[svn-r9351]

Purpose:  enhanced feature

Description:  enable  size adjustment for compound datatype.  The size
can be increased and decreased(as long as the members are not cut).

Solution:  mainly check if any member is being cut when decreasing the
size.  Others are simply taking out the assertion against 0 size.

Platforms tested:  h5committest and fuss.

Misc. update:  RELEASE.txt

5 files changed, 107 insertions, 9 deletions

diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 4c11f62..af1637f 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -39,6 +39,10 @@ New Features
 
     Library:
     --------
+        - Compound datatype has been enhanced with a new feature of size 
+            adjustment.  The size can be increased and decreased(without
+            cutting the last member).  No API change is involved.  SLU - 
+            2004/10/1
 
     Parallel Library:
     -----------------
diff --git a/src/H5T.c b/src/H5T.c
index 446b2df..f6462db 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -1356,8 +1356,8 @@ H5Tcreate(H5T_class_t type, size_t size)
     FUNC_ENTER_API(H5Tcreate, FAIL);
     H5TRACE2("i","Ttz",type,size);
 
-    /* check args */
-    if (size == 0)
+    /* check args. We start to support size adjustment for compound type. */
+    if (size == 0 && type != H5T_COMPOUND)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid size");
 
     /* create the type */
@@ -2629,8 +2629,6 @@ H5T_create(H5T_class_t type, size_t size)
 
     FUNC_ENTER_NOAPI(H5T_create, NULL);
 
-    assert(size != 0);
-
     switch (type) {
         case H5T_INTEGER:
         case H5T_FLOAT:
@@ -3378,7 +3376,6 @@ H5T_set_size(H5T_t *dt, size_t size)
     assert(size!=0);
     assert(H5T_REFERENCE!=dt->shared->type);
     assert(!(H5T_ENUM==dt->shared->type && 0==dt->shared->u.enumer.nmembs));
-    assert(!(H5T_COMPOUND==dt->shared->type && 0==dt->shared->u.compnd.nmembs));
 
     if (dt->shared->parent) {
         if (H5T_set_size(dt->shared->parent, size)<0)
@@ -3415,8 +3412,33 @@ H5T_set_size(H5T_t *dt, size_t size)
                 break;
 
             case H5T_COMPOUND:
-                if(size<dt->shared->size)
-                    HGOTO_ERROR(H5E_DATATYPE, H5E_BADVALUE, FAIL, "can't shrink compound datatype");
+                /* If decreasing size, check the last member isn't being cut. */
+                if(size<dt->shared->size) {
+                    int         num_membs;
+                    unsigned    i, max_index=0;
+                    H5T_t       *memb_type;
+                    size_t      memb_offset, max_offset=0;
+                    size_t      max_size;
+
+                    if((num_membs = H5T_get_nmembers(dt))<0)    
+                        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "unable to get number of members");
+
+                    for(i=0; i<num_membs; i++) {
+                        memb_offset = H5T_get_member_offset(dt, i);
+                        if(memb_offset > max_offset) {
+                            max_offset = memb_offset;
+                            max_index = i;
+                        }
+                    }
+                    
+                    if((memb_type = H5T_get_member_type(dt, max_index))==NULL)    
+                        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "unable to get type of member");
+
+                    max_size = H5T_get_size(memb_type);
+
+                    if(size<(max_offset+max_size))
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "size shrinking will cut off last member ");
+                }
                 break;
 
             case H5T_STRING:
diff --git a/src/H5Tcompound.c b/src/H5Tcompound.c
index f50676f..f9c0035 100644
--- a/src/H5Tcompound.c
+++ b/src/H5Tcompound.c
@@ -38,7 +38,6 @@ static herr_t H5T_init_compound_interface(void);
 #define H5T_COMPND_INC	64	/*typical max numb of members per struct */
 
 /* Static local functions */
-static size_t H5T_get_member_offset(H5T_t *dt, int membno);
 static herr_t H5T_pack(H5T_t *dt);
 
 
@@ -128,7 +127,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static size_t
+size_t
 H5T_get_member_offset(H5T_t *dt, int membno)
 {
     size_t	ret_value;
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index bc2841f..e29b873 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -877,5 +877,6 @@ H5_DLL H5T_t * H5T_array_create(H5T_t *base, int ndims,
 
 /* Compound functions */
 H5_DLL htri_t H5T_is_packed(H5T_t *dt);
+H5_DLL size_t H5T_get_member_offset(H5T_t *dt, int membno);
 
 #endif
diff --git a/test/dtypes.c b/test/dtypes.c
index 00001f3..83e41ad 100644
--- a/test/dtypes.c
+++ b/test/dtypes.c
@@ -2034,6 +2034,77 @@ test_compound_11(void)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    test_compound_12
+ *
+ * Purpose:     Tests size adjustment of compound data types.  Start with 
+ *              no member and 0 size, increase the size as inserting 
+ *              members.
+ *
+ * Return:      Success:        0
+ *
+ *              Failure:        number of errors
+ *
+ * Programmer:  Raymond Lu
+ *              Wednesday, September 29, 2004
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+test_compound_12(void)
+{
+    complex_t               tmp;
+    hid_t                   complex_id;
+    size_t                  size = 0;
+    size_t                  offset, new_size;
+    herr_t ret;
+
+    TESTING("adjust size of compound data types");
+
+    /* Create the empty compound type */
+    if ((complex_id = H5Tcreate(H5T_COMPOUND, 0))<0) goto error;
+
+    /* Add a couple fields and adjust the size */
+    offset = size;
+    if((size+=H5Tget_size(H5T_NATIVE_DOUBLE))<0) goto error; 
+    if (H5Tset_size(complex_id, size)<0) goto error;
+    if (H5Tinsert(complex_id, "real", offset,
+		  H5T_NATIVE_DOUBLE)<0) goto error;
+
+    offset = size;
+    if((size+=H5Tget_size(H5T_NATIVE_DOUBLE))<0) goto error; 
+    if (H5Tset_size(complex_id, size)<0) goto error;
+    if (H5Tinsert(complex_id, "imaginary", offset,
+		  H5T_NATIVE_DOUBLE)<0) goto error;
+
+    /* Increase and decrease the size. */
+    if((size+=H5Tget_size(H5T_NATIVE_DOUBLE))<0) goto error; 
+    if (H5Tset_size(complex_id, size)<0) goto error;
+   
+    if((size-=H5Tget_size(H5T_NATIVE_DOUBLE))<0) goto error; 
+    if (H5Tset_size(complex_id, size)<0) goto error;
+
+    /* Verify the size */
+    if((new_size=H5Tget_size(complex_id))<0) goto error; 
+    if(new_size!=size) goto error;
+
+    /* Tries to cut last member.  Supposed to fail. */
+    size--;
+    H5E_BEGIN_TRY {
+        H5Tset_size(complex_id, size);
+    } H5E_END_TRY;  
+    
+    if (H5Tclose (complex_id)<0) goto error;
+    PASSED();
+    return 0;
+
+  error:
+    return 1;
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:    test_query
  *
  * Purpose:     Tests query functions of compound and enumeration types.
@@ -5216,6 +5287,7 @@ main(void)
     nerrors += test_compound_9();
     nerrors += test_compound_10();
     nerrors += test_compound_11();
+    nerrors += test_compound_12();
     nerrors += test_conv_int ();
     nerrors += test_conv_enum_1();
     nerrors += test_conv_enum_2();