
        itr != track_allocator::allocated_blocks.end();
        ++itr)
    {
        delete [] *itr;
    }
    track_allocator::allocated_blocks.clear();
    return boost::report_errors();
}