SF_vector.h

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// SPDX-FileCopyrightText: Copyright (c) NumeriCor GmbH
// SPDX-License-Identifier: Apache-2.0
 
#ifndef _SF_VECTOR_H
#define _SF_VECTOR_H
 
#include <iterator>
#include <cstring>
 
namespace SF {
 
template <class T>
class vector
{
public:
  vector(): _data(NULL), _capacity(0), _size(0)
  {}
 
  vector(size_t n): _data(NULL), _capacity(0), _size(0)
  {
    this->resize(n);
  }
 
  vector(size_t n, const T val): _data(NULL), _capacity(0), _size(0)
  {
    this->assign(n, val);
  }
 
  vector(const vector<T> &vec): _data(NULL), _capacity(0), _size(0)
  {
    this->assign(vec.begin(), vec.end());
  }
 
  virtual ~vector()
  {
    delete [] _data;
  }
 
  inline const T& operator[](size_t i) const
  {
    return _data[i];
  }
 
  inline T& operator[](size_t i)
  {
    return _data[i];
  }
 
  inline void operator= (const vector<T> & vec)
  {
    this->assign(vec.begin(), vec.end());
  }
 
  inline T* data()
  {
    return _data;
  }
 
  inline const T* data() const
  {
    return _data;
  }
 
 
  inline size_t size() const
  {
    return _size;
  }
 
  inline size_t capacity() const
  {
    return _capacity;
  }
 
  inline const T* begin() const
  {
    return _data;
  }
 
  inline T* begin()
  {
    return _data;
  }
 
  inline const T* end() const
  {
    return _data + _size;
  }
 
  inline T* end()
  {
    return _data + _size;
  }
 
  T& front()
  {
      return _data[0];
  }
 
  T& back()
  {
      return _data[_size - 1];
  }
 
  const T& front() const
  {
      return _data[0];
  }
 
  const T& back() const
  {
      return _data[_size - 1];
  }
 
  template<class InputIterator>
  inline void assign(InputIterator s, InputIterator e)
  {
    long int n = std::distance(s, e);
    assert(n >= 0);
 
    // realloc if necessary
    if ( ((long int)_capacity) < n) {
      delete [] _data;
      _data = new T[n];
      _capacity = n;
    }
 
    // copy data
    size_t idx = 0;
    while(s != e) {
      _data[idx++] = *s;
      ++s;
    }
 
    _size = n;
  }
 
  inline void assign(size_t n, T val = T()) {
    if (_capacity < n) {
      if(_size > 0) delete [] _data;
      _data = new T[n];
      _capacity = n;
    }
 
    for (size_t i = 0; i < n; i++) _data[i] = val;
    _size = n;
  }
 
  inline void assign(size_t n, T* array, bool del) {
    if (del) delete [] _data;
    _data = array;
    _size = n;
    _capacity = n;
  }
 
  inline void resize(size_t n)
  {
    if(_capacity < n)
    {
      if(_size > 0) {
        T* buf = _data;
        _data = new T[n];
        for (size_t i = 0; i < _size; i++) _data[i] = buf[i];
        delete [] buf;
      }
      else {
        _data = new T[n];
      }
      _capacity = n;
    }
    _size = n;
  }
 
  inline void resize(size_t n, const T val)
  {
    size_t oldsize = this->size();
    this->resize(n);
 
    if(n > oldsize) {
      T*     out = _data + oldsize;
      size_t num = n - oldsize;
 
      for (size_t i = 0; i < num; i++) out[i] = val;
    }
  }
 
  void reserve(size_t n)
  {
    size_t osize = _size;
    this->resize(n);
    this->resize(osize);
  }
 
  void zero()
  {
    if(_size != 0) memset(_data, 0, _size * sizeof(T));
  }
 
  inline void reallocate()
  {
    _capacity = _size;
    T* buf = _data;
    _data = new T[_size];
    for (size_t i = 0; i < _size; i++) _data[i] = buf[i];
    delete [] buf;
  }
 
  template<class InputIterator>
  inline void append(InputIterator s, InputIterator e)
  {
    size_t addsize = std::distance(s, e);
    size_t oldsize = _size;
 
    this->resize(oldsize + addsize);
 
    // copy data
    size_t idx = 0;
    while(s != e) {
      _data[oldsize + idx++] = *s;
      ++s;
    }
  }
 
  T & push_back(T val)
  {
    if(_capacity > _size)
    {
      _data[_size] = val;
      _size++;
    }
    else {
      // if current capacity is not larger than size + 1 we reallocate, but keep size to
      // old value plus one.
      size_t newcap = _capacity > 0 ? _capacity * 2 : 1;
      size_t cursize = _size;
      this->resize(newcap);
      _data[cursize] = val;
      _size = cursize + 1;
    }
    return _data[_size-1];
  }
private:
  T* _data;         
  size_t _capacity; 
  size_t _size;     
 
};
 
template<class T>
inline void dsp_from_cnt(const vector<T> & cnt, vector<T> & dsp)
{
  dsp.resize(cnt.size()+1);
  dsp[0] = 0;
  for(size_t i=0; i<cnt.size(); i++) dsp[i+1] = dsp[i] + cnt[i];
}
 
template<class T>
inline void cnt_from_dsp(const vector<T> & dsp, vector<T> & cnt)
{
  cnt.resize(dsp.size() - 1);
  for(size_t i=0; i<dsp.size()-1; i++) cnt[i] = dsp[i+1] - dsp[i];
}
 
template<class T, class S>
inline void count(const vector<T> & data, vector<S> & cnt)
{
  cnt.zero();
  for(size_t i=0; i<data.size(); i++) cnt[data[i]]++;
}
 
template<class T>
inline T sum(const vector<T> & vec)
{
  T sum = 0;
  for(size_t i=0; i<vec.size(); i++) sum += vec[i];
  return sum;
}
 
 
template<class T>
inline void interval(vector<T> & vec, size_t start, size_t end)
{
  vec.resize(end - start);
  for(size_t i=0; i<vec.size(); i++) vec[i] = start + i;
}
 
template<class T>
inline void divide(const size_t gsize, const size_t num_parts, vector<T> & loc_sizes)
{
  // initialize the distribution to gsize / size
  loc_sizes.assign(size_t(num_parts), T(gsize/num_parts));
 
  // then we evenly distribute the remainder of the division
  for(size_t i=0; i<size_t(gsize % num_parts); i++) loc_sizes[i]++;
}
 
 
template<class S, class V>
inline void vec_assign(S* lhs, const V* rhs, size_t size)
{
  for(size_t i=0; i<size; i++) lhs[i] = (S)rhs[i];
}
 
template<class T>
inline bool isEmpty(vector<T> & v)
{
  bool ret = true;
  for(size_t i=0; i<v.size(); i++)
    if(v[i] != T(0)) {ret = false; break;}
 
  return ret;
}
 
 
}
 
#endif