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1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2008-2014 Gael Guennebaud <gael.guennebaud@inria.fr>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #ifndef EIGEN_COMPRESSED_STORAGE_H
11 #define EIGEN_COMPRESSED_STORAGE_H
12 
13 namespace Eigen {
14 
15 namespace internal {
16 
17 /** \internal
18   * Stores a sparse set of values as a list of values and a list of indices.
19   *
20   */
21 template<typename _Scalar,typename _StorageIndex>
22 class CompressedStorage
23 {
24   public:
25 
26     typedef _Scalar Scalar;
27     typedef _StorageIndex StorageIndex;
28 
29   protected:
30 
31     typedef typename NumTraits<Scalar>::Real RealScalar;
32 
33   public:
34 
CompressedStorage()35     CompressedStorage()
36       : m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
37     {}
38 
CompressedStorage(Index size)39     explicit CompressedStorage(Index size)
40       : m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
41     {
42       resize(size);
43     }
44 
CompressedStorage(const CompressedStorage & other)45     CompressedStorage(const CompressedStorage& other)
46       : m_values(0), m_indices(0), m_size(0), m_allocatedSize(0)
47     {
48       *this = other;
49     }
50 
51     CompressedStorage& operator=(const CompressedStorage& other)
52     {
53       resize(other.size());
54       if(other.size()>0)
55       {
56         internal::smart_copy(other.m_values,  other.m_values  + m_size, m_values);
57         internal::smart_copy(other.m_indices, other.m_indices + m_size, m_indices);
58       }
59       return *this;
60     }
61 
swap(CompressedStorage & other)62     void swap(CompressedStorage& other)
63     {
64       std::swap(m_values, other.m_values);
65       std::swap(m_indices, other.m_indices);
66       std::swap(m_size, other.m_size);
67       std::swap(m_allocatedSize, other.m_allocatedSize);
68     }
69 
~CompressedStorage()70     ~CompressedStorage()
71     {
72       delete[] m_values;
73       delete[] m_indices;
74     }
75 
reserve(Index size)76     void reserve(Index size)
77     {
78       Index newAllocatedSize = m_size + size;
79       if (newAllocatedSize > m_allocatedSize)
80         reallocate(newAllocatedSize);
81     }
82 
squeeze()83     void squeeze()
84     {
85       if (m_allocatedSize>m_size)
86         reallocate(m_size);
87     }
88 
89     void resize(Index size, double reserveSizeFactor = 0)
90     {
91       if (m_allocatedSize<size)
92       {
93         Index realloc_size = (std::min<Index>)(NumTraits<StorageIndex>::highest(),  size + Index(reserveSizeFactor*double(size)));
94         if(realloc_size<size)
95           internal::throw_std_bad_alloc();
96         reallocate(realloc_size);
97       }
98       m_size = size;
99     }
100 
append(const Scalar & v,Index i)101     void append(const Scalar& v, Index i)
102     {
103       Index id = m_size;
104       resize(m_size+1, 1);
105       m_values[id] = v;
106       m_indices[id] = internal::convert_index<StorageIndex>(i);
107     }
108 
size()109     inline Index size() const { return m_size; }
allocatedSize()110     inline Index allocatedSize() const { return m_allocatedSize; }
clear()111     inline void clear() { m_size = 0; }
112 
valuePtr()113     const Scalar* valuePtr() const { return m_values; }
valuePtr()114     Scalar* valuePtr() { return m_values; }
indexPtr()115     const StorageIndex* indexPtr() const { return m_indices; }
indexPtr()116     StorageIndex* indexPtr() { return m_indices; }
117 
value(Index i)118     inline Scalar& value(Index i) { eigen_internal_assert(m_values!=0); return m_values[i]; }
value(Index i)119     inline const Scalar& value(Index i) const { eigen_internal_assert(m_values!=0); return m_values[i]; }
120 
index(Index i)121     inline StorageIndex& index(Index i) { eigen_internal_assert(m_indices!=0); return m_indices[i]; }
index(Index i)122     inline const StorageIndex& index(Index i) const { eigen_internal_assert(m_indices!=0); return m_indices[i]; }
123 
124     /** \returns the largest \c k such that for all \c j in [0,k) index[\c j]\<\a key */
searchLowerIndex(Index key)125     inline Index searchLowerIndex(Index key) const
126     {
127       return searchLowerIndex(0, m_size, key);
128     }
129 
130     /** \returns the largest \c k in [start,end) such that for all \c j in [start,k) index[\c j]\<\a key */
searchLowerIndex(Index start,Index end,Index key)131     inline Index searchLowerIndex(Index start, Index end, Index key) const
132     {
133       while(end>start)
134       {
135         Index mid = (end+start)>>1;
136         if (m_indices[mid]<key)
137           start = mid+1;
138         else
139           end = mid;
140       }
141       return start;
142     }
143 
144     /** \returns the stored value at index \a key
145       * If the value does not exist, then the value \a defaultValue is returned without any insertion. */
146     inline Scalar at(Index key, const Scalar& defaultValue = Scalar(0)) const
147     {
148       if (m_size==0)
149         return defaultValue;
150       else if (key==m_indices[m_size-1])
151         return m_values[m_size-1];
152       // ^^  optimization: let's first check if it is the last coefficient
153       // (very common in high level algorithms)
154       const Index id = searchLowerIndex(0,m_size-1,key);
155       return ((id<m_size) && (m_indices[id]==key)) ? m_values[id] : defaultValue;
156     }
157 
158     /** Like at(), but the search is performed in the range [start,end) */
159     inline Scalar atInRange(Index start, Index end, Index key, const Scalar &defaultValue = Scalar(0)) const
160     {
161       if (start>=end)
162         return defaultValue;
163       else if (end>start && key==m_indices[end-1])
164         return m_values[end-1];
165       // ^^  optimization: let's first check if it is the last coefficient
166       // (very common in high level algorithms)
167       const Index id = searchLowerIndex(start,end-1,key);
168       return ((id<end) && (m_indices[id]==key)) ? m_values[id] : defaultValue;
169     }
170 
171     /** \returns a reference to the value at index \a key
172       * If the value does not exist, then the value \a defaultValue is inserted
173       * such that the keys are sorted. */
174     inline Scalar& atWithInsertion(Index key, const Scalar& defaultValue = Scalar(0))
175     {
176       Index id = searchLowerIndex(0,m_size,key);
177       if (id>=m_size || m_indices[id]!=key)
178       {
179         if (m_allocatedSize<m_size+1)
180         {
181           m_allocatedSize = 2*(m_size+1);
182           internal::scoped_array<Scalar> newValues(m_allocatedSize);
183           internal::scoped_array<StorageIndex> newIndices(m_allocatedSize);
184 
185           // copy first chunk
186           internal::smart_copy(m_values,  m_values +id, newValues.ptr());
187           internal::smart_copy(m_indices, m_indices+id, newIndices.ptr());
188 
189           // copy the rest
190           if(m_size>id)
191           {
192             internal::smart_copy(m_values +id,  m_values +m_size, newValues.ptr() +id+1);
193             internal::smart_copy(m_indices+id,  m_indices+m_size, newIndices.ptr()+id+1);
194           }
195           std::swap(m_values,newValues.ptr());
196           std::swap(m_indices,newIndices.ptr());
197         }
198         else if(m_size>id)
199         {
200           internal::smart_memmove(m_values +id, m_values +m_size, m_values +id+1);
201           internal::smart_memmove(m_indices+id, m_indices+m_size, m_indices+id+1);
202         }
203         m_size++;
204         m_indices[id] = internal::convert_index<StorageIndex>(key);
205         m_values[id] = defaultValue;
206       }
207       return m_values[id];
208     }
209 
210     void prune(const Scalar& reference, const RealScalar& epsilon = NumTraits<RealScalar>::dummy_precision())
211     {
212       Index k = 0;
213       Index n = size();
214       for (Index i=0; i<n; ++i)
215       {
216         if (!internal::isMuchSmallerThan(value(i), reference, epsilon))
217         {
218           value(k) = value(i);
219           index(k) = index(i);
220           ++k;
221         }
222       }
223       resize(k,0);
224     }
225 
226   protected:
227 
reallocate(Index size)228     inline void reallocate(Index size)
229     {
230       #ifdef EIGEN_SPARSE_COMPRESSED_STORAGE_REALLOCATE_PLUGIN
231         EIGEN_SPARSE_COMPRESSED_STORAGE_REALLOCATE_PLUGIN
232       #endif
233       eigen_internal_assert(size!=m_allocatedSize);
234       internal::scoped_array<Scalar> newValues(size);
235       internal::scoped_array<StorageIndex> newIndices(size);
236       Index copySize = (std::min)(size, m_size);
237       if (copySize>0) {
238         internal::smart_copy(m_values, m_values+copySize, newValues.ptr());
239         internal::smart_copy(m_indices, m_indices+copySize, newIndices.ptr());
240       }
241       std::swap(m_values,newValues.ptr());
242       std::swap(m_indices,newIndices.ptr());
243       m_allocatedSize = size;
244     }
245 
246   protected:
247     Scalar* m_values;
248     StorageIndex* m_indices;
249     Index m_size;
250     Index m_allocatedSize;
251 
252 };
253 
254 } // end namespace internal
255 
256 } // end namespace Eigen
257 
258 #endif // EIGEN_COMPRESSED_STORAGE_H
259