path: root/tools/lib/h5diff.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the files COPYING and Copyright.html.  COPYING can be found at the root   *
 * of the source code distribution tree; Copyright.html can be found at the  *
 * root level of an installed copy of the electronic HDF5 document set and   *
 * is linked from the top-level documents page.  It can also be found at     *
 * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
 * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include <stdlib.h>
#include "h5diff.h"
#include "H5private.h"
#include "ph5diff.h"



/*-------------------------------------------------------------------------
 * Function: print_objname
 *
 * Purpose: print object name only when:
 *  1) verbose mode
 *  2) when diff was found (normal mode)
 *-------------------------------------------------------------------------
 */
int
print_objname (diff_opt_t * options, hsize_t nfound)
{
  return ((options->m_verbose || nfound) && !options->m_quiet) ? 1 : 0;
}

#ifdef H5_HAVE_PARALLEL
/*-------------------------------------------------------------------------
 * Function: phdiff_dismiss_workers
 *
 * Purpose: tell all workers to end.
 *
 * Return: none
 *
 * Programmer: Albert Cheng
 *
 * Date: Feb 6, 2005
 *
 *-------------------------------------------------------------------------
 */
void phdiff_dismiss_workers(void)
{
    int i;

    for(i=1; i<g_nTasks; i++)
	MPI_Send(NULL, 0, MPI_BYTE, i, MPI_TAG_END, MPI_COMM_WORLD);
}


/*-------------------------------------------------------------------------
 * Function: print_manager_output
 *
 * Purpose: special function that prints any output accumulated by the
 * 	    manager task.
 *
 * Return: none
 *
 * Programmer: Leon Arber
 *
 * Date: Feb 7, 2005
 *
 *-------------------------------------------------------------------------
 */
void print_manager_output(void)
{
      /* If there was something we buffered, let's print it now */
      if( (outBuffOffset>0) && g_Parallel)
      {
	  printf("%s", outBuff); 
	  fflush(stdout);
	  memset(outBuff, 0, OUTBUFF_SIZE);
	  outBuffOffset = 0;
      }
      else if( (outBuffOffset>0) && !g_Parallel)
      {
	  printf("h5diff error: outBuffOffset>0, but we're not in parallel\n");
      }
}

#endif

/*-------------------------------------------------------------------------
 * Function: h5diff
 *
 * Purpose: public function, can be called in an application program.
 *   return differences between 2 HDF5 files
 *
 * Return: Number of differences found.
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: October 22, 2003
 *
 * Modifications: Jan 2005 Leon Arber, larber@uiuc.edu
 * 			Added support for parallel diffing
 *
 *-------------------------------------------------------------------------
 */

hsize_t
h5diff (const char *fname1,
	const char *fname2,
	const char *objname1, const char *objname2, diff_opt_t * options)
{
  int nobjects1, nobjects2, i;
  trav_info_t *info1 = NULL;
  trav_info_t *info2 = NULL;
  hid_t        file1_id=(-1), file2_id=(-1); 
  char filenames[2][1024];
  hsize_t nfound = 0;
 
  memset(filenames, 0, 1024*2);


  if (options->m_quiet && (options->m_verbose || options->m_report))
    {
      printf
	("Error: -q (quiet mode) cannot be added to verbose or report modes\n");
      options->err_stat = 1;
      return 0;
    }

/*-------------------------------------------------------------------------
 * open the files first; if they are not valid, no point in continuing
 *-------------------------------------------------------------------------
 */

  /* disable error reporting */
  H5E_BEGIN_TRY
  {
    /* Open the files */
    if ((file1_id = H5Fopen (fname1, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0)
      {
	printf ("h5diff: <%s>: unable to open file\n", fname1);
	options->err_stat = 1;

#ifdef H5_HAVE_PARALLEL
	if(g_Parallel)
	{
	    /* Let tasks know that they won't be needed */
	    phdiff_dismiss_workers();
	}
#endif

	goto out;
      }
    if ((file2_id = H5Fopen (fname2, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0)
    {
	printf ("h5diff: <%s>: unable to open file\n", fname2);
	options->err_stat = 1;

#ifdef H5_HAVE_PARALLEL
	if(g_Parallel)
	{
	    /* Let tasks know that they won't be needed */
	    phdiff_dismiss_workers();
	}
#endif

	goto out;
      }
    /* enable error reporting */
  }
  H5E_END_TRY;


/*-------------------------------------------------------------------------
 * get the number of objects in the files
 *-------------------------------------------------------------------------
 */
  nobjects1 = h5trav_getinfo (file1_id, NULL, 0);
  nobjects2 = h5trav_getinfo (file2_id, NULL, 0);

  if (nobjects1 < 0 || nobjects2 < 0)
    {
      printf ("Error: Could not get get file contents\n");
      options->err_stat = 1;
#ifdef H5_HAVE_PARALLEL
	if(g_Parallel)
	{
	    /* Let tasks know that they won't be needed */
	    phdiff_dismiss_workers();
	}
#endif
      goto out;
    }

  assert (nobjects1 > 0);
  assert (nobjects2 > 0);

/*-------------------------------------------------------------------------
 * get the list of objects in the files
 *-------------------------------------------------------------------------
 */

  info1 = (trav_info_t *) malloc (nobjects1 * sizeof (trav_info_t));
  info2 = (trav_info_t *) malloc (nobjects2 * sizeof (trav_info_t));
  if (info1 == NULL || info2 == NULL)
    {
      printf ("Error: Not enough memory for object list\n");
      options->err_stat = 1;
      if (info1)
	h5trav_freeinfo (info1, nobjects1);
      if (info2)
	h5trav_freeinfo (info2, nobjects1);
#ifdef H5_HAVE_PARALLEL
	if(g_Parallel)
	{
	    /* Let tasks know that they won't be needed */
	    phdiff_dismiss_workers();
	}
#endif
      goto out;
    }

  h5trav_getinfo (file1_id, info1, 0);
  h5trav_getinfo (file2_id, info2, 0);

/*-------------------------------------------------------------------------
 * object name was supplied
 *-------------------------------------------------------------------------
 */
 
  if (objname1)
    {
	
#ifdef H5_HAVE_PARALLEL
	if(g_Parallel)
	{
	    /* Let tasks know that they won't be needed */
	    for(i=1; i<g_nTasks; i++)
		MPI_Send(filenames, 1024*2, MPI_CHAR, i, MPI_TAG_END, MPI_COMM_WORLD);
	}
#endif
      assert (objname2);
      options->cmn_objs = 1;	/* eliminate warning */
      nfound = diff_compare (file1_id, fname1, objname1, nobjects1, info1,
			     file2_id, fname2, objname2, nobjects2, info2,
			     options);
#ifdef H5_HAVE_PARALLEL
      /* If there was something we buffered, let's print it now */
      print_manager_output();
#endif
    }

/*-------------------------------------------------------------------------
 * compare all
 *-------------------------------------------------------------------------
 */

  else
  {

#ifdef H5_HAVE_PARALLEL
      if(g_Parallel)
      {
	  if(  (strlen(fname1) > 1024) || (strlen(fname2) > 1024))
	  {
	      printf("The parallel diff only supports path names up to 1024 characters\n");
	      MPI_Abort(MPI_COMM_WORLD, 0);
	  }

	  strcpy(filenames[0], fname1);
	  strcpy(filenames[1], fname2);

	  /* Alert the worker tasks that there's going to be work. */

	  for(i=1; i<g_nTasks; i++)
	      MPI_Send(filenames, 1024*2, MPI_CHAR, i, MPI_TAG_PARALLEL, MPI_COMM_WORLD);
      }
#endif
      nfound = diff_match (file1_id, nobjects1, info1,
	      file2_id, nobjects2, info2, options);
  }


  h5trav_freeinfo (info1, nobjects1);
  h5trav_freeinfo (info2, nobjects2);

out:
  /* close */
  H5E_BEGIN_TRY
  {
      H5Fclose (file1_id);
      H5Fclose (file2_id);
  }
  H5E_END_TRY;

  return nfound;
}



/*-------------------------------------------------------------------------
 * Function: diff_match
 *
 * Purpose: Find common objects; the algorithm used for this search is the 
 *  cosequential match algorithm and is described in 
 *  Folk, Michael; Zoellick, Bill. (1992). File Structures. Addison-Wesley.
 *
 * Return: Number of differences found
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: May 9, 2003
 * 
 * Modifications: Jan 2005 Leon Arber, larber@uiuc.edu
 * 			Added support for parallel diffing
 *
 *-------------------------------------------------------------------------
 */
hsize_t
diff_match (hid_t file1_id,
	int nobjects1,
	trav_info_t * info1,
	hid_t file2_id,
	int nobjects2, trav_info_t * info2, diff_opt_t * options)
{
    int more_names_exist = (nobjects1 > 0 && nobjects2 > 0) ? 1 : 0;
    trav_table_t *table = NULL;
    int cmp;
    int curr1 = 0;
    int curr2 = 0;
    unsigned infile[2];
    char c1, c2;
    hsize_t nfound = 0;
    int i;

    /*-------------------------------------------------------------------------
     * build the list
     *-------------------------------------------------------------------------
     */
    trav_table_init (&table);

    while (more_names_exist)
    {
	/* criteria is string compare */
	cmp = strcmp (info1[curr1].name, info2[curr2].name);
	if (cmp == 0)
	{
	    infile[0] = 1;
	    infile[1] = 1;
	    trav_table_addflags (infile, info1[curr1].name, info1[curr1].type,
		    table);

	    curr1++;
	    curr2++;
	}
	else if (cmp < 0)
	{
	    infile[0] = 1;
	    infile[1] = 0;
	    trav_table_addflags (infile, info1[curr1].name, info1[curr1].type,
		    table);
	    curr1++;
	}
	else
	{
	    infile[0] = 0;
	    infile[1] = 1;
	    trav_table_addflags (infile, info2[curr2].name, info2[curr2].type,
		    table);
	    curr2++;
	}

	more_names_exist = (curr1 < nobjects1 && curr2 < nobjects2) ? 1 : 0;


    }				/* end while */

    /* list1 did not end */
    if (curr1 < nobjects1)
    {
	while (curr1 < nobjects1)
	{
	    infile[0] = 1;
	    infile[1] = 0;
	    trav_table_addflags (infile, info1[curr1].name, info1[curr1].type,
		    table);
	    curr1++;
	}
    }

    /* list2 did not end */
    if (curr2 < nobjects2)
    {
	while (curr2 < nobjects2)
	{
	    infile[0] = 0;
	    infile[1] = 1;
	    trav_table_addflags (infile, info2[curr2].name, info2[curr2].type,
		    table);
	    curr2++;
	}
    }

    /*-------------------------------------------------------------------------
     * print the list
     *-------------------------------------------------------------------------
     */

    if (options->m_verbose)
    {
	printf ("\n");
	printf ("file1     file2\n");
	printf ("---------------------------------------\n");
	for (i = 0; i < table->nobjs; i++)
	{
	    c1 = (table->objs[i].flags[0]) ? 'x' : ' ';
	    c2 = (table->objs[i].flags[1]) ? 'x' : ' ';
	    printf ("%5c %6c    %-15s\n", c1, c2, table->objs[i].name);
	}
	printf ("\n");
    }


    /*-------------------------------------------------------------------------
     * do the diff for common objects
     *-------------------------------------------------------------------------
     */
    {
#ifdef H5_HAVE_PARALLEL
	char* workerTasks = malloc((g_nTasks-1) * sizeof(char));
	int n;
	int busyTasks=0;
	hsize_t nFoundbyWorker;
	struct diff_args args;
	int havePrintToken = 1;
	MPI_Status Status;
	
	/*set all tasks as free */
	memset(workerTasks, 1, g_nTasks-1);
#endif

	for (i = 0; i < table->nobjs; i++)
	{
	    if (table->objs[i].flags[0] && table->objs[i].flags[1])
	    {
		int workerFound = 0;
		options->cmn_objs = 1;
		if(!g_Parallel)
		{
		    nfound += diff (file1_id,
			    table->objs[i].name,
			    file2_id,
			    table->objs[i].name, options, table->objs[i].type);
		}
#ifdef H5_HAVE_PARALLEL
		else
		{
		    /* We're in parallel mode */
		    /* Since the data type of diff value is hsize_t which can
		     * be arbitary large such that there is no MPI type that
		     * matches it, the value is passed between processes as
		     * an array of bytes in order to be portable.  But this
		     * may not work in non-homogeneous MPI environments.
		     */

		    /*Set up args to pass to worker task. */ 
		    if(strlen(table->objs[i].name) > 255)
		    {
			printf("The parallel diff only supports object names up to 255 characters\n");
			MPI_Abort(MPI_COMM_WORLD, 0);
		    }
		    
		    strcpy(args.name, table->objs[i].name);
		    args.options = *options;
		    args.type= table->objs[i].type;

		    /* if there are any outstanding print requests, let's handle one. */
		    if(busyTasks > 0)
		    {
			int incomingMessage;
			/* check if any tasks freed up, and didn't need to print. */
			MPI_Iprobe(MPI_ANY_SOURCE, MPI_TAG_DONE, MPI_COMM_WORLD, &incomingMessage, &Status);

			if(incomingMessage)
			{
			    workerTasks[Status.MPI_SOURCE-1] = 1;
			    MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_DONE, MPI_COMM_WORLD, &Status);
			    nfound += nFoundbyWorker;
			    busyTasks--;
			}

			/* check to see if the print token was returned. */
			if(!havePrintToken)
			{

			    /* check incoming queue for token */
			    MPI_Iprobe(MPI_ANY_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &incomingMessage, &Status);

			    /* incoming token implies free task. */
			    if(incomingMessage)
			    {
				workerTasks[Status.MPI_SOURCE-1] = 1;
				MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);
				nfound += nFoundbyWorker;
				busyTasks--;
				havePrintToken = 1;
			    }
			}

			/* check to see if anyone needs the print token. */
			if(havePrintToken)
			{
			    /* check incoming queue for print token requests */
			    MPI_Iprobe(MPI_ANY_SOURCE, MPI_TAG_TOK_REQUEST, MPI_COMM_WORLD, &incomingMessage, &Status);
			    if(incomingMessage)
			    {
				MPI_Recv(NULL, 0, MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_REQUEST, MPI_COMM_WORLD, &Status);
				MPI_Send(NULL, 0, MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_PRINT_TOK, MPI_COMM_WORLD);
				havePrintToken = 0;
			    }
			}
		    }

		    /* check array of tasks to see which ones are free.
		     * Manager task never does work, so freeTasks[0] is really 
		     * worker task 0. */

		    for(n=1; (n<g_nTasks) && !workerFound; n++)
		    {
			if(workerTasks[n-1])
			{
			    /* send file id's and names to first free worker */
			    MPI_Send(&args, sizeof(struct diff_args), MPI_BYTE, n, MPI_TAG_ARGS, MPI_COMM_WORLD);

			    /* increment counter for total number of prints. */
			    busyTasks++;

			    /* mark worker as busy */
			    workerTasks[n-1] = 0;
			    workerFound = 1;
			}

		    }


		    if(!workerFound)
		    {
			/* if they were all busy, we've got to wait for one free up before we can move on.
			 * if we don't have the token, some task is currently printing so we'll wait for that task to return it. */
			if(!havePrintToken)
			{
			    MPI_Probe(MPI_ANY_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);

			    if(Status.MPI_TAG == MPI_TAG_TOK_RETURN)
			    {
				MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);
				havePrintToken = 1;
				nfound += nFoundbyWorker;
				/* send this task the work unit. */
				MPI_Send(&args, sizeof(struct diff_args), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_ARGS, MPI_COMM_WORLD);
			    }
			    else
			    {
				printf("ERROR: Invalid (%d) tag received\n", Status.MPI_TAG);
				MPI_Abort(MPI_COMM_WORLD, 0);
				MPI_Finalize();
			    }
			}
			/* if we do have the token, check for task to free up, or wait for a task to request it */
			else
			{
			    MPI_Probe(MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &Status);

			    if(Status.MPI_TAG == MPI_TAG_DONE)
			    {
				MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_DONE, MPI_COMM_WORLD, &Status);
				nfound += nFoundbyWorker;
				MPI_Send(&args, sizeof(struct diff_args), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_ARGS, MPI_COMM_WORLD);
			    }
			    else if(Status.MPI_TAG == MPI_TAG_TOK_REQUEST)
			    {
				MPI_Recv(NULL, 0, MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_REQUEST, MPI_COMM_WORLD, &Status);
				MPI_Send(NULL, 0, MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_PRINT_TOK, MPI_COMM_WORLD);

				MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);
				nfound += nFoundbyWorker;
				MPI_Send(&args, sizeof(struct diff_args), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_ARGS, MPI_COMM_WORLD);
			    }
			    else
			    {
				printf("ERROR: Invalid tag (%d) received \n", Status.MPI_TAG);
				MPI_Abort(MPI_COMM_WORLD, 0);
				MPI_Finalize();
			    }
			}



		    }
		}
#endif
	    }
	}

#ifdef H5_HAVE_PARALLEL
	if(g_Parallel)
	{
	    while(busyTasks > 0) /* make sure all tasks are done */
	    {
		MPI_Probe(MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &Status);
		if(Status.MPI_TAG == MPI_TAG_DONE)
		{
		    MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_DONE, MPI_COMM_WORLD, &Status);
		    nfound += nFoundbyWorker;
		    busyTasks--;
		}
		else if(Status.MPI_TAG == MPI_TAG_TOK_REQUEST)
		{
		    MPI_Recv(NULL, 0, MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_REQUEST, MPI_COMM_WORLD, &Status);
		    if(havePrintToken) 
		    {
			MPI_Send(NULL, 0, MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_PRINT_TOK, MPI_COMM_WORLD);
			MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);
			nfound += nFoundbyWorker;
			busyTasks--;
		    }
		    else /* someone else must have it...wait for them to return it, then give it to the task that just asked for it. */
		    {
			int source = Status.MPI_SOURCE;
			MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, MPI_ANY_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);
			nfound += nFoundbyWorker;
			busyTasks--;
			MPI_Send(NULL, 0, MPI_BYTE, source, MPI_TAG_PRINT_TOK, MPI_COMM_WORLD);
		    }
		}
		else if(Status.MPI_TAG == MPI_TAG_TOK_RETURN)
		{
		    MPI_Recv(&nFoundbyWorker, sizeof(nFoundbyWorker), MPI_BYTE, Status.MPI_SOURCE, MPI_TAG_TOK_RETURN, MPI_COMM_WORLD, &Status);
		    nfound += nFoundbyWorker;
		    busyTasks--;
		    havePrintToken = 1;
		}
		else
		{
		    printf("ERROR!! Invalid tag (%d) received \n", Status.MPI_TAG);
		    MPI_Abort(MPI_COMM_WORLD, 0);
		}
	    }

	    for(i=1; i<g_nTasks; i++)
		MPI_Send(NULL, 0, MPI_BYTE, i, MPI_TAG_END, MPI_COMM_WORLD);
	}

	free(workerTasks);
#endif
    }
    /* free table */
    trav_table_free (table);


    /*-------------------------------------------------------------------------
     * do the diff for the root.
     * this is a special case, we get an ID for the root group and call diff() 
     * with this ID; it compares only the root group attributes
     *-------------------------------------------------------------------------
     */

    /* the manager can do this. */
    nfound += diff (file1_id, "/", file2_id, "/", options, H5G_GROUP);
#ifdef H5_HAVE_PARALLEL
    /* If there was something we buffered, let's print it now */
    print_manager_output();
#endif

    return nfound;
}


/*-------------------------------------------------------------------------
 * Function: diff_compare
 *
 * Purpose: get objects from list, and check for the same type
 *
 * Return: Number of differences found
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: May 9, 2003
 *
 *-------------------------------------------------------------------------
 */

hsize_t
diff_compare (hid_t file1_id,
	const char *file1_name,
	const char *obj1_name,
	int nobjects1,
	trav_info_t * info1,
	hid_t file2_id,
	const char *file2_name,
	const char *obj2_name,
	int nobjects2, trav_info_t * info2, diff_opt_t * options)
{

    int f1 = 0, f2 = 0;
    hsize_t nfound = 0;

    int i = h5trav_getindex (obj1_name, nobjects1, info1);
    int j = h5trav_getindex (obj2_name, nobjects2, info2);

    if (i == -1)
    {
	printf ("Object <%s> could not be found in <%s>\n", obj1_name,
		file1_name);
	f1 = 1;
    }
	    if (j == -1)
	    {
		printf ("Object <%s> could not be found in <%s>\n", obj2_name,
			file2_name);
		f2 = 1;
	    }
	    if (f1 || f2)
	    {
		options->err_stat = 1;
		return 0;
	    }

	    /* use the name with "/" first, as obtained by iterator function */
	    obj1_name = info1[i].name;
  obj2_name = info2[j].name;

  /* objects are not the same type */
  if (info1[i].type != info2[j].type)
    {
      if (options->m_verbose)
	printf
	  ("Comparison not possible: <%s> is of type %s and <%s> is of type %s\n",
	   obj1_name, get_type (info1[i].type), obj2_name,
	   get_type (info2[j].type));
      return 0;
    }

  nfound =
    diff (file1_id, obj1_name, file2_id, obj2_name, options, info1[i].type);

  return nfound;
}


/*-------------------------------------------------------------------------
 * Function: diff
 *
 * Purpose: switch between types and choose the diff function
 * TYPE is either
 *  H5G_LINK     Object is a symbolic link	
 *  H5G_GROUP		  Object is a group		
 *  H5G_DATASET 	Object is a dataset		
 *  H5G_TYPE     Object is a named data type	
 *
 * Return: Number of differences found
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: May 9, 2003
 *
 *-------------------------------------------------------------------------
 */

hsize_t
diff (hid_t file1_id,
      const char *path1,
      hid_t file2_id, const char *path2, diff_opt_t * options, H5G_obj_t type)
{
    hid_t       type1_id=(-1);
    hid_t       type2_id=(-1);
    hid_t       grp1_id=(-1);
    hid_t       grp2_id=(-1);
    int ret;
    H5G_stat_t sb1;
    H5G_stat_t sb2;
    char *buf1 = NULL;
    char *buf2 = NULL;
    hsize_t nfound = 0;

    switch (type)
    {
	/*-------------------------------------------------------------------------
	 * H5G_DATASET
	 *-------------------------------------------------------------------------
	 */
	case H5G_DATASET:

	    /* always print name */
	    if (options->m_verbose)
	    {
		if (print_objname (options, (hsize_t)1))
		    parallel_print("Dataset:     <%s> and <%s>\n", path1, path2); 
		nfound = diff_dataset (file1_id, file2_id, path1, path2, options);

	    }
	    /* check first if we have differences */
	    else
	    {
		if (options->m_quiet == 0)
		{
		    /* shut up temporarily */
		    options->m_quiet = 1;
		    nfound =
			diff_dataset (file1_id, file2_id, path1, path2, options);
		    /* print again */
		    options->m_quiet = 0;
		    if (nfound)
		    {
			if (print_objname (options, nfound))
			    parallel_print("Dataset:     <%s> and <%s>\n", path1, path2);
			nfound = diff_dataset (file1_id, file2_id, path1, path2, options);
		    }		/*if */
		}			/*if */
		/* in quiet mode, just count differences */
		else
		{
		    nfound = diff_dataset (file1_id, file2_id, path1, path2, options);
		}
	    }			/*else */

	    break;

	    /*-------------------------------------------------------------------------
	     * H5G_TYPE
	     *-------------------------------------------------------------------------
	     */
	case H5G_TYPE:
	    if ((type1_id = H5Topen (file1_id, path1)) < 0)
		goto out;
	    if ((type2_id = H5Topen (file2_id, path2)) < 0)
		goto out;

	    if ((ret = H5Tequal (type1_id, type2_id)) < 0)
		goto out;

	    /* if H5Tequal is > 0 then the datatypes refer to the same datatype */
	    nfound = (ret > 0) ? 0 : 1;

	    if (print_objname (options, nfound))
		parallel_print("Datatype:    <%s> and <%s>\n", path1, path2);

	    /*-------------------------------------------------------------------------
	     * compare attributes
	     * the if condition refers to cases when the dataset is a referenced object
	     *-------------------------------------------------------------------------
	     */
	        if (path1)
		  diff_attr (type1_id, type2_id, path1, path2, options); 

	    if (H5Tclose (type1_id) < 0)
		goto out;
	    if (H5Tclose (type2_id) < 0)
		goto out;

	    break;

	    /*-------------------------------------------------------------------------
	     * H5G_GROUP
	     *-------------------------------------------------------------------------
	     */
	case H5G_GROUP:
	    if ((grp1_id = H5Gopen (file1_id, path1)) < 0)
		goto out;
	    if ((grp2_id = H5Gopen (file2_id, path2)) < 0)
		goto out;

	    ret = HDstrcmp (path1, path2);

	    /* if "path1" != "path2" then the groups are "different" */
	    nfound = (ret != 0) ? 1 : 0;

	    if (print_objname (options, nfound))
		parallel_print("Group:       <%s> and <%s>\n", path1, path2);

	    /*-------------------------------------------------------------------------
	     * compare attributes
	     * the if condition refers to cases when the dataset is a referenced object
	     *-------------------------------------------------------------------------
	     */
	    if (path1)
		diff_attr (grp1_id, grp2_id, path1, path2, options);

	    if (H5Gclose (grp1_id) < 0)
		goto out;
	    if (H5Gclose (grp2_id) < 0)
		goto out;

	    break;


	    /*-------------------------------------------------------------------------
	     * H5G_LINK
	     *-------------------------------------------------------------------------
	     */
	case H5G_LINK:
	    if (H5Gget_objinfo (file1_id, path1, FALSE, &sb1) < 0)
		goto out;
	    if (H5Gget_objinfo (file1_id, path1, FALSE, &sb2) < 0)
		goto out;

	    buf1 = malloc (sb1.linklen);
	    buf2 = malloc (sb2.linklen);

	    if (H5Gget_linkval (file1_id, path1, sb1.linklen, buf1) < 0)
		goto out;
	    if (H5Gget_linkval (file2_id, path2, sb1.linklen, buf2) < 0)
		goto out;

	    ret = HDstrcmp (buf1, buf2);

	    /* if "buf1" != "buf2" then the links are "different" */
	    nfound = (ret != 0) ? 1 : 0;

	    if (print_objname (options, nfound))
		parallel_print("Link:        <%s> and <%s>\n", path1, path2);

	    if (buf1)
	    {
		free (buf1);
		buf1 = NULL;
	    }

	    if (buf2)
	    {
		free (buf2);
		buf2 = NULL;
	    }

	    break;


	default:
	    nfound = 0;
	    if (options->m_verbose)
	    {
		parallel_print("Comparison not supported: <%s> and <%s> are of type %s\n",
			path1, path2, get_type (type));
	    }	

	    break;
    }


out:

    /* close */
    /* disable error reporting */
    H5E_BEGIN_TRY
    {
	H5Tclose (type1_id);
	H5Tclose (type2_id);
	H5Gclose (grp1_id);
	H5Tclose (grp2_id);
	/* enable error reporting */
    }
    H5E_END_TRY;

    if (buf1)
	free (buf1);
    if (buf2)
	free (buf2);

    return nfound;
}