Array1.hpp

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// Copyright (c) 2011 Michael D. Adams
// All rights reserved.

// __START_OF_LICENSE__
// 
// Copyright (c) 2015 Michael D. Adams
// All rights reserved.
// 
// This file is part of the Signal Processing Library (SPL).
// 
// 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 3,
// 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; see the file LICENSE.  If not,
// see <http://www.gnu.org/licenses/>.
// 
// __END_OF_LICENSE__

#ifndef SPL_Array1_hpp
#define SPL_Array1_hpp

//

//#define SPL_ARRAY1_DEBUG

#if defined(SPL_ARRAY1_DEBUG)
#define SPL_ARRAY1_INLINE
#else
#define SPL_ARRAY1_INLINE inline
#endif

// Header Files.

#include <SPL/config.hpp>
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <vector>
#include <cassert>
#include <algorithm>
#include <functional>
#include <iterator>
#include <numeric>
#include <SPL/misc.hpp>

//

namespace SPL {

// One-Dimensional Array Template Class
// (with lazy copying and reference counting)

template <class> class Array1;


/*
 * An array data block, which can be shared by multiple arrays.
 */

template <class T>
class ArrayRep1
{
private:

        template <class> friend class Array1;

        ArrayRep1(int size);

        ArrayRep1(int size, const T& value);

        template <class InputIterator>
        ArrayRep1(int size, InputIterator data);

        ~ArrayRep1();

        // Prevent copy construction.
        // This function is never defined.
        ArrayRep1(const ArrayRep1&);

        // Prevent copy assignment.
        // This function is never defined.
        ArrayRep1& operator=(const ArrayRep1&);

        // Create a copy of this data block.
        ArrayRep1* clone() const;

        // Get the reference count for the underlying data.
        int getRefCount() const;

        // Increment the reference count for the underlying data.
        void hold();

        // Decrement the reference count for the underlying data, deallocating
        // the underlying data if the reference count reaches zero.
        void release();

        // The array data.
        std::vector<T> data_;

        // The number of arrays referencing the array data.
        int refCount_;
};


template <class T>
class Array1
{
public:

        // Types

        typedef T ElemType;

        typedef typename std::vector<T>::iterator Iterator;

        typedef typename std::vector<T>::const_iterator ConstIterator;

        // Constructors and destructor

        Array1();

        explicit Array1(int size);

        Array1(int size, const T& value);

        template <class InputIterator>
        Array1(int size, InputIterator data);

        Array1(const Array1& a);

        template<class OtherType>
        Array1(const Array1<OtherType>& a);

        ~Array1();

        // Assignment operators

        Array1& operator=(const Array1& a);

        template<class OtherType>
        Array1<T>& operator=(const Array1<OtherType>& a);

        // Compound assignment operators

        Array1& operator+=(const Array1& a);

        Array1& operator-=(const Array1& a);

        Array1& operator*=(const Array1& a);

        Array1& operator/=(const Array1& a);

        Array1& operator+=(const T& value);

        Array1& operator-=(const T& value);

        Array1& operator*=(const T& value);

        Array1& operator/=(const T& value);

        // Basic queries

        int getSize() const;

    bool isShared() const;

    bool isSharedWith(const Array1& a) const;

        // Accessors

        T& operator()(int i);

        const T& operator()(int i) const;

        // Iterators

        ConstIterator begin() const;

        Iterator begin();

        ConstIterator end() const;

        Iterator end();

        // Array resizing

        void resize(int size);

        template <class InputIterator>
        void resize(int size, InputIterator data);

        // Get various statistics

        T max() const;

        T min() const;

        T sum() const;

        // Input/output

        std::ostream& output(std::ostream& out, int fieldWidth) const;

        int load(const char* fileName);

        int save(const char* fileName) const;

        // Miscellaneous

        void fill(const T& value = T(0));

        void swap(Array1& a);

        void dump(std::ostream& out) const;

private:

        template <class> friend class Array1;
        typedef ArrayRep1<T> Rep;

        // Get the reference count for the underlying data.
        int getRefCount() const;

        // Force the underlying data to be copied if the data is shared.
        void unshare() const;

        // Force the underlying data to be copied.
        // The data is assumed to be shared.
        void copyOnWrite() const;

        // The underlying data.
        mutable Rep* ptr_;
};

// Code for the ArrayRep1 class


template <class T>
SPL_ARRAY1_INLINE int ArrayRep1<T>::getRefCount() const
{
        return refCount_;
}

template <class T>
SPL_ARRAY1_INLINE void ArrayRep1<T>::hold()
{
        ++refCount_;
}

template <class T>
SPL_ARRAY1_INLINE void ArrayRep1<T>::release()
{
        if (--refCount_ == 0) {
                delete this;
        }
}

template <class T>
SPL_ARRAY1_INLINE ArrayRep1<T>::ArrayRep1(int size) : data_(size),
  refCount_(1)
{
        assert(size >= 0);
}

template <class T>
SPL_ARRAY1_INLINE ArrayRep1<T>::ArrayRep1(int size, const T& value) : data_(size, value),
  refCount_(1)
{
        assert(size >= 0);
}

template <class T>
template <class InputIterator>
SPL_ARRAY1_INLINE ArrayRep1<T>::ArrayRep1(int size, InputIterator data) :
  data_(), refCount_(1)
{
        assert(size >= 0);
        data_.reserve(size);
        SPL::copy_n(data, size, std::back_inserter(data_));
        assert(data_.size() == size);
}

template <class T>
SPL_ARRAY1_INLINE ArrayRep1<T>::~ArrayRep1()
{
        assert(!refCount_);
}

template <class T>
SPL_ARRAY1_INLINE ArrayRep1<T>* ArrayRep1<T>::clone() const
{
        return new ArrayRep1(data_.size(), data_.begin());
}


// Constructors and destructor

template <class T>
SPL_ARRAY1_INLINE Array1<T>::Array1()
{
        ptr_ = new Rep(0);
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::default_ctor() "
          << "["
          << this << " "
          << ptr_
          << "]"
          << "\n";
#endif
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>::Array1(int size)
{
        ptr_ = new Rep(size);
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::ctor(" << size << ") "
          << "["
          << this << " "
          << ptr_
          << "]"
          << "\n";
#endif
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>::Array1(const Array1<T>& a)
{
        ptr_ = a.ptr_;
        ptr_->hold();
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::copy_ctor(" << (&a) << ") "
          << "["
          << this << " "
          << ptr_
          << "]"
          << "\n";
#endif
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>::Array1(int size, const T& value)
{
        ptr_ = new Rep(size, value);
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::ctor(" << size << ", " << value << ") "
          << "["
          << this << " "
          << ptr_
          << "]"
          << "\n";
#endif
}

template <class T>
template <class InputIterator>
SPL_ARRAY1_INLINE Array1<T>::Array1(int size, InputIterator data)
{
        ptr_ = new Rep(size, data);
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::ctor(" << size << ", " << "InputIterator" << ") "
          << "["
          << this << " "
          << ptr_
          << "]"
          << "\n";
#endif
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>::~Array1()
{
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::dtor() "
          << "["
          << this << " "
          << ptr_
          << "]"
          << "\n";
#endif
        ptr_->release();
}

template <class T>
template <class OtherType>
SPL_ARRAY1_INLINE Array1<T>::Array1(const Array1<OtherType>& a)
{
        ptr_ = new Rep(a.getSize(), a.begin());
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "pseudo_copy_ctor(" << this << ") "
          << this << " " << ptr_ << "\n";
#endif
}

// Assignment operators

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator=(const Array1<T>& a)
{
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::operator=(" << (&a) << ") "
          << "["
          << this << " " << ptr_ << " "
          << (&a) << " " << a.ptr_ << ""
          << "]"
          << "\n";
#endif
        if (this != &a) {
                ptr_->release();
                ptr_ = a.ptr_;
                ptr_->hold();
        }
        return *this;
}

template <class T>
template <class OtherType>
Array1<T>& Array1<T>::operator=(const Array1<OtherType>& a)
{
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "Array1::operator= special\n";
#endif
        if (reinterpret_cast<void*>(this) != reinterpret_cast<const void*>(&a)) {
                resize(a.getSize());
                unshare();
                std::copy(a.ptr_->data_.begin(), a.ptr_->data_.end(),
                  ptr_->data_.begin());
        }
        return *this;
}

// Compound assignment operators

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator+=(const Array1<T>& a)
{
        assert(getSize() == a.getSize());
        unshare();
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          a.ptr_->data_.begin(), ptr_->data_.begin(), std::plus<T>());
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator-=(const Array1<T>& a)
{
        assert(getSize() == a.getSize());
        unshare();
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          a.ptr_->data_.begin(), ptr_->data_.begin(), std::minus<T>());
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator*=(const Array1<T>& a)
{
        assert(getSize() == a.getSize());
        unshare();
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          a.ptr_->data_.begin(), ptr_->data_.begin(), std::multiplies<T>());
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator/=(const Array1<T>& a)
{
        assert(getSize() == a.getSize());
        unshare();
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          a.ptr_->data_.begin(), ptr_->data_.begin(), std::divides<T>());
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator+=(const T& value)
{
        unshare();
#if 0
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), std::bind2nd(std::plus<T>(), value));
#else
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), [=](auto x){return x + value;});
#endif
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator-=(const T& value)
{
        unshare();
#if 0
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), std::bind2nd(std::minus<T>(), value));
#else
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), [=](auto x){return x - value;});
#endif
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator*=(const T& value)
{
        unshare();
#if 0
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), std::bind2nd(std::multiplies<T>(), value));
#else
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), [=](auto x){return x * value;});
#endif
        return *this;
}

template <class T>
SPL_ARRAY1_INLINE Array1<T>& Array1<T>::operator/=(const T& value)
{
        unshare();
#if 0
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), std::bind2nd(std::divides<T>(), value));
#else
        std::transform(ptr_->data_.begin(), ptr_->data_.end(),
          ptr_->data_.begin(), [=](auto x){return x / value;});
#endif
        return *this;
}

// Basic queries

template <class T>
SPL_ARRAY1_INLINE int Array1<T>::getSize() const
{
        return ptr_->data_.size();
}

template <class T>
SPL_ARRAY1_INLINE bool Array1<T>::isShared() const
{
        return ptr_->getRefCount() > 1;
}

template <class T>
SPL_ARRAY1_INLINE bool Array1<T>::isSharedWith(const Array1& a) const
{
        return ptr_ == a.ptr_;
}

// Accessors

template <class T>
SPL_ARRAY1_INLINE T& Array1<T>::operator()(int i)
{
        assert(i >= 0 && i < getSize());
        unshare();
        return ptr_->data_[i];
}

template <class T>
SPL_ARRAY1_INLINE const T& Array1<T>::operator()(int i) const
{
        assert(i >= 0 && i < getSize());
        return ptr_->data_[i];
}

// Iterators

template <class T>
SPL_ARRAY1_INLINE typename Array1<T>::Iterator Array1<T>::begin()
{
        unshare();
        return ptr_->data_.begin();
}

template <class T>
SPL_ARRAY1_INLINE typename Array1<T>::Iterator Array1<T>::end()
{
        unshare();
        return ptr_->data_.end();
}

template <class T>
SPL_ARRAY1_INLINE typename Array1<T>::ConstIterator Array1<T>::begin() const
{
        return ptr_->data_.begin();
}

template <class T>
SPL_ARRAY1_INLINE typename Array1<T>::ConstIterator Array1<T>::end() const
{
        return ptr_->data_.end();
}

// Resizing

template <class T>
void Array1<T>::resize(int size)
{
        assert(size >= 0);
        if (getSize() != size) {
                ptr_->release();
                ptr_ = new Rep(size);
        }
}

template <class T>
template <class InputIterator>
void Array1<T>::resize(int size, InputIterator data)
{
        assert(size >= 0);
        if (getSize() == size && ptr_->getRefCount() == 1) {
                SPL::copy_n(data, size, ptr_->data_.begin());
        } else {
                ptr_->release();
                ptr_ = new Rep(size, data);
        }
}

// Get various statistics

template<class T>
SPL_ARRAY1_INLINE T Array1<T>::max() const
{
        assert(getSize() > 0);
        return *std::max_element(begin(), end());
}

template<class T>
SPL_ARRAY1_INLINE T Array1<T>::min() const
{
        assert(getSize() > 0);
        return *std::min_element(begin(), end());
}

template<class T>
SPL_ARRAY1_INLINE T Array1<T>::sum() const
{
        return std::accumulate(begin(), end(), T(0));
}

// Input/output

template<class T>
std::ostream& Array1<T>::output(std::ostream& out, int fieldWidth) const
{
        out << getSize() << "\n";
        for (int i = 0; i < getSize(); ++i) {
                T val = operator()(i);
                std::stringstream str;
                str << std::setw(fieldWidth) << val;
                std::string buf = str.str();
                if (buf.size() > fieldWidth) {
                        buf = buf.substr(0, fieldWidth);
                }
                out << buf;
                if (i < getSize() - 1) {
                        out << " ";
                }
        }
        out << "\n";
        return out;
}

template<class T>
int Array1<T>::load(const char* fileName)
{
        std::ifstream in(fileName);
        in >> *this;
        if (!in) {
                return -1;
        }
        return 0;
}

template<class T>
int Array1<T>::save(const char* fileName) const
{
        std::ofstream out(fileName);
        out << *this;
        if (!out) {
                return -1;
        }
        out.close();
        return 0;
}

template <class T>
std::ostream& operator<<(std::ostream& out, const Array1<T>& a)
{
        out << a.getSize() << " ";
        typename Array1<T>::ConstIterator dataIter = a.begin();
        for (int i = 0; i < a.getSize(); ++i) {
                if (i) {
                        out << " ";
                }
                out << *dataIter;
                ++dataIter;
        }
//      out << " ";
        return out;
}

template<class T>
std::istream& operator>>(std::istream& in, Array1<T>& a)
{
        int size;
        in >> size;
        if (!in) {
                return in;
        }
        a.resize(size);
        for (int i = 0; i < a.getSize(); ++i) {
                T value;
                in >> value;
                if (!in) {
                        return in;
                }
                a(i) = value;
        }
        return in;
}

// Miscellaneous

template <class T>
SPL_ARRAY1_INLINE void Array1<T>::swap(Array1<T>& a)
{
        if (this != &a) {
                // Both reference counts increase and then decrease, for no
                // overall net change.
                std::swap(ptr_, a.ptr_);
        }
}

template <class T>
SPL_ARRAY1_INLINE void Array1<T>::fill(const T& value)
{
        unshare();
        std::fill(begin(), end(), value);
}

template<class T>
bool operator==(const Array1<T>& a, const Array1<T>& b)
{
        if (a.getSize() != b.getSize()) {
                return false;
        } else {
                if (a.isSharedWith(b)) {
                        return true;
                }
                return std::equal(a.begin(), a.end(), b.begin());
        }
}

template<class T>
SPL_ARRAY1_INLINE bool operator!=(const Array1<T>& a, const Array1<T>& b)
{
        return !(a == b);
}

template<class T>
void Array1<T>::dump(std::ostream& out) const
{
        out
          << "refCount=" << ptr_->getRefCount() << " "
          << "size=" << getSize() << "\n";
}

// Private code

template <class T>
SPL_ARRAY1_INLINE void Array1<T>::copyOnWrite() const
{
#if defined(SPL_ARRAY1_DEBUG)
        std::cerr << "copyOnWrite "
          << "["
          << this << " "
          << ptr_ << " "
          << ptr_->getRefCount()
          << "]"
          << "\n";
        std::cerr << "copied array size " << getSize() << "\n";
#endif
        assert(ptr_->getRefCount() > 1);
        ptr_->release();
        //const_cast<Array1*>(this)->ptr_ = ptr_->clone();
        this->ptr_ = ptr_->clone();
}

template <class T>
SPL_ARRAY1_INLINE void Array1<T>::unshare() const
{
        if (ptr_->getRefCount() > 1) {
                copyOnWrite();
        }
}

// Basic types

typedef Array1<double> RealArray1;

typedef Array1<int> IntArray1;

//

}

#endif