Function GB_Iterator_attach

deps/GraphBLAS/Source/GB_Iterator_attach.c:13–82

#define GB_FREE_ALL ;

GrB_Info GB_Iterator_attach
(
    // input/output:
    GxB_Iterator iterator,      // iterator to attach to the matrix A
    // input
    GrB_Matrix A,               // matrix to attach
    GxB_Format_Value format,    // by row, by col, or by entry (GxB_NO_FORMAT)
    GrB_Descriptor desc
)
{

    //--------------------------------------------------------------------------
    // check inputs
    //--------------------------------------------------------------------------

    GB_RETURN_IF_NULL (iterator) ;
    GB_RETURN_IF_NULL_OR_FAULTY (A) ;

    if ((format == GxB_BY_ROW &&  A->is_csc) ||
        (format == GxB_BY_COL && !A->is_csc))
    { 
        return (GrB_NOT_IMPLEMENTED) ;
    }

    //--------------------------------------------------------------------------
    // finish any pending work on the matrix
    //--------------------------------------------------------------------------

    if (GB_ANY_PENDING_WORK (A))
    {
        GrB_Info info ;
        GB_CONTEXT ("GxB_Iterator_attach") ;
        if (desc != NULL)
        { 
            // get the # of threads to use
            Context->nthreads_max = desc->nthreads_max ;
            Context->chunk = desc->chunk ;
        }
        GB_OK (GB_wait (A, "A", Context)) ;
    }

    //--------------------------------------------------------------------------
    // clear the current position
    //--------------------------------------------------------------------------

    iterator->pstart = 0 ;
    iterator->pend = 0 ;
    iterator->p = 0 ;
    iterator->k = 0 ;

    //--------------------------------------------------------------------------
    // get the matrix and save its contents in the iterator
    //--------------------------------------------------------------------------

    iterator->pmax = (GB_nnz (A) == 0) ? 0 : GB_nnz_held (A) ;
    iterator->avlen = A->vlen ;
    iterator->avdim = A->vdim ;
    iterator->anvec = A->nvec ;