one2many.cpp
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	#include "mpi.h"
	#include "one2many.h"
	#include "memory.h"

	#include <map>

	/* ---------------------------------------------------------------------- */

	One2Many::One2Many(MPI_Comm caller_comm)
	{
	comm = caller_comm;
	MPI_Comm_rank(comm,&me);
	MPI_Comm_size(comm,&nprocs);

	memory = new Memory(comm);
	hash = new std::map<int,int>();
	}

	/* ---------------------------------------------------------------------- */

	One2Many::~One2Many()
	{
	delete memory;
	delete hash;
	}

	/* ---------------------------------------------------------------------- */

	void One2Many::setup(int nsrc_in, int ndest, int *id)
	{
	nsrc = nsrc_in;

	// store my local IDs in hash

	hash->clear();
	for (int i = 0; i < ndest; i++)
	hash->insert(std::pair<int,int> (id[i],i));
	}

	/* ---------------------------------------------------------------------- */

	void One2Many::scatter(double src, int n, double dest)
	{
	int i,j,k,m;

	// allocate src on procs that don't have it

	int flag = 0;
	if (src == NULL) {
	src = (double ) memory->smalloc(nnsrc*sizeof(double),"one2many:src");
	flag = 1;
	}

	// broadcast src from 0 to other procs

	MPI_Bcast(src,n*nsrc,MPI_DOUBLE,0,comm);

	// each proc loops over entire src
	// if I own the global ID, copy src values into dest

	std::map<int,int>::iterator loc;
	for (m = 1; m <= nsrc; m++) {
	loc = hash->find(m);
	if (loc == hash->end()) continue;
	i = n*loc->second;
	j = 3*(m-1);
	if (n == 1) dest[i] = src[j];
	else
	for (k = 0; k < n; k++)
	dest[i++] = src[j++];
	}

	// free locally allocated src

	if (flag) memory->sfree(src);
	}