dht.hpp

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/*
 * $Id: dht.hpp 293 2012-12-17 20:27:36Z jdl3 $
 * Copyright (C) 2012 John D Lamb
 *
 * 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; either version 2 of the License, 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
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
#ifndef CCGSL_DHT_HPP
#define CCGSL_DHT_HPP
 
#include<new>
#include<exception>
#include<gsl/gsl_dht.h>
 
namespace gsl {
  class dht {
  public:
    dht(){
      ccgsl_pointer = 0;
      count = 0; // initially nullptr will do
    }
    // Refines random access container
    // Refines assignable
    explicit dht( size_t const size ){
      ccgsl_pointer = gsl_dht_alloc( size );
      // just plausibly we could allocate dht but not count
      try { count = new size_t; } catch( std::bad_alloc& e ){
    // try to tidy up before rethrowing
    gsl_dht_free( ccgsl_pointer );
    throw e;
      }
      *count = 1; // initially there is just one reference to ccgsl_pointer
    }
    dht( size_t size, double nu, double xmax ){
      ccgsl_pointer = gsl_dht_new( size, nu, xmax );
      // just plausibly we could allocate dht but not count
      try { count = new size_t; } catch( std::bad_alloc& e ){
    // try to tidy up before rethrowing
    gsl_dht_free( ccgsl_pointer );
    throw e;
      }
      *count = 1; // initially there is just one reference to ccgsl_pointer
    }
 
    explicit dht( gsl_dht* v ){
      ccgsl_pointer = v;
      // just plausibly we could fail to allocate count: no further action needed.
      count = new size_t;
      *count = 1; // initially there is just one reference to ccgsl_pointer
    }
    // copy constructor
    dht( dht const& v ){ ccgsl_pointer = v.ccgsl_pointer;
      count = v.count; if( count != 0 ) ++*count; }
    // assignment operator
    dht& operator=( dht const& v ){
      // first, possibly delete anything pointed to by this
      if( count == 0 or --*count == 0 ){
    if( ccgsl_pointer != 0 ) gsl_dht_free( ccgsl_pointer );
    delete count;
      } // Then copy
      ccgsl_pointer = v.ccgsl_pointer; count = v.count; if( count != 0 ) ++*count; return *this;
    }
    // destructor
    ~dht(){
      if( count == 0 or --*count == 0 ){
    // could have allocated null pointer
    if( ccgsl_pointer != 0 ) gsl_dht_free( ccgsl_pointer );
    delete count;
      }
    }
#ifdef __GXX_EXPERIMENTAL_CXX0X__
    dht( dht&& v ) : ccgsl_pointer( v.ccgsl_pointer ), count( nullptr ){
      std::swap( count, v.count );
      v.ccgsl_pointer = nullptr;
    }
    dht& operator=( dht&& v ){
      dht( std::move( v ) ).swap( *this );
      return *this;
    }
#endif
    // Refines equality comparable
    // == operator
    bool operator==( dht const& v ) const { return ccgsl_pointer == v.ccgsl_pointer; }
    // != operator
    bool operator!=( dht const& v ) const { return not operator==( v ); }
    // Refines forward container
    // Refines less than comparable
    // operator<
    bool operator<( dht const& v ) const { return ccgsl_pointer < v.ccgsl_pointer; }
    // operator>
    bool operator>( dht const& v ) const { return ccgsl_pointer > v.ccgsl_pointer; }
    // operator<=
    bool operator<=( dht const& v ) const { return ccgsl_pointer <= v.ccgsl_pointer; }
    // operator>=
    bool operator>=( dht const& v ) const { return ccgsl_pointer >= v.ccgsl_pointer; }
    bool empty() const { return ccgsl_pointer == 0; }
    // swap() --- should work even if sizes don't match
    void swap( dht& v ){
      std::swap( ccgsl_pointer, v.ccgsl_pointer );
      std::swap( count, v.count );
    }
  private:
    gsl_dht* ccgsl_pointer;
    size_t* count;
  public:
    // shared reference functions
    gsl_dht* get() const { return ccgsl_pointer; }
    bool unique() const { return count != 0 and *count == 1; }
    size_t use_count() const { return count == 0 ? 0 : *count; }
#ifdef __GXX_EXPERIMENTAL_CXX0X__
    explicit
#endif
    operator bool() const { return ccgsl_pointer != 0; }
 
    int init( double nu, double xmax ){ return gsl_dht_init( get(), nu, xmax ); }
 
    double x_sample( int n ) const { return gsl_dht_x_sample( get(), n ); }
 
    double k_sample( int n ) const { return gsl_dht_k_sample( get(), n ); }
 
    int apply( double* f_in, double* f_out ) const {
      return gsl_dht_apply( get(), f_in, f_out ); }
    
    template<typename ARRAY>
    int apply( ARRAY& f_in, ARRAY& f_out ) const {
      size_t n = get()->size;
      if( f_in.size() != n )
    throw std::length_error("gsl::dht::apply(): f_in must have same size as *this.");
      if( f_out.size() != n )
    throw std::length_error("gsl::dht::apply(): f_out must have same size as *this.");
      return gsl_dht_apply( get(), f_in.data(), f_out.data() ); }
 
  };
}
#endif