[svn-r303] Changes since 19980228

----------------------

./html/Dataspaces.html
./html/Errors.html
./html/Files.html
./html/H5.api.html
./html/review1.html
./src/H5private.h
./src/H5public.h
./test/dsets.c
./test/dtypes.c
	Removed all the types like `int32' and `intn' into private
	headers since they violate the naming scheme and pollute
	application name space.  Besides, our test files only use them
	in a handful of places and it's probably useless to export
	them to the app.  The app is always written in terms of
	standard numeric types or its own numeric types and probably
	never in terms of HDF5 numeric types.  If it were, then the
	user would have to copy from their type to hdf5 type for
	almost every hdf5 API function call!  Same goes for return
	values.  I also removed SUCCEED/FAIL from the API since apps
	should be checking against zero anyway.

	       if (FAIL==(space=H5Screate_simple(...))) /*wrong*/
	       if ((space=H5Fcreate_simple(...)<0))     /*right*/


./src/H5.c
	Changed arguments of H5version() from `uintn' to `unsigned'.

./src/H5Tpublic.h
./src/H5T.c
	Changed return type of H5Tget_nmembers() from `intn' to `int'


./src/H5A.c
./src/H5Aprivate.h
./src/H5Apublic.h
	Changed `H5Asearch_func_t' to `H5A_search_func_t' and moved
	its definition from the public to the private header file.


./html/H5.format.html
	Documented changes made to the external file list (H5O_EFL)
	message.

./src/H5D.c
./src/H5Dprivate.h
./src/H5E.c
./src/H5Epublic.h
./src/H5O.c
./src/H5Oefl.c
./src/H5Oprivate.h
./src/H5P.c
./src/H5Ppublic.h
	Added partial support for external raw data files.  HDF5 can
	now describe external raw data files by listing the file
	names, offsets, and size for a dataset. However, we will
	restrict a dataset to be stored "contiguously" when the
	external file list is viewed as a single address space. The
	current implementation is unable to read/write to external
	files--that will come later this week as will documentation.
	For now, take a look at ./test/external.c, particularly the
	calls to H5Pset_external().

./test/Makefile.in
./test/external.c		[NEW]
./MANIFEST
	Added tests for external storage.  Note: the read test is
	supposed to fail at this point since reading external datasets
	is not implemented yet.  There is no write test.

./src/H5S.c
./src/H5Sprivate.h
./src/H5Ssimp.c
	Added H5S_get_npoints_max() to return the maximum possible
	number of data points in a data space.

	Added an extra argument to H5S_get_dims() which returns the
	maximum dims.

./src/H5F.c
./src/H5Fprivate.h
./src/H5Fpublic.h
./src/H5M.c			[DEPRICATED]
./src/H5Mpublic.h		[DEPRICATED]
	Changed `template' to `property list' in lots of places.

./src/H5Osdspace.c
	Removed an extra `\n' from a print statement.

./src/H5S_public.h
	Changed H5S_UNLIMITED to the maximum size_t value.

./test/extend.c
	"Extendable" is spelled "extendible".

./src/H5Farray.c
./src/H5V.c
./src/H5Vprivate.h
./test/hyperslab.c
	Strides are now type ssize_t instead of int.  These have
	nothing to do with the sample granularity arguments for
	hyperslabs, which are also called "strides" in the code.

./test/tstab.c
	Changed assumptions about default address and length sizes.

1 files changed, 162 insertions, 91 deletions

diff --git a/src/H5D.c b/src/H5D.c
index c7ac56b..a3694ee 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -16,18 +16,19 @@ static char		RcsId[] = "@(#)$Revision$";
 
 /* $Id$ */
 
-#include <H5private.h>		/* Generic Functions			  */
-#include <H5Aprivate.h>		/* Atoms			  */
-#include <H5ACprivate.h>	/* Cache			  */
-#include <H5Pprivate.h>		/* Templates				  */
-#include <H5Dprivate.h>		/* Dataset functions			  */
-#include <H5Eprivate.h>		/* Error handling		  */
-#include <H5Gprivate.h>		/* Group headers		  */
-#include <H5Mprivate.h>		/* Meta data				  */
-#include <H5MFprivate.h>	/* File space allocation header		  */
-#include <H5MMprivate.h>	/* Memory management			  */
-#include <H5Mprivate.h>		/* Meta-Object API			  */
-#include <H5Oprivate.h>		/* Object headers		  */
+#include <H5private.h>		/* Generic Functions			*/
+#include <H5Aprivate.h>		/* Atoms			  	*/
+#include <H5ACprivate.h>	/* Cache			  	*/
+#include <H5Dprivate.h>		/* Dataset functions			*/
+#include <H5Eprivate.h>		/* Error handling		  	*/
+#include <H5Gprivate.h>		/* Group headers		  	*/
+#include <H5Hprivate.h>		/* Name heap				*/
+#include <H5Mprivate.h>		/* Meta data				*/
+#include <H5MFprivate.h>	/* File space allocation header		*/
+#include <H5MMprivate.h>	/* Memory management			*/
+#include <H5Mprivate.h>		/* Meta-Object API			*/
+#include <H5Oprivate.h>		/* Object headers		  	*/
+#include <H5Pprivate.h>		/* Property lists			*/
 
 #define PABLO_MASK	H5D_mask
 
@@ -35,35 +36,37 @@ static char		RcsId[] = "@(#)$Revision$";
  * A dataset is the following struct.
  */
 struct H5D_t {
-    H5G_entry_t		    ent;	/*cached object header stuff	*/
-    H5T_t		   *type;	/*datatype of this dataset	*/
-    H5S_t		   *space;	/*dataspace of this dataset	*/
-    H5D_create_t	    create_parms; /*creation parameters		*/
-    H5O_layout_t	    layout;	/*data layout			*/
+    H5G_entry_t		ent;		/*cached object header stuff	*/
+    H5T_t		*type;		/*datatype of this dataset	*/
+    H5S_t		*space;		/*dataspace of this dataset	*/
+    H5D_create_t	*create_parms;	/*creation parameters		*/
+    H5O_layout_t	layout;		/*data layout			*/
 };
 
-/* Default dataset creation template */
-const H5D_create_t	H5D_create_dflt =
-{
+/* Default dataset creation property list */
+const H5D_create_t	H5D_create_dflt = {
     H5D_CONTIGUOUS,		/* Layout				*/
     1,				/* Chunk dimensions			*/
-    {1, 1, 1, 1, 1, 1, 1, 1,	/* Chunk size.	These default values.... */
-     1, 1, 1, 1, 1, 1, 1, 1,	/*...are quite useless.	 Larger chunks.. */
-     1, 1, 1, 1, 1, 1, 1, 1,	/*...produce fewer, but larger I/O...... */
+    {1, 1, 1, 1, 1, 1, 1, 1,	/* Chunk size.	These default values....*/
+     1, 1, 1, 1, 1, 1, 1, 1,	/*...are quite useless.	 Larger chunks..*/
+     1, 1, 1, 1, 1, 1, 1, 1,	/*...produce fewer, but larger I/O......*/
      1, 1, 1, 1, 1, 1, 1, 1},	/*...requests.				*/
+    {H5F_ADDR_UNDEF,		/* External file list heap address	*/
+     0,				/*...slots allocated			*/
+     0,				/*...slots used				*/
+     NULL}			/*...slot array				*/
 };
 
-/* Default dataset transfer template */
-const H5D_xfer_t	H5D_xfer_dflt =
-{
+/* Default dataset transfer property list */
+const H5D_xfer_t	H5D_xfer_dflt = {
     0,				/* Place holder - remove this later	*/
 };
 
 /* Interface initialization? */
-static hbool_t		interface_initialize_g = FALSE;
+static hbool_t interface_initialize_g = FALSE;
 #define INTERFACE_INIT H5D_init_interface
-static herr_t		H5D_init_interface(void);
-static void		H5D_term_interface(void);
+static herr_t H5D_init_interface(void);
+static void H5D_term_interface(void);
 
 
 /*--------------------------------------------------------------------------
@@ -143,7 +146,7 @@ H5D_term_interface(void)
  *
  * Errors:
  *		ARGS	  BADTYPE	Not a data space. 
- *		ARGS	  BADTYPE	Not a dataset creation template. 
+ *		ARGS	  BADTYPE	Not a dataset creation plist. 
  *		ARGS	  BADTYPE	Not a file. 
  *		ARGS	  BADTYPE	Not a type. 
  *		ARGS	  BADVALUE	No name. 
@@ -190,7 +193,7 @@ H5Dcreate(hid_t file_id, const char *name, hid_t type_id, hid_t space_id,
 	if (H5P_DATASET_CREATE != H5Pget_class(create_parms_id) ||
 	    NULL == (create_parms = H5A_object(create_parms_id))) {
 	    HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-			  "not a dataset creation template");
+			  "not a dataset creation property list");
 	}
     } else {
 	create_parms = &H5D_create_dflt;
@@ -198,13 +201,14 @@ H5Dcreate(hid_t file_id, const char *name, hid_t type_id, hid_t space_id,
 
     /* build and open the new dataset */
     if (NULL == (new_dset = H5D_create(f, name, type, space, create_parms))) {
-	HRETURN_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't create dataset");
+	HRETURN_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL,
+		      "unable to create dataset");
     }
     /* Register the new datatype and get an ID for it */
     if ((ret_value = H5A_register(H5_DATASET, new_dset)) < 0) {
 	H5D_close(new_dset);
 	HRETURN_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL,
-		      "can't register dataset");
+		      "unable to register dataset");
     }
     FUNC_LEAVE(ret_value);
 }
@@ -322,7 +326,7 @@ H5Dclose(hid_t dataset_id)
  *		Failure:	FAIL
  *
  * Programmer:	Robb Matzke
- *              Wednesday, January 28, 1998
+ *		Wednesday, January 28, 1998
  *
  * Modifications:
  *
@@ -364,14 +368,14 @@ H5Dget_space (hid_t dataset_id)
  *
  * Purpose:	Returns a copy of the file data type for a dataset.
  *
- * Return:	Success:	ID for a copy of the data type.  The data
+ * Return:	Success:	ID for a copy of the data type.	 The data
  *				type should be released by calling
  *				H5Tclose().
  *
  *		Failure:	FAIL
  *
  * Programmer:	Robb Matzke
- *              Tuesday, February  3, 1998
+ *		Tuesday, February  3, 1998
  *
  * Modifications:
  *
@@ -411,16 +415,16 @@ H5Dget_type (hid_t dataset_id)
 /*-------------------------------------------------------------------------
  * Function:	H5Dget_create_parms
  *
- * Purpose:	Returns a copy of the dataset creation template.
+ * Purpose:	Returns a copy of the dataset creation property list.
  *
  * Return:	Success:	ID for a copy of the dataset creation
- *				template.  The template should be released by
- *				calling H5Pclose().
+ *				property list.  The template should be
+ *				released by calling H5Pclose().
  *
  *		Failure:	FAIL
  *
  * Programmer:	Robb Matzke
- *              Tuesday, February  3, 1998
+ *		Tuesday, February  3, 1998
  *
  * Modifications:
  *
@@ -441,18 +445,18 @@ H5Dget_create_parms (hid_t dataset_id)
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset");
     }
 
-    /* Copy the creation template */
+    /* Copy the creation property list */
     if (NULL==(copied_parms=H5P_copy (H5P_DATASET_CREATE,
-				      &(dataset->create_parms)))) {
+				      dataset->create_parms))) {
 	HRETURN_ERROR (H5E_DATASET, H5E_CANTINIT, FAIL,
-		       "unable to copy the creation template");
+		       "unable to copy the creation property list");
     }
 
     /* Create an atom */
     if ((ret_value=H5A_register ((group_t)(H5_TEMPLATE_0+H5P_DATASET_CREATE),
 				 copied_parms))<0) {
 	HRETURN_ERROR (H5E_ATOM, H5E_CANTREGISTER, FAIL,
-		       "unable to register creation template");
+		       "unable to register creation property list");
     }
 
     FUNC_LEAVE (ret_value);
@@ -653,7 +657,7 @@ H5Dwrite(hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id,
  *		Failure:	FAIL
  *
  * Programmer:	Robb Matzke
- *              Friday, January 30, 1998
+ *		Friday, January 30, 1998
  *
  * Modifications:
  *
@@ -740,9 +744,9 @@ H5D_t *
 H5D_create(H5F_t *f, const char *name, const H5T_t *type, const H5S_t *space,
 	   const H5D_create_t *create_parms)
 {
-    H5D_t		   *new_dset = NULL;
-    H5D_t		   *ret_value = NULL;
-    intn		    i;
+    H5D_t		*new_dset = NULL;
+    H5D_t		*ret_value = NULL;
+    intn		i;
 
     FUNC_ENTER(H5D_create, NULL);
 
@@ -758,43 +762,41 @@ H5D_create(H5F_t *f, const char *name, const H5T_t *type, const H5S_t *space,
     H5F_addr_undef(&(new_dset->ent.header));
     new_dset->type = H5T_copy(type);
     new_dset->space = H5S_copy(space);
-    new_dset->create_parms = *create_parms;
-
-    /*
-     * Create (open for write access) an object header.
-     */
-    if (H5O_create(f, 0, &(new_dset->ent)) < 0) {
-	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
-		    "unable to create dataset object header");
-    }
-    /* Update the type and space header messages */
-    if (H5O_modify(&(new_dset->ent), H5O_DTYPE, 0, 0, new_dset->type) < 0 ||
-	H5S_modify(&(new_dset->ent), new_dset->space) < 0) {
-	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
-		    "can't update type or space header messages");
-    }
+    new_dset->create_parms = H5P_copy (H5P_DATASET_CREATE, create_parms);
 
     /* Total raw data size */
-    new_dset->layout.type = new_dset->create_parms.layout;
+    new_dset->layout.type = new_dset->create_parms->layout;
     new_dset->layout.ndims = H5S_get_ndims(space) + 1;
     assert(new_dset->layout.ndims <= NELMTS(new_dset->layout.dim));
     new_dset->layout.dim[new_dset->layout.ndims - 1] = H5T_get_size(type);
 
-    switch (new_dset->create_parms.layout) {
+    switch (new_dset->create_parms->layout) {
     case H5D_CONTIGUOUS:
-	if (H5S_get_dims(space, new_dset->layout.dim) < 0) {
+	if (H5S_get_dims(space, new_dset->layout.dim, NULL) < 0) {
 	    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
 			"unable to initialize contiguous storage");
 	}
+	if (new_dset->create_parms->efl.nused>0) {
+	    size_t max_points = H5S_get_npoints_max (space);
+	    if (max_points*H5T_get_size (type) >
+		H5O_efl_total_size (&(new_dset->create_parms->efl))) {
+		HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL,
+			     "max size exceeds external storage size");
+	    }
+	}
 	break;
 
     case H5D_CHUNKED:
-	if (new_dset->create_parms.chunk_ndims != H5S_get_ndims(space)) {
+	if (new_dset->create_parms->chunk_ndims != H5S_get_ndims(space)) {
 	    HGOTO_ERROR(H5E_DATASET, H5E_BADVALUE, NULL,
 		   "dimensionality of chunks doesn't match the data space");
 	}
+	if (new_dset->create_parms->efl.nused>0) {
+	    HGOTO_ERROR (H5E_DATASET, H5E_BADVALUE, NULL,
+			 "external storage not supported with chunked layout");
+	}
 	for (i = 0; i < new_dset->layout.ndims - 1; i++) {
-	    new_dset->layout.dim[i] = new_dset->create_parms.chunk_size[i];
+	    new_dset->layout.dim[i] = new_dset->create_parms->chunk_size[i];
 	}
 	break;
 
@@ -802,14 +804,52 @@ H5D_create(H5F_t *f, const char *name, const H5T_t *type, const H5S_t *space,
 	HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "not implemented yet");
     }
 
-    /*
-     * Initialize storage
-     */
-    if (H5F_arr_create(f, &(new_dset->layout)) < 0 ||
-	H5O_modify(&(new_dset->ent), H5O_LAYOUT, 0, 0,
-		   &(new_dset->layout)) < 0) {
+    /* Create (open for write access) an object header */
+    if (H5O_create(f, 0, &(new_dset->ent)) < 0) {
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
-		    "unable to initialize storage");
+		    "unable to create dataset object header");
+    }
+
+    /* Update the type and space header messages */
+    if (H5O_modify(&(new_dset->ent), H5O_DTYPE, 0, H5O_FLAG_CONSTANT,
+		   new_dset->type) < 0 ||
+	H5S_modify(&(new_dset->ent), new_dset->space) < 0) {
+	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
+		    "can't update type or space header messages");
+    }
+
+    /* Initialize storage */
+    if (0==new_dset->create_parms->efl.nused) {
+	if (H5F_arr_create(f, &(new_dset->layout)) < 0) {
+	    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
+			"unable to initialize storage");
+	}
+    } else {
+	H5F_addr_undef (&(new_dset->layout.addr));
+    }
+    if (H5O_modify (&(new_dset->ent), H5O_LAYOUT, 0, H5O_FLAG_CONSTANT,
+		    &(new_dset->layout)) < 0) {
+	HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL,
+		     "unable to update layout message");
+    }
+    if (new_dset->create_parms->efl.nused>0) {
+	size_t heap_size = H5H_ALIGN (1);
+	for (i=0; i<new_dset->create_parms->efl.nused; i++) {
+	    size_t n = strlen (new_dset->create_parms->efl.slot[i].name)+1;
+	    heap_size += H5H_ALIGN (n);
+	}
+	if (H5H_create (f, H5H_LOCAL, heap_size,
+			&(new_dset->create_parms->efl.heap_addr))<0 ||
+	    H5H_insert (f, &(new_dset->create_parms->efl.heap_addr),
+			1, "")<0) {
+	    HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL,
+			 "unable to create external file list name heap");
+	}
+	if (H5O_modify (&(new_dset->ent), H5O_EFL, 0, H5O_FLAG_CONSTANT,
+			&(new_dset->create_parms->efl))<0) {
+	    HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL,
+			 "unable to update external file list message");
+	}
     }
 
     /* Give the dataset a name */
@@ -822,10 +862,12 @@ H5D_create(H5F_t *f, const char *name, const H5T_t *type, const H5S_t *space,
 
   done:
     if (!ret_value && new_dset) {
-	if (new_dset->type)
-	    H5T_close(new_dset->type);
-	if (new_dset->space)
-	    H5S_close(new_dset->space);
+	if (new_dset->type) H5T_close(new_dset->type);
+	if (new_dset->space) H5S_close(new_dset->space);
+	if (new_dset->create_parms) {
+	    H5P_close (H5P_DATASET_CREATE, new_dset->create_parms);
+	    new_dset->create_parms = NULL;
+	}
 	if (H5F_addr_defined(&(new_dset->ent.header))) {
 	    H5O_close(&(new_dset->ent));
 	}
@@ -854,7 +896,7 @@ H5D_create(H5F_t *f, const char *name, const H5T_t *type, const H5S_t *space,
  *
  *-------------------------------------------------------------------------
  */
-H5D_t		       *
+H5D_t *
 H5D_open(H5F_t *f, const char *name)
 {
     H5D_t	*dataset = NULL;	/*the dataset which was found	*/
@@ -868,7 +910,7 @@ H5D_open(H5F_t *f, const char *name)
     assert(name && *name);
 
     dataset = H5MM_xcalloc(1, sizeof(H5D_t));
-    dataset->create_parms = H5D_create_dflt;
+    dataset->create_parms = H5P_copy (H5P_DATASET_CREATE, &H5D_create_dflt);
     H5F_addr_undef(&(dataset->ent.header));
 
     /* Open the dataset object */
@@ -878,16 +920,18 @@ H5D_open(H5F_t *f, const char *name)
     if (H5O_open(f, &(dataset->ent)) < 0) {
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTOPENOBJ, NULL, "unable to open");
     }
+    
     /* Get the type and space */
     if (NULL==(dataset->type=H5O_read(&(dataset->ent), H5O_DTYPE, 0, NULL)) ||
 	NULL==(dataset->space=H5S_read(f, &(dataset->ent)))) {
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL,
 		    "unable to load type or space info from dataset header");
     }
+    
     /*
      * Get the raw data layout info.  It's actually stored in two locations:
      * the storage message of the dataset (dataset->storage) and certain
-     * values are copied to the dataset create template so the user can query
+     * values are copied to the dataset create plist so the user can query
      * them.
      */
     if (NULL==H5O_read(&(dataset->ent), H5O_LAYOUT, 0, &(dataset->layout))) {
@@ -896,19 +940,19 @@ H5D_open(H5F_t *f, const char *name)
     }
     switch (dataset->layout.type) {
     case H5D_CONTIGUOUS:
-	dataset->create_parms.layout = H5D_CONTIGUOUS;
+	dataset->create_parms->layout = H5D_CONTIGUOUS;
 	break;
 
     case H5D_CHUNKED:
 	/*
-	 * Chunked storage.  The creation template's dimension is one less than
+	 * Chunked storage.  The creation plist's dimension is one less than
 	 * the chunk dimension because the chunk includes a dimension for the
 	 * individual bytes of the data type.
 	 */
-	dataset->create_parms.layout = H5D_CHUNKED;
-	dataset->create_parms.chunk_ndims = dataset->layout.ndims - 1;
+	dataset->create_parms->layout = H5D_CHUNKED;
+	dataset->create_parms->chunk_ndims = dataset->layout.ndims - 1;
 	for (i = 0; i < dataset->layout.ndims - 1; i++) {
-	    dataset->create_parms.chunk_size[i] = dataset->layout.dim[i];
+	    dataset->create_parms->chunk_size[i] = dataset->layout.dim[i];
 	}
 	break;
 
@@ -917,6 +961,14 @@ H5D_open(H5F_t *f, const char *name)
 	HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "not implemented yet");
     }
 
+    /* Get the external file list message, which might not exist */
+    if (!H5F_addr_defined (&(dataset->layout.addr)) &&
+	NULL==H5O_read (&(dataset->ent), H5O_EFL, 0,
+			&(dataset->create_parms->efl))) {
+	HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL,
+		     "storage address is undefined an no external file list");
+    }
+
     /* Success */
     ret_value = dataset;
 
@@ -925,10 +977,15 @@ H5D_open(H5F_t *f, const char *name)
 	if (H5F_addr_defined(&(dataset->ent.header))) {
 	    H5O_close(&(dataset->ent));
 	}
-	if (dataset->type)
+	if (dataset->type) {
 	    H5T_close(dataset->type);
-	if (dataset->space)
+	}
+	if (dataset->space) {
 	    H5S_close(dataset->space);
+	}
+	if (dataset->create_parms) {
+	    H5P_close (H5P_DATASET_CREATE, dataset->create_parms);
+	}
 	dataset->ent.file = NULL;
 	H5MM_xfree(dataset);
     }
@@ -972,7 +1029,8 @@ H5D_close(H5D_t *dataset)
      * these fails, so we just continue.
      */
     free_failed = (H5T_close(dataset->type) < 0 ||
-		   H5S_close(dataset->space) < 0);
+		   H5S_close(dataset->space) < 0 ||
+		   H5P_close (H5P_DATASET_CREATE, dataset->create_parms)); 
 
     /* Close the dataset object */
     H5O_close(&(dataset->ent));
@@ -1070,6 +1128,10 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
 	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
 		     "src and dest data spaces have different sizes");
     }
+    if (dataset->create_parms->efl.nused>0) {
+	HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL,
+		     "reading externally-stored data is not implemented yet");
+    }
     
     /*
      * Compute the size of the request and allocate scratch buffers.
@@ -1213,6 +1275,10 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
 	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
 		     "src and dest data spaces have different sizes");
     }
+    if (dataset->create_parms->efl.nused>0) {
+	HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL,
+		     "writing externally-stored data is not implemente yet");
+    }
     
     /*
      * Compute the size of the request and allocate scratch buffers.
@@ -1290,7 +1356,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
  *		Failure:	FAIL
  *
  * Programmer:	Robb Matzke
- *              Friday, January 30, 1998
+ *		Friday, January 30, 1998
  *
  * Modifications:
  *
@@ -1307,6 +1373,11 @@ H5D_extend (H5D_t *dataset, const size_t *size)
     assert (dataset);
     assert (size);
 
+    if (dataset->create_parms->efl.nused>0) {
+	HRETURN_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL,
+		       "extending externally-stored data is not implemente yet");
+    }
+    
     /* This is only allowed for data spaces with chunked layout */
     if (H5D_CHUNKED!=dataset->layout.type) {
 	HRETURN_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL,