Code cleanup before moving into production mode.

git-svn-id: http://svn.cactuscode.org/arrangements/CactusPUGHIO/IOHDF5Util/trunk@58 7842ec3a-9562-4be5-9c5b-06ba18f2b668

1 files changed, 311 insertions, 615 deletions

diff --git a/src/DumpVar.c b/src/DumpVar.c
index 109df75..96148d9 100644
--- a/src/DumpVar.c
+++ b/src/DumpVar.c
@@ -2,9 +2,9 @@
    @file      DumpVar.c
    @date      Fri May 21 1999
    @author    Thomas Radke
-   @desc 
+   @desc
               Routines for writing variables into HDF5 data or checkpoint files.
-              These routines are used by other HDF5 IO methods.
+              These routines are used by other HDF5 I/O methods.
    @enddesc
    @version   $Id$
  @@*/
@@ -15,77 +15,40 @@
 #include "cctk.h"
 #include "cctk_Parameters.h"
 #include "CactusPUGH/PUGH/src/include/pugh.h"
-#include "CactusPUGH/PUGHSlab/src/NewPUGHSlab.h" 
+#include "CactusPUGH/PUGHSlab/src/NewPUGHSlab.h"
 #include "CactusBase/IOUtil/src/ioGH.h"
 #include "ioHDF5UtilGH.h"
 
-
 /* the rcs ID and its dummy function to use it */
 static const char *rcsid = "$Header$";
 CCTK_FILEVERSION(BetaThorns_IOHDF5Util_DumpVar_c)
 
-/* #define DEBUG_ME 1 */
-
-#define IOTAGBASE 20000 /* This may break on more than 2000 processors */
 
-
-/* info structure describing how to dump a given CCTK variable type */
-typedef struct
-{
-  int iohdf5_type;              /* the HDF5 type to use */
-  int element_size;             /* size of a single data element */
-#ifdef CCTK_MPI
-  MPI_Datatype mpi_type;        /* the data type for MPI communication */
+/********************************************************************
+ ********************    Macro Definitions   ************************
+ ********************************************************************/
+/* uncomment the following line to enable some debugging output */
+/* #define IOHDF5UTIL_DEBUG 1 */
+
+/* tag base for MPI messages (this may break on more than 2000 processors) */
+#define MPITAGBASE 20000
+
+
+/********************************************************************
+ ********************    Internal Routines   ************************
+ ********************************************************************/
+static int WriteGS (const cGH *GH, const ioSlab *slab, const char *name,
+                    hid_t file);
+static int WriteGA (const cGH *GH, const ioSlab *slab, const char *name,
+                    hid_t file);
+static int GetLocalHyperslab (const cGH *GH, const ioSlab *slab, void **data,
+                              int *free_data);
+static void WriteData (const cGH *GH, const ioSlab *slab, const char *name,
+                       const void *data, int proc, hid_t file);
+#if defined(CCTK_MPI) && defined(H5_HAVE_PARALLEL)
+static void WriteDataCollective (const cGH *GH, const ioSlab *slab,
+                                 const char *name, const void *data,hid_t file);
 #endif
-} dumpInfo;
-
-
-/* prototypes of routines defined in this source file */
-static int IOHDF5Util_DumpGS (const cGH *GH,
-                              int vindex,
-                              int timelevel,
-                              int iohdf5_type,
-                              const ioHDF5Geo_t *request,  
-                              int check_exisiting_objects,
-                              hid_t file);
-static int IOHDF5Util_DumpGA (const cGH *GH,
-                              int vindex,
-                              int timelevel,
-                              const ioHDF5Geo_t *request,  
-                              const dumpInfo *info,
-                              int check_exisiting_objects,
-                              hid_t file);
-static int IOHDF5Util_getDumpData (const cGH *GH,
-                                   int vindex,
-                                   int timelevel,
-                                   const ioHDF5Geo_t *request,  
-                                   void **outme,
-                                   int *free_outme, 
-                                   CCTK_INT *geom);
-static void IOHDF5Util_procDump (const cGH *GH,
-                                 int vindex,
-                                 int timelevel,
-                                 const ioHDF5Geo_t *request,  
-                                 const void *outme,
-                                 const CCTK_INT *geom,
-                                 int proc, 
-                                 int iohdf5_type,
-                                 int check_exisiting_objects,
-                                 hid_t file);
-#ifdef CCTK_MPI
-#ifdef H5_HAVE_PARALLEL
-static void IOHDF5Util_collectiveDump (const cGH *GH,
-                                       int vindex,
-                                       int timelevel,
-                                       const ioHDF5Geo_t *request,  
-                                       const void *outme,
-                                       const CCTK_INT *geom, 
-                                       int hdf5io_type,
-                                       int check_exisiting_objects,
-                                       hid_t file);
-#endif /* H5_HAVE_PARALLEL */
-#endif /* MPI */
-
 
 
 /*@@
@@ -96,27 +59,17 @@ static void IOHDF5Util_collectiveDump (const cGH *GH,
                Generic dump routine, just calls the type-specific dump routine.
    @enddesc
 
-   @calls      IOHDF5Util_DumpGS
-               IOHDF5Util_DumpGA
+   @calls      WriteGS
+               WriteGA
 
    @var        GH
-   @vdesc      Pointer to CCTK grid hierarchy
+   @vdesc      pointer to CCTK grid hierarchy
    @vtype      const cGH *
    @vio        in
    @endvar
-   @var        vindex
-   @vdesc      index of the variable to be dumped
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        timelevel
-   @vdesc      the timelevel to dump
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        request
-   @vdesc      pointer to the IO request structure
-   @vtype      const ioHDF5Geo_t *
+   @var        slab
+   @vdesc      reference to the I/O hyperslab description
+   @vtype      const ioSlab *
    @vio        in
    @endvar
    @var        file
@@ -124,141 +77,83 @@ static void IOHDF5Util_collectiveDump (const cGH *GH,
    @vtype      hid_t
    @vio        in
    @endvar
-   @var        check_exisiting_objects
-   @vdesc      flag indicating if we should check for already existing objects
-               before these are created anew
-               This might happen for existing files reopened after recovery.
-   @vtype      int
-   @vio        in
-   @endvar
 
    @returntype int
    @returndesc
-               -1 if variable has unknown type
-               or return code of either
-                 @seeroutine IOHDF5Util_DumpGS or
-                 @seeroutine IOHDF5Util_DumpGA
+               -1 if variable has unknown group type
+               or return code of either @seeroutine WriteGS or
+                 @seeroutine WriteGA
    @endreturndesc
 @@*/
-int IOHDF5Util_DumpVar (const cGH *GH,
-                        int vindex,
-                        int timelevel,
-                        const ioHDF5Geo_t *request,
-                        hid_t file,
-                        int check_exisiting_objects)
+int IOHDF5Util_DumpVar (const cGH *GH, const ioSlab *slab, hid_t file)
 {
-  int vtype, gtype;
-  pGH *pughGH;
-  ioHDF5UtilGH *myGH;
-  ioGH *ioUtilGH;
-  dumpInfo info;
-  int retval;
+  int gtype, retval;
+  char *fullname, *objectname;
 
 
-  /* Get the handle for PUGH, IOUtil, and IOHDF5Util extensions */
-  pughGH = PUGH_pGH (GH);
-  ioUtilGH = (ioGH *) CCTK_GHExtension (GH, "IO");
-  myGH = (ioHDF5UtilGH *) CCTK_GHExtension (GH, "IOHDF5Util");
+  /* build the unique name for the file object to write */
+  fullname = CCTK_FullName (slab->vindex);
+  objectname = (char *) malloc (strlen (fullname) + 80);
+  sprintf (objectname, "%s timelevel %d at iteration %d",
+           fullname, slab->timelevel, GH->cctk_iteration);
 
-  vtype = CCTK_VarTypeI (vindex);
-  /* downgrade the output precision if requested */
-  if (ioUtilGH->out_single)
+  /* check whether the object already exists */
+  if (slab->check_exist && file >= 0)
   {
-    /* Do we only want to downgrade generic CCTK types ? */
-#ifdef CCTK_REAL4
-    if (vtype == CCTK_VARIABLE_REAL)
-    {
-      vtype = CCTK_VARIABLE_REAL4;
-    }
-    else if (vtype == CCTK_VARIABLE_COMPLEX)
-    {
-      vtype = CCTK_VARIABLE_COMPLEX8;
-    }
-#endif
-#ifdef CCTK_INT4
-    if (vtype == CCTK_VARIABLE_INT)
+    H5E_BEGIN_TRY
     {
-      vtype = CCTK_VARIABLE_INT4;
-    }
-#endif
-  }
-  info.element_size = CCTK_VarTypeSize (vtype);
-#ifdef CCTK_MPI
-  info.mpi_type = PUGH_MPIDataType (pughGH, vtype);
-#endif
-  info.iohdf5_type = IOHDF5Util_DataType (myGH, vtype);
-
-  if (info.element_size <= 0 ||
-#ifdef CCTK_MPI
-      info.mpi_type == MPI_DATATYPE_NULL ||
-#endif
-      info.iohdf5_type < 0)
-  {
-    CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "Unsupported variable type %d", vtype);
-    return (-1);
+      H5Gunlink (file, objectname);
+    } H5E_END_TRY;
   }
 
-  /* now branch to the appropriate dump routine */
-  gtype = CCTK_GroupTypeFromVarI (vindex);
+  /* branch to the appropriate dump routine */
+  gtype = CCTK_GroupTypeFromVarI (slab->vindex);
   if (gtype == CCTK_SCALAR)
   {
-    retval = IOHDF5Util_DumpGS (GH, vindex, timelevel, info.iohdf5_type,
-                                request, check_exisiting_objects, file);
+    retval = WriteGS (GH, slab, objectname, file);
   }
   else if (gtype == CCTK_ARRAY || gtype == CCTK_GF)
   {
-    retval = IOHDF5Util_DumpGA (GH, vindex, timelevel, request, &info,
-                                check_exisiting_objects, file);
+    retval = WriteGA (GH, slab, objectname, file);
   }
   else
   {
     CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "Invalid group type %d", gtype);
+                "Invalid group type %d for variable '%s'", gtype, fullname);
     retval = -1;
   }
 
+  /* clean up */
+  free (objectname);
+  free (fullname);
+
   return (retval);
 }
 
 
+/********************************************************************
+ ********************    Internal Routines   ************************
+ ********************************************************************/
 /*@@
-   @routine    IOHDF5Util_DumpGS
+   @routine    WriteGS
    @date       May 21 1999
    @author     Thomas Radke
    @desc
-               Dumps a CCTK_SCALAR type variable into a HDF5 file.
-   @enddesc 
+               Writes a CCTK_SCALAR type variable into a HDF5 file.
+   @enddesc
    @var        GH
-   @vdesc      Pointer to CCTK grid hierarchy
+   @vdesc      pointer to CCTK grid hierarchy
    @vtype      const cGH *
    @vio        in
    @endvar
-   @var        vindex
-   @vdesc      index of the variable to be dumped
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        timelevel
-   @vdesc      the timelevel to dump
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        iohdf5_type
-   @vdesc      the HDF5 datatype
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        request
-   @vdesc      pointer to the IO request structure
-   @vtype      const ioHDF5Geo_t *
+   @var        slab
+   @vdesc      reference to the I/O hyperslab description
+   @vtype      const ioSlab *
    @vio        in
    @endvar
-   @var        check_exisiting_objects
-   @vdesc      flag indicating if we should check for already existing objects
-               before these are created anew
-               This might happen for existing files reopened after recovery.
-   @vtype      int
+   @var        name
+   @vdesc      name of the dataset to write
+   @vtype      const char *
    @vio        in
    @endvar
    @var        file
@@ -272,113 +167,68 @@ int IOHDF5Util_DumpVar (const cGH *GH,
                0 for success, or -1 if file handle is invalid
    @endreturndesc
 @@*/
-static int IOHDF5Util_DumpGS (const cGH *GH,
-                              int vindex,
-                              int timelevel,
-                              int iohdf5_type,
-                              const ioHDF5Geo_t *request,  
-                              int check_exisiting_objects,
-                              hid_t file)
+static int WriteGS (const cGH *GH, const ioSlab *slab, const char *name,
+                    hid_t file)
 {
   ioGH *ioUtilGH;
   ioHDF5UtilGH *myGH;
-  hid_t dataset;
-  char *fullname;
-  char *datasetname;
-  static CCTK_INT global_shape[1] = {0};
-
+  hid_t dataset, hdf5type;
 
-  /* immediately return if file handle is invalid */
-  if (file < 0)
-  {
-    return (-1);
-  }
 
-  /* Get the handles for IOHDF5Util and IOUtil extensions */
   ioUtilGH = (ioGH *) CCTK_GHExtension (GH, "IO");
   myGH = (ioHDF5UtilGH *) CCTK_GHExtension (GH, "IOHDF5Util");
 
+  /* only I/O processors write data */
   if (CCTK_MyProc (GH) != ioUtilGH->ioproc)
   {
     return (0);
   }
 
-  fullname = CCTK_FullName (vindex);
-  datasetname = (char *) malloc (strlen (fullname) + 80);
-  sprintf (datasetname, "%s timelevel %d at iteration %d",
-           fullname, timelevel, GH->cctk_iteration);
-
-  /* if restart from recovery delete an already existing dataset
-     so that it can be created as anew */
-  if (check_exisiting_objects)
+  /* check if file handle is invalid */
+  if (file < 0)
   {
-    IOHDF5_ERROR (H5Eset_auto (NULL, NULL));
-    H5Gunlink (file, datasetname);
-    IOHDF5_ERROR (H5Eset_auto (myGH->print_error_fn, myGH->print_error_fn_arg));
+    return (-1);
   }
 
-  IOHDF5_ERROR (dataset = H5Dcreate (file, datasetname, iohdf5_type,
-                                     myGH->scalar_dataspace, H5P_DEFAULT));
-  IOHDF5_ERROR (H5Dwrite (dataset, iohdf5_type, H5S_ALL, H5S_ALL, H5P_DEFAULT,
-                          CCTK_VarDataPtrI (GH, timelevel, vindex)));
-    
-  IOHDF5Util_DumpCommonAttributes (GH, vindex, timelevel, global_shape,
-                                   request, dataset);
+  hdf5type = IOHDF5Util_DataType (myGH, slab->hdatatype);
+  HDF5_ERROR (dataset = H5Dcreate (file, name, hdf5type, myGH->scalar_dataspace,
+                                   H5P_DEFAULT));
+  HDF5_ERROR (H5Dwrite (dataset, hdf5type, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+                        CCTK_VarDataPtrI (GH, slab->timelevel, slab->vindex)));
 
-  IOHDF5_ERROR (H5Dclose (dataset));
+  IOHDF5Util_DumpCommonAttributes (GH, slab, dataset);
 
-  free (datasetname);
-  free (fullname);
+  HDF5_ERROR (H5Dclose (dataset));
 
   return (0);
 }
 
 
 /*@@
-   @routine    IOHDF5Util_DumpGA
+   @routine    WriteGA
    @date       May 21 1999
    @author     Paul Walker
    @desc
-               Dumps a CCTK_GF or CCTK_ARRAY type variable into a HDF5 file.
-   @enddesc 
+               Writes a grid array into a HDF5 file.
+   @enddesc
 
-   @calls      IOHDF5Util_getDumpData
-               IOHDF5Util_procDump
-               IOHDF5Util_collectiveDump
+   @calls      GetLocalHyperslab
+               WriteData
+               WriteDataCollective
 
    @var        GH
-   @vdesc      Pointer to CCTK grid hierarchy
+   @vdesc      pointer to CCTK grid hierarchy
    @vtype      const cGH *
    @vio        in
    @endvar
-   @var        vindex
-   @vdesc      index of the variable to be dumped
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        timelevel
-   @vdesc      the timelevel to dump
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        request
-   @vdesc      pointer to the IO request structure
-   @vtype      const ioHDF5Geo_t *
-   @vio        in
-   @endvar
-   @var        info
-   @vdesc      info structure describing
-                 - the HDF5 datatype to store
-                 - the size of an element of variable
-                 - the MPI datatype to communicate
-   @vtype      const dumpInfo *
+   @var        slab
+   @vdesc      reference to the I/O hyperslab description
+   @vtype      const ioSlab *
    @vio        in
    @endvar
-   @var        check_exisiting_objects
-   @vdesc      flag indicating if we should check for already existing objects
-               before these are created anew
-               This might happen for existing files reopened after recovery.
-   @vtype      int
+   @var        name
+   @vdesc      name of the dataset to write
+   @vtype      const char *
    @vio        in
    @endvar
    @var        file
@@ -390,45 +240,36 @@ static int IOHDF5Util_DumpGS (const cGH *GH,
    @returntype int
    @returndesc
                0 for success
-               or returncode of @seeroutine IOHDF5Util_getDumpData
+               or returncode of @seeroutine GetLocalHyperslab
    @endreturndesc
 @@*/
-static int IOHDF5Util_DumpGA (const cGH *GH,
-                              int vindex,
-                              int timelevel,
-                              const ioHDF5Geo_t *request,  
-                              const dumpInfo *info,
-                              int check_exisiting_objects,
-                              hid_t file)
+static int WriteGA (const cGH *GH, const ioSlab *slab, const char *name,
+                    hid_t file)
 {
   ioGH *ioUtilGH;
-  pGH *pughGH;
-  int myproc;
-  int nprocs;
-  CCTK_INT *geom; /* Lower bounds, sizes and global shape of data */
-  void *outme;    /* The data pointer to dump ... */
-  int free_outme; /* and whether it needs freeing */
-  int retval;
+  ioHDF5UtilGH *myGH;
+  int myproc, nprocs, retval;
+  void *data;    /* The data pointer to dump ... */
+  int free_data; /* and whether it needs freeing */
 #ifdef CCTK_MPI
   void *tmpd;
-  int incoming;
-  int outgoing;
-  int i, j;
+  int i, j, incoming, outgoing;
+  MPI_Comm comm;
   MPI_Status ms;
+  MPI_Datatype mpitype;
 #endif
   DECLARE_CCTK_PARAMETERS
 
 
-  /* Get the handles for PUGH and IOUtil extensions */
-  pughGH   = PUGH_pGH (GH);
+  myGH = (ioHDF5UtilGH *) CCTK_GHExtension (GH, "IOHDF5Util");
   ioUtilGH = (ioGH *) CCTK_GHExtension (GH, "IO");
 
-  /* allocate the geometry buffer */
-  geom = (CCTK_INT *) malloc (3 * request->sdim * sizeof (CCTK_INT));
-  
-  /* Get the pointer to the data we want to output (includes downsampling) */
-  retval = IOHDF5Util_getDumpData (GH, vindex, timelevel, request, &outme,
-                                   &free_outme, geom);
+#ifdef CCTK_MPI
+  mpitype = PUGH_MPIDataType (PUGH_pGH (GH), slab->hdatatype);
+#endif
+
+  /* get the pointer to the data we want to output (includes downsampling) */
+  retval = GetLocalHyperslab (GH, slab, &data, &free_data);
   if (retval < 0)
   {
     return (retval);
@@ -441,87 +282,82 @@ static int IOHDF5Util_DumpGA (const cGH *GH,
 #ifdef H5_HAVE_PARALLEL
   if (ioUtilGH->unchunked)
   {
-    IOHDF5Util_collectiveDump (GH, vindex, timelevel, request, outme, geom,
-                               info->iohdf5_type, check_exisiting_objects,file);
-    if (free_outme)
+    WriteDataCollective (GH, slab, name, data, file);
+    if (free_data)
     {
-      free (outme);
+      free (data);
     }
-    free (geom);
     return (0);
   }
 #endif
 #endif
 
-  /* Dump data held on IO processor */
+  /* dump data held on I/O processor */
   if (myproc == ioUtilGH->ioproc)
   {
-    IOHDF5Util_procDump (GH, vindex, timelevel, request, outme, geom,
-                         myproc, info->iohdf5_type, check_exisiting_objects,
-                         file);
+    WriteData (GH, slab, name, data, myproc, file);
   }
 #ifdef CCTK_MPI
+  comm = PUGH_pGH (GH)->PUGH_COMM_WORLD;
   if (myproc == ioUtilGH->ioproc)
   {
-    /* Dump data from all other processors */
+    /* dump data from all other processors */
     for (i = myproc+1; i < myproc+ioUtilGH->ioproc_every && i < nprocs; i++)
     {
-      /* receive geometry */
-      CACTUS_MPI_ERROR (MPI_Recv (geom, 3*request->sdim, PUGH_MPI_INT, i,
-                                  2*i + IOTAGBASE + 1, pughGH->PUGH_COMM_WORLD,
-                                  &ms));
+      /* receive geometry (this assumes the geometry arrays
+         to be contiguous starting at hoffset */
+      CACTUS_MPI_ERROR (MPI_Recv (slab->hoffset, 3*slab->hdim, PUGH_MPI_INT, i,
+                                  2*i + MPITAGBASE + 1, comm, &ms));
 
-      incoming = geom[request->sdim];
-      for (j = 1; j < request->sdim; j++)
+      incoming = 1;
+      for (j = 0; j < slab->hdim; j++)
       {
-        incoming *= geom[request->sdim + j];
+        incoming *= slab->hsize_chunk[slab->hdim + j];
       }
 
       /* receive data */
+      tmpd = NULL;
       if (incoming > 0)
       {
-        tmpd = malloc (incoming * info->element_size);
-        CACTUS_MPI_ERROR (MPI_Recv (tmpd, incoming, info->mpi_type, i,
-                                    2*i + IOTAGBASE, pughGH->PUGH_COMM_WORLD,
-                                    &ms));
+        tmpd = malloc (incoming * CCTK_VarTypeSize (slab->hdatatype));
+        CACTUS_MPI_ERROR (MPI_Recv (tmpd, incoming, mpitype, i,
+                                    2*i + MPITAGBASE, comm, &ms));
       }
-      else
-      {
-        tmpd = NULL;
-      }
-      IOHDF5Util_procDump (GH, vindex, timelevel, request, tmpd, geom, i,
-                           info->iohdf5_type, check_exisiting_objects, file);
+
+      /* write data */
+      WriteData (GH, slab, name, tmpd, i, file);
+
       if (tmpd)
       {
         free (tmpd);
       }
 
-    } /* End loop over processors */
+    } /* end loop over processors */
 
   }
   else
   {
-
-    /* Send the geometry and data from the non-IO processors
-     * to the IO processors
+    /*
+     * send the geometry and data from non-I/O processors to the I/O processors
      */
-    outgoing = geom[request->sdim];
-    for (i = 1; i < request->sdim; i++)
+    outgoing = 1;
+    for (i = 0; i < slab->hdim; i++)
     {
-      outgoing *= geom[request->sdim + i];
+      outgoing *= slab->hsize_chunk[slab->hdim + i];
     }
 
-    /* send geometry */
-    CACTUS_MPI_ERROR (MPI_Send (geom, 3*request->sdim, PUGH_MPI_INT,
-                                ioUtilGH->ioproc, 2*myproc + IOTAGBASE + 1,
-                                pughGH->PUGH_COMM_WORLD));
+    /* send geometry (this assumes the geometry arrays
+       to be contiguous starting at hoffset */
+    CACTUS_MPI_ERROR (MPI_Send (slab->hoffset, 3*slab->hdim, PUGH_MPI_INT,
+                                ioUtilGH->ioproc, 2*myproc + MPITAGBASE + 1,
+                                comm));
+    /* send data */
     if (outgoing > 0)
     {
-      /* send data if outgoing>0 */
-      CACTUS_MPI_ERROR (MPI_Send (outme, outgoing, info->mpi_type,
-                                  ioUtilGH->ioproc, 2*myproc + IOTAGBASE,
-                                  pughGH->PUGH_COMM_WORLD));
-#ifdef DEBUG_ME
+      CACTUS_MPI_ERROR (MPI_Send (data, outgoing, mpitype,
+                                  ioUtilGH->ioproc, 2*myproc + MPITAGBASE,
+                                  comm));
+#ifdef IOHDF5UTIL_DEBUG
       printf ("Processor %d sent %d data points\n", myproc, outgoing);
 #endif
     }
@@ -532,118 +368,95 @@ static int IOHDF5Util_DumpGA (const cGH *GH,
 #endif
 
   /* free allocated resources */
-  if (free_outme)
+  if (free_data)
   {
-    free (outme);
+    free (data);
   }
-  free (geom);
 
   return (retval);
 }
 
 
-/**************************************************************************/
-/*                             local functions                            */
-/**************************************************************************/
-static int IOHDF5Util_getDumpData (const cGH *GH,
-                                   int vindex,
-                                   int timelevel,
-                                   const ioHDF5Geo_t *request, 
-                                   void **outme,
-                                   int *free_outme, 
-                                   CCTK_INT *geom)
+static int GetLocalHyperslab (const cGH *GH, const ioSlab *slab, void **data,
+                              int *free_data)
 {
   int i, retval;
-  int cctk_output_type;
-  ioGH *ioUtilGH;
-  int *hsizes, *hsizes_global, *hsizes_offset; /* geometry information */
   char *fullname;
-  
-
-  /* get GH extension for IOUtil */
-  ioUtilGH = (ioGH *) CCTK_GHExtension (GH, "IO");
-
-  /* determine the datatype for the hyperslab */
-  cctk_output_type = CCTK_VarTypeI (vindex);
-  if (ioUtilGH->out_single)
-  {
-#ifdef CCTK_INT4
-    if (cctk_output_type == CCTK_VARIABLE_INT)
-    {
-      cctk_output_type = CCTK_VARIABLE_INT4;
-    }
-#endif
-#ifdef CCTK_REAL4
-    if (cctk_output_type == CCTK_VARIABLE_REAL)
-    {
-      cctk_output_type = CCTK_VARIABLE_REAL4;
-    }
-    else if (cctk_output_type == CCTK_VARIABLE_COMPLEX)
-    {
-      cctk_output_type = CCTK_VARIABLE_COMPLEX8;
-    }
-#endif
-  }
 
-  /* FIXME */
-  /* allocate array to hold size information of request */
-  hsizes        = (int *) malloc (3 * request->sdim * sizeof (int));
-  hsizes_global = hsizes + 1*request->sdim;
-  hsizes_offset = hsizes + 2*request->sdim;
 
 #if 0
-  FIXME: what is this for ???
-  /* Get the start indeces for the request from origin. */
-  /* Slab_start from the geo structure is not a true start index,
-     it is currently used as the intersection point of three surfaces,
-     that's why two entries have to be set to zero in the case of a
-     surface (one entry for line)
-     FIXME */
-  for (i = 0; i < vdim; i++)
+  mapping = Hyperslab_DefineLocalMappingByIndex (GH, vindex, slab->hdim,
+                                                 slab->direction, slab->origin,
+                                                 slab->extent, slab->downsample,
+                                                 -1, NULL, slab->hsize_local,
+                                                 slab->hsize_global,
+                                                 slab->hoffset_global);
+           const cGH          *GH,
+           CCTK_INT            vindex,
+           CCTK_INT            hdim,
+           const CCTK_INT     *direction         /* vdim*hdim */,
+           const CCTK_INT     *origin            /* vdim */,
+           const CCTK_INT     *extent            /* hdim */,
+           const CCTK_INT     *downsample        /* hdim */,
+           CCTK_INT            table_handle,
+           t_hslabConversionFn conversion_fn,
+           CCTK_INT           *hsize_local,      /* hdim */
+           CCTK_INT           *hsize_global,     /* hdim */
+           CCTK_INT           *hoffset_global    /* hdim */);
+
+  if (mapping < 0)
   {
-    slabstart[i] = request->origin[i];
+    fullname = CCTK_FullName (vindex);
+    CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
+                "Failed to extract hyperslab for variable '%s'", fullname);
+    free (fullname);
   }
-  for (i = 0; i < request->sdim; i++)
-  {
-    slabstart[request->direction[i]] = 0;
-  }     
-#endif
 
-  retval = NewHyperslab_GetLocalHyperslab (GH, vindex, timelevel, request->sdim,
-                                      cctk_output_type, NULL, request->origin,
-                                      request->direction, request->length,
-                                      request->downsample, outme, free_outme,
+#else
+{
+  int *hsizes, *hsizes_global, *hsizes_offset; /* geometry information */
+
+  /* allocate array to hold size information of request */
+  hsizes        = (int *) malloc (3 * slab->hdim * sizeof (int));
+  hsizes_global = hsizes + 1*slab->hdim;
+  hsizes_offset = hsizes + 2*slab->hdim;
+
+  retval = NewHyperslab_GetLocalHyperslab (GH, slab->vindex, slab->timelevel, slab->hdim,
+                                      slab->hdatatype, NULL, slab->origin,
+                                      slab->direction, slab->extent,
+                                      slab->downsample, data, free_data,
                                       hsizes, hsizes_global, hsizes_offset);
   if (retval == 0)
   {
-    for (i = 0; i < request->sdim; i++)
+    for (i = 0; i < slab->hdim; i++)
     {
-      geom[i + 0*request->sdim] = hsizes_offset[i];
-      geom[i + 1*request->sdim] = hsizes[i];        
-      geom[i + 2*request->sdim] = hsizes_global[i];
-      request->actlen[i]  = hsizes_global[i];
+      slab->hoffset[i] = hsizes_offset[i];
+      slab->hsize[i] = hsizes_global[i];
+      slab->hsize_chunk[i] = hsizes[i];
     }
   }
   else
   {
-    fullname = CCTK_FullName (vindex);
+    fullname = CCTK_FullName (slab->vindex);
     CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
                 "Failed to extract hyperslab for variable '%s'", fullname);
     free (fullname);
   }
 
   free (hsizes);
+}
+#endif
 
   return (retval);
 }
 
 
 /*@@
-   @routine    IOHDF5Util_procDump
+   @routine    WriteData
    @author     Thomas Radke
    @date       May 21 1999
    @desc
-               All IO processors dump the data of their group into the file,
+               All I/O processors dump the data of their group into the file,
                either as one chunk per processor or unchunked
                (depending on parameter "unchunked").
    @enddesc
@@ -651,78 +464,44 @@ static int IOHDF5Util_getDumpData (const cGH *GH,
    @calls      IOHDF5Util_DumpCommonAttributes
 
    @var        GH
-   @vdesc      Pointer to CCTK grid hierarchy
+   @vdesc      pointer to CCTK grid hierarchy
    @vtype      const cGH *
    @vio        in
    @endvar
-   @var        vindex
-   @vdesc      global index of the variable to be dumped
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        timelevel
-   @vdesc      the timelevel to store
-   @vtype      int
+   @var        slab
+   @vdesc      reference to the I/O hyperslab description
+   @vtype      const ioSlab *
    @vio        in
    @endvar
-   @var        request
-   @vdesc      pointer to the IO request structure
-   @vtype      const ioHDF5Geo_t *
+   @var        name
+   @vdesc      name of the dataset to write
+   @vtype      const char *
    @vio        in
    @endvar
-   @var        outme
+   @var        data
    @vdesc      pointer to the chunk to dump
    @vtype      const void *
    @vio        in
    @endvar
-   @var        geom
-   @vdesc      bounds and sizes of the output
-   @vtype      const CCTK_INT[3*dim]
-   @vio        in
-   @vcomment   geom[0*dim..1*dim-1]: lower bounds
-               geom[1*dim..2*dim-1]: (local) data sizes
-               geom[2*dim..3*dim-1]: global space
-   @endvar 
    @var        proc
    @vdesc      the processor which's chunk is to be dumped
    @vtype      int
    @vio        in
    @endvar
-   @var        hdf5io_type
-   @vdesc      the HDF5 datatype identifier
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        check_exisiting_objects
-   @vdesc      flag indicating if we should check for already existing objects
-               before these are created anew
-               This might happen for existing files reopened after recovery.
-   @vtype      int
-   @vio        in
-   @endvar
    @var        file
    @vdesc      the HDF5 file handle
    @vtype      hid_t
    @vio        in
    @endvar
 @@*/
-static void IOHDF5Util_procDump (const cGH *GH,
-                                 int vindex,
-                                 int timelevel,
-                                 const ioHDF5Geo_t *request,
-                                 const void *outme,
-                                 const CCTK_INT *geom,
-                                 int proc, 
-                                 int iohdf5_type,
-                                 int check_exisiting_objects,
-                                 hid_t file)
+static void WriteData (const cGH *GH, const ioSlab *slab, const char *name,
+                       const void *data, int proc, hid_t file)
 {
-  int i, sdim;
-  int myproc;
+  int i, myproc;
   ioGH *ioUtilGH;
   ioHDF5UtilGH *myGH;
-  hid_t group, dataset, memspace, filespace, plist;
-  char *fullname, *datasetname, *chunkname;
+  hid_t hdf5type, group, dataset, memspace, filespace, plist;
+  char *chunkname;
   hssize_t *chunk_origin;
   hsize_t *chunk_dims, *file_dims;
   hsize_t buffersize;
@@ -738,160 +517,132 @@ static void IOHDF5Util_procDump (const cGH *GH,
   ioUtilGH = (ioGH *) CCTK_GHExtension (GH, "IO");
   myGH = (ioHDF5UtilGH *) CCTK_GHExtension (GH, "IOHDF5Util");
 
-  sdim = request->sdim;
-  myproc = CCTK_MyProc (GH);
-
-  chunk_origin = (hssize_t *) malloc (sdim * sizeof (hssize_t));
-  chunk_dims   = (hsize_t *)  malloc (2*sdim * sizeof (hsize_t));
-  file_dims    = chunk_dims + sdim;
-
-  /* HDF5 needs it in reverse order */
-  for (i = 0; i < sdim; i++)
+  /* copy the size arrays from CCTK_INT to appropriate types
+     note that HDF5 wants elements in reverse order */
+  chunk_origin = (hssize_t *) malloc (slab->hdim * sizeof (hssize_t));
+  chunk_dims   = (hsize_t *)  malloc (2*slab->hdim * sizeof (hsize_t));
+  file_dims    = chunk_dims + slab->hdim;
+  for (i = 0; i < slab->hdim; i++)
   {
-    chunk_origin[i] = geom[1*sdim - 1 - i];
-    chunk_dims  [i] = geom[2*sdim - 1 - i];
-    file_dims   [i] = geom[3*sdim - 1 - i];
+    chunk_origin[i] = slab->hoffset[slab->hdim - 1 - i];
+    file_dims   [i] = slab->hsize[slab->hdim - 1 - i];
+    chunk_dims  [i] = slab->hsize_chunk[slab->hdim - 1 - i];
   }
 
-  /* build the unique dataset name from the variable's full name,
-     the timelevel and the current iteration number */
-  fullname = CCTK_FullName (vindex);
-  datasetname = (char *) malloc (strlen (fullname) + 80);
-  sprintf (datasetname, "%s timelevel %d at iteration %d",
-           fullname, timelevel, GH->cctk_iteration);
-
-  /* if restart from recovery delete an already existing dataset
-      so that it can be created as anew */
-  if (proc == myproc && check_exisiting_objects)
-  {
-    IOHDF5_ERROR (H5Eset_auto (NULL, NULL));
-    H5Gunlink (file, datasetname);
-    IOHDF5_ERROR (H5Eset_auto (myGH->print_error_fn, myGH->print_error_fn_arg));
-  }
+  myproc = CCTK_MyProc (GH);
 
-  if (outme)
+  memspace = -1;
+  if (data)
   {
     /* create the memspace according to chunk dims */
-    IOHDF5_ERROR (memspace = H5Screate_simple (sdim, chunk_dims, NULL));
-  }
-  else
-  {
-    memspace = -1;
+    HDF5_ERROR (memspace = H5Screate_simple (slab->hdim, chunk_dims, NULL));
   }
 
+  hdf5type = IOHDF5Util_DataType (myGH, slab->hdatatype);
   if (ioUtilGH->unchunked)
   {
     /* create the (global) filespace and set the hyperslab for the chunk */
-    IOHDF5_ERROR (filespace = H5Screate_simple (sdim, file_dims, NULL));
-    IOHDF5_ERROR (H5Sselect_hyperslab (filespace, H5S_SELECT_SET,
-                                       chunk_origin, NULL, chunk_dims, NULL));
-   
-    /* the IO processor creates the dataset and adds the common attributes
+    HDF5_ERROR (filespace = H5Screate_simple (slab->hdim, file_dims, NULL));
+    HDF5_ERROR (H5Sselect_hyperslab (filespace, H5S_SELECT_SET, chunk_origin,
+                                     NULL, chunk_dims, NULL));
+
+    /* the I/O processor creates the dataset and adds the common attributes
        when writing its own data, otherwise the dataset is reopened */
     if (proc == myproc)
     {
-      IOHDF5_ERROR (plist = H5Pcreate (H5P_DATASET_CREATE));
+      HDF5_ERROR (plist = H5Pcreate (H5P_DATASET_CREATE));
       /* enable compression for chunked dataset if compression was requested */
       if (compression_level)
       {
-        IOHDF5_ERROR (H5Pset_chunk (plist, sdim, chunk_dims));
-        IOHDF5_ERROR (H5Pset_deflate (plist, compression_level));
+        HDF5_ERROR (H5Pset_chunk (plist, slab->hdim, chunk_dims));
+        HDF5_ERROR (H5Pset_deflate (plist, compression_level));
       }
-      IOHDF5_ERROR (dataset = H5Dcreate (file, datasetname,
-                                         iohdf5_type, filespace, plist));
-      IOHDF5_ERROR (H5Pclose (plist));
-      IOHDF5Util_DumpCommonAttributes (GH, vindex, timelevel, &geom[2*sdim],
-                                       request, dataset);
+      HDF5_ERROR (dataset = H5Dcreate (file, name, hdf5type, filespace, plist));
+      HDF5_ERROR (H5Pclose (plist));
+      IOHDF5Util_DumpCommonAttributes (GH, slab, dataset);
     }
     else
     {
-      IOHDF5_ERROR (dataset = H5Dopen (file, datasetname));
+      HDF5_ERROR (dataset = H5Dopen (file, name));
     }
 
     if (memspace >= 0)
     {
       /* increase the buffer size if the default isn't sufficient */
-      IOHDF5_ERROR (plist = H5Pcreate (H5P_DATASET_XFER));
+      HDF5_ERROR (plist = H5Pcreate (H5P_DATASET_XFER));
       buffersize = H5Dget_storage_size (dataset);
       if (buffersize > H5Pget_buffer (plist, NULL, NULL))
       {
-        IOHDF5_ERROR (H5Pset_buffer (plist, buffersize, NULL, NULL));
+        HDF5_ERROR (H5Pset_buffer (plist, buffersize, NULL, NULL));
       }
 
       /* write the data */
-      IOHDF5_ERROR (H5Dwrite (dataset, iohdf5_type, memspace, filespace,
-                              plist, outme));
+      HDF5_ERROR (H5Dwrite (dataset, hdf5type, memspace, filespace, plist,
+                            data));
 
       /* close the transfer property list */
-      IOHDF5_ERROR (H5Pclose (plist));
+      HDF5_ERROR (H5Pclose (plist));
     }
     /* close the file dataspace */
-    IOHDF5_ERROR (H5Sclose (filespace));
+    HDF5_ERROR (H5Sclose (filespace));
   }
   else
   {
-    /* the IO processor creates the chunk group and adds common attributes */
+    /* the I/O processor creates the chunk group and adds common attributes */
     if (proc == myproc)
     {
-      IOHDF5_ERROR (group = H5Gcreate (file, datasetname, 0));
-      IOHDF5Util_DumpCommonAttributes (GH, vindex, timelevel, &geom[2*sdim],
-                                       request, group);
-      IOHDF5_ERROR (H5Gclose (group));
+      HDF5_ERROR (group = H5Gcreate (file, name, 0));
+      IOHDF5Util_DumpCommonAttributes (GH, slab, group);
+      HDF5_ERROR (H5Gclose (group));
     }
 
+    dataset = -1;
     if (memspace >= 0)
     {
       /* now the chunk dataset for each processor is created within the group */
-      chunkname = (char *) malloc (strlen (datasetname) + 20);
-      sprintf (chunkname, "%s/chunk%d", datasetname, proc - myproc);
-      IOHDF5_ERROR (plist = H5Pcreate (H5P_DATASET_CREATE));
+      chunkname = (char *) malloc (strlen (name) + 20);
+      sprintf (chunkname, "%s/chunk%d", name, proc - myproc);
+      HDF5_ERROR (plist = H5Pcreate (H5P_DATASET_CREATE));
       /* enable compression for chunked dataset if compression was requested */
       if (compression_level)
       {
-        IOHDF5_ERROR (H5Pset_chunk (plist, sdim, chunk_dims));
-        IOHDF5_ERROR (H5Pset_deflate (plist, compression_level));
-      } 
+        HDF5_ERROR (H5Pset_chunk (plist, slab->hdim, chunk_dims));
+        HDF5_ERROR (H5Pset_deflate (plist, compression_level));
+      }
       /* create the chunk dataset and dump the chunk data */
-      IOHDF5_ERROR (dataset = H5Dcreate (file, chunkname,
-                                         iohdf5_type, memspace, plist));
-      IOHDF5_ERROR (H5Pclose (plist));
-      IOHDF5_ERROR (H5Dwrite (dataset, iohdf5_type, H5S_ALL, H5S_ALL,
-                              H5P_DEFAULT, outme));
+      HDF5_ERROR (dataset = H5Dcreate (file, chunkname, hdf5type, memspace,
+                                       plist));
+      HDF5_ERROR (H5Pclose (plist));
+      HDF5_ERROR (H5Dwrite (dataset, hdf5type, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+                            data));
 
       /* add the "origin" attribute for the chunk */
-      WRITE_ATTRIBUTE ("chunk_origin", geom, dataset, myGH->array_dataspace,
-                       sdim, IOHDF5_INT);
+      WRITE_ATTRIBUTE ("chunk_origin", slab->hoffset, dataset, myGH, slab->hdim,
+                       HDF5_INT);
 
       free (chunkname);
     }
-    else
-    {
-      dataset = -1;
-    }
   }
 
   /* close the dataset and the memspace */
   if (dataset >= 0)
   {
-    IOHDF5_ERROR (H5Dclose (dataset));
+    HDF5_ERROR (H5Dclose (dataset));
   }
   if (memspace >= 0)
   {
-    IOHDF5_ERROR (H5Sclose (memspace));
+    HDF5_ERROR (H5Sclose (memspace));
   }
 
   /* free allocated resources */
-  free (datasetname);
-  free (fullname);
   free (chunk_origin);
   free (chunk_dims);
 }
 
 
-#ifdef CCTK_MPI
-#ifdef H5_HAVE_PARALLEL
+#if defined(CCTK_MPI) && defined(H5_HAVE_PARALLEL)
 /*@@
-   @routine    IOHDF5Util_collectiveDump
+   @routine    WriteDataCollective
    @author     Thomas Radke
    @date       May 21 1999
    @desc
@@ -901,70 +652,36 @@ static void IOHDF5Util_procDump (const cGH *GH,
    @calls      IOHDF5Util_DumpCommonAttributes
 
    @var        GH
-   @vdesc      Pointer to CCTK grid hierarchy
+   @vdesc      pointer to CCTK grid hierarchy
    @vtype      const cGH *
    @vio        in
    @endvar
-   @var        vindex
-   @vdesc      global index of the variable to be dumped
-   @vtype      int
+   @var        slab
+   @vdesc      reference to the I/O hyperslab description
+   @vtype      const ioSlab *
    @vio        in
    @endvar
-   @var        timelevel
-   @vdesc      the timelevel to store
-   @vtype      int
+   @var        name
+   @vdesc      name of the dataset to write
+   @vtype      const char *
    @vio        in
    @endvar
-   @var        request
-   @vdesc      pointer to the IO request structure
-   @vtype      const ioHDF5Geo_t *
-   @vio        in
-   @endvar
-   @var        outme
+   @var        data
    @vdesc      pointer to the chunk to dump
    @vtype      const void *
    @vio        in
    @endvar
-   @var        geom
-   @vdesc      bounds and sizes of the output
-   @vtype      const CCTK_INT[3*dim]
-   @vio        in
-   @vcomment   geom[0*dim..1*dim-1]: lower bounds
-               geom[1*dim..2*dim-1]: (local) data sizes
-               geom[2*dim..3*dim-1]: global space
-   @endvar 
-   @var        hdf5io_type
-   @vdesc      the HDF5 datatype identifier
-   @vtype      int
-   @vio        in
-   @endvar
-   @var        check_exisiting_objects
-   @vdesc      flag indicating if we should check for already existing objects
-               before these are created anew
-               This might happen for existing files reopened after recovery.
-   @vtype      int
-   @vio        in
-   @endvar
    @var        file
    @vdesc      the HDF5 file handle
    @vtype      hid_t
    @vio        in
    @endvar
 @@*/
-static void IOHDF5Util_collectiveDump (const cGH *GH,
-                                       int vindex,
-                                       int timelevel,
-                                       const ioHDF5Geo_t *request,  
-                                       const void *outme,
-                                       const CCTK_INT *geom, 
-                                       int hdf5io_type,
-                                       int check_exisiting_objects,
-                                       hid_t file)
+static void WriteDataCollective (const cGH *GH, const ioSlab *slab,
+                                 const char *name, const void *data, hid_t file)
 {
   int i, dim;
-  ioHDF5UtilGH *myGH;
-  hid_t dataset, memspace, filespace, plist;
-  char *fullname, *datasetname;
+  hid_t hdf5type, dataset, memspace, filespace, plist;
   hssize_t *chunk_origin;
   hsize_t *chunk_dims, *file_dims;
   hsize_t buffersize;
@@ -977,84 +694,63 @@ static void IOHDF5Util_collectiveDump (const cGH *GH,
     return;
   }
 
-  myGH = (ioHDF5UtilGH *) CCTK_GHExtension (GH, "IOHDF5Util");
-
-  /* get the dimension of the variable */
-  chunk_origin = (hssize_t *) malloc (request->sdim * sizeof (hssize_t));
-  chunk_dims   = (hsize_t *)  malloc (2*request->sdim * sizeof (hsize_t));
-  file_dims    = chunk_dims + request->sdim;
-
-  /* HDF5 needs it in reverse order */
-  for (i = 0; i < request->sdim; i++)
+  /* copy the size arrays from CCTK_INT to appropriate types
+     note that HDF5 wants elements in reverse order */
+  chunk_origin = (hssize_t *) malloc (slab->hdim * sizeof (hssize_t));
+  chunk_dims   = (hsize_t *)  malloc (2*slab->hdim * sizeof (hsize_t));
+  file_dims    = chunk_dims + slab->hdim;
+  for (i = 0; i < slab->hdim; i++)
   {
-    chunk_origin[i] = geom[1*request->sdim - 1 - i];
-    chunk_dims  [i] = geom[2*request->sdim - 1 - i];
-    file_dims   [i] = geom[3*request->sdim - 1 - i];
+    chunk_origin[i] = slab->hoffset[slab->hdim - 1 - i];
+    chunk_dims  [i] = slab->hsize_chunk[slab->hdim - 1 - i];
+    file_dims   [i] = slab->hsize_global[slab->hdim - 1 - i];
   }
 
-  /* build the unique dataset name */
-  fullname = CCTK_FullName (vindex);
-  datasetname = (char *) malloc (strlen (fullname) + 80);
-  sprintf (datasetname, "%s timelevel %d at iteration %d",
-           fullname, timelevel, GH->cctk_iteration);
-
   /* create the memspace according to chunk dims */
-  IOHDF5_ERROR (memspace = H5Screate_simple (request->sdim, chunk_dims, NULL));
+  HDF5_ERROR (memspace = H5Screate_simple (slab->hdim, chunk_dims, NULL));
 
   /* create the (global) filespace and set the hyperslab for the chunk */
-  IOHDF5_ERROR (filespace = H5Screate_simple (request->sdim, file_dims, NULL));
-  IOHDF5_ERROR (H5Sselect_hyperslab (filespace, H5S_SELECT_SET,
-                                     chunk_origin, NULL, chunk_dims, NULL));
+  HDF5_ERROR (filespace = H5Screate_simple (slab->hdim, file_dims, NULL));
+  HDF5_ERROR (H5Sselect_hyperslab (filespace, H5S_SELECT_SET, chunk_origin,
+                                   NULL, chunk_dims, NULL));
 
-  /* the IO processor creates the dataset and adds the common attributes
+  /* the I/O processor creates the dataset and adds the common attributes
      when writing its own data, otherwise the dataset is reopened */
-  /* if restart from recovery delete an already existing group
-     so that it can be created as anew */
-  if (check_exisiting_objects)
-  {
-    IOHDF5_ERROR (H5Eset_auto (NULL, NULL));
-    H5Gunlink (file, datasetname);
-    IOHDF5_ERROR (H5Eset_auto (myGH->print_error_fn, myGH->print_error_fn_arg));
-  }
+  hdf5type = IOHDF5Util_DataType (myGH, slab->hdatatype);
+
   /* enable compression for chunked dataset if compression was requested */
-  IOHDF5_ERROR (plist = H5Pcreate (H5P_DATASET_CREATE));
+  HDF5_ERROR (plist = H5Pcreate (H5P_DATASET_CREATE));
   if (compression_level)
   {
-    IOHDF5_ERROR (H5Pset_chunk (plist, request->sdim, chunk_dims));
-    IOHDF5_ERROR (H5Pset_deflate (plist, compression_level));
+    HDF5_ERROR (H5Pset_chunk (plist, slab->hdim, chunk_dims));
+    HDF5_ERROR (H5Pset_deflate (plist, compression_level));
   }
-  IOHDF5_ERROR (dataset = H5Dcreate (file, datasetname, hdf5io_type, filespace,
-                                     plist));
-  IOHDF5_ERROR (H5Pclose (plist));
+  HDF5_ERROR (dataset = H5Dcreate (file, name, hdf5type, filespace, plist));
+  HDF5_ERROR (H5Pclose (plist));
   if (CCTK_MyProc (GH) == 0)
   {
-    IOHDF5Util_DumpCommonAttributes (GH, vindex, timelevel,
-                                     &geom[2*request->sdim], request, dataset);
+    IOHDF5Util_DumpCommonAttributes (GH, slab, dataset);
   }
 
   /* increase the buffer size if the default isn't sufficient */
-  IOHDF5_ERROR (plist = H5Pcreate (H5P_DATASET_XFER));
+  HDF5_ERROR (plist = H5Pcreate (H5P_DATASET_XFER));
   buffersize = H5Dget_storage_size (dataset);
   if (buffersize > H5Pget_buffer (plist, NULL, NULL))
   {
-    IOHDF5_ERROR (H5Pset_buffer (plist, buffersize, NULL, NULL));
+    HDF5_ERROR (H5Pset_buffer (plist, buffersize, NULL, NULL));
   }
 
   /* write the data */
-  IOHDF5_ERROR (H5Dwrite (dataset, hdf5io_type, memspace, filespace, plist,
-                          outme));
+  HDF5_ERROR (H5Dwrite (dataset, hdf5type, memspace, filespace, plist, data));
 
   /* close resources */
-  IOHDF5_ERROR (H5Pclose (plist));
-  IOHDF5_ERROR (H5Sclose (filespace));
-  IOHDF5_ERROR (H5Dclose (dataset));
-  IOHDF5_ERROR (H5Sclose (memspace));
+  HDF5_ERROR (H5Pclose (plist));
+  HDF5_ERROR (H5Sclose (filespace));
+  HDF5_ERROR (H5Dclose (dataset));
+  HDF5_ERROR (H5Sclose (memspace));
 
   /* free allocated resources */
-  free (datasetname);
-  free (fullname);
   free (chunk_origin);
   free (chunk_dims);
 }
-#endif /* H5_HAVE_PARALLEL */
-#endif /* MPI */
+#endif /* CCTK_MPI && H5_HAVE_PARALLEL */