mariadb-columnstore-engine/utils/common/poolallocator.cpp

/* Copyright (C) 2014 InfiniDB, Inc.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; version 2 of
   the License.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

/******************************************************************************************
* $Id$
*
******************************************************************************************/

#include <iostream>
//#define NDEBUG
#include <cassert>

#include "poolallocator.h"

using namespace std;
using namespace boost;

namespace utils
{

PoolAllocator& PoolAllocator::operator=(const PoolAllocator& v)
{
    allocSize = v.allocSize;
    tmpSpace = v.tmpSpace;
    deallocateAll();
    return *this;
}

void PoolAllocator::deallocateAll()
{
    capacityRemaining = 0;
    nextAlloc = NULL;
    memUsage = 0;
    mem.clear();
    oob.clear();
}

void PoolAllocator::newBlock()
{
    shared_array<uint8_t> next;

    capacityRemaining = allocSize;

    if (!tmpSpace || mem.size() == 0)
    {
        next.reset(new uint8_t[allocSize]);
        mem.push_back(next);
        nextAlloc = next.get();
    }
    else
        nextAlloc = mem.front().get();
}

void* PoolAllocator::allocate(uint64_t size)
{
    void* ret;

    if (size > allocSize)
    {
        OOBMemInfo memInfo;

        memUsage += size;
        memInfo.mem.reset(new uint8_t[size]);
        memInfo.size = size;
        ret = (void*) memInfo.mem.get();
        oob[ret] = memInfo;
        return ret;
    }

    if (size > capacityRemaining)
        newBlock();

    ret = (void*) nextAlloc;
    nextAlloc += size;
    capacityRemaining -= size;
    memUsage += size;
    return ret;
}

void PoolAllocator::deallocate(void* p)
{
    OutOfBandMap::iterator it = oob.find(p);

    if (it == oob.end())
        return;

    memUsage -= it->second.size;
    oob.erase(it);
}

}