/* This is part of the netCDF package.  Copyright 2020 University
   Corporation for Atmospheric Research/Unidata See COPYRIGHT file for
   conditions of use.

   Test HDF5 file code. These are not intended to be exhaustive tests,
   but they use HDF5 the same way that netCDF-4 does, so if these
   tests don't work, than netCDF-4 won't work either.

   This files tests parallel I/O.

   Ed Hartnett
*/
#include <nc_tests.h>
#include "err_macros.h"
#include <hdf5.h>

/* Defining USE_MPE causes the MPE trace library to be used (and you
 * must also relink with -llmpe -lmpe). This causes clog2 output to be
 * written, which can be converted to slog2 (by the program
 * clog2TOslog2) and then used in the analysis program jumpshot. */
/*#define USE_MPE 1*/

#ifdef USE_MPE
#include <mpe.h>
#endif /* USE_MPE */

#define FILE_NAME "tst_h_par.h5"
#define VAR_NAME "HALs_memory"
#define NDIMS 1
#define MILLION 1000000
#define DIM2_LEN 16000000
#define SC1 100000 /* slice count. */

int
main(int argc, char **argv)
{
    int p, my_rank;

#ifdef USE_MPE
    int s_init, e_init, s_define, e_define, s_write, e_write, s_close, e_close;
#endif /* USE_MPE */

    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &p);

#ifdef USE_MPE
    MPE_Init_log();
    s_init = MPE_Log_get_event_number();
    e_init = MPE_Log_get_event_number();
    s_define = MPE_Log_get_event_number();
    e_define = MPE_Log_get_event_number();
    s_write = MPE_Log_get_event_number();
    e_write = MPE_Log_get_event_number();
    s_close = MPE_Log_get_event_number();
    e_close = MPE_Log_get_event_number();
    MPE_Describe_state(s_init, e_init, "Init", "red");
    MPE_Describe_state(s_define, e_define, "Define", "yellow");
    MPE_Describe_state(s_write, e_write, "Write", "green");
    MPE_Describe_state(s_close, e_close, "Close", "purple");
    MPE_Start_log();
    MPE_Log_event(s_init, 0, "start init");
#endif /* USE_MPE */

    if (!my_rank)
        printf("*** Creating file for parallel I/O read, and rereading it...");
    {
        hid_t fapl_id, fileid, whole_spaceid, dsid, slice_spaceid, whole_spaceid1, xferid;
        hsize_t start[NDIMS], count[NDIMS];
        hsize_t dims[1];
        int data[SC1], data_in[SC1];
        int num_steps;
        double ftime;
        int write_us, read_us;
        int max_write_us, max_read_us;
        float write_rate, read_rate;
        int i, s;

        /* We will write the same slice of random data over and over to
         * fill the file. */
        for (i = 0; i < SC1; i++)
            data[i] = rand();

#ifdef USE_MPE
        MPE_Log_event(e_init, 0, "end init");
        MPE_Log_event(s_define, 0, "start define file");
#endif /* USE_MPE */

        /* Create file. */
        if ((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0) ERR;
        if (H5Pset_fapl_mpio(fapl_id, MPI_COMM_WORLD, MPI_INFO_NULL) < 0) ERR;
        if ((fileid = H5Fcreate(FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT,
                                fapl_id)) < 0) ERR;

        /* Create a space to deal with one slice in memory. */
        dims[0] = SC1;
        if ((slice_spaceid = H5Screate_simple(NDIMS, dims, NULL)) < 0) ERR;

        /* Create a space to write all slices. */
        dims[0] = DIM2_LEN;
        if ((whole_spaceid = H5Screate_simple(NDIMS, dims, NULL)) < 0) ERR;

        /* Create dataset. */
        if ((dsid = H5Dcreate1(fileid, VAR_NAME, H5T_NATIVE_INT,
                               whole_spaceid, H5P_DEFAULT)) < 0) ERR;

        /* Use collective write operations. */
        if ((xferid = H5Pcreate(H5P_DATASET_XFER)) < 0) ERR;
        if (H5Pset_dxpl_mpio(xferid, H5FD_MPIO_COLLECTIVE) < 0) ERR;

#ifdef USE_MPE
        MPE_Log_event(e_define, 0, "end define file");
        if (my_rank)
            sleep(my_rank);
#endif /* USE_MPE */

        /* Write the data in num_step steps. */
        ftime = MPI_Wtime();
        num_steps = (DIM2_LEN/SC1) / p;
        for (s = 0; s < num_steps; s++)
        {
#ifdef USE_MPE
            MPE_Log_event(s_write, 0, "start write slab");
#endif /* USE_MPE */

            /* Select hyperslab for write of one slice. */
            start[0] = s * SC1 * p + my_rank * SC1;
            count[0] = SC1;
            if (H5Sselect_hyperslab(whole_spaceid, H5S_SELECT_SET,
                                    start, NULL, count, NULL) < 0) ERR;

            if (H5Dwrite(dsid, H5T_NATIVE_INT, slice_spaceid, whole_spaceid,
                         xferid, data) < 0) ERR;

#ifdef USE_MPE
            MPE_Log_event(e_write, 0, "end write file");
#endif /* USE_MPE */
        }
        write_us = (MPI_Wtime() - ftime) * MILLION;
        MPI_Reduce(&write_us, &max_write_us, 1, MPI_INT, MPI_MAX, 0, MPI_COMM_WORLD);
        if (!my_rank)
        {
            write_rate = (float)(DIM2_LEN * sizeof(int))/(float)max_write_us;
            printf("\np=%d, write_rate=%g", p, write_rate);
        }

#ifdef USE_MPE
        MPE_Log_event(s_close, 0, "start close file");
#endif /* USE_MPE */

        /* Close. These collective operations will allow every process
         * to catch up. */
        if (H5Dclose(dsid) < 0 ||
            H5Sclose(whole_spaceid) < 0 ||
            H5Sclose(slice_spaceid) < 0 ||
            H5Pclose(fapl_id) < 0 ||
            H5Fclose(fileid) < 0)
            ERR;

#ifdef USE_MPE
        MPE_Log_event(e_close, 0, "end close file");
#endif /* USE_MPE */

        /* Open the file. */
        if ((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0) ERR;
        if (H5Pset_fapl_mpio(fapl_id, MPI_COMM_WORLD, MPI_INFO_NULL) < 0) ERR;


        if (H5Pset_libver_bounds(fapl_id, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0) ERR;
        if ((fileid = H5Fopen(FILE_NAME, H5F_ACC_RDONLY, fapl_id)) < 0) ERR;

        /* Create a space to deal with one slice in memory. */
        dims[0] = SC1;
        if ((slice_spaceid = H5Screate_simple(NDIMS, dims, NULL)) < 0) ERR;

        /* Open the dataset. */
        if ((dsid = H5Dopen(fileid, VAR_NAME)) < 0) ERR;
        if ((whole_spaceid1 = H5Dget_space(dsid)) < 0) ERR;

        ftime = MPI_Wtime();

        /* Read the data, a slice at a time. */
        for (s = 0; s < num_steps; s++)
        {
            /* Select hyperslab for read of one slice. */
            start[0] = s * SC1 * p + my_rank * SC1;
            count[0] = SC1;
            if (H5Sselect_hyperslab(whole_spaceid1, H5S_SELECT_SET,
                                    start, NULL, count, NULL) < 0)
            {
                ERR;
                return 2;
            }

            if (H5Dread(dsid, H5T_NATIVE_INT, slice_spaceid, whole_spaceid1,
                        H5P_DEFAULT, data_in) < 0)
            {
                ERR;
                return 2;
            }

            /* Check the slice of data. */
            for (i = 0; i < SC1; i++)
                if (data[i] != data_in[i])
                {
                    ERR;
                    return 2;
                }
        }
        read_us = (MPI_Wtime() - ftime) * MILLION;
        MPI_Reduce(&read_us, &max_read_us, 1, MPI_INT, MPI_MAX, 0, MPI_COMM_WORLD);
        if (!my_rank)
        {
            read_rate = (float)(DIM2_LEN * sizeof(int))/(float)max_read_us;
            printf(", read_rate=%g\n", read_rate);
        }

        /* Close down. */
        if (H5Dclose(dsid) < 0 ||
            H5Sclose(slice_spaceid) < 0 ||
            H5Sclose(whole_spaceid1) < 0 ||
            H5Pclose(fapl_id) < 0 ||
            H5Fclose(fileid) < 0)
            ERR;
    }
    if (!my_rank)
        SUMMARIZE_ERR;

    MPI_Finalize();

    if (!my_rank)
        FINAL_RESULTS;
    return 0;
}
