/* -*- c++ -*- (enables emacs c++ mode) */
/*===========================================================================
 
 Copyright (C) 1995-2012 Yves Renard
 
 This file is a part of GETFEM++
 
 Getfem++  is  free software;  you  can  redistribute  it  and/or modify it
 under  the  terms  of the  GNU  Lesser General Public License as published
 by  the  Free Software Foundation;  either version 3 of the License,  or
 (at your option) any later version along with the GCC Runtime Library
 Exception either version 3.1 or (at your option) any later version.
 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 Lesser General Public
 License and GCC Runtime Library Exception for more details.
 You  should  have received a copy of the GNU Lesser General Public License
 along  with  this program;  if not, write to the Free Software Foundation,
 Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
 
 As a special exception, you  may use  this file  as it is a part of a free
 software  library  without  restriction.  Specifically,  if   other  files
 instantiate  templates  or  use macros or inline functions from this file,
 or  you compile this  file  and  link  it  with other files  to produce an
 executable, this file  does  not  by itself cause the resulting executable
 to be covered  by the GNU Lesser General Public License.  This   exception
 does not  however  invalidate  any  other  reasons why the executable file
 might be covered by the GNU Lesser General Public License.
 
===========================================================================*/

/**@file dal_basic.h
   @author  Yves Renard <Yves.Renard@insa-lyon.fr>
   @date June 01, 1995.
   @brief Dynamic array class.
*/
#ifndef DAL_BASIC_H__
#define DAL_BASIC_H__

/* *********************************************************************** */
/* Remarks for future improvements:                                        */
/*									   */
/* - For the moment, the allocation is made by new and delete[].           */
/*									   */
/* *********************************************************************** */

#include <vector>
#include "dal_config.h"

/// Dynamic Array Library
namespace dal
{
  template<class T, unsigned char pks = 5> class dynamic_array;
  
  /// Iterator class for dynamic array.
  template<class T, unsigned char pks> struct dna_iterator {
    typedef T             value_type;
    typedef value_type*   pointer;
    typedef value_type&   reference;
    typedef size_t        size_type;
    typedef ptrdiff_t     difference_type;
    typedef std::random_access_iterator_tag iterator_category;
    
#   define DNAMPKS__ ((size_type(1) << pks) - 1)
    dynamic_array<T,pks> *p;
    size_type in;
    pointer pT;
    
    dna_iterator(void) {}
    dna_iterator(dynamic_array<T,pks> &da, size_type ii)
      { p = &da; in = ii; pT = p->pt_to(in); }

    inline size_type index(void) const { return in; }
    /// next element.
    dna_iterator operator ++(int) {
      dna_iterator tmp = *this;
      if ((++in)&DNAMPKS__) pT++; else pT=p->pt_to(in); return tmp;
    }
    /// previous element.
    dna_iterator operator --(int) {
      dna_iterator tmp = *this;
      if ((in--)&DNAMPKS__) pT--; else pT=p->pt_to(in); return tmp;
    }
    /// next element.
    dna_iterator &operator ++()
      { if ((++in)&DNAMPKS__) pT++; else pT=p->pt_to(in); return *this; }
    /// previous element.
    dna_iterator &operator --()
      { if ((in--)&DNAMPKS__) pT--; else pT=p->pt_to(in); return *this; }
    /// go i elements forward.
    dna_iterator &operator +=(difference_type i)
      { in += i; pT=p->pt_to(in); return *this; }
    /// go i elements backward.
    dna_iterator &operator -=(difference_type i)
      { in -= i; pT=p->pt_to(in); return *this; }
    /// gives an iterator pointing i elements forward.
    dna_iterator operator +(difference_type i) const
      { dna_iterator it = *this; return (it += i); }
    /// gives an iterator pointing i elements backward.
    dna_iterator operator -(difference_type i) const
      { dna_iterator it = *this; return (it -= i); }
    /// Gives the difference, in term of elements between two iterators.
    difference_type operator -(const dna_iterator &i) const
      { return difference_type(in - i.in); }
    
    reference operator  *() const { return (*pT); }
    pointer   operator ->() const { return pT;    }
    reference operator [](size_type ii) const { return (*p)[in+ii]; }
    
    bool operator ==(const dna_iterator &i) const { return (i.in==in);}
    bool operator !=(const dna_iterator &i) const { return (i.in!=in);}
    bool operator < (const dna_iterator &i) const { return ( in<i.in);}
  };
  
  /// Constant iterator class for dynamic array.
  template<class T, unsigned char pks> struct dna_const_iterator {
    typedef T                  value_type;
    typedef const value_type*  pointer;
    typedef const value_type&  reference;
    typedef size_t             size_type;
    typedef ptrdiff_t          difference_type;
    typedef std::random_access_iterator_tag iterator_category;
    
#   define DNAMPKS__ ((size_type(1) << pks) - 1)
    const dynamic_array<T,pks> *p;
    size_type in;
    pointer pT;
    
    dna_const_iterator(void) {}
    dna_const_iterator(const dynamic_array<T,pks> &da, size_type ii)
      { p = &da; in = ii; pT = p->pt_to(in); }
    dna_const_iterator(const dna_iterator<T, pks> &it)
      : p(it.p), in(it.in), pT(it.pT) {}
    
    inline size_type index(void) const { return in; }
    dna_const_iterator operator ++(int) {
      dna_const_iterator tmp = *this;
      if ((++in)&DNAMPKS__) pT++; else pT=p->pt_to(in); return tmp;
    }
    dna_const_iterator operator --(int) {
      dna_const_iterator tmp = *this;
      if ((in--)&DNAMPKS__) pT--; else pT=p->pt_to(in); return tmp;
    }
    dna_const_iterator &operator ++()
      { if ((++in)&DNAMPKS__) pT++; else pT=p->pt_to(in); return *this; }
    dna_const_iterator &operator --()
      { if ((in--)&DNAMPKS__) pT--; else pT=p->pt_to(in); return *this; }
    dna_const_iterator &operator +=(difference_type i)
      { in += i; pT=p->pt_to(in); return *this; }
    dna_const_iterator &operator -=(difference_type i)
      { in -= i; pT=p->pt_to(in); return *this; }
    dna_const_iterator operator +(difference_type i) const
      { dna_const_iterator it = *this; return (it += i); }
    dna_const_iterator operator -(difference_type i) const
      { dna_const_iterator it = *this; return (it -= i); }
    difference_type operator -(const dna_const_iterator &i) const
      { return difference_type(in - i.in); }
    
    reference operator  *() const { return (*pT); }
    pointer   operator ->() const { return pT;    }
    reference operator [](size_type ii) const { return (*p)[in+ii]; }
    
    bool operator ==(const dna_const_iterator &i) const
      { return (i.in == in); }
    bool operator !=(const dna_const_iterator &i) const
      { return (i.in != in); }
    bool operator < (const dna_const_iterator &i) const
      { return (in < i.in); }
  };
  
  /**  Dynamic Array. Defines the basic container of the library which is 
   *  dal::dynamic_array<T, pks>. This container is virtually an
   * infinite array of element of type T. When a random acces tab[i] is
   * called, a control is made on i and an allocation is made if 
   * needed. The allocation is made by blocks of n elements, where
   * @f$n = 2^{pks}@f$. @f$pks@f$ is an optional parameter assumed to be 5.
   * The structure of this container is similar to the one of std::deque<T>
   * but with a faster random access.
   *
   *
   * <h3>Example of code</h3>
   *  If T is any type (with or without trivial constructor/destructor, 
   *  and with constructor T(0) and T(1)), the
   *  following code is valid:
   * @code
   *  #include<dal_basic.h>
   *  dal::dynamic_array<T> tab;
   *  tab[50] = T(0); // 51 elements in tab.
   *  std::fill(tab.begin(), tab.end(), T(0)); // 51 elements initialized
   *  dal::dynamic_array<T>::iterator it = tab.begin(); 
   *  dal::dynamic_array<T>::iterator ite = it + 50; 
   *  for( ; it != ite; ++it)
   *    { *it = T(1); } // only the 50 first elements are changed.
   * @endcode
   */
  template<class T, unsigned char pks> class dynamic_array {
  public :
    
    typedef T                    value_type;
    typedef value_type*          pointer;
    typedef const value_type*    const_pointer;
    typedef value_type&          reference;
    typedef const value_type&    const_reference;
    typedef size_t               size_type;
    typedef ptrdiff_t            difference_type;
    typedef unsigned char        pack_size_type;
    typedef std::vector<pointer> pointer_array;
    typedef dna_iterator<T, pks> iterator;
    typedef dna_const_iterator<T, pks> const_iterator;
    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
    typedef std::reverse_iterator<iterator> reverse_iterator;
    
  protected :
    
#   define DNAMPKS__ ((size_type(1) << pks) - 1)
    pointer_array array;
    pack_size_type ppks;   /* size of pointer packs (2^ppks).            */
    size_type m_ppks;      /* = (2^ppks) - 1.                            */
    size_type last_ind;    /* allocated = 0 .. last_ind-1.               */
    size_type last_accessed; /* valid = 0 .. last_accessed-1.            */
    
  public :
    
    /// Number of allocated elements.
    size_type size(void) const { return last_accessed; }
    size_type capacity(void) const { return last_ind; }
    size_type max_size(void) const { return (size_type(-1)) / 2; }
    /// True if no space is allocated.
    bool empty(void) const { return last_accessed == 0; }
    /// Iterator on the first element.
    iterator begin(void) { return iterator(*this, 0); }
    /// Constant iterator on the first element.
    const_iterator begin(void) const { return const_iterator(*this, 0); }
    /// Iterator on the last + 1 element.
    iterator end(void) { return iterator(*this, size()); }
    /// Constant iterator on the last + 1 element.
    const_iterator end(void) const
      { return const_iterator(*this, size()); }
    reverse_iterator rbegin(void) { return reverse_iterator(end()); }
    const_reverse_iterator rbegin(void) const
      { return const_reverse_iterator(end()); }
    reverse_iterator rend(void) { return reverse_iterator(begin()); }
    const_reverse_iterator rend(void) const
      { return const_reverse_iterator(begin()); }
    
    reference front(void) { return *begin(); }
    const_reference front(void) const { return *begin(); }
    reference back(void) { return *(end() - 1); }
    const_reference back(void) const { return *(end() - 1); }
    
    void swap(dynamic_array<T,pks> &da);
    /// Clear and desallocate all the elements.
    void clear(void);
    dynamic_array<T,pks> &operator =(const dynamic_array<T,pks> &da);
    
  protected:
    
    void init(void)
      { last_accessed = last_ind = 0; array.resize(8); ppks = 3; m_ppks = 7; }
    
    
  public:
    
    dynamic_array(const dynamic_array<T,pks> &da) { init(); *this = da; }
    dynamic_array(void) { init(); }
    ~dynamic_array(void) { clear(); }
    inline pointer pt_to(size_type ii) /* used by iterators.             */
      { return (ii >=last_ind) ? NULL : &((array[ii>>pks])[ii&DNAMPKS__]); }
    inline const_pointer pt_to(size_type ii) const
      { return (ii >=last_ind) ? NULL : &((array[ii>>pks])[ii&DNAMPKS__]); }
    
    /// Gives a constant reference on element ii.
    const_reference operator [](size_type ii) const;
    /// Gives a reference on element ii.
    reference operator [](size_type ii);
    void resize(size_type i) { (*this)[i-1]; }
    
    /// Gives the total memory occupied by the array.
    size_type memsize(void) const {
      return sizeof(pointer) * array.capacity()
	+ last_ind*sizeof(T) + sizeof(dynamic_array<T,pks>);
    }
    
    /// Swap element i1 and i2.
    void swap(size_type i1, size_type i2)
      { std::swap((*this)[i1], (*this)[i2]); }
  };

  
  /* ********************************************************************* */
  /* Menbers functions							   */
  /* ********************************************************************* */


  template<class T, unsigned char pks>
  void dynamic_array<T,pks>::swap(dynamic_array<T,pks> &da) {
    array.swap(da.array); 
    std::swap(last_ind, da.last_ind);
    std::swap(last_accessed, da.last_accessed);
    std::swap(ppks, da.ppks); std::swap(m_ppks, da.m_ppks);
  }
  
  template<class T, unsigned char pks>
  void dynamic_array<T,pks>::clear(void) { 
    typename pointer_array::iterator it  = array.begin();
    typename pointer_array::iterator ite = it+ ((last_ind + DNAMPKS__) >> pks);
    while (it != ite) delete[] *it++;
    array.clear(); init();
  }
  
  template<class T, unsigned char pks> dynamic_array<T,pks>
  &dynamic_array<T,pks>::operator = (const dynamic_array<T,pks> &da) {
    clear(); /* evitable ... ? */
    array.resize(da.array.size());
    last_ind = da.last_ind;
    last_accessed = da.last_accessed;
    ppks = da.ppks; m_ppks = da.m_ppks;
    typename pointer_array::iterator it = array.begin();
    typename pointer_array::const_iterator ita = da.array.begin();
    typename pointer_array::iterator ite = it+ ((last_ind + DNAMPKS__) >> pks);
    while (it != ite) {
      register pointer p = *it++ = new T[DNAMPKS__+1];
      register pointer pe = p + (DNAMPKS__+1);
      register const_pointer pa = *ita++;
      while (p != pe) *p++ = *pa++;
    }
    return *this;
  }

  template<class T, unsigned char pks> 
    typename dynamic_array<T,pks>::const_reference
      dynamic_array<T,pks>::operator [](size_type ii) const { 
    static T *f = NULL;
    if (f == NULL) { f = new T(); }
    return (ii<last_ind) ? (array[ii>>pks])[ii&DNAMPKS__] : *f;
  }

  template<class T, unsigned char pks> typename dynamic_array<T,pks>::reference
    dynamic_array<T,pks>::operator [](size_type ii) {
    if (ii >= last_accessed) {
      GMM_ASSERT2(ii < INT_MAX, "out of range");
      
      last_accessed = ii + 1;
      if (ii >= last_ind) {
	if ((ii >> (pks+ppks)) > 0) {
	  while ((ii >> (pks+ppks)) > 0) ppks++; 
	  array.resize(m_ppks = (size_type(1) << ppks)); m_ppks--;
	}
	for (size_type jj = (last_ind >> pks); ii >= last_ind;
	     jj++, last_ind += (DNAMPKS__ + 1))
	  { array[jj] = new T[DNAMPKS__ + 1]; }
      }
    }
    return (array[ii >> pks])[ii & DNAMPKS__];
  }


  /* ********************************************************************* */
  /* Templates functions					      	   */
  /* ********************************************************************* */

  template<class T, unsigned char pks>
    bool operator==(const dynamic_array<T,pks> &x,
		    const dynamic_array<T,pks> &y) {
    typename dynamic_array<T,pks>::const_iterator itxb=x.begin(), itxe=x.end();
    typename dynamic_array<T,pks>::const_iterator ityb=y.begin(), itye=y.end();
    typename dynamic_array<T,pks>::size_type d = std::min(itxe-itxb,itye-ityb);
    typename dynamic_array<T,pks>::const_iterator itxc = itxb+d, ityc = ityb+d;

    if  (!std::equal(itxb, itxc, ityb)) return false;
    for (; itxc != itxe; itxc++) if (*itxc != T()) return false;
    for (; ityc != itye; ityc++) if (*ityc != T()) return false;
    return true;
  }

  template<class T, unsigned char pks> 
    bool operator < (const dynamic_array<T,pks> &x,
		     const dynamic_array<T,pks> &y)
  { return std::lexicographical_compare(x.begin(),x.end(),y.begin(),y.end()); }

  template<class T, unsigned char pks> inline
    void swap(const dynamic_array<T,pks> &x, const dynamic_array<T,pks> &y)
  { x.swap(y); }


  /** 
   *  A very simple pointer collection
   *  which destroys the content of its pointers 
   */
  template<class T> class ptr_collection : public std::vector<T*> {
  public:
    typedef typename std::vector<T*>::size_type size_type;
    typedef typename std::vector<T*>::iterator iterator;
    typedef typename std::vector<T*>::const_iterator const_iterator;
    ptr_collection() : std::vector<T*>() {}
    ptr_collection(size_type sz) : std::vector<T*>(sz) { std::fill(this->begin(),this->end(),0); }
    ~ptr_collection() { for (iterator i=this->begin(); i != this->end(); ++i) { if (*i) delete *i; *i = 0; } }
  };

}
#endif /* DAL_BASIC_H__  */
