[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

1 files changed, 55 insertions, 28 deletions

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);