[svn-r8330] Purpose: Last step of check-in for Null dataspace

Description:  Mainly are header message changes for dataspace.  In last round
of check-in, a new header message for dataspace to created, which is not a good
way.  Now, there will be no new message for dataspace, but just add the type of
dataspace in the message while increment its version number.  Backward compatibility
is addressed.  The attribute design is modified accordingly.


Platforms tested: h5committest

7 files changed, 143 insertions, 548 deletions

diff --git a/src/H5A.c b/src/H5A.c
index dc2f29d..0ad4992 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -267,7 +267,7 @@ H5A_create(const H5G_entry_t *ent, const char *name, const H5T_t *type,
     else
         attr->dt_size=H5O_raw_size(H5O_DTYPE_ID,attr->ent.file,type);
     assert(attr->dt_size>0);
-    attr->ds_size=H5O_raw_size(H5O_SDSPACE_ID,attr->ent.file,&(space->extent.u.simple));
+    attr->ds_size=H5O_raw_size(H5O_SDSPACE_ID,attr->ent.file,&(space->extent));
     assert(attr->ds_size>0);
     H5_ASSIGN_OVERFLOW(attr->data_size,H5S_get_simple_extent_npoints(attr->ds)*H5T_get_size(attr->dt),hssize_t,size_t);
 
@@ -1555,7 +1555,7 @@ H5A_close(H5A_t *attr)
     assert(attr);
 
     /* Check if the attribute has any data yet, if not, fill with zeroes */
-    if(attr->ent_opened && !attr->initialized) {
+    if(attr->ent_opened && !attr->initialized && attr->data_size) {
         uint8_t *tmp_buf=H5MM_calloc(attr->data_size);
         if (NULL == tmp_buf)
             HGOTO_ERROR(H5E_ATTR, H5E_NOSPACE, FAIL, "memory allocation failed for attribute fill-value")
diff --git a/src/H5O.c b/src/H5O.c
index 63b0719..956815c 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -104,8 +104,8 @@ static herr_t H5O_init_interface(void);
 /* ID to type mapping */
 static const H5O_class_t *const message_type_g[] = {
     H5O_NULL,		/*0x0000 Null					*/
-    H5O_SDSPACE,	/*0x0001 Simple Dimensionality (old)		*/
-    H5O_SDSPACE_NEW,	/*0x0002 Extent Dimensionality (new)		*/
+    H5O_SDSPACE,	/*0x0001 Extent Dimensionality		        */
+    NULL,	        /*0x0002 Not assigned 		                */
     H5O_DTYPE,		/*0x0003 Data Type				*/
     H5O_FILL,       	/*0x0004 Old data storage -- fill value         */
     H5O_FILL_NEW,	/*0x0005 New Data storage -- fill value 	*/
diff --git a/src/H5Oattr.c b/src/H5Oattr.c
index 8714fdb..7ca18cf 100644
--- a/src/H5Oattr.c
+++ b/src/H5Oattr.c
@@ -74,8 +74,8 @@ static int		interface_initialize_g = 0;
 /* Declare external the free list for H5S_t's */
 H5FL_EXTERN(H5S_t);
 
-/* Declare external the free list for H5S_simple_t's */
-H5FL_EXTERN(H5S_simple_t);
+/* Declare external the free list for H5S_extent_t's */
+H5FL_EXTERN(H5S_extent_t);
 
 /*--------------------------------------------------------------------------
  NAME
@@ -101,12 +101,16 @@ H5FL_EXTERN(H5S_simple_t);
  *
  * 	Robb Matzke, 20 Jul 1998
  *	Added a version number at the beginning.
+ *
+ *	Raymond Lu, 8 April 2004
+ *	Changed Dataspace operation on H5S_simple_t to H5S_extent_t.
+ *
 --------------------------------------------------------------------------*/
 static void *
 H5O_attr_decode(H5F_t *f, hid_t dxpl_id, const uint8_t *p, H5O_shared_t UNUSED *sh)
 {
     H5A_t		*attr = NULL;
-    H5S_simple_t	*simple;	/*simple dimensionality information  */
+    H5S_extent_t	*extent;	/*extent dimensionality information  */
     size_t		name_len;   	/*attribute name length */
     int		        version;	/*message version number*/
     unsigned            flags=0;        /* Attribute flags */
@@ -176,33 +180,49 @@ H5O_attr_decode(H5F_t *f, hid_t dxpl_id, const uint8_t *p, H5O_shared_t UNUSED *
     /* decode the attribute dataspace */
     if (NULL==(attr->ds = H5FL_CALLOC(H5S_t)))
 	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-    if((simple=(H5O_SDSPACE->decode)(f,dxpl_id,p,NULL))!=NULL) {
-        hsize_t nelem;  /* Number of elements in extent */
-        unsigned u;     /* Local index variable */
-
-        /* Set the dataspace type to be simple or scalar as appropriate */
-        if(simple->rank>0)
-            attr->ds->extent.type = H5S_SIMPLE;
-        else
-            attr->ds->extent.type = H5S_SCALAR;
+    
+    if((extent=(H5O_SDSPACE->decode)(f,dxpl_id,p,NULL))!=NULL) {
+        unsigned i;     /* Local index variable */
+
+        if(extent->type != H5S_NO_CLASS) {  /* File is new, created by version 1.7 or after */
+            /* Compute the number of elements in the extent */
+            if(extent->type == H5S_NULL)
+                extent->nelem = 0;
+            else {
+                for(i=0, extent->nelem=1; i<extent->u.simple.rank; i++)
+                    extent->nelem*=extent->u.simple.size[i];
+            }
+        } else { /* File was created by version 1.6 or before, when there was no H5S_NULL */
+            /* Set the dataspace type to be simple or scalar as appropriate */
+            if(extent->u.simple.rank>0)
+                extent->type = H5S_SIMPLE;
+            else
+                extent->type = H5S_SCALAR;
+
+            /* Compute the number of elements in the extent */
+            for(i=0, extent->nelem=1; i<extent->u.simple.rank; i++)
+                extent->nelem*=extent->u.simple.size[i];
+        }
 
         /* Copy the extent information */
-        HDmemcpy(&(attr->ds->extent.u.simple),simple, sizeof(H5S_simple_t));
+        HDmemcpy(&(attr->ds->extent),extent, sizeof(H5S_extent_t));
 
         /* Release temporary extent information */
-        H5FL_FREE(H5S_simple_t,simple);
-
-        /* Compute the number of elements in the extent */
-        for(u=0, nelem=1; u<attr->ds->extent.u.simple.rank; u++)
-            nelem*=attr->ds->extent.u.simple.size[u];
-        attr->ds->extent.nelem = nelem;
+        H5FL_FREE(H5S_extent_t,extent);
+    } else {
+        attr->ds->extent.type = H5S_NULL;
+        attr->ds->extent.nelem = 0;
+    }
+   
+    if(attr->ds->extent.type == H5S_NULL) {
+         if(H5S_select_none(attr->ds)<0)
+            HGOTO_ERROR (H5E_DATASPACE, H5E_CANTSET, NULL, "unable to set none selection");
     } else {
-        attr->ds->extent.type = H5S_SCALAR;
-        attr->ds->extent.nelem = 1;
+        /* Default to entire dataspace being selected */
+        if(H5S_select_all(attr->ds,0)<0)
+            HGOTO_ERROR (H5E_DATASPACE, H5E_CANTSET, NULL, "unable to set all selection");
     }
-    /* Default to entire dataspace being selected */
-    if(H5S_select_all(attr->ds,0)<0)
-        HGOTO_ERROR (H5E_DATASPACE, H5E_CANTSET, NULL, "unable to set all selection");
+
     if(version < H5O_ATTR_VERSION_NEW)
         p += H5O_ALIGN(attr->ds_size);
     else
@@ -212,9 +232,11 @@ H5O_attr_decode(H5F_t *f, hid_t dxpl_id, const uint8_t *p, H5O_shared_t UNUSED *
     H5_ASSIGN_OVERFLOW(attr->data_size,H5S_get_simple_extent_npoints(attr->ds)*H5T_get_size(attr->dt),hsize_t,size_t);
 
     /* Go get the data */
-    if (NULL==(attr->data = H5MM_malloc(attr->data_size)))
-	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-    HDmemcpy(attr->data,p,attr->data_size);
+    if(attr->data_size) {
+        if (NULL==(attr->data = H5MM_malloc(attr->data_size)))
+            HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
+        HDmemcpy(attr->data,p,attr->data_size);
+    }
 
     /* Indicate that the fill values aren't to be written out */
     attr->initialized=1;
@@ -249,6 +271,11 @@ done:
  *
  * 	Robb Matzke, 20 Jul 1998
  *	Added a version number at the beginning.
+ *
+ *	Raymond Lu, 8 April 2004
+ *	For data space, changed the operation on H5S_simple_t to 
+ *	H5S_extent_t
+ *
 --------------------------------------------------------------------------*/
 static herr_t
 H5O_attr_encode(H5F_t *f, uint8_t *p, const void *mesg)
@@ -336,7 +363,7 @@ H5O_attr_encode(H5F_t *f, uint8_t *p, const void *mesg)
         p += attr->dt_size;
 
     /* encode the attribute dataspace */
-    if((H5O_SDSPACE->encode)(f,p,&(attr->ds->extent.u.simple))<0)
+    if((H5O_SDSPACE->encode)(f,p,&(attr->ds->extent))<0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL, "can't encode attribute dataspace");
     if(version < H5O_ATTR_VERSION_NEW) {
         HDmemset(p+attr->ds_size, 0, H5O_ALIGN(attr->ds_size)-attr->ds_size);
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index a92543e..a4867dd 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -109,16 +109,11 @@ typedef struct H5O_t {
 H5_DLLVAR const H5O_class_t H5O_NULL[1];
 
 /*
- * Old simple Data Space Message.
+ * Extent Data Space Message.
  */
 H5_DLLVAR const H5O_class_t H5O_SDSPACE[1];
 
 /*
- * New Extent Data Space Message.
- */
-H5_DLLVAR const H5O_class_t H5O_SDSPACE_NEW[1];
-
-/*
  * Data Type Message.
  */
 H5_DLLVAR const H5O_class_t H5O_DTYPE[1];
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 330d949..a6bd5a3 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -52,8 +52,7 @@
 
 /* Header message IDs */
 #define H5O_NULL_ID	0x0000          /* Null Message.  */
-#define H5O_SDSPACE_ID	0x0001          /* Simple Dataspace Message.(old) */
-#define H5O_SDSPACE_NEW_ID	0x0002  /* Simple Dataspace Message.(new) */
+#define H5O_SDSPACE_ID	0x0001          /* Extent Dataspace Message.*/
 /* Complex dataspace is/was planned for message 0x0002 */
 #define H5O_DTYPE_ID	0x0003          /* Datatype Message.  */
 #define H5O_FILL_ID     0x0004          /* Fill Value Message. (Old)  */
@@ -72,7 +71,6 @@
 #define H5O_STAB_ID	0x0011          /* Symbol table message.  */
 #define H5O_MTIME_NEW_ID 0x0012         /* Modification time message. (New)  */
 
-
 /*
  * Fill Value Message. (Old)
  * (Data structure in memory)
diff --git a/src/H5Osdspace.c b/src/H5Osdspace.c
index e293d94..02b932a 100644
--- a/src/H5Osdspace.c
+++ b/src/H5Osdspace.c
@@ -25,17 +25,7 @@
 
 #define PABLO_MASK	H5O_sdspace_mask
 
-/* new PRIVATE PROTOTYPES */
-static void *H5O_sdspace_new_decode(H5F_t *f, hid_t dxpl_id, const uint8_t *p, H5O_shared_t *sh);
-static herr_t H5O_sdspace_new_encode(H5F_t *f, uint8_t *p, const void *_mesg);
-static void *H5O_sdspace_new_copy(const void *_mesg, void *_dest);
-static size_t H5O_sdspace_new_size(H5F_t *f, const void *_mesg);
-static herr_t H5O_sdspace_new_reset(void *_mesg);
-static herr_t H5O_sdspace_new_free (void *_mesg);
-static herr_t H5O_sdspace_new_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg,
-				    FILE * stream, int indent, int fwidth);
-
-/* old PRIVATE PROTOTYPES */
+/* PRIVATE PROTOTYPES */
 static void *H5O_sdspace_decode(H5F_t *f, hid_t dxpl_id, const uint8_t *p, H5O_shared_t *sh);
 static herr_t H5O_sdspace_encode(H5F_t *f, uint8_t *p, const void *_mesg);
 static void *H5O_sdspace_copy(const void *_mesg, void *_dest);
@@ -48,8 +38,8 @@ static herr_t H5O_sdspace_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg,
 /* This message derives from H5O, for old dataspace before version 1.7  */
 const H5O_class_t H5O_SDSPACE[1] = {{
     H5O_SDSPACE_ID,	    	/* message id number		    	*/
-    "simple_dspace",	    	/* message name for debugging	   	*/
-    sizeof(H5S_simple_t),   	/* native message size		    	*/
+    "extent_dspace",	    	/* message name for debugging	   	*/
+    sizeof(H5S_extent_t),   	/* native message size		    	*/
     H5O_sdspace_decode,	    	/* decode message			*/
     H5O_sdspace_encode,	    	/* encode message			*/
     H5O_sdspace_copy,	    	/* copy the native value		*/
@@ -63,24 +53,6 @@ const H5O_class_t H5O_SDSPACE[1] = {{
     H5O_sdspace_debug,	        /* debug the message		    	*/
 }};
 
-/* This message derives from H5O, for new dataspace after version 1.6   */
-const H5O_class_t H5O_SDSPACE_NEW[1] = {{
-    H5O_SDSPACE_NEW_ID,	    	        /* message id number		    	*/
-    "extent_dataspace",	    	        /* message name for debugging	   	*/
-    sizeof(H5S_extent_t),   	        /* native message size		    	*/
-    H5O_sdspace_new_decode,	    	/* decode message			*/
-    H5O_sdspace_new_encode,	    	/* encode message			*/
-    H5O_sdspace_new_copy,	    	/* copy the native value		*/
-    H5O_sdspace_new_size,	    	/* size of symbol table entry	    	*/
-    H5O_sdspace_new_reset,	    	/* default reset method		    	*/
-    H5O_sdspace_new_free,		/* free method				*/
-    NULL,		                /* file delete method		        */
-    NULL,			        /* link method			        */
-    NULL,		    	        /* get share method			*/
-    NULL, 			        /* set share method			*/
-    H5O_sdspace_new_debug,	        /* debug the message		    	*/
-}};
-
 /* Initial version of the "old" data space information */
 #define H5O_SDSPACE_VERSION	1
 /* Initial version of the "new" data space information */
@@ -90,9 +62,6 @@ const H5O_class_t H5O_SDSPACE_NEW[1] = {{
 static int interface_initialize_g = 0;
 #define INTERFACE_INIT NULL
 
-/* Declare external the free list for H5S_simple_t's */
-H5FL_EXTERN(H5S_simple_t);
-
 /* Declare external the free list for H5S_extent_t's */
 H5FL_EXTERN(H5S_extent_t);
 
@@ -102,9 +71,9 @@ H5FL_ARR_EXTERN(hsize_t);
 
 /*--------------------------------------------------------------------------
  NAME
-    H5O_sdspace_new_decode
+    H5O_sdspace_decode
  PURPOSE
-    Decode a extent dimensionality message and return a pointer to a memory
+    Decode an extent dimensionality message and return a pointer to a memory
 	struct with the decoded information
  USAGE
     void *H5O_sdspace_decode(f, raw_size, p)
@@ -119,16 +88,20 @@ H5FL_ARR_EXTERN(hsize_t);
     within this function using malloc() and is returned to the caller.
 
  MODIFICATIONS
+    Raymond Lu
+    April 8, 2004
+    Added the type of dataspace into this header message using a reserved byte.
+
 --------------------------------------------------------------------------*/
 static void *
-H5O_sdspace_new_decode(H5F_t *f, hid_t UNUSED dxpl_id, const uint8_t *p, H5O_shared_t UNUSED *sh)
+H5O_sdspace_decode(H5F_t *f, hid_t UNUSED dxpl_id, const uint8_t *p, H5O_shared_t UNUSED *sh)
 {
     H5S_extent_t	*sdim = NULL;/* New extent dimensionality structure */
     void		*ret_value;
     unsigned		i;		/* local counting variable */
     unsigned		flags, version;
     
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_decode, NULL);
+    FUNC_ENTER_NOAPI(H5O_sdspace_decode, NULL);
 
     /* check args */
     assert(f);
@@ -142,6 +115,8 @@ H5O_sdspace_new_decode(H5F_t *f, hid_t UNUSED dxpl_id, const uint8_t *p, H5O_sha
             HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "wrong version number in data space message");
         if(version==H5O_SDSPACE_VERSION_2)
             sdim->type = *p++;
+        else
+            sdim->type = H5S_NO_CLASS;
         sdim->u.simple.rank = *p++;
         if (sdim->u.simple.rank>H5S_MAX_RANK)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "simple data space dimensionality is too large");
@@ -190,96 +165,9 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
-    H5O_sdspace_decode
- PURPOSE
-    Decode a simple dimensionality message and return a pointer to a memory
-	struct with the decoded information
- USAGE
-    void *H5O_sdspace_decode(f, raw_size, p)
-	H5F_t *f;	  IN: pointer to the HDF5 file struct
-	size_t raw_size;	IN: size of the raw information buffer
-	const uint8 *p;		IN: the raw information buffer
- RETURNS
-    Pointer to the new message in native order on success, NULL on failure
- DESCRIPTION
-	This function decodes the "raw" disk form of a simple dimensionality
-    message into a struct in memory native format.  The struct is allocated
-    within this function using malloc() and is returned to the caller.
-
- MODIFICATIONS
-	Robb Matzke, 1998-04-09
-	The current and maximum dimensions are now H5F_SIZEOF_SIZET bytes
-	instead of just four bytes.
- 
-  	Robb Matzke, 1998-07-20
-        Added a version number and reformatted the message for aligment.
---------------------------------------------------------------------------*/
-static void *
-H5O_sdspace_decode(H5F_t *f, hid_t UNUSED dxpl_id, const uint8_t *p, H5O_shared_t UNUSED *sh)
-{
-    H5S_simple_t	*sdim = NULL;/* New simple dimensionality structure */
-    void		*ret_value;
-    unsigned		u;		/* local counting variable */
-    unsigned		flags, version;
-    
-    FUNC_ENTER_NOAPI(H5O_sdspace_decode, NULL);
-
-    /* check args */
-    assert(f);
-    assert(p);
-    assert (!sh);
-
-    /* decode */
-    if ((sdim = H5FL_CALLOC(H5S_simple_t)) != NULL) {
-        version = *p++;
-        if (version!=H5O_SDSPACE_VERSION)
-            HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "wrong version number in data space message");
-        sdim->rank = *p++;
-        if (sdim->rank>H5S_MAX_RANK)
-            HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "simple data space dimensionality is too large");
-        flags = *p++;
-        p += 5; /*reserved*/
-
-        if (sdim->rank > 0) {
-            if (NULL==(sdim->size=H5FL_ARR_MALLOC(hsize_t,sdim->rank)))
-                HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-            for (u = 0; u < sdim->rank; u++)
-                H5F_DECODE_LENGTH (f, p, sdim->size[u]);
-            if (flags & H5S_VALID_MAX) {
-                if (NULL==(sdim->max=H5FL_ARR_MALLOC(hsize_t,sdim->rank)))
-                    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-                for (u = 0; u < sdim->rank; u++)
-                    H5F_DECODE_LENGTH (f, p, sdim->max[u]);
-            }
-#ifdef LATER
-            if (flags & H5S_VALID_PERM) {
-                if (NULL==(sdim->perm=H5FL_ARR_MALLOC(hsize_t,sdim->rank)))
-                    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-                for (u = 0; u < sdim->rank; u++)
-                    H5F_DECODE_LENGTH (f, p, sdim->perm[u]);
-            }
-#endif /* LATER */
-        }
-    }
-
-    /* Set return value */
-    ret_value = (void*)sdim;	/*success*/
-    
-done:
-    if (!ret_value && sdim) {
-        H5S_release_simple(sdim);
-        H5FL_FREE(H5S_simple_t,sdim);
-    } /* end if */
-
-    FUNC_LEAVE_NOAPI(ret_value);
-}
-
-
-/*--------------------------------------------------------------------------
- NAME
-    H5O_sdspace_new_encode
+    H5O_sdspace_encode
  PURPOSE
-    Encode a simple dimensionality message 
+    Encode an extent dimensionality message 
  USAGE
     herr_t H5O_sdspace_encode(f, raw_size, p, mesg)
 	H5F_t *f;	        IN: pointer to the HDF5 file struct
@@ -293,17 +181,20 @@ done:
     dimensionality message in the "raw" disk form.
 
  MODIFICATIONS
+    Raymond Lu
+    April 8, 2004
+    Added the type of dataspace into this header message using a reserved byte.
 
 --------------------------------------------------------------------------*/
 static herr_t
-H5O_sdspace_new_encode(H5F_t *f, uint8_t *p, const void *mesg)
+H5O_sdspace_encode(H5F_t *f, uint8_t *p, const void *mesg)
 {
     const H5S_extent_t	*sdim = (const H5S_extent_t *) mesg;
     unsigned		u;  /* Local counting variable */
     unsigned		flags = 0;
     herr_t ret_value=SUCCEED;   /* Return value */
 
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_encode, FAIL);
+    FUNC_ENTER_NOAPI(H5O_sdspace_encode, FAIL);
 
     /* check args */
     assert(f);
@@ -350,85 +241,7 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
-    H5O_sdspace_encode
- PURPOSE
-    Encode a simple dimensionality message 
- USAGE
-    herr_t H5O_sdspace_encode(f, raw_size, p, mesg)
-	H5F_t *f;	  IN: pointer to the HDF5 file struct
-	size_t raw_size;	IN: size of the raw information buffer
-	const uint8 *p;		IN: the raw information buffer
-	const void *mesg;	IN: Pointer to the simple dimensionality struct
- RETURNS
-    Non-negative on success/Negative on failure
- DESCRIPTION
-	This function encodes the native memory form of the simple
-    dimensionality message in the "raw" disk form.
-
- MODIFICATIONS
-	Robb Matzke, 1998-04-09
-	The current and maximum dimensions are now H5F_SIZEOF_SIZET bytes
-	instead of just four bytes.
- 
-  	Robb Matzke, 1998-07-20
-        Added a version number and reformatted the message for aligment.
---------------------------------------------------------------------------*/
-static herr_t
-H5O_sdspace_encode(H5F_t *f, uint8_t *p, const void *mesg)
-{
-    const H5S_simple_t	*sdim = (const H5S_simple_t *) mesg;
-    unsigned		u;  /* Local counting variable */
-    unsigned		flags = 0;
-    herr_t ret_value=SUCCEED;   /* Return value */
-
-    FUNC_ENTER_NOAPI(H5O_sdspace_encode, FAIL);
-
-    /* check args */
-    assert(f);
-    assert(p);
-    assert(sdim);
-
-    /* set flags */
-    if (sdim->max)
-        flags |= H5S_VALID_MAX;
-#ifdef LATER
-    if (sdim->perm)
-        flags |= H5S_VALID_PERM;
-#endif
-
-    /* encode */
-    *p++ = H5O_SDSPACE_VERSION;
-    *p++ = sdim->rank;
-    *p++ = flags;
-    *p++ = 0; /*reserved*/
-    *p++ = 0; /*reserved*/
-    *p++ = 0; /*reserved*/
-    *p++ = 0; /*reserved*/
-    *p++ = 0; /*reserved*/
-
-    if (sdim->rank > 0) {
-        for (u = 0; u < sdim->rank; u++)
-            H5F_ENCODE_LENGTH (f, p, sdim->size[u]);
-        if (flags & H5S_VALID_MAX) {
-            for (u = 0; u < sdim->rank; u++) 
-                H5F_ENCODE_LENGTH (f, p, sdim->max[u]);
-        }
-#ifdef LATER
-        if (flags & H5S_VALID_PERM) {
-            for (u = 0; u < sdim->rank; u++)
-                H5F_ENCODE_LENGTH (f, p, sdim->perm[u]);
-        }
-#endif
-    }
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}
-
-
-/*--------------------------------------------------------------------------
- NAME
-    H5O_sdspace_new_copy
+    H5O_sdspace_copy
  PURPOSE
     Copies a message from MESG to DEST, allocating DEST if necessary.
  USAGE
@@ -440,15 +253,20 @@ done:
  DESCRIPTION
 	This function copies a native (memory) extent dimensionality message,
     allocating the destination structure if necessary.
+ MODIFICATIONS
+    Raymond Lu
+    April 8, 2004
+    Changed operation on H5S_simple_t to H5S_extent_t.
+
 --------------------------------------------------------------------------*/
 static void *
-H5O_sdspace_new_copy(const void *mesg, void *dest)
+H5O_sdspace_copy(const void *mesg, void *dest)
 {
     const H5S_extent_t	   *src = (const H5S_extent_t *) mesg;
     H5S_extent_t	   *dst = (H5S_extent_t *) dest;
     void                   *ret_value;          /* Return value */
 
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_copy, NULL);
+    FUNC_ENTER_NOAPI(H5O_sdspace_copy, NULL);
 
     /* check args */
     assert(src);
@@ -486,69 +304,11 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
-    H5O_sdspace_copy
- PURPOSE
-    Copies a message from MESG to DEST, allocating DEST if necessary.
- USAGE
-    void *H5O_sdspace_copy(mesg, dest)
-	const void *mesg;	IN: Pointer to the source simple dimensionality struct
-	const void *dest;	IN: Pointer to the destination simple dimensionality struct
- RETURNS
-    Pointer to DEST on success, NULL on failure
- DESCRIPTION
-	This function copies a native (memory) simple dimensionality message,
-    allocating the destination structure if necessary.
---------------------------------------------------------------------------*/
-static void *
-H5O_sdspace_copy(const void *mesg, void *dest)
-{
-    const H5S_simple_t	   *src = (const H5S_simple_t *) mesg;
-    H5S_simple_t	   *dst = (H5S_simple_t *) dest;
-    void                   *ret_value;          /* Return value */
-
-    FUNC_ENTER_NOAPI(H5O_sdspace_copy, NULL);
-
-    /* check args */
-    assert(src);
-    if (!dst && NULL==(dst = H5FL_MALLOC(H5S_simple_t)))
-	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-
-    /* deep copy -- pointed-to values are copied also */
-    HDmemcpy(dst, src, sizeof(H5S_simple_t));
-    
-    if (src->size) {
-	if (NULL==(dst->size = H5FL_ARR_MALLOC(hsize_t,src->rank)))
-	    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-	HDmemcpy (dst->size, src->size, src->rank*sizeof(src->size[0]));
-    }
-    if (src->max) {
-	if (NULL==(dst->max=H5FL_ARR_MALLOC(hsize_t,src->rank)))
-	    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-	HDmemcpy (dst->max, src->max, src->rank*sizeof(src->max[0]));
-    }
-#ifdef LATER
-    if (src->perm) {
-	if (NULL==(dst->perm=H5FL_ARR_MALLOC(hsize_t,src->rank)))
-	    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-	HDmemcpy (dst->perm, src->perm, src->rank*sizeof(src->perm[0]));
-    }
-#endif
-
-    /* Set return value */
-    ret_value=dst;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}
-
-
-/*--------------------------------------------------------------------------
- NAME
-    H5O_sdspace_new_size
+    H5O_sdspace_size
  PURPOSE
     Return the raw message size in bytes
  USAGE
-    void *H5O_sdspace_new_size(f, mesg)
+    void *H5O_sdspace_size(f, mesg)
 	H5F_t *f;	  IN: pointer to the HDF5 file struct
 	const void *mesg;	IN: Pointer to the source extent dimensionality struct
  RETURNS
@@ -561,58 +321,9 @@ done:
  MODIFICATIONS
 --------------------------------------------------------------------------*/
 static size_t
-H5O_sdspace_new_size(H5F_t *f, const void *mesg)
-{
-    const H5S_extent_t	   *space = (const H5S_extent_t *) mesg;
-    
-    /*
-     * All dimensionality messages are at least 8 bytes long.
-     */
-    size_t		    ret_value = 8;
-
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_size, 0);
-
-    /* add in the dimension sizes */
-    ret_value += space->u.simple.rank * H5F_SIZEOF_SIZE (f);
-
-    /* add in the space for the maximum dimensions, if they are present */
-    ret_value += space->u.simple.max ? space->u.simple.rank * H5F_SIZEOF_SIZE (f) : 0;
-
-#ifdef LATER
-    /* add in the space for the dimension permutations, if they are present */
-    ret_value += space->u.simple.perm ? space->u.simple.rank * 4 : 0;
-#endif
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}
-
-
-/*--------------------------------------------------------------------------
- NAME
-    H5O_sdspace_size
- PURPOSE
-    Return the raw message size in bytes
- USAGE
-    void *H5O_sdspace_copy(f, mesg)
-	H5F_t *f;	  IN: pointer to the HDF5 file struct
-	const void *mesg;	IN: Pointer to the source simple dimensionality struct
- RETURNS
-    Size of message on success, zero on failure
- DESCRIPTION
-	This function returns the size of the raw simple dimensionality message on
-    success.  (Not counting the message type or size fields, only the data
-    portion of the message).  It doesn't take into account alignment.
-
- MODIFICATIONS
-	Robb Matzke, 1998-04-09
-	The current and maximum dimensions are now H5F_SIZEOF_SIZET bytes
-	instead of just four bytes.
---------------------------------------------------------------------------*/
-static size_t
 H5O_sdspace_size(H5F_t *f, const void *mesg)
 {
-    const H5S_simple_t	   *space = (const H5S_simple_t *) mesg;
+    const H5S_extent_t	   *space = (const H5S_extent_t *) mesg;
     
     /*
      * All dimensionality messages are at least 8 bytes long.
@@ -621,16 +332,18 @@ H5O_sdspace_size(H5F_t *f, const void *mesg)
 
     FUNC_ENTER_NOAPI(H5O_sdspace_size, 0);
 
-    /* add in the dimension sizes */
-    ret_value += space->rank * H5F_SIZEOF_SIZE (f);
+    if(space->type != H5S_NULL) {
+        /* add in the dimension sizes */
+        ret_value += space->u.simple.rank * H5F_SIZEOF_SIZE (f);
 
-    /* add in the space for the maximum dimensions, if they are present */
-    ret_value += space->max ? space->rank * H5F_SIZEOF_SIZE (f) : 0;
+        /* add in the space for the maximum dimensions, if they are present */
+        ret_value += space->u.simple.max ? space->u.simple.rank * H5F_SIZEOF_SIZE (f) : 0;
 
 #ifdef LATER
-    /* add in the space for the dimension permutations, if they are present */
-    ret_value += space->perm ? space->rank * 4 : 0;
+        /* add in the space for the dimension permutations, if they are present */
+        ret_value += space->u.simple.perm ? space->u.simple.rank * 4 : 0;
 #endif
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
@@ -638,7 +351,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5O_sdspace_new_reset
+ * Function:	H5O_sdspace_reset
  *
  * Purpose:	Frees the inside of a dataspace message and resets it to some
  *		initial value.
@@ -653,44 +366,14 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_sdspace_new_reset(void *_mesg)
-{
-    H5S_extent_t	*mesg = (H5S_extent_t*)_mesg;
-    herr_t ret_value=SUCCEED;   /* Return value */
-    
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_reset, FAIL);
-
-    H5S_release_extent(mesg);
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5O_sdspace_reset
- *
- * Purpose:	Frees the inside of a dataspace message and resets it to some
- *		initial value.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Thursday, April 30, 1998
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
 H5O_sdspace_reset(void *_mesg)
 {
-    H5S_simple_t	*mesg = (H5S_simple_t*)_mesg;
+    H5S_extent_t	*mesg = (H5S_extent_t*)_mesg;
     herr_t ret_value=SUCCEED;   /* Return value */
     
     FUNC_ENTER_NOAPI(H5O_sdspace_reset, FAIL);
 
-    H5S_release_simple(mesg);
+    H5S_release_extent(mesg);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
@@ -698,7 +381,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5O_sdsdpace_new_free
+ * Function:	H5O_sdsdpace_free
  *
  * Purpose:	Free's the message
  *
@@ -712,36 +395,6 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_sdspace_new_free (void *mesg)
-{
-    herr_t ret_value=SUCCEED;   /* Return value */
-
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_free, FAIL);
-
-    assert (mesg);
-
-    H5FL_FREE(H5S_extent_t,mesg);
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5O_sdsdpace_free
- *
- * Purpose:	Free's the message
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Quincey Koziol
- *              Thursday, March 30, 2000
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
 H5O_sdspace_free (void *mesg)
 {
     herr_t ret_value=SUCCEED;   /* Return value */
@@ -750,7 +403,7 @@ H5O_sdspace_free (void *mesg)
 
     assert (mesg);
 
-    H5FL_FREE(H5S_simple_t,mesg);
+    H5FL_FREE(H5S_extent_t,mesg);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
@@ -759,11 +412,11 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
-    H5O_sdspace_new_debug
+    H5O_sdspace_debug
  PURPOSE
     Prints debugging information for an extent dimensionality message
  USAGE
-    void *H5O_sdspace_new_debug(f, mesg, stream, indent, fwidth)
+    void *H5O_sdspace_debug(f, mesg, stream, indent, fwidth)
 	H5F_t *f;	        IN: pointer to the HDF5 file struct
 	const void *mesg;	IN: Pointer to the source extent dimensionality struct
 	FILE *stream;		IN: Pointer to the stream for output data
@@ -776,14 +429,14 @@ done:
     parameter.
 --------------------------------------------------------------------------*/
 static herr_t
-H5O_sdspace_new_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *mesg,
+H5O_sdspace_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *mesg,
 		  FILE * stream, int indent, int fwidth)
 {
     const H5S_extent_t	   *sdim = (const H5S_extent_t *) mesg;
     unsigned		    u;	/* local counting variable */
     herr_t ret_value=SUCCEED;   /* Return value */
 
-    FUNC_ENTER_NOAPI(H5O_sdspace_new_debug, FAIL);
+    FUNC_ENTER_NOAPI(H5O_sdspace_debug, FAIL);
 
     /* check args */
     assert(f);
@@ -831,79 +484,3 @@ H5O_sdspace_new_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *mesg,
 done:
     FUNC_LEAVE_NOAPI(ret_value);
 }
-
-
-/*--------------------------------------------------------------------------
- NAME
-    H5O_sdspace_debug
- PURPOSE
-    Prints debugging information for a simple dimensionality message
- USAGE
-    void *H5O_sdspace_debug(f, mesg, stream, indent, fwidth)
-	H5F_t *f;	  IN: pointer to the HDF5 file struct
-	const void *mesg;	IN: Pointer to the source simple dimensionality struct
-	FILE *stream;		IN: Pointer to the stream for output data
-	int indent;		IN: Amount to indent information by
-	int fwidth;		IN: Field width (?)
- RETURNS
-    Non-negative on success/Negative on failure
- DESCRIPTION
-	This function prints debugging output to the stream passed as a 
-    parameter.
---------------------------------------------------------------------------*/
-static herr_t
-H5O_sdspace_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *mesg,
-		  FILE * stream, int indent, int fwidth)
-{
-    const H5S_simple_t	   *sdim = (const H5S_simple_t *) mesg;
-    unsigned		    u;	/* local counting variable */
-    herr_t ret_value=SUCCEED;   /* Return value */
-
-    FUNC_ENTER_NOAPI(H5O_sdspace_debug, FAIL);
-
-    /* check args */
-    assert(f);
-    assert(sdim);
-    assert(stream);
-    assert(indent >= 0);
-    assert(fwidth >= 0);
-
-    HDfprintf(stream, "%*s%-*s %lu\n", indent, "", fwidth,
-	    "Rank:",
-	    (unsigned long) (sdim->rank));
-    
-    if(sdim->rank>0) {
-        HDfprintf(stream, "%*s%-*s {", indent, "", fwidth, "Dim Size:");
-        for (u = 0; u < sdim->rank; u++)
-            HDfprintf (stream, "%s%Hu", u?", ":"", sdim->size[u]);
-        HDfprintf (stream, "}\n");
-        
-        HDfprintf(stream, "%*s%-*s ", indent, "", fwidth, "Dim Max:");
-        if (sdim->max) {
-            HDfprintf (stream, "{");
-            for (u = 0; u < sdim->rank; u++) {
-                if (H5S_UNLIMITED==sdim->max[u]) {
-                    HDfprintf (stream, "%sINF", u?", ":"");
-                } else {
-                    HDfprintf (stream, "%s%Hu", u?", ":"", sdim->max[u]);
-                }
-            }
-            HDfprintf (stream, "}\n");
-        } else {
-            HDfprintf (stream, "CONSTANT\n");
-        }
-
-#ifdef LATER
-        if (sdim->perm) {
-            HDfprintf(stream, "%*s%-*s {", indent, "", fwidth, "Dim Perm:");
-            for (u = 0; u < sdim->rank; u++) {
-                HDfprintf (stream, "%s%lu", u?", ":"",
-                     (unsigned long) (sdim->perm[u]));
-            }
-        }
-#endif
-    } /* end if */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}
diff --git a/src/H5S.c b/src/H5S.c
index d2feb43..90cd6ef 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -1138,7 +1138,7 @@ H5S_modify(H5G_entry_t *ent, const H5S_t *ds, hbool_t update_time, hid_t dxpl_id
         case H5S_NULL:
         case H5S_SCALAR:
         case H5S_SIMPLE:
-            if (H5O_modify(ent, H5O_SDSPACE_NEW_ID, 0, 0, update_time, &(ds->extent), dxpl_id)<0)
+            if (H5O_modify(ent, H5O_SDSPACE_ID, 0, 0, update_time, &(ds->extent), dxpl_id)<0)
                 HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't update simple data space message");
             break;
 
@@ -1185,7 +1185,7 @@ H5S_append(H5F_t *f, hid_t dxpl_id, struct H5O_t *oh, const H5S_t *ds)
         case H5S_NULL:
         case H5S_SCALAR:
         case H5S_SIMPLE:
-            if (H5O_append(f, dxpl_id, oh, H5O_SDSPACE_NEW_ID, 0, &(ds->extent))<0)
+            if (H5O_append(f, dxpl_id, oh, H5O_SDSPACE_ID, 0, &(ds->extent))<0)
                 HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't update simple data space message");
             break;
 
@@ -1234,7 +1234,36 @@ H5S_read(H5G_entry_t *ent, hid_t dxpl_id)
     if (NULL==(ds = H5FL_CALLOC(H5S_t)))
         HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
 
-    if (H5O_read(ent, H5O_SDSPACE_NEW_ID, 0, &(ds->extent), dxpl_id) != NULL) { /* New data space header message */
+    if (H5O_read(ent, H5O_SDSPACE_ID, 0, &(ds->extent), dxpl_id) == NULL)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, NULL, "unable to load dataspace info from dataset header");
+
+    if (ds->extent.type == H5S_NO_CLASS) { /* For backward compatibility, if file is created by version 1.6 or before. */
+        if(ds->extent.u.simple.rank != 0) {
+            hsize_t nelem;  /* Number of elements in extent */
+            unsigned u;     /* Local index variable */
+
+            ds->extent.type = H5S_SIMPLE;
+
+            /* Compute the number of elements in the extent */
+            for(u=0, nelem=1; u<ds->extent.u.simple.rank; u++)
+                nelem*=ds->extent.u.simple.size[u];
+            ds->extent.nelem = nelem;
+        } else {  
+            ds->extent.type = H5S_SCALAR;
+            ds->extent.nelem = 1;
+        } /* end if */
+
+        /* Default to entire dataspace being selected */
+        if(H5S_select_all(ds,0)<0)
+            HGOTO_ERROR (H5E_DATASPACE, H5E_CANTSET, NULL, "unable to set all selection");
+
+        /* Allocate space for the offset and set it to zeros */
+        if(ds->extent.u.simple.rank>0) {
+            if (NULL==(ds->select.offset = H5FL_ARR_CALLOC(hssize_t,ds->extent.u.simple.rank)))
+                HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
+        } else
+            ds->select.offset = NULL;
+    } else {  /* If file is new, created by version 1.7 or after */
         switch(ds->extent.type) {
             case H5S_NULL:
                 ds->extent.nelem = 0;
@@ -1273,36 +1302,7 @@ H5S_read(H5G_entry_t *ent, hid_t dxpl_id)
             default:
                 HGOTO_ERROR (H5E_DATASPACE, H5E_CANTSET, NULL, "unknown data space type");
         }
-    } else { /* For backward compatibility, if file is created by version 1.6 or before. */
-        if (H5O_read(ent, H5O_SDSPACE_ID, 0, &(ds->extent.u.simple), dxpl_id) == NULL)
-            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, NULL, "unable to load dataspace info from dataset header");
-
-        if(ds->extent.u.simple.rank != 0) {
-            hsize_t nelem;  /* Number of elements in extent */
-            unsigned u;     /* Local index variable */
-
-            ds->extent.type = H5S_SIMPLE;
-
-            /* Compute the number of elements in the extent */
-            for(u=0, nelem=1; u<ds->extent.u.simple.rank; u++)
-                nelem*=ds->extent.u.simple.size[u];
-            ds->extent.nelem = nelem;
-        } else {  
-            ds->extent.type = H5S_SCALAR;
-            ds->extent.nelem = 1;
-        } /* end if */
-
-        /* Default to entire dataspace being selected */
-        if(H5S_select_all(ds,0)<0)
-            HGOTO_ERROR (H5E_DATASPACE, H5E_CANTSET, NULL, "unable to set all selection");
-
-        /* Allocate space for the offset and set it to zeros */
-        if(ds->extent.u.simple.rank>0) {
-            if (NULL==(ds->select.offset = H5FL_ARR_CALLOC(hssize_t,ds->extent.u.simple.rank)))
-                HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
-        } else
-            ds->select.offset = NULL;
-    } /* end if */
+    }
     
     /* Set the value for successful return */
     ret_value=ds;
@@ -2165,9 +2165,7 @@ H5S_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg, FILE *stream, int indent,
         case H5S_SIMPLE:
             fprintf(stream, "%*s%-*s H5S_SIMPLE\n", indent, "", fwidth,
                     "Space class:");
-            /*H5O_debug_id(H5O_SDSPACE_ID, f, dxpl_id, &(mesg->extent.u.simple), stream,
-                                 indent+3, MAX(0, fwidth-3));*/
-            H5O_debug_id(H5O_SDSPACE_NEW_ID, f, dxpl_id, &(mesg->extent), stream,
+            H5O_debug_id(H5O_SDSPACE_ID, f, dxpl_id, &(mesg->extent), stream,
                                  indent+3, MAX(0, fwidth-3));
             break;