Eigen/src/SparseCore/CompressedStorage.h - eigen/fuchsia - Git at Google

 // This file is part of Eigen, a lightweight C++ template library
 // for linear algebra.
 //
 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
 //
 // This Source Code Form is subject to the terms of the Mozilla
 // Public License v. 2.0. If a copy of the MPL was not distributed
 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

 #ifndef EIGEN_COMPRESSED_STORAGE_H
 #define EIGEN_COMPRESSED_STORAGE_H

 namespace Eigen {

 namespace internal {

 /** \internal
   * Stores a sparse set of values as a list of values and a list of indices.
   *
   */
 template<typename _Scalar,typename _Index>
 class CompressedStorage
 {
   public:

     typedef _Scalar Scalar;
     typedef _Index Index;

   protected:

     typedef typename NumTraits<Scalar>::Real RealScalar;

   public:

     CompressedStorage()
       : m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
     {}

     CompressedStorage(size_t size)
       : m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
     {
       resize(size);
     }

     CompressedStorage(const CompressedStorage& other)
       : m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
     {
       *this = other;
     }

     CompressedStorage& operator=(const CompressedStorage& other)
     {
       resize(other.size());
       internal::smart_copy(other.m_values,  other.m_values  + m_size, m_values);
       internal::smart_copy(other.m_indices, other.m_indices + m_size, m_indices);
       return *this;
     }

     void swap(CompressedStorage& other)
     {
       std::swap(m_values, other.m_values);
       std::swap(m_indices, other.m_indices);
       std::swap(m_size, other.m_size);
       std::swap(m_allocatedSize, other.m_allocatedSize);
     }

     ~CompressedStorage()
     {
       delete[] m_values;
       delete[] m_indices;
     }

     void reserve(size_t size)
     {
       size_t newAllocatedSize = m_size + size;
       if (newAllocatedSize > m_allocatedSize)
         reallocate(newAllocatedSize);
     }

     void squeeze()
     {
       if (m_allocatedSize>m_size)
         reallocate(m_size);
     }

     void resize(size_t size, float reserveSizeFactor = 0)
     {
       if (m_allocatedSize<size)
         reallocate(size + static_cast<size_t>(reserveSizeFactor *
                                             static_cast<float>(size)));
       m_size = size;
     }

     void append(const Scalar& v, Index i)
     {
       Index id = static_cast<Index>(m_size);
       resize(m_size+1, 1);
       m_values[id] = v;
       m_indices[id] = i;
     }

     inline size_t size() const { return m_size; }
     inline size_t allocatedSize() const { return m_allocatedSize; }
     inline void clear() { m_size = 0; }

     inline Scalar& value(size_t i) { return m_values[i]; }
     inline const Scalar& value(size_t i) const { return m_values[i]; }

     inline Index& index(size_t i) { return m_indices[i]; }
     inline const Index& index(size_t i) const { return m_indices[i]; }

     static CompressedStorage Map(Index* indices, Scalar* values, size_t size)
     {
       CompressedStorage res;
       res.m_indices = indices;
       res.m_values = values;
       res.m_allocatedSize = res.m_size = size;
       return res;
     }

     /** \returns the largest \c k such that for all \c j in [0,k) index[\c j]\<\a key */
     inline Index searchLowerIndex(Index key) const
     {
       return searchLowerIndex(0, m_size, key);
     }

     /** \returns the largest \c k in [start,end) such that for all \c j in [start,k) index[\c j]\<\a key */
     inline Index searchLowerIndex(size_t start, size_t end, Index key) const
     {
       while(end>start)
       {
         size_t mid = (end+start)>>1;
         if (m_indices[mid]<key)
           start = mid+1;
         else
           end = mid;
       }
       return static_cast<Index>(start);
     }

     /** \returns the stored value at index \a key
       * If the value does not exist, then the value \a defaultValue is returned without any insertion. */
     inline Scalar at(Index key, const Scalar& defaultValue = Scalar(0)) const
     {
       if (m_size==0)
         return defaultValue;
       else if (key==m_indices[m_size-1])
         return m_values[m_size-1];
       // ^^  optimization: let's first check if it is the last coefficient
       // (very common in high level algorithms)
       const size_t id = searchLowerIndex(0,m_size-1,key);
       return ((id<m_size) && (m_indices[id]==key)) ? m_values[id] : defaultValue;
     }

     /** Like at(), but the search is performed in the range [start,end) */
     inline Scalar atInRange(size_t start, size_t end, Index key, const Scalar& defaultValue = Scalar(0)) const
     {
       if (start>=end)
         return Scalar(0);
       else if (end>start && key==m_indices[end-1])
         return m_values[end-1];
       // ^^  optimization: let's first check if it is the last coefficient
       // (very common in high level algorithms)
       const size_t id = searchLowerIndex(start,end-1,key);
       return ((id<end) && (m_indices[id]==key)) ? m_values[id] : defaultValue;
     }

     /** \returns a reference to the value at index \a key
       * If the value does not exist, then the value \a defaultValue is inserted
       * such that the keys are sorted. */
     inline Scalar& atWithInsertion(Index key, const Scalar& defaultValue = Scalar(0))
     {
       size_t id = searchLowerIndex(0,m_size,key);
       if (id>=m_size || m_indices[id]!=key)
       {
         resize(m_size+1,1);
         for (size_t j=m_size-1; j>id; --j)
         {
           m_indices[j] = m_indices[j-1];
           m_values[j] = m_values[j-1];
         }
         m_indices[id] = key;
         m_values[id] = defaultValue;
       }
       return m_values[id];
     }

     void prune(const Scalar& reference, const RealScalar& epsilon = NumTraits<RealScalar>::dummy_precision())
     {
       size_t k = 0;
       size_t n = size();
       for (size_t i=0; i<n; ++i)
       {
         if (!internal::isMuchSmallerThan(value(i), reference, epsilon))
         {
           value(k) = value(i);
           index(k) = index(i);
           ++k;
         }
       }
       resize(k,0);
     }

   protected:

     inline void reallocate(size_t size)
     {
       Scalar* newValues  = new Scalar[size];
       Index* newIndices = new Index[size];
       size_t copySize = (std::min)(size, m_size);
       // copy
       if (copySize>0) {
         internal::smart_copy(m_values, m_values+copySize, newValues);
         internal::smart_copy(m_indices, m_indices+copySize, newIndices);
       }
       // delete old stuff
       delete[] m_values;
       delete[] m_indices;
       m_values = newValues;
       m_indices = newIndices;
       m_allocatedSize = size;
     }

   protected:
     Scalar* m_values;
     Index* m_indices;
     size_t m_size;
     size_t m_allocatedSize;

 };

 } // end namespace internal

 } // end namespace Eigen

 #endif // EIGEN_COMPRESSED_STORAGE_H
	// This file is part of Eigen, a lightweight C++ template library
	// for linear algebra.
	//
	// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
	//
	// This Source Code Form is subject to the terms of the Mozilla
	// Public License v. 2.0. If a copy of the MPL was not distributed
	// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

	#ifndef EIGEN_COMPRESSED_STORAGE_H
	#define EIGEN_COMPRESSED_STORAGE_H

	namespace Eigen {

	namespace internal {

	/** \internal
	* Stores a sparse set of values as a list of values and a list of indices.
	*
	*/
	template<typename _Scalar,typename _Index>
	class CompressedStorage
	{
	public:

	typedef _Scalar Scalar;
	typedef _Index Index;

	protected:

	typedef typename NumTraits<Scalar>::Real RealScalar;

	public:

	CompressedStorage()
	: m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
	{}

	CompressedStorage(size_t size)
	: m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
	{
	resize(size);
	}

	CompressedStorage(const CompressedStorage& other)
	: m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
	{
	*this = other;
	}

	CompressedStorage& operator=(const CompressedStorage& other)
	{
	resize(other.size());
	internal::smart_copy(other.m_values, other.m_values + m_size, m_values);
	internal::smart_copy(other.m_indices, other.m_indices + m_size, m_indices);
	return *this;
	}

	void swap(CompressedStorage& other)
	{
	std::swap(m_values, other.m_values);
	std::swap(m_indices, other.m_indices);
	std::swap(m_size, other.m_size);
	std::swap(m_allocatedSize, other.m_allocatedSize);
	}

	~CompressedStorage()
	{
	delete[] m_values;
	delete[] m_indices;
	}

	void reserve(size_t size)
	{
	size_t newAllocatedSize = m_size + size;
	if (newAllocatedSize > m_allocatedSize)
	reallocate(newAllocatedSize);
	}

	void squeeze()
	{
	if (m_allocatedSize>m_size)
	reallocate(m_size);
	}

	void resize(size_t size, float reserveSizeFactor = 0)
	{
	if (m_allocatedSize<size)
	reallocate(size + static_cast<size_t>(reserveSizeFactor *
	static_cast<float>(size)));
	m_size = size;
	}

	void append(const Scalar& v, Index i)
	{
	Index id = static_cast<Index>(m_size);
	resize(m_size+1, 1);
	m_values[id] = v;
	m_indices[id] = i;
	}

	inline size_t size() const { return m_size; }
	inline size_t allocatedSize() const { return m_allocatedSize; }
	inline void clear() { m_size = 0; }

	inline Scalar& value(size_t i) { return m_values[i]; }
	inline const Scalar& value(size_t i) const { return m_values[i]; }

	inline Index& index(size_t i) { return m_indices[i]; }
	inline const Index& index(size_t i) const { return m_indices[i]; }

	static CompressedStorage Map(Index* indices, Scalar* values, size_t size)
	{
	CompressedStorage res;
	res.m_indices = indices;
	res.m_values = values;
	res.m_allocatedSize = res.m_size = size;
	return res;
	}

	/** \returns the largest \c k such that for all \c j in [0,k) index[\c j]\<\a key */
	inline Index searchLowerIndex(Index key) const
	{
	return searchLowerIndex(0, m_size, key);
	}

	/** \returns the largest \c k in [start,end) such that for all \c j in [start,k) index[\c j]\<\a key */
	inline Index searchLowerIndex(size_t start, size_t end, Index key) const
	{
	while(end>start)
	{
	size_t mid = (end+start)>>1;
	if (m_indices[mid]<key)
	start = mid+1;
	else
	end = mid;
	}
	return static_cast<Index>(start);
	}

	/** \returns the stored value at index \a key
	* If the value does not exist, then the value \a defaultValue is returned without any insertion. */
	inline Scalar at(Index key, const Scalar& defaultValue = Scalar(0)) const
	{
	if (m_size==0)
	return defaultValue;
	else if (key==m_indices[m_size-1])
	return m_values[m_size-1];
	// ^^ optimization: let's first check if it is the last coefficient
	// (very common in high level algorithms)
	const size_t id = searchLowerIndex(0,m_size-1,key);
	return ((id<m_size) && (m_indices[id]==key)) ? m_values[id] : defaultValue;
	}

	/** Like at(), but the search is performed in the range [start,end) */
	inline Scalar atInRange(size_t start, size_t end, Index key, const Scalar& defaultValue = Scalar(0)) const
	{
	if (start>=end)
	return Scalar(0);
	else if (end>start && key==m_indices[end-1])
	return m_values[end-1];
	// ^^ optimization: let's first check if it is the last coefficient
	// (very common in high level algorithms)
	const size_t id = searchLowerIndex(start,end-1,key);
	return ((id<end) && (m_indices[id]==key)) ? m_values[id] : defaultValue;
	}

	/** \returns a reference to the value at index \a key
	* If the value does not exist, then the value \a defaultValue is inserted
	* such that the keys are sorted. */
	inline Scalar& atWithInsertion(Index key, const Scalar& defaultValue = Scalar(0))
	{
	size_t id = searchLowerIndex(0,m_size,key);
	if (id>=m_size \|\| m_indices[id]!=key)
	{
	resize(m_size+1,1);
	for (size_t j=m_size-1; j>id; --j)
	{
	m_indices[j] = m_indices[j-1];
	m_values[j] = m_values[j-1];
	}
	m_indices[id] = key;
	m_values[id] = defaultValue;
	}
	return m_values[id];
	}

	void prune(const Scalar& reference, const RealScalar& epsilon = NumTraits<RealScalar>::dummy_precision())
	{
	size_t k = 0;
	size_t n = size();
	for (size_t i=0; i<n; ++i)
	{
	if (!internal::isMuchSmallerThan(value(i), reference, epsilon))
	{
	value(k) = value(i);
	index(k) = index(i);
	++k;
	}
	}
	resize(k,0);
	}

	protected:

	inline void reallocate(size_t size)
	{
	Scalar* newValues = new Scalar[size];
	Index* newIndices = new Index[size];
	size_t copySize = (std::min)(size, m_size);
	// copy
	if (copySize>0) {
	internal::smart_copy(m_values, m_values+copySize, newValues);
	internal::smart_copy(m_indices, m_indices+copySize, newIndices);
	}
	// delete old stuff
	delete[] m_values;
	delete[] m_indices;
	m_values = newValues;
	m_indices = newIndices;
	m_allocatedSize = size;
	}

	protected:
	Scalar* m_values;
	Index* m_indices;
	size_t m_size;
	size_t m_allocatedSize;

	};

	} // end namespace internal

	} // end namespace Eigen

	#endif // EIGEN_COMPRESSED_STORAGE_H