Class sparse_matrix_block_impl

deps/Eigen/src/SparseCore/SparseBlock.h:93–256

template <typename SparseMatrixType, int BlockRows, int BlockCols>
class sparse_matrix_block_impl : public SparseCompressedBase<Block<SparseMatrixType, BlockRows, BlockCols, true> > {
  typedef internal::remove_all_t<typename SparseMatrixType::Nested> MatrixTypeNested_;
  typedef Block<SparseMatrixType, BlockRows, BlockCols, true> BlockType;
  typedef SparseCompressedBase<Block<SparseMatrixType, BlockRows, BlockCols, true> > Base;
  using Base::convert_index;

 public:
  enum { IsRowMajor = internal::traits<BlockType>::IsRowMajor };
  EIGEN_SPARSE_PUBLIC_INTERFACE(BlockType)
 protected:
  typedef typename Base::IndexVector IndexVector;
  enum { OuterSize = IsRowMajor ? BlockRows : BlockCols };

 public:
  inline sparse_matrix_block_impl(SparseMatrixType& xpr, Index i)
      : m_matrix(xpr), m_outerStart(convert_index(i)), m_outerSize(OuterSize) {}

  inline sparse_matrix_block_impl(SparseMatrixType& xpr, Index startRow, Index startCol, Index blockRows,
                                  Index blockCols)
      : m_matrix(xpr),
        m_outerStart(convert_index(IsRowMajor ? startRow : startCol)),
        m_outerSize(convert_index(IsRowMajor ? blockRows : blockCols)) {}

  template <typename OtherDerived>
  inline BlockType& operator=(const SparseMatrixBase<OtherDerived>& other) {
    typedef internal::remove_all_t<typename SparseMatrixType::Nested> NestedMatrixType_;
    NestedMatrixType_& matrix = m_matrix;
    // This assignment is slow if this vector set is not empty
    // and/or it is not at the end of the nonzeros of the underlying matrix.

    // 1 - eval to a temporary to avoid transposition and/or aliasing issues
    Ref<const SparseMatrix<Scalar, IsRowMajor ? RowMajor : ColMajor, StorageIndex> > tmp(other.derived());
    eigen_internal_assert(tmp.outerSize() == m_outerSize.value());

    // 2 - let's check whether there is enough allocated memory
    Index nnz = tmp.nonZeros();
    Index start =
        m_outerStart == 0 ? 0 : m_matrix.outerIndexPtr()[m_outerStart];        // starting position of the current block
    Index end = m_matrix.outerIndexPtr()[m_outerStart + m_outerSize.value()];  // ending position of the current block
    Index block_size = end - start;                                            // available room in the current block
    Index tail_size = m_matrix.outerIndexPtr()[m_matrix.outerSize()] - end;

    Index free_size = m_matrix.isCompressed() ? Index(matrix.data().allocatedSize()) + block_size : block_size;

    Index tmp_start = tmp.outerIndexPtr()[0];

    bool update_trailing_pointers = false;
    if (nnz > free_size) {
      // realloc manually to reduce copies
      typename SparseMatrixType::Storage newdata(m_matrix.data().allocatedSize() - block_size + nnz);

      internal::smart_copy(m_matrix.valuePtr(), m_matrix.valuePtr() + start, newdata.valuePtr());
      internal::smart_copy(m_matrix.innerIndexPtr(), m_matrix.innerIndexPtr() + start, newdata.indexPtr());

      internal::smart_copy(tmp.valuePtr() + tmp_start, tmp.valuePtr() + tmp_start + nnz, newdata.valuePtr() + start);
      internal::smart_copy(tmp.innerIndexPtr() + tmp_start, tmp.innerIndexPtr() + tmp_start + nnz,
                           newdata.indexPtr() + start);