MemPool.h

/*
 * MemPool.h
 *
 *  Created on: 28 Oct 2015
 *      Author: hieu
 */

#pragma once

#include <algorithm>
#include <iostream>
#include <vector>
#include <stdint.h>
#include <stdlib.h>
#include <limits>
#include <iostream>

namespace Moses2
{

class MemPool
{
  struct Page {
    uint8_t *mem;
    uint8_t *end;
    size_t size;

    Page() {
    }
    Page(std::size_t size);
    ~Page();
  };

public:
  MemPool(std::size_t initSize = 10000);

  ~MemPool();

  uint8_t *Allocate(std::size_t size) {
    size = (size + 3) & 0xfffffffc;

    uint8_t *ret = current_;
    current_ += size;

    Page &page = *m_pages[m_currPage];
    if (current_ <= page.end) {
      // return what we got
    } else {
      ret = More(size);
    }
    return ret;

  }

  template<typename T>
  T *Allocate() {
    uint8_t *ret = Allocate(sizeof(T));
    return (T*) ret;
  }

  template<typename T>
  T *Allocate(size_t num) {
    uint8_t *ret = Allocate(sizeof(T) * num);
    return (T*) ret;
  }

  // re-use pool
  void Reset();

private:
  uint8_t *More(std::size_t size);

  std::vector<Page*> m_pages;

  size_t m_currSize;
  size_t m_currPage;
  uint8_t *current_;

  // no copying
  MemPool(const MemPool &);
  MemPool &operator=(const MemPool &);
};

////////////////////////////////////////////////////////////////////////////////////////////////
template<typename T>
class ObjectPoolContiguous
{

public:
  ObjectPoolContiguous(std::size_t initSize = 100000) :
    m_size(0), m_actualSize(initSize) {
    m_vec = (T*) malloc(sizeof(T) * initSize);
  }

  ~ObjectPoolContiguous() {
    free(m_vec);
  }

  void Add(T &obj) {
    if (m_size >= m_actualSize) {
      //std::cerr << std::endl << "MORE " << m_size << std::endl;
      m_actualSize *= 2;
      m_vec = (T*) realloc(m_vec, sizeof(T) * m_actualSize);

    }
    m_vec[m_size] = obj;
    ++m_size;
  }

  bool IsEmpty() const {
    return m_size == 0;
  }

  void Reset() {
    m_size = 0;
  }

  // vector op
  size_t GetSize() const {
    return m_size;
  }

  const T& operator[](size_t ind) const {
    return m_vec[ind];
  }

  // stack op
  const T &Get() const {
    return m_vec[m_size - 1];
  }

  void Pop() {
    --m_size;
  }

  T *GetData() {
    return m_vec;
  }

  template<typename ORDERER>
  void Sort(const ORDERER &orderer) {
    std::sort(m_vec, m_vec + m_size, orderer);
  }

private:
  T *m_vec;
  size_t m_size, m_actualSize;

  // no copying
  ObjectPoolContiguous(const ObjectPoolContiguous &);
  ObjectPoolContiguous &operator=(const ObjectPoolContiguous &);
};

//////////////////////////////////////////////////////////////////////////////////////////


}