/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
 *
 *  (C) 2001 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

#include "mpiimpl.h"

/* -- Begin Profiling Symbol Block for routine MPI_Graph_create */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Graph_create = PMPI_Graph_create
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Graph_create  MPI_Graph_create
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Graph_create as PMPI_Graph_create
#elif defined(HAVE_WEAK_ATTRIBUTE)
int MPI_Graph_create(MPI_Comm comm_old, int nnodes, const int indx[], const int edges[],
                     int reorder, MPI_Comm * comm_graph)
    __attribute__ ((weak, alias("PMPI_Graph_create")));
#endif
/* -- End Profiling Symbol Block */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
   the MPI routines */
#ifndef MPICH_MPI_FROM_PMPI
#undef MPI_Graph_create
#define MPI_Graph_create PMPI_Graph_create

#endif

/* Note on index and indx - index is an (old) function name in string.h;
   while it is valid to use it as a variable or parameter name, it can
   solicit warning messages from the compiler.  To avoid those, the name
   indx is used instead of index in this file */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
   the MPI routines */
#ifndef MPICH_MPI_FROM_PMPI

#undef FUNCNAME
#define FUNCNAME MPIR_Graph_create
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Graph_create(MPIR_Comm * comm_ptr, int nnodes,
                      const int indx[], const int edges[], int reorder, MPI_Comm * comm_graph)
{
    int mpi_errno = MPI_SUCCESS;
    int i, nedges;
    MPIR_Comm *newcomm_ptr = NULL;
    MPIR_Topology *graph_ptr = NULL;
    MPIR_CHKPMEM_DECL(3);

    /* Set this to null in case there is an error */
    *comm_graph = MPI_COMM_NULL;

    /* Create a new communicator */
    if (reorder) {
        int nrank;

        /* Allow the cart map routine to remap the assignment of ranks to
         * processes */
        mpi_errno = MPIR_Graph_map_impl(comm_ptr, nnodes, indx, edges, &nrank);
        if (mpi_errno)
            MPIR_ERR_POP(mpi_errno);
        /* Create the new communicator with split, since we need to reorder
         * the ranks (including the related internals, such as the connection
         * tables */
        mpi_errno = MPIR_Comm_split_impl(comm_ptr,
                                         nrank == MPI_UNDEFINED ? MPI_UNDEFINED : 1,
                                         nrank, &newcomm_ptr);
        if (mpi_errno)
            MPIR_ERR_POP(mpi_errno);
    } else {
        /* Just use the first nnodes processes in the communicator */
        mpi_errno = MPII_Comm_copy((MPIR_Comm *) comm_ptr, nnodes, &newcomm_ptr);
        if (mpi_errno)
            MPIR_ERR_POP(mpi_errno);
    }


    /* If this process is not in the resulting communicator, return a
     * null communicator and exit */
    if (!newcomm_ptr) {
        *comm_graph = MPI_COMM_NULL;
        goto fn_exit;
    }

    nedges = indx[nnodes - 1];
    MPIR_CHKPMEM_MALLOC(graph_ptr, MPIR_Topology *, sizeof(MPIR_Topology),
                        mpi_errno, "graph_ptr", MPL_MEM_COMM);

    graph_ptr->kind = MPI_GRAPH;
    graph_ptr->topo.graph.nnodes = nnodes;
    graph_ptr->topo.graph.nedges = nedges;
    MPIR_CHKPMEM_MALLOC(graph_ptr->topo.graph.index, int *,
                        nnodes * sizeof(int), mpi_errno, "graph.index", MPL_MEM_COMM);
    MPIR_CHKPMEM_MALLOC(graph_ptr->topo.graph.edges, int *,
                        nedges * sizeof(int), mpi_errno, "graph.edges", MPL_MEM_COMM);
    for (i = 0; i < nnodes; i++)
        graph_ptr->topo.graph.index[i] = indx[i];
    for (i = 0; i < nedges; i++)
        graph_ptr->topo.graph.edges[i] = edges[i];

    /* Finally, place the topology onto the new communicator and return the
     * handle */
    mpi_errno = MPIR_Topology_put(newcomm_ptr, graph_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    MPIR_OBJ_PUBLISH_HANDLE(*comm_graph, newcomm_ptr->handle);

    /* ... end of body of routine ... */

  fn_exit:
    return mpi_errno;

  fn_fail:
    /* --BEGIN ERROR HANDLING-- */
    MPIR_CHKPMEM_REAP();
#ifdef HAVE_ERROR_CHECKING
    {
        mpi_errno =
            MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,
                                 "**mpi_graph_create", "**mpi_graph_create %C %d %p %p %d %p",
                                 comm_ptr->handle, nnodes, indx, edges, reorder, comm_graph);
    }
#endif
    mpi_errno = MPIR_Err_return_comm((MPIR_Comm *) comm_ptr, FCNAME, mpi_errno);
    goto fn_exit;
    /* --END ERROR HANDLING-- */
}
#endif

#undef FUNCNAME
#define FUNCNAME MPI_Graph_create
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
/*@
MPI_Graph_create - Makes a new communicator to which topology information
                 has been attached

Input Parameters:
+ comm_old - input communicator without topology (handle)
. nnodes - number of nodes in graph (integer)
. indx - array of integers describing node degrees (see below)
. edges - array of integers describing graph edges (see below)
- reorder - ranking may be reordered (true) or not (false) (logical)

Output Parameters:
. comm_graph - communicator with graph topology added (handle)

Notes:
Each process must provide a description of the entire graph, not just the
neigbors of the calling process.

Algorithm:
We ignore the 'reorder' info currently.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_TOPOLOGY
.N MPI_ERR_COMM
.N MPI_ERR_ARG

@*/
int MPI_Graph_create(MPI_Comm comm_old, int nnodes, const int indx[],
                     const int edges[], int reorder, MPI_Comm * comm_graph)
{
    int mpi_errno = MPI_SUCCESS;
    MPIR_Comm *comm_ptr = NULL;
    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_GRAPH_CREATE);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_GRAPH_CREATE);

    /* Validate parameters, especially handles needing to be converted */
#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            MPIR_ERRTEST_COMM(comm_old, mpi_errno);
        }
        MPID_END_ERROR_CHECKS;
    }
#endif

    /* Convert MPI object handles to object pointers */
    MPIR_Comm_get_ptr(comm_old, comm_ptr);

    /* Validate parameters and objects (post conversion) */
#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            /* Validate comm_ptr */
            MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, FALSE);
            if (mpi_errno)
                goto fn_fail;
            /* If comm_ptr is not valid, it will be reset to null */
            if (comm_ptr) {
                MPIR_ERRTEST_COMM_INTRA(comm_ptr, mpi_errno);
            }
            MPIR_ERRTEST_ARGNEG(nnodes, "nnodes", mpi_errno);
            if (nnodes > 0) {
                MPIR_ERRTEST_ARGNULL(indx, "index", mpi_errno);
                MPIR_ERRTEST_ARGNULL(edges, "edges", mpi_errno);
            }
            MPIR_ERRTEST_ARGNULL(comm_graph, "comm_graph", mpi_errno);
        }
        MPID_END_ERROR_CHECKS;
    }
#endif /* HAVE_ERROR_CHECKING */

#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            int comm_size = comm_ptr->remote_size;
            int i;

            /* Check that the communicator is large enough */
            if (nnodes > comm_size) {
                mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                 MPIR_ERR_RECOVERABLE,
                                                 FCNAME, __LINE__,
                                                 MPI_ERR_ARG,
                                                 "**topotoolarge", "**topotoolarge %d %d",
                                                 nnodes, comm_size);
            }

            /* Perform the remaining tests only if nnodes is valid.
             * This avoids SEGVs from accessing invalid parts of the
             * edges or index arrays */
            if (mpi_errno)
                goto fn_fail;

            /* Check that index is monotone nondecreasing */
            /* Use ERR_ARG instead of ERR_TOPOLOGY because there is no
             * topology yet */
            for (i = 0; i < nnodes; i++) {
                if (indx[i] < 0) {
                    mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                     MPIR_ERR_RECOVERABLE,
                                                     FCNAME, __LINE__,
                                                     MPI_ERR_ARG,
                                                     "**indexneg", "**indexneg %d %d", i, indx[i]);
                }
                if (i + 1 < nnodes && indx[i] > indx[i + 1]) {
                    mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                     MPIR_ERR_RECOVERABLE,
                                                     FCNAME, __LINE__,
                                                     MPI_ERR_ARG,
                                                     "**indexnonmonotone",
                                                     "**indexnonmonotone %d %d %d", i, indx[i],
                                                     indx[i + 1]);
                }
            }

            /* Check that edge number is in range. Note that the
             * edges refer to a rank in the communicator, and can
             * be greater than nnodes */
            if (nnodes > 0) {
                for (i = 0; i < indx[nnodes - 1]; i++) {
                    if (edges[i] > comm_size || edges[i] < 0) {
                        mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                         MPIR_ERR_RECOVERABLE,
                                                         FCNAME, __LINE__,
                                                         MPI_ERR_ARG,
                                                         "**edgeoutrange",
                                                         "**edgeoutrange %d %d %d", i, edges[i],
                                                         comm_size);
                    }
                }
            }
            if (mpi_errno)
                goto fn_fail;
        }
        MPID_END_ERROR_CHECKS;
    }
#endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */

    /* Test for empty communicator */
    if (nnodes == 0) {
        *comm_graph = MPI_COMM_NULL;
        goto fn_exit;
    }

    if (comm_ptr->topo_fns != NULL && comm_ptr->topo_fns->graphCreate != NULL) {
        /* --BEGIN USEREXTENSION-- */
        mpi_errno = comm_ptr->topo_fns->graphCreate(comm_ptr, nnodes,
                                                    (const int *) indx,
                                                    (const int *) edges, reorder, comm_graph);
        /* --END USEREXTENSION-- */
    } else {
        mpi_errno = MPIR_Graph_create(comm_ptr, nnodes,
                                      (const int *) indx, (const int *) edges, reorder, comm_graph);
    }
    if (mpi_errno)
        goto fn_fail;

    /* ... end of body of routine ... */

  fn_exit:
    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_GRAPH_CREATE);
    MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
    return mpi_errno;

  fn_fail:
    /* --BEGIN ERROR HANDLING-- */
#ifdef HAVE_ERROR_CHECKING
    {
        mpi_errno =
            MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,
                                 "**mpi_graph_create", "**mpi_graph_create %C %d %p %p %d %p",
                                 comm_old, nnodes, indx, edges, reorder, comm_graph);
    }
#endif
    mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);
    goto fn_exit;
    /* --END ERROR HANDLING-- */
}
