[svn-r305] Changes since 19980304

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

./MANIFEST
	New files

./html/extern1.gif		[NEW]
./html/extern1.obj		[NEW]
./html/extern2.gif		[NEW]
./html/extern2.obj		[NEW]
./html/Datasets.html
	Documented external raw data storage.

./html/Datasets.html
./html/chunk1.gif		[NEW]
./html/chunk1.obj		[NEW]
	Added a picture and better description for chunking since it
	seems that people are thinking chunks are fixed-size at the
	file level instead of at the array level.

./src/H5D.c
./src/H5Dpublic.h
./test/external.c
	Changed H5Dget_create_parms() to H5Dget_create_plist().

./src/H5D.c
./src/H5Farray.c
./src/H5Fprivate.h
./src/H5Oefl.c
./src/H5Oprivate.h
./src/H5Sprivate.h
./src/H5Ssimp.c
./test/external.c
./test/istore.c
	External raw data file I/O for contiguous storage is now
	working.  The library supports segments of various sizes which
	can be scattered throughout multiple files in any order.

./test/Makefile.in
	Remove more temporary files.

13 files changed, 490 insertions, 94 deletions

diff --git a/MANIFEST b/MANIFEST
index 7623f84..6681137 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -52,9 +52,15 @@
 ./html/MemoryManagement.html
 ./html/ObjectHeader.txt
 ./html/Properties.html
+./html/chunk1.gif
+./html/chunk1.obj
 ./html/compat.html
 ./html/dataset_p1.gif
 ./html/dataset_p1.obj
+./html/extern1.gif
+./html/extern1.obj
+./html/extern2.gif
+./html/extern2.obj
 ./html/group_p1.gif
 ./html/group_p1.obj
 ./html/group_p2.gif
diff --git a/src/H5D.c b/src/H5D.c
index a3694ee..da470d3 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -413,7 +413,7 @@ H5Dget_type (hid_t dataset_id)
 }
 
 /*-------------------------------------------------------------------------
- * Function:	H5Dget_create_parms
+ * Function:	H5Dget_create_plist
  *
  * Purpose:	Returns a copy of the dataset creation property list.
  *
@@ -431,13 +431,13 @@ H5Dget_type (hid_t dataset_id)
  *-------------------------------------------------------------------------
  */
 hid_t
-H5Dget_create_parms (hid_t dataset_id)
+H5Dget_create_plist (hid_t dataset_id)
 {
     H5D_t		*dataset = NULL;
     H5D_create_t	*copied_parms = NULL;
     hid_t		ret_value = FAIL;
     
-    FUNC_ENTER (H5Dget_create_parms, FAIL);
+    FUNC_ENTER (H5Dget_create_plist, FAIL);
 
     /* Check args */
     if (H5_DATASET!=H5A_group (dataset_id) ||
@@ -962,9 +962,9 @@ H5D_open(H5F_t *f, const char *name)
     }
 
     /* 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))) {
+    if (NULL==H5O_read (&(dataset->ent), H5O_EFL, 0,
+			&(dataset->create_parms->efl)) &&
+	!H5F_addr_defined (&(dataset->layout.addr))) {
 	HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL,
 		     "storage address is undefined an no external file list");
     }
@@ -1128,10 +1128,6 @@ 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.
@@ -1157,6 +1153,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
      * later ;-)
      */
     if ((sconv_func->fgath)(dataset->ent.file, &(dataset->layout),
+			    &(dataset->create_parms->efl), 
 			    H5T_get_size (dataset->type), file_space,
 			    &numbering, 0, nelmts,
 			    tconv_buf/*out*/)!=nelmts) {
@@ -1275,11 +1272,7 @@ 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.
      */
@@ -1310,6 +1303,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
     }
     if (H5T_BKG_YES==cdata->need_bkg) {
 	if ((sconv_func->fgath)(dataset->ent.file, &(dataset->layout),
+				&(dataset->create_parms->efl),
 				H5T_get_size (dataset->type), file_space,
 				&numbering, 0, nelmts,
 				bkg_buf/*out*/)!=nelmts) {
@@ -1332,6 +1326,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
      * Scatter the data out to the file.
      */
     if ((sconv_func->fscat)(dataset->ent.file, &(dataset->layout),
+			    &(dataset->create_parms->efl),
 			    H5T_get_size (dataset->type), file_space,
 			    &numbering, 0, nelmts, tconv_buf)<0) {
 	HGOTO_ERROR (H5E_DATASET, H5E_WRITEERROR, FAIL, "scatter failed");
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index 80a1340..192ed96 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -41,7 +41,7 @@ hid_t H5Dopen (hid_t file_id, const char *name);
 herr_t H5Dclose (hid_t dataset_id);
 hid_t H5Dget_space (hid_t dataset_id);
 hid_t H5Dget_type (hid_t dataset_id);
-hid_t H5Dget_create_parms (hid_t dataset_id);
+hid_t H5Dget_create_plist (hid_t dataset_id);
 herr_t H5Dread (hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id,
                 hid_t file_space_id, hid_t xfer_parms_id, void *buf/*out*/);
 herr_t H5Dwrite (hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id,
diff --git a/src/H5Farray.c b/src/H5Farray.c
index 7deeead..eb7d7b1 100644
--- a/src/H5Farray.c
+++ b/src/H5Farray.c
@@ -89,8 +89,9 @@ H5F_arr_create (H5F_t *f, struct H5O_layout_t *layout/*in,out*/)
  *
  * Purpose:	Reads a hyperslab of a file byte array into a hyperslab of
  *		a byte array in	memory.  The data is read from file F and the
- *		array's size and storage information is in LAYOUT.  The
- *		hyperslab offset is FILE_OFFSET[] in the file and
+ *		array's size and storage information is in LAYOUT.  External
+ *		files are described according to the external file list, EFL.
+ *		The hyperslab offset is FILE_OFFSET[] in the file and
  *		MEM_OFFSET[] in memory (offsets are relative to the origin of
  *		the array) and the size of the hyperslab is HSLAB_SIZE[]. The
  *		total size of the file array is implied in the LAYOUT
@@ -111,6 +112,7 @@ H5F_arr_create (H5F_t *f, struct H5O_layout_t *layout/*in,out*/)
  */
 herr_t
 H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
+	      const struct H5O_efl_t *efl,
 	      const size_t _hslab_size[], const size_t mem_size[],
 	      const size_t mem_offset[], const size_t file_offset[],
 	      void *_buf/*out*/)
@@ -165,7 +167,11 @@ H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
 	 */
 	H5V_vector_cpy (ndims, idx, hslab_size);
 	nelmts = H5V_vector_reduce_product (ndims, hslab_size);
-	addr = layout->addr;
+	if (efl && efl->nused>0) {
+	    H5F_addr_reset (&addr);
+	} else {
+	    addr = layout->addr;
+	}
 	H5F_addr_inc (&addr, file_start);
 	buf += mem_start;
 
@@ -176,7 +182,12 @@ H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
 	for (z=0; z<nelmts; z++) {
 
 	    /* Read from file */
-	    if (H5F_block_read (f, &addr, elmt_size, buf)<0) {
+	    if (efl && efl->nused>0) {
+		if (H5O_efl_read (f, efl, &addr, elmt_size, buf)<0) {
+		    HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
+				   "external data read failed");
+		}
+	    } else if (H5F_block_read (f, &addr, elmt_size, buf)<0) {
 		HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
 			       "block read failed");
 	    }
@@ -195,8 +206,14 @@ H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
 
     case H5D_CHUNKED:
 	/*
-	 * This method is unable to copy into a proper hyperslab.
+	 * This method is unable to access external raw data files or to copy
+	 * into a proper hyperslab.
 	 */
+	if (efl && efl->nused>0) {
+	    HRETURN_ERROR (H5E_IO, H5E_UNSUPPORTED, FAIL,
+			   "chunking and external files are mutually "
+			   "exclusive");
+	}
 	for (i=0; i<layout->ndims; i++) {
 	    if (0!=mem_offset[i] || hslab_size[i]!=mem_size[i]) {
 		HRETURN_ERROR (H5E_IO, H5E_UNSUPPORTED, FAIL,
@@ -224,13 +241,14 @@ H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
  * Purpose:	Copies a hyperslab of a memory array to a hyperslab of a
  *		file array.  The data is written to file F and the file
  *		array's size and storage information is implied by LAYOUT.
- *		The hyperslab offset is FILE_OFFSET[] in the file and
- *		MEM_OFFSET[] in memory (offsets are relative to the origin of
- *		the array) and the size of the hyperslab is HSLAB_SIZE[].
- *		The total size of the file array is implied by the LAYOUT
- *		argument and the total size of the memory array is
- *		MEM_SIZE[].  The dimensionality of these vectors is implied
- *		by the LAYOUT argument.
+ *		The data is stored in external files according to the
+ *		external file list, EFL. The hyperslab offset is
+ *		FILE_OFFSET[] in the file and MEM_OFFSET[] in memory (offsets
+ *		are relative to the origin of the array) and the size of the
+ *		hyperslab is HSLAB_SIZE[].  The total size of the file array
+ *		is implied by the LAYOUT argument and the total size of the
+ *		memory array is MEM_SIZE[].  The dimensionality of these
+ *		vectors is implied by the LAYOUT argument.
  *
  * Return:	Success:	SUCCEED
  *
@@ -245,9 +263,9 @@ H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
  */
 herr_t
 H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
-	       const size_t _hslab_size[], const size_t mem_size[],
-	       const size_t mem_offset[], const size_t file_offset[],
-	       const void *_buf)
+	       const struct H5O_efl_t *efl, const size_t _hslab_size[],
+	       const size_t mem_size[], const size_t mem_offset[],
+	       const size_t file_offset[], const void *_buf)
 {
     const uint8	*buf = (const uint8 *)_buf;	/*cast for arithmetic	*/
     ssize_t	file_stride[H5O_LAYOUT_NDIMS];	/*strides through file	*/
@@ -300,7 +318,11 @@ H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
 	 */
 	H5V_vector_cpy (ndims, idx, hslab_size);
 	nelmts = H5V_vector_reduce_product (ndims, hslab_size);
-	addr = layout->addr;
+	if (efl && efl->nused>0) {
+	    H5F_addr_reset (&addr);
+	} else {
+	    addr = layout->addr;
+	}
 	H5F_addr_inc (&addr, file_start);
 	buf += mem_start;
 
@@ -311,7 +333,12 @@ H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
 	for (z=0; z<nelmts; z++) {
 
 	    /* Write to file */
-	    if (H5F_block_write (f, &addr, elmt_size, buf)<0) {
+	    if (efl && efl->nused>0) {
+		if (H5O_efl_write (f, efl, &addr, elmt_size, buf)<0) {
+		    HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
+				   "external data write failed");
+		}
+	    } else if (H5F_block_write (f, &addr, elmt_size, buf)<0) {
 		HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
 			       "block write failed");
 	    }
@@ -331,8 +358,14 @@ H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
 
     case H5D_CHUNKED:
 	/*
-	 * This method is unable to copy from a proper hyperslab.
+	 * This method is unable to access external raw daa files or to copy
+	 * from a proper hyperslab.
 	 */
+	if (efl && efl->nused>0) {
+	    HRETURN_ERROR (H5E_IO, H5E_UNSUPPORTED, FAIL,
+			   "chunking and external files are mutually "
+			   "exclusive");
+	}
 	for (i=0; i<layout->ndims; i++) {
 	    if (0!=mem_offset[i] || hslab_size[i]!=mem_size[i]) {
 		HRETURN_ERROR (H5E_IO, H5E_UNSUPPORTED, FAIL,
diff --git a/src/H5Flow.c b/src/H5Flow.c
index 6455571..125f8ed 100644
--- a/src/H5Flow.c
+++ b/src/H5Flow.c
@@ -628,7 +628,7 @@ H5F_addr_defined(const haddr_t *addr)
  *-------------------------------------------------------------------------
  */
 void
-H5F_addr_reset(haddr_t *addr /*out */ )
+H5F_addr_reset(haddr_t *addr/*out*/)
 {
     assert(addr);
     addr->offset = 0;
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 4700bae..497a9a0 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -449,6 +449,7 @@ typedef struct H5F_t {
 }
 
 struct H5O_layout_t;		/*forward decl for prototype arguments */
+struct H5O_efl_t;		/*forward decl for prototype arguments */
 
 /* library variables */
 extern const H5F_create_t H5F_create_dflt;
@@ -467,13 +468,13 @@ herr_t H5F_debug(H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
 /* Functions that operate on array storage */
 herr_t H5F_arr_create(H5F_t *f, struct H5O_layout_t *layout /*in,out*/);
 herr_t H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
-		     const size_t _hslab_size[], const size_t mem_size[],
-		     const size_t mem_offset[], const size_t file_offset[],
-		     void *_buf/*out*/);
+		     const struct H5O_efl_t *efl, const size_t _hslab_size[],
+		     const size_t mem_size[], const size_t mem_offset[],
+		     const size_t file_offset[], void *_buf/*out*/);
 herr_t H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
-		      const size_t _hslab_size[], const size_t mem_size[],
-		      const size_t mem_offset[], const size_t file_offset[],
-		      const void *_buf);
+		      const struct H5O_efl_t *efl, const size_t _hslab_size[],
+		      const size_t mem_size[], const size_t mem_offset[],
+		      const size_t file_offset[], const void *_buf);
 
 /* Functions that operate on indexed storage */
 herr_t H5F_istore_create(H5F_t *f, struct H5O_layout_t *layout /*in,out*/);
diff --git a/src/H5Oefl.c b/src/H5Oefl.c
index eb82c30..ac65101 100644
--- a/src/H5Oefl.c
+++ b/src/H5Oefl.c
@@ -350,6 +350,169 @@ H5O_efl_total_size (H5O_efl_t *efl)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5O_efl_read
+ *
+ * Purpose:	Reads data from an external file list.  It is an error to
+ *		read past the logical end of file, but reading past the end
+ *		of any particular member of the external file list results in
+ *		zeros.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, March  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_efl_read (H5F_t *f, const H5O_efl_t *efl, haddr_t *addr, size_t size,
+	      uint8 *buf)
+{
+    int		i, fd=-1;
+    size_t	to_read, cur, skip;
+    ssize_t	n;
+    herr_t	ret_value = FAIL;
+    
+    FUNC_ENTER (H5O_efl_read, FAIL);
+
+    /* Check args */
+    assert (efl && efl->nused>0);
+    assert (addr && H5F_addr_defined (addr));
+    assert (buf || 0==size);
+
+    /* Find the first efl member from which to read */
+    for (i=0, cur=0; i<efl->nused; i++) {
+	if (addr->offset < cur+efl->slot[i].size) {
+	    skip = addr->offset - cur;
+	    break;
+	}
+	cur += efl->slot[i].size;
+    }
+    
+    /* Read the data */
+    while (size) {
+	if (i>=efl->nused) {
+	    HGOTO_ERROR (H5E_EFL, H5E_OVERFLOW, FAIL,
+			 "read past logical end of file");
+	}
+	if ((fd=open (efl->slot[i].name, O_RDONLY))<0) {
+	    HGOTO_ERROR (H5E_EFL, H5E_CANTOPENFILE, FAIL,
+			 "unable to open external raw data file");
+	}
+	if (lseek (fd, efl->slot[i].offset+skip, SEEK_SET)<0) {
+	    HGOTO_ERROR (H5E_EFL, H5E_SEEKERROR, FAIL,
+			 "unable to seek in external raw data file");
+	}
+	to_read = MIN(efl->slot[i].size-skip, size);
+	if ((n=read (fd, buf, to_read))<0) {
+	    HGOTO_ERROR (H5E_EFL, H5E_READERROR, FAIL,
+			 "read error in external raw data file");
+	} else if (n<to_read) {
+	    HDmemset (buf+n, 0, to_read-n);
+	}
+	close (fd);
+	fd = -1;
+	size -= to_read;
+	buf += to_read;
+	skip = 0;
+	i++;
+    }
+    ret_value = SUCCEED;
+    
+ done:
+    if (fd>=0) close (fd);
+    FUNC_LEAVE (ret_value);
+}
+	
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_efl_write
+ *
+ * Purpose:	Writes data to an external file list.  It is an error to
+ *		write past the logical end of file, but writing past the end
+ *		of any particular member of the external file list just
+ *		extends that file.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, March  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_efl_write (H5F_t *f, const H5O_efl_t *efl, haddr_t *addr, size_t size,
+	       const uint8 *buf)
+{
+    int		i, fd=-1;
+    size_t	to_write, cur, skip;
+    ssize_t	n;
+    herr_t	ret_value = FAIL;
+    
+    FUNC_ENTER (H5O_efl_write, FAIL);
+
+    /* Check args */
+    assert (efl && efl->nused>0);
+    assert (addr && H5F_addr_defined (addr));
+    assert (buf || 0==size);
+
+    /* Find the first efl member in which to write */
+    for (i=0, cur=0; i<efl->nused; i++) {
+	if (addr->offset < cur+efl->slot[i].size) {
+	    skip = addr->offset - cur;
+	    break;
+	}
+	cur += efl->slot[i].size;
+    }
+    
+    /* Write the data */
+    while (size) {
+	if (i>=efl->nused) {
+	    HGOTO_ERROR (H5E_EFL, H5E_OVERFLOW, FAIL,
+			 "write past logical end of file");
+	}
+	if ((fd=open (efl->slot[i].name, O_RDWR))<0) {
+	    if (access (efl->slot[i].name, F_OK)<0) {
+		HGOTO_ERROR (H5E_EFL, H5E_CANTOPENFILE, FAIL,
+			     "external raw data file does not exist");
+	    } else {
+		HGOTO_ERROR (H5E_EFL, H5E_CANTOPENFILE, FAIL,
+			     "unable to open external raw data file");
+	    }
+	}
+	if (lseek (fd, efl->slot[i].offset+skip, SEEK_SET)<0) {
+	    HGOTO_ERROR (H5E_EFL, H5E_SEEKERROR, FAIL,
+			 "unable to seek in external raw data file");
+	}
+	to_write = MIN(efl->slot[i].size-skip, size);
+	if ((n=write (fd, buf, to_write))!=to_write) {
+	    HGOTO_ERROR (H5E_EFL, H5E_READERROR, FAIL,
+			 "write error in external raw data file");
+	} 
+	close (fd);
+	fd = -1;
+	size -= to_write;
+	buf += to_write;
+	skip = 0;
+	i++;
+    }
+    ret_value = SUCCEED;
+    
+ done:
+    if (fd>=0) close (fd);
+    FUNC_LEAVE (ret_value);
+}
+	
+
+/*-------------------------------------------------------------------------
  * Function:	H5O_efl_debug
  *
  * Purpose:	Prints debugging info for a message.
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index f7dafb8..079ba24 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -216,5 +216,9 @@ herr_t H5O_debug (H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
 
 /* EFL operators */
 size_t H5O_efl_total_size (H5O_efl_t *efl);
+herr_t H5O_efl_read (H5F_t *f, const H5O_efl_t *efl, haddr_t *addr,
+		     size_t size, uint8 *buf);
+herr_t H5O_efl_write (H5F_t *f, const H5O_efl_t *efl, haddr_t *addr,
+		      size_t size, const uint8 *buf);
 
 #endif
diff --git a/src/H5Sprivate.h b/src/H5Sprivate.h
index 79d7bf2..c8a3aae 100644
--- a/src/H5Sprivate.h
+++ b/src/H5Sprivate.h
@@ -69,9 +69,9 @@ typedef struct H5S_tconv_t {
 
     /* Gather elements from disk to type conversion buffer */
     size_t (*fgath)(H5F_t *f, const struct H5O_layout_t *layout,
-                    size_t elmt_size, const H5S_t *file_space,
-                    const H5S_number_t *numbering, size_t start, size_t nelmts,
-                    void *tconv_buf/*out*/);
+		    const struct H5O_efl_t *efl, size_t elmt_size,
+		    const H5S_t *file_space, const H5S_number_t *numbering,
+		    size_t start, size_t nelmts, void *tconv_buf/*out*/);
 
     /* Scatter elements from type conversion buffer to application buffer */
     herr_t (*mscat)(const void *tconv_buf, size_t elmt_size,
@@ -85,9 +85,9 @@ typedef struct H5S_tconv_t {
 
     /* Scatter elements from type conversion buffer to disk */
     herr_t (*fscat)(H5F_t *f, const struct H5O_layout_t *layout,
-                    size_t elmt_size, const H5S_t *file_space,
-                    const H5S_number_t *numbering, size_t start, size_t nelmts,
-                    const void *tconv_buf);
+		    const struct H5O_efl_t *efl, size_t elmt_size,
+		    const H5S_t *file_space, const H5S_number_t *numbering,
+		    size_t start, size_t nelmts, const void *tconv_buf);
 } H5S_conv_t;
 
 H5S_t *H5S_copy (const H5S_t *src);
@@ -112,9 +112,9 @@ size_t H5S_simp_init (const struct H5O_layout_t *layout,
                       const H5S_t *mem_space, const H5S_t *file_space,
                       H5S_number_t *numbering/*out*/);
 size_t H5S_simp_fgath (H5F_t *f, const struct H5O_layout_t *layout,
-                       size_t elmt_size, const H5S_t *file_space,
-                       const H5S_number_t *numbering, size_t start,
-                       size_t nelmts, void *tconv_buf/*out*/);
+		       const struct H5O_efl_t *efl, size_t elmt_size,
+		       const H5S_t *file_space, const H5S_number_t *numbering,
+		       size_t start, size_t nelmts, void *tconv_buf/*out*/);
 herr_t H5S_simp_mscat (const void *tconv_buf, size_t elmt_size,
                        const H5S_t *mem_space, const H5S_number_t *numbering,
                        size_t start, size_t nelmts, void *buf/*out*/);
@@ -122,7 +122,7 @@ size_t H5S_simp_mgath (const void *buf, size_t elmt_size,
                        const H5S_t *mem_space, const H5S_number_t *numbering,
                        size_t start, size_t nelmts, void *tconv_buf/*out*/);
 herr_t H5S_simp_fscat (H5F_t *f, const struct H5O_layout_t *layout,
-                       size_t elmt_size, const H5S_t *file_space,
-                       const H5S_number_t *numbering, size_t start,
-                       size_t nelmts, const void *tconv_buf);
+		       const struct H5O_efl_t *efl, size_t elmt_size,
+		       const H5S_t *file_space, const H5S_number_t *numbering,
+		       size_t start, size_t nelmts, const void *tconv_buf);
 #endif
diff --git a/src/H5Ssimp.c b/src/H5Ssimp.c
index 6f4dd4f..ee2d680 100644
--- a/src/H5Ssimp.c
+++ b/src/H5Ssimp.c
@@ -63,7 +63,8 @@ H5S_simp_init (const struct H5O_layout_t *layout, const H5S_t *mem_space,
  *
  * Purpose:	Gathers data points from file F and accumulates them in the
  *		type conversion buffer BUF.  The LAYOUT argument describes
- *		how the data is stored on disk.  ELMT_SIZE is the size in
+ *		how the data is stored on disk and EFL describes how the data
+ *		is organized in external files.  ELMT_SIZE is the size in
  *		bytes of a datum which this function treats as opaque.
  *		FILE_SPACE describes the data space of the dataset on disk
  *		and the elements that have been selected for reading (via
@@ -85,6 +86,7 @@ H5S_simp_init (const struct H5O_layout_t *layout, const H5S_t *mem_space,
  */
 size_t
 H5S_simp_fgath (H5F_t *f, const struct H5O_layout_t *layout,
+		const struct H5O_efl_t *efl,
 		size_t elmt_size, const H5S_t *file_space,
 		const H5S_number_t *numbering, size_t start, size_t nelmts,
 		void *buf/*out*/)
@@ -153,7 +155,7 @@ H5S_simp_fgath (H5F_t *f, const struct H5O_layout_t *layout,
     /*
      * Gather from file.
      */
-    if (H5F_arr_read (f, layout, hsize, hsize, zero, file_offset,
+    if (H5F_arr_read (f, layout, efl, hsize, hsize, zero, file_offset,
 		      buf/*out*/)<0) {
 	HRETURN_ERROR (H5E_DATASPACE, H5E_READERROR, 0, "read error");
     }
@@ -375,10 +377,10 @@ H5S_simp_mgath (const void *buf, size_t elmt_size,
  * Purpose:	Scatters dataset elements from the type conversion buffer BUF
  *		to the file F where the data points are arranged according to
  *		the file data space FILE_SPACE and stored according to
- *		LAYOUT. Each element is ELMT_SIZE bytes and has a unique
- *		number according to NUMBERING.  The caller is requesting that
- *		NELMTS elements are coppied beginning with element number
- *		START.
+ *		LAYOUT and EFL. Each element is ELMT_SIZE bytes and has a
+ *		unique number according to NUMBERING.  The caller is
+ *		requesting that NELMTS elements are coppied beginning with
+ *		element number START.
  *
  * Return:	Success:	SUCCEED
  *
@@ -393,6 +395,7 @@ H5S_simp_mgath (const void *buf, size_t elmt_size,
  */
 herr_t
 H5S_simp_fscat (H5F_t *f, const struct H5O_layout_t *layout,
+		const struct H5O_efl_t *efl,
 		size_t elmt_size, const H5S_t *file_space,
 		const H5S_number_t *numbering, size_t start, size_t nelmts,
 		const void *buf)
@@ -461,7 +464,8 @@ H5S_simp_fscat (H5F_t *f, const struct H5O_layout_t *layout,
     /*
      * Scatter to file.
      */
-    if (H5F_arr_write (f, layout, hsize, hsize, zero, file_offset, buf)<0) {
+    if (H5F_arr_write (f, layout, efl, hsize, hsize, zero,
+		       file_offset, buf)<0) {
 	HRETURN_ERROR (H5E_DATASPACE, H5E_WRITEERROR, FAIL, "write error");
     }
 
diff --git a/test/Makefile.in b/test/Makefile.in
index 826ad23..d7a2c91 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -16,7 +16,9 @@ TESTS=$(PROGS)
 
 # Temporary files
 MOSTLYCLEAN=cmpd_dset.h5 dataset.h5 extend.h5 istore.h5 tfile1.h5 tfile2.h5  \
-	    tfile3.h5 th5s1.h5 theap.h5 tohdr.h5 tstab1.h5 tstab2.h5
+	    tfile3.h5 th5s1.h5 theap.h5 tohdr.h5 tstab1.h5 tstab2.h5 \
+	    extern_1.h5 extern_2.h5 extern_1.raw extern_1b.raw extern_2.raw \
+	    extern_2b.raw extern_3.raw extern_3b.raw extern_4.raw extern_4b.raw
 
 # Source and object files for programs...  The PROG_SRC list contains all the
 # source files and is used for things like dependencies, archiving, etc.  The
diff --git a/test/external.c b/test/external.c
index 36c9cdf..53f1c15 100644
--- a/test/external.c
+++ b/test/external.c
@@ -12,8 +12,11 @@
 #include <hdf5.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
+static int nerrors_g = 0;
+
 
 /*-------------------------------------------------------------------------
  * Function:	display_error_cb
@@ -36,19 +39,62 @@ display_error_cb (void *client_data)
 {
     puts ("*FAILED*");
     H5Eprint (stdout);
+    nerrors_g++;
     return 0;
 }
 
 
 /*-------------------------------------------------------------------------
+ * Function:	same_contents
+ *
+ * Purpose:	Determines whether two files are exactly the same.
+ *
+ * Return:	Success:	nonzero if same, zero if different.
+ *
+ *		Failure:	zero
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, March  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+same_contents (const char *name1, const char *name2)
+{
+    int		fd1, fd2;
+    ssize_t	n1, n2;
+    char	buf1[1024], buf2[1024];
+
+    fd1 = open (name1, O_RDONLY);
+    fd2 = open (name2, O_RDONLY);
+    assert (fd1>=0 && fd2>=0);
+
+    while (1) {
+	n1 = read (fd1, buf1, sizeof(buf1));
+	n2 = read (fd2, buf2, sizeof(buf2));
+	assert (n1==n2);
+	if (n1<=0 && n2<=0) break;
+	if (memcmp (buf1, buf2, n1)) {
+	    close (fd1);
+	    close (fd2);
+	    return 0;
+	}
+    }
+    close (fd1);
+    close (fd2);
+    return 1;
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	test_1
  *
  * Purpose:	Describes various external datasets in an HDF5 file without
  *		actually creating the external raw files.
  *
- * Return:	Success:	0
- *
- *		Failure:	-1
+ * Return:	void
  *
  * Programmer:	Robb Matzke
  *              Tuesday, March  3, 1998
@@ -57,7 +103,7 @@ display_error_cb (void *client_data)
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
+static void
 test_1 (void) 
 {
     hid_t	file, plist, space, dset, grp;
@@ -78,8 +124,6 @@ test_1 (void)
     grp = H5Gcreate (file, "emit-diagnostics", 8);
     H5Gclose (grp);
 
-    printf ("Testing external storage descriptions...\n");
-    
     /*
      * A single external file for a non-extendible dataset.
      */
@@ -127,6 +171,7 @@ test_1 (void)
 	if (dset>=0) {
 	    puts ("*FAILED*");
 	    printf ("   Small external file succeeded instead of failing\n");
+	    nerrors_g++;
 	    H5Dclose (dset);
 	    break;
 	}
@@ -188,6 +233,7 @@ test_1 (void)
 	    puts ("*FAILED*");
 	    printf ("   Small external file succeeded instead of failing\n");
 	    H5Dclose (dset);
+	    nerrors_g++;
 	    break;
 	}
 	puts (" PASSED");
@@ -234,7 +280,7 @@ test_1 (void)
 
 	dset = H5Dopen (file, "dset1");
 	assert (dset>=0);
-	plist = H5Dget_create_parms (dset);
+	plist = H5Dget_create_plist (dset);
 	assert (plist>=0);
 
 	n = H5Pget_external_count (plist);
@@ -242,6 +288,7 @@ test_1 (void)
 	if (1!=n) {
 	    puts ("*FAILED*");
 	    printf ("   Returned external count is wrong.\n");
+	    nerrors_g++;
 	    break;
 	}
 	strcpy (name+sizeof(name)-4, "...");
@@ -253,10 +300,12 @@ test_1 (void)
 	} else if (file_offset!=0) {
 	    puts ("*FAILED*");
 	    printf ("   Wrong file offset.\n");
+	    nerrors_g++;
 	    break;
 	} else if (file_size!=400) {
 	    puts ("*FAILED*");
 	    printf ("   Wrong file size.\n");
+	    nerrors_g++;
 	    break;
 	}
 	puts (" PASSED");
@@ -279,7 +328,7 @@ test_1 (void)
 
 	dset = H5Dopen (file, "dset5");
 	assert (dset>=0);
-	plist = H5Dget_create_parms (dset);
+	plist = H5Dget_create_plist (dset);
 	assert (plist>=0);
 
 	n = H5Pget_external_count (plist);
@@ -287,6 +336,7 @@ test_1 (void)
 	if (1!=n) {
 	    puts ("*FAILED*");
 	    printf ("   Returned external count is wrong.\n");
+	    nerrors_g++;
 	    break;
 	}
 	strcpy (name+sizeof(name)-4, "...");
@@ -298,10 +348,12 @@ test_1 (void)
 	} else if (file_offset!=0) {
 	    puts ("*FAILED*");
 	    printf ("   Wrong file offset.\n");
+	    nerrors_g++;
 	    break;
 	} else if (H5F_UNLIMITED!=file_size) {
 	    puts ("*FAILED*");
 	    printf ("   Wrong file size.\n");
+	    nerrors_g++;
 	    break;
 	}
 	puts (" PASSED");
@@ -358,6 +410,7 @@ test_1 (void)
 	if (status>=0) {
 	    puts ("*FAILED*");
 	    puts ("   H5Pset_external() succeeded when it should have failed");
+	    nerrors_g++;
 	    break;
 	}
 
@@ -367,6 +420,8 @@ test_1 (void)
 	if (1!=n) {
 	    puts ("*FAILED*");
 	    puts ("   Wrong external file count returned.");
+	    nerrors_g++;
+	    break;
 	}
 	puts (" PASSED");
     } while (0);
@@ -392,6 +447,7 @@ test_1 (void)
 	if (status>=0) {
 	    puts ("*FAILED*");
 	    puts ("   H5Pset_external() succeeded when it should have failed");
+	    nerrors_g++;
 	    break;
 	}
 	puts (" PASSED");
@@ -402,7 +458,6 @@ test_1 (void)
 
     /* END OF TESTS */
     H5Fclose (file);
-    return 0;
 }
 
 
@@ -411,9 +466,7 @@ test_1 (void)
  *
  * Purpose:	Tests reading from an external file set.
  *
- * Return:	Success:	0
- *
- *		Failure:	-1
+ * Return:	void
  *
  * Programmer:	Robb Matzke
  *              Wednesday, March  4, 1998
@@ -422,7 +475,7 @@ test_1 (void)
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
+static void
 test_2 (void)
 {
     hid_t	file, plist, space, dset, grp;
@@ -434,7 +487,6 @@ test_2 (void)
     size_t	size;
 
     /* Write the data to external files */
-    printf ("Writing external data...\n");
     for (i=0; i<4; i++) {
 	for (j=0; j<25; j++) {
 	    part[j] = i*25+j;
@@ -443,6 +495,8 @@ test_2 (void)
 	sprintf (fname, "extern_%d.raw", i+1);
 	fd = open (fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
 	assert (fd>=0);
+	n = lseek (fd, i*10, SEEK_SET);
+	assert (n==i*10);
 	n = write (fd, part, sizeof(part));
 	assert (n==sizeof(part));
 	close (fd);
@@ -457,18 +511,17 @@ test_2 (void)
     assert (file>=0);
     grp = H5Gcreate (file, "emit-diagnostics", 8);
     H5Gclose (grp);
-    printf ("Testing external data reading...\n");
 
     /* Create the external file list */
     plist = H5Pcreate (H5P_DATASET_CREATE);
     assert (plist>=0);
     status = H5Pset_external (plist, "extern_1.raw", 0, sizeof(part));
     assert (status>=0);
-    status = H5Pset_external (plist, "extern_2.raw", 0, sizeof(part));
+    status = H5Pset_external (plist, "extern_2.raw", 10, sizeof(part));
     assert (status>=0);
-    status = H5Pset_external (plist, "extern_3.raw", 0, sizeof(part));
+    status = H5Pset_external (plist, "extern_3.raw", 20, sizeof(part));
     assert (status>=0);
-    status = H5Pset_external (plist, "extern_4.raw", 0, sizeof(part));
+    status = H5Pset_external (plist, "extern_4.raw", 30, sizeof(part));
     assert (status>=0);
 
     /* Create the data space */
@@ -487,6 +540,8 @@ test_2 (void)
 	/* Read from the dataset */
 	printf ("%-70s", "...reading entire dataset");
 	fflush (stdout);
+
+	memset (whole, 0, sizeof(whole));
 	status = H5Dread (dset, H5T_NATIVE_INT, space, space,
 			  H5P_DEFAULT, whole);
 	if (status<0) {
@@ -498,6 +553,53 @@ test_2 (void)
 	    if (whole[i]!=i) {
 		puts ("*FAILED*");
 		puts ("   Incorrect value(s) read.");
+		nerrors_g++;
+		break;
+	    }
+	}
+	puts (" PASSED");
+    } while (0);
+
+
+    
+    /*
+     * Read the middle of the dataset
+     */
+    do {
+	hid_t hs_space;
+	int hs_start = 30;
+	size_t hs_count = 25;
+
+	/* Read from the dataset */
+	printf ("%-70s", "...reading partial dataset");
+	fflush (stdout);
+
+	hs_space = H5Scopy (space);
+	assert (hs_space>=0);
+	status = H5Sset_hyperslab (hs_space, &hs_start, &hs_count, NULL);
+	assert (status>=0);
+
+	memset (whole, 0, sizeof(whole));
+	status = H5Dread (dset, H5T_NATIVE_INT, hs_space, hs_space,
+			  H5P_DEFAULT, whole);
+	H5Sclose (hs_space);
+	if (status<0) {
+	    puts ("   Failed to read dataset");
+	    break;
+	}
+
+#if 0
+	for (i=0; i<100; i++) {
+	    printf ("  #%02d %3d %s\n",
+		    i, whole[i], whole[i]==i?"":" <------------------------");
+	}
+#endif
+
+	for (i=hs_start; i<hs_start+hs_count; i++) {
+	    if (whole[i]!=i) {
+		puts ("*FAILED*");
+		puts ("   Incorrect value(s) read.");
+		nerrors_g++;
 		break;
 	    }
 	}
@@ -508,11 +610,98 @@ test_2 (void)
     H5Pclose (plist);
     H5Sclose (space);
     H5Fclose (file);
-    return 0;
 }
 
 
 /*-------------------------------------------------------------------------
+ * Function:	test_3
+ *
+ * Purpose:	Tests writing to an external file set.
+ *
+ * Return:	void
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, March  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void
+test_3 (void)
+{
+    hid_t	file, plist, space, dset;
+    herr_t	status;
+    int		i;
+    int		part[25], whole[100];
+    size_t	size;
+
+    /*
+     * Open the file from test_2().
+     */
+    file = H5Fcreate ("extern_2.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    assert (file>=0);
+
+    /* Create the external file list */
+    plist = H5Pcreate (H5P_DATASET_CREATE);
+    assert (plist>=0);
+    status = H5Pset_external (plist, "extern_1b.raw", 0, sizeof(part));
+    assert (status>=0);
+    status = H5Pset_external (plist, "extern_2b.raw", 10, sizeof(part));
+    assert (status>=0);
+    status = H5Pset_external (plist, "extern_3b.raw", 20, sizeof(part));
+    assert (status>=0);
+    status = H5Pset_external (plist, "extern_4b.raw", 30, sizeof(part));
+    assert (status>=0);
+
+    /* Touch the files so they exist */
+    system ("touch extern_1b.raw extern_2b.raw extern_3b.raw extern_4b.raw");
+
+    /* Create the data space */
+    size = 100;
+    space = H5Screate_simple (1, &size, NULL);
+    assert (space>=0);
+
+    /* Create the dataset */
+    dset = H5Dcreate (file, "dset1", H5T_NATIVE_INT, space, plist);
+    assert (dset>=0);
+
+    /*
+     * Write the entire dataset and compare with the original
+     */
+    do {
+	/* Write to the dataset */
+	printf ("%-70s", "...writing entire dataset");
+	fflush (stdout);
+
+	for (i=0; i<100; i++) whole[i] = i;
+	status = H5Dwrite (dset, H5T_NATIVE_INT, space, space,
+			   H5P_DEFAULT, whole);
+	if (status<0) break;
+	for (i=0; i<4; i++) {
+	    char name1[64], name2[64];
+	    sprintf (name1, "extern_%d.raw", i+1);
+	    sprintf (name2, "extern_%db.raw", i+1);
+	    if (!same_contents (name1, name2)) {
+		puts ("*FAIL*");
+		puts ("   Output differs from expected value.");
+		nerrors_g++;
+		break;
+	    }
+	}
+	puts (" PASSED");
+    } while (0);
+
+
+    H5Dclose (dset);
+    H5Pclose (plist);
+    H5Sclose (space);
+    H5Fclose (file);
+}
+
+
+
+/*-------------------------------------------------------------------------
  * Function:	main
  *
  * Purpose:	Runs external dataset tests.
@@ -531,20 +720,17 @@ test_2 (void)
 int
 main (void)
 {
-    herr_t	status;
-    int		nerrors=0;
-
     H5Eset_auto (display_error_cb, NULL);
 
-    status = test_1 ();
-    nerrors += (status<0 ? 1 : 0);
-
-    status = test_2 ();
-    nerrors += (status<0 ? 1 : 0);
+    test_1 ();
+    test_2 ();
+    test_3 ();
 
-    if (0==nerrors) {
+    if (0==nerrors_g) {
 	printf ("All external storage tests passed.\n");
+    } else {
+	printf ("%d TEST%s FAILED.\n", nerrors_g, 1==nerrors_g?"":"s");
     }
 
-    exit (nerrors?1:0);
+    exit (nerrors_g?1:0);
 }
diff --git a/test/istore.c b/test/istore.c
index 4a07337..68feb9c 100644
--- a/test/istore.c
+++ b/test/istore.c
@@ -316,7 +316,7 @@ test_extend(H5F_t *f, const char *prefix,
         memset(buf, 128 + ctr, nelmts);
 
         /* Write to disk */
-        if (H5F_arr_write(f, &layout, size, size, zero, offset, buf) < 0) {
+        if (H5F_arr_write(f, &layout, NULL, size, size, zero, offset, buf)<0) {
             puts("*FAILED*");
             if (!isatty(1)) {
                 AT();
@@ -326,7 +326,8 @@ test_extend(H5F_t *f, const char *prefix,
         }
         /* Read from disk */
         memset(check, 0xff, nelmts);
-        if (H5F_arr_read(f, &layout, size, size, zero, offset, check) < 0) {
+        if (H5F_arr_read(f, &layout, NULL, size, size, zero, offset,
+			 check)<0) {
             puts("*FAILED*");
             if (!isatty(1)) {
                 AT();
@@ -359,7 +360,8 @@ test_extend(H5F_t *f, const char *prefix,
 
     /* Now read the entire array back out and check it */
     memset(buf, 0xff, nx * ny * nz);
-    if (H5F_arr_read(f, &layout, whole_size, whole_size, zero, zero, buf)<0) {
+    if (H5F_arr_read(f, &layout, NULL, whole_size, whole_size, zero, zero,
+		     buf)<0) {
         puts("*FAILED*");
         if (!isatty(1)) {
             AT();
@@ -478,7 +480,7 @@ test_sparse(H5F_t *f, const char *prefix, size_t nblocks,
         memset(buf, 128 + ctr, nx * ny * nz);
 
         /* write to disk */
-        if (H5F_arr_write(f, &layout, size, size, zero, offset, buf) < 0) {
+        if (H5F_arr_write(f, &layout, NULL, size, size, zero, offset, buf)<0) {
             puts("*FAILED*");
             if (!isatty(1)) {
                 AT();