[svn-r876] Changes since 19981102

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

./bin/snapshot
	Made same fix as for the release script yesterday.

./src/H5D.c
./src/H5Dprivate.h
./src/H5G.c
./src/H5Gprivate.h
./src/H5Gpublic.h
./src/H5O.c
./src/H5Oprivate.h
./src/H5RA.c
./src/H5RAprivate.h
./src/H5T.c
./src/H5Tprivate.h
	Improved object type checking.  Instead of determining the
	object type by trying to open each of the possible types, we
	keep a table of associations between object type number (like
	H5G_GROUP, H5G_DATASET, H5D_TYPE, and H5D_RAGGED) and an `isa'
	function that returns true if the object header has the right
	messages to make the object a particular type.  This mechanism
	also allows specialization of object types by permitting an
	object to satisfy more than one `isa' function.

	Added `isa' functions for groups, datasets, ragged arrays, and
	committed data types.

./src/H5config.h.in
	Added HAVE_STAT_ST_BLOCKS.  I thought this had already been
	added, but apparently not.

./tools/h5ls.c
	Removed system include files since they're already included by
	H5private.h and since I wasn't including them portably anyway.

	By default, 1-byte integer types are printed as integer values
	instead of ASCII characters. However, the `-s' or `--string'
	command-line switch causes the data to be interpretted as
	ASCII.  String data types are always printed as character
	data.

	Ragged arrays are now identified as ragged arrays and h5ls
	doesn't descend into the group automatically.  This uses the
	new object type specialization stuff.

./tools/h5tools.c
./tools/h5tools.h
	Added the ability to print 1-byte integer types as either
	ASCII or numeric data instead of always ASCII.  The default is
	to print as numeric data.

12 files changed, 425 insertions, 43 deletions

diff --git a/src/H5D.c b/src/H5D.c
index 62e6b74..65dca31 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -1101,7 +1101,57 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
     FUNC_LEAVE(ret_value);
 }
 
+
 /*-------------------------------------------------------------------------
+ * Function:	H5D_isa
+ *
+ * Purpose:	Determines if an object has the requisite messages for being
+ *		a dataset.
+ *
+ * Return:	Success:	TRUE if the required dataset messages are
+ *				present; FALSE otherwise.
+ *
+ *		Failure:	FAIL if the existence of certain messages
+ *				cannot be determined.
+ *
+ * Programmer:	Robb Matzke
+ *              Monday, November  2, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5D_isa(H5G_entry_t *ent)
+{
+    htri_t	exists;
+    
+    FUNC_ENTER(H5D_isa, FAIL);
+    assert(ent);
+
+    /* Data type */
+    if ((exists=H5O_exists(ent, H5O_DTYPE, 0))<0) {
+	HRETURN_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL,
+		      "unable to read object header");
+    } else if (!exists) {
+	HRETURN(FALSE);
+    }
+
+    /* Layout */
+    if ((exists=H5O_exists(ent, H5O_LAYOUT, 0))<0) {
+	HRETURN_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL,
+		      "unable to read object header");
+    } else if (!exists) {
+	HRETURN(FALSE);
+    }
+    
+
+    
+    FUNC_LEAVE(TRUE);
+}
+
+/*
+ *------------------------------------------------------------------------- 
  * Function:	H5D_open
  *
  * Purpose:	Finds a dataset named NAME in file F and builds a descriptor
@@ -1130,7 +1180,7 @@ H5D_open(H5G_entry_t *loc, const char *name)
 {
     H5D_t	*dataset = NULL;	/*the dataset which was found	*/
     H5D_t	*ret_value = NULL;	/*return value			*/
-    H5G_entry_t ent;            /* Dataset symbol table entry */
+    H5G_entry_t ent;            	/*dataset symbol table entry	*/
     
     FUNC_ENTER(H5D_open, NULL);
 
@@ -1173,10 +1223,10 @@ done:
 H5D_t *
 H5D_open_oid(H5G_entry_t *ent)
 {
-    H5D_t *dataset = NULL;      /* New dataset struct */
-    H5D_t *ret_value = NULL;	/*return value			*/
+    H5D_t 	*dataset = NULL;	/*new dataset struct 		*/
+    H5D_t 	*ret_value = NULL;	/*return value			*/
+    H5S_t	*space = NULL;		/*data space			*/
     intn	i;
-    H5S_t	*space = NULL;
     
     FUNC_ENTER(H5D_open_oid, NULL);
 
@@ -1290,8 +1340,7 @@ H5D_open_oid(H5G_entry_t *ent)
     ret_value = dataset;
 
 done:
-    if (space)
-        H5S_close (space);
+    if (space) H5S_close (space);
     if (ret_value==NULL && dataset) {
         if (H5F_addr_defined(&(dataset->ent.header))) {
             H5O_close(&(dataset->ent));
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index bdf66f7..3a30731 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -71,6 +71,7 @@ H5D_t *H5D_create (H5G_entry_t *loc, const char *name, const H5T_t *type,
 		   const H5S_t *space, const H5D_create_t *create_parms);
 H5D_t *H5D_open (H5G_entry_t *loc, const char *name);
 herr_t H5D_close (H5D_t *dataset);
+htri_t H5D_isa(H5G_entry_t *ent);
 herr_t H5D_read (H5D_t *dataset, const H5T_t *mem_type,
 		 const H5S_t *mem_space, const H5S_t *file_space,
 		 const H5D_xfer_t *xfer_parms, void *buf/*out*/);
diff --git a/src/H5G.c b/src/H5G.c
index bf15f3d..992de26 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -95,6 +95,9 @@ static hbool_t interface_initialize_g = FALSE;
 #define INTERFACE_INIT	H5G_init_interface
 static herr_t H5G_init_interface(void);
 static void H5G_term_interface(void);
+static H5G_typeinfo_t *H5G_type_g = NULL;	/*object typing info	*/
+static size_t H5G_ntypes_g = 0;			/*entries in type table	*/
+static size_t H5G_atypes_g = 0;			/*entries allocated	*/
 
 
 /*-------------------------------------------------------------------------
@@ -523,8 +526,9 @@ H5Gget_objinfo(hid_t loc_id, const char *name, hbool_t follow_link,
  *		most SIZE characters (counting the null terminator) are
  *		copied to the BUF result buffer.
  *
- * Return:	Non-negative on success (the link value is in BUF.) /Negative on
- *              failure
+ * Return:	Success:	Non-negative with the link value in BUF.
+ *
+ * 		Failure:	Negative
  *
  * Programmer:	Robb Matzke
  *              Monday, April 13, 1998
@@ -684,6 +688,17 @@ H5G_init_interface(void)
 	HRETURN_ERROR(H5E_SYM, H5E_CANTINIT, FAIL,
 		      "unable to initialize interface");
     }
+
+    /*
+     * Initialize the type info table.  Begin with the most general types and
+     * end with the most specific. For instance, any object that has a data
+     * type message is a data type but only some of them are datasets.
+     */
+    H5G_register_type(H5G_TYPE,    H5T_isa,  "data type");
+    H5G_register_type(H5G_GROUP,   H5G_isa,  "group");
+    H5G_register_type(H5G_DATASET, H5D_isa,  "dataset");
+    H5G_register_type(H5G_RAGGED,  H5RA_isa, "ragged array");
+
     FUNC_LEAVE(SUCCEED);
 }
 
@@ -710,6 +725,85 @@ H5G_term_interface(void)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5G_register_type
+ *
+ * Purpose:	Register a new object type so H5G_get_type() can detect it.
+ *		One should always register a general type before a more
+ *		specific type.  For instance, any object that has a data type
+ *		message is a data type, but only some of those objects are
+ *		datasets.
+ *
+ * Return:	Success:	Non-negative
+ *
+ *		Failure:	Negative
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, November  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5G_register_type(intn type, htri_t(*isa)(H5G_entry_t*), const char *_desc)
+{
+    char	*desc = NULL;
+    size_t	i;
+    herr_t	ret_value = FAIL;
+    
+    FUNC_ENTER(H5G_register_type, FAIL);
+    assert(type>=0);
+    assert(isa);
+    assert(_desc);
+
+    /* Copy the description */
+    if (NULL==(desc=H5MM_strdup(_desc))) {
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
+		    "memory allocation failed for object type description");
+    }
+
+    /*
+     * If the type is already registered then just update its entry without
+     * moving it to the end
+     */
+    for (i=0; i<H5G_ntypes_g; i++) {
+	if (H5G_type_g[i].type==type) {
+	    H5G_type_g[i].isa = isa;
+	    H5MM_xfree(H5G_type_g[i].desc);
+	    H5G_type_g[i].desc = desc;
+	    ret_value = SUCCEED;
+	    goto done;
+	}
+    }
+
+    /* Increase table size */
+    if (H5G_ntypes_g>=H5G_atypes_g) {
+	size_t n = MAX(32, 2*H5G_atypes_g);
+	H5G_typeinfo_t *x = H5MM_realloc(H5G_type_g,
+					 n*sizeof(H5G_typeinfo_t));
+	if (!x) {
+	    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
+			"memory allocation failed for objec type table");
+	}
+	H5G_atypes_g = n;
+	H5G_type_g = x;
+    }
+    
+    /* Add a new entry */
+    H5G_type_g[H5G_ntypes_g].type = type;
+    H5G_type_g[H5G_ntypes_g].isa = isa;
+    H5G_type_g[H5G_ntypes_g].desc = desc; /*already copied*/
+    H5G_ntypes_g++;
+
+    ret_value = SUCCEED;
+
+ done:
+    if (ret_value<0) H5MM_xfree(desc);
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5G_component
  *
  * Purpose:	Returns the pointer to the first component of the
@@ -842,14 +936,14 @@ H5G_basename(const char *name, size_t *size_p)
  *		
  * Errors:
  *
- * Return:	Success:	Non-negative if name can be fully resolved.	See
- *				above for values of REST, GRP_ENT, and
+ * Return:	Success:	Non-negative if name can be fully resolved.
+ *				See above for values of REST, GRP_ENT, and
  *				OBJ_ENT.  NLINKS has been decremented for
  *				each symbolic link that was followed.
  *
- *		Failure:	Negative if the name could not be fully resolved.
- *				See above for values of REST, GRP_ENT, and
- *				OBJ_ENT.
+ *		Failure:	Negative if the name could not be fully
+ *				resolved. See above for values of REST,
+ *				GRP_ENT, and OBJ_ENT.
  *
  * Programmer:	Robb Matzke
  *		matzke@llnl.gov
@@ -1191,6 +1285,42 @@ H5G_create(H5G_entry_t *loc, const char *name, size_t size_hint)
     grp->nref = 1;
     FUNC_LEAVE(grp);
 }
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_isa
+ *
+ * Purpose:	Determines if an object has the requisite messages for being
+ *		a group.
+ *
+ * Return:	Success:	TRUE if the required group messages are
+ *				present; FALSE otherwise.
+ *
+ *		Failure:	FAIL if the existence of certain messages
+ *				cannot be determined.
+ *
+ * Programmer:	Robb Matzke
+ *              Monday, November  2, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5G_isa(H5G_entry_t *ent)
+{
+    htri_t	exists;
+    
+    FUNC_ENTER(H5G_isa, FAIL);
+    assert(ent);
+
+    if ((exists=H5O_exists(ent, H5O_STAB, 0))<0) {
+	HRETURN_ERROR(H5E_SYM, H5E_CANTINIT, FAIL,
+		      "unable to read object header");
+    }
+    FUNC_LEAVE(exists);
+}
+    
 
 /*-------------------------------------------------------------------------
  * Function:	H5G_open
@@ -1431,8 +1561,8 @@ H5G_insert(H5G_entry_t *loc, const char *name, H5G_entry_t *ent)
  *
  * Errors:
  *
- * Return:	Success:	Non-negative, see above for values of GRP_ENT and
- *				OBJ_ENT.
+ * Return:	Success:	Non-negative, see above for values of GRP_ENT
+ *				and OBJ_ENT.
  *
  *		Failure:	Negative
  *
@@ -1761,12 +1891,54 @@ H5G_link (H5G_entry_t *loc, H5G_link_t type, const char *cur_name,
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5G_get_type
+ *
+ * Purpose:	Returns the type of object pointed to by `ent'.
+ *
+ * Return:	Success:	An object type defined in H5Gpublic.h
+ *
+ *		Failure:	H5G_UNKNOWN
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, November  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+intn
+H5G_get_type(H5G_entry_t *ent)
+{
+    htri_t	isa;
+    size_t	i;
+    
+    FUNC_ENTER(H5G_get_type, H5G_UNKNOWN);
+
+    for (i=H5G_ntypes_g; i>0; --i) {
+	if ((isa=(H5G_type_g[i-1].isa)(ent))<0) {
+	    HRETURN_ERROR(H5E_SYM, H5E_CANTINIT, FAIL,
+			  "unable to determine object type");
+	} else if (isa) {
+	    HRETURN(H5G_type_g[i-1].type);
+	}
+    }
+
+    if (0==i) {
+	HRETURN_ERROR(H5E_SYM, H5E_CANTINIT, FAIL,
+		      "unable to determine object type");
+    }
+    FUNC_LEAVE(H5G_UNKNOWN);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5G_get_objinfo
  *
  * Purpose:	Returns information about an object.
  *
- * Return:	Success:	Non-negative with info about the object returned
- *				through STATBUF if it isn't the null pointer.
+ * Return:	Success:	Non-negative with info about the object
+ *				returned through STATBUF if it isn't the null
+ *				pointer.
  *
  *		Failure:	Negative
  *
@@ -1784,9 +1956,6 @@ H5G_get_objinfo (H5G_entry_t *loc, const char *name, hbool_t follow_link,
     H5O_stab_t		stab_mesg;
     H5G_entry_t		grp_ent, obj_ent;
     const char		*s = NULL;
-    H5D_t		*temp_dset = NULL;
-    H5G_t		*temp_grp = NULL;
-    H5T_t		*temp_type = NULL;
     
     FUNC_ENTER (H5G_get_objinfo, FAIL);
 
@@ -1833,24 +2002,7 @@ H5G_get_objinfo (H5G_entry_t *loc, const char *name, hbool_t follow_link,
 		H5E_clear();
 		statbuf->mtime = 0;
 	    }
-
-	    /*
-	     * Determining the type of an object is a rather expensive
-	     * operation compared to the other stuff here.  It's also not
-	     * very flexible.
-	     */
-	    if (NULL!=(temp_dset=H5D_open (loc, name))) {
-		statbuf->type = H5G_DATASET;
-		H5D_close (temp_dset);
-	    } else if (NULL!=(temp_grp=H5G_open (loc, name))) {
-		statbuf->type = H5G_GROUP;
-		H5G_close (temp_grp);
-	    } else if (NULL!=(temp_type=H5T_open(loc, name))) {
-		statbuf->type = H5G_TYPE;
-		H5T_close(temp_type);
-	    } else {
-		statbuf->type = H5G_UNKNOWN;
-	    }
+	    statbuf->type = H5G_get_type(&obj_ent);
 	    H5E_clear(); /*clear errors resulting from checking type*/
 	}
     }
@@ -1864,8 +2016,8 @@ H5G_get_objinfo (H5G_entry_t *loc, const char *name, hbool_t follow_link,
  *
  * Purpose:	Returns the value of a symbolic link.
  *
- * Return:	Success:	Non-negative, with at most SIZE bytes of the link
- *				value copied into the BUF buffer.  If the
+ * Return:	Success:	Non-negative, with at most SIZE bytes of the
+ *				link value copied into the BUF buffer.  If the
  *				link value is larger than SIZE characters
  *				counting the null terminator then the BUF
  *				result will not be null terminated.
diff --git a/src/H5Gprivate.h b/src/H5Gprivate.h
index 1cf448f..ac430c1 100644
--- a/src/H5Gprivate.h
+++ b/src/H5Gprivate.h
@@ -96,9 +96,22 @@ typedef struct H5G_entry_t {
 typedef struct H5G_t H5G_t;
 
 /*
+ * This table contains a list of object types, descriptions, and the
+ * functions that determine if some object is a particular type.  The table
+ * is allocated dynamically.
+ */
+typedef struct H5G_typeinfo_t {
+    intn	type;			/*one of the public H5G_* types	     */
+    htri_t	(*isa)(H5G_entry_t*);	/*function to determine type	     */
+    char	*desc;			/*description of object type	     */
+} H5G_typeinfo_t;
+
+/*
  * Library prototypes...  These are the ones that other packages routinely
  * call.
  */
+herr_t H5G_register_type(intn type, htri_t(*isa)(H5G_entry_t*),
+			 const char *desc);
 H5G_entry_t *H5G_loc (hid_t loc_id);
 herr_t H5G_mkroot (H5F_t *f, H5G_entry_t *root_entry);
 H5G_entry_t *H5G_entof (H5G_t *grp);
@@ -108,8 +121,10 @@ H5G_t *H5G_open (H5G_entry_t *loc, const char *name);
 H5G_t *H5G_reopen (H5G_t *grp);
 herr_t H5G_close (H5G_t *grp);
 H5G_t *H5G_rootof(H5F_t *f);
+htri_t H5G_isa(H5G_entry_t *ent);
 herr_t H5G_link (H5G_entry_t *loc, H5G_link_t type, const char *cur_name,
 		 const char *new_name, uintn namei_flags);
+intn H5G_get_type(H5G_entry_t *ent);
 herr_t H5G_get_objinfo (H5G_entry_t *loc, const char *name,
 			hbool_t follow_link, H5G_stat_t *statbuf/*out*/);
 herr_t H5G_linkval (H5G_entry_t *loc, const char *name, size_t size,
diff --git a/src/H5Gpublic.h b/src/H5Gpublic.h
index cc3cc7d..32fc1d4 100644
--- a/src/H5Gpublic.h
+++ b/src/H5Gpublic.h
@@ -34,13 +34,27 @@ typedef enum H5G_link_t {
     H5G_LINK_SOFT	= 1
 } H5G_link_t;
 
-/* An object has a certain type */
+/*
+ * An object has a certain type. The first few numbers are reserved for use
+ * internally by HDF5. Users may add their own types with higher values.  The
+ * values are never stored in the file -- they only exist while an
+ * application is running.  An object may satisfy the `isa' function for more
+ * than one type.
+ */
 #define H5G_UNKNOWN	(-1)		/* Unknown object type		*/
 #define H5G_LINK	0		/* Object is a symbolic link	*/
 #define H5G_GROUP	1		/* Object is a group		*/
 #define H5G_DATASET	2		/* Object is a dataset		*/
 #define H5G_TYPE	3		/* Object is a named data type	*/
-#define H5G_NTYPES	4		/* THIS MUST BE LAST		*/
+#define H5G_RAGGED	4		/* Object is a ragged array	*/
+#define H5G_RESERVED_5	5		/* Reserved for future use	*/
+#define H5G_RESERVED_6	6		/* Reserved for future use	*/
+#define H5G_RESERVED_7	7		/* Reserved for future use	*/
+
+#define H5G_NTYPES	256		/* Max possible number of types	*/
+#define H5G_NLIBTYPES	8		/* Number of internal types	*/
+#define H5G_NUSERTYPES	(H5G_NTYPES-H5G_NLIBTYPES)
+#define H5G_USERTYPE(X)	(8+(X))		/* User defined types		*/
 
 /* Information about an object */
 typedef struct H5G_stat_t {
diff --git a/src/H5O.c b/src/H5O.c
index 8d7ee63..d1e1d07 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -878,6 +878,55 @@ H5O_count (H5G_entry_t *ent, const H5O_class_t *type)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5O_exists
+ *
+ * Purpose:	Determines if a particular message exists in an object
+ *		header without trying to decode the message.
+ *
+ * Return:	Success:	FALSE if the message does not exist; TRUE if
+ *				th message exists.
+ *
+ *		Failure:	FAIL if the existence of the message could
+ *				not be determined due to some error such as
+ *				not being able to read the object header.
+ *
+ * Programmer:	Robb Matzke
+ *              Monday, November  2, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5O_exists(H5G_entry_t *ent, const H5O_class_t *type, intn sequence)
+{
+    H5O_t	*oh=NULL;
+    intn	i;
+    
+    FUNC_ENTER(H5O_exists, FAIL);
+    assert(ent);
+    assert(ent->file);
+    assert(type);
+    assert(sequence>=0);
+
+    /* Load the object header */
+    if (NULL==(oh=H5AC_find(ent->file, H5AC_OHDR, &(ent->header),
+			    NULL, NULL))) {
+	HRETURN_ERROR(H5E_OHDR, H5E_CANTLOAD, FAIL,
+		      "unable to load object header");
+    }
+
+    /* Scan through the messages looking for the right one */
+    for (i=0; i<oh->nmesgs; i++) {
+	if (type->id!=oh->mesg[i].type->id) continue;
+	if (--sequence<0) break;
+    }
+
+    FUNC_LEAVE(sequence<0);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5O_read
  *
  * Purpose:	Reads a message from an object header and returns a pointer
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 7dff3c9..16fbded 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -273,6 +273,7 @@ herr_t H5O_open (H5G_entry_t *ent);
 herr_t H5O_close (H5G_entry_t *ent);
 intn H5O_link (H5G_entry_t *ent, intn adjust);
 intn H5O_count (H5G_entry_t *ent, const H5O_class_t *type);
+htri_t H5O_exists(H5G_entry_t *ent, const H5O_class_t *type, intn sequence);
 void *H5O_read (H5G_entry_t *ent, const H5O_class_t *type, intn sequence,
 		void *mesg);
 intn H5O_modify (H5G_entry_t *ent, const H5O_class_t *type, intn overwrite,
diff --git a/src/H5RA.c b/src/H5RA.c
index c0ed491..11d02e9 100644
--- a/src/H5RA.c
+++ b/src/H5RA.c
@@ -398,6 +398,67 @@ H5RAopen(hid_t loc_id, const char *name)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5RA_isa
+ *
+ * Purpose:	Determines if an object is a ragged array.
+ *
+ * Return:	Success:	TRUE if the object is a ragged array; FALSE
+ *				otherwise.
+ *
+ *		Failure:	Negative
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, November  4, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5RA_isa(H5G_entry_t *ent)
+{
+    htri_t	exists;
+    H5G_entry_t	d_ent;
+    
+    FUNC_ENTER(H5RA_isa, FAIL);
+
+    /* Open the container group */
+    if ((exists=H5G_isa(ent))<0) {
+	HRETURN_ERROR(H5E_RAGGED, H5E_CANTINIT, FAIL,
+		      "unable to read object header");
+    } else if (!exists) {
+	HRETURN(FALSE);
+    }
+
+    /* Is `raw' a dataset? */
+    if (H5G_find(ent, "raw", NULL, &d_ent)<0 ||
+	(exists=H5D_isa(&d_ent))<0) {
+	HRETURN_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found");
+    } else if (!exists) {
+	HRETURN(FALSE);
+    }
+
+    /* Is `over' a dataset? */
+    if (H5G_find(ent, "over", NULL, &d_ent)<0 ||
+	(exists=H5D_isa(&d_ent))<0) {
+	HRETURN_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found");
+    } else if (!exists) {
+	HRETURN(FALSE);
+    }
+
+    /* Is `meta' a dataset? */
+    if (H5G_find(ent, "meta", NULL, &d_ent)<0 ||
+	(exists=H5D_isa(&d_ent))<0) {
+	HRETURN_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found");
+    } else if (!exists) {
+	HRETURN(FALSE);
+    }
+
+    FUNC_LEAVE(TRUE);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5RA_open
  *
  * Purpose:	Open a ragged array.  The name of the array is the same as
diff --git a/src/H5RAprivate.h b/src/H5RAprivate.h
index 19e11d7..89e83db 100644
--- a/src/H5RAprivate.h
+++ b/src/H5RAprivate.h
@@ -19,6 +19,7 @@ herr_t H5RA_close(H5RA_t *ra);
 H5RA_t *H5RA_create(H5G_entry_t *loc, const char *name, H5T_t *type,
 		  const H5D_create_t *dcpl);
 H5RA_t *H5RA_open(H5G_entry_t *loc, const char *name);
+htri_t H5RA_isa(H5G_entry_t *ent);
 herr_t H5RA_write(H5RA_t *ra, hssize_t start_row, hsize_t nrows, H5T_t *type,
 		 hsize_t size[], void *buf[]);
 herr_t H5RA_read(H5RA_t *ra, hssize_t start_row, hsize_t nrows, H5T_t *type,
diff --git a/src/H5T.c b/src/H5T.c
index 916bc87..517e6a3 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -3466,6 +3466,41 @@ H5T_create(H5T_class_t type, size_t size)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5T_isa
+ *
+ * Purpose:	Determines if an object has the requisite messages for being
+ *		a data type.
+ *
+ * Return:	Success:	TRUE if the required data type messages are
+ *				present; FALSE otherwise.
+ *
+ *		Failure:	FAIL if the existence of certain messages
+ *				cannot be determined.
+ *
+ * Programmer:	Robb Matzke
+ *              Monday, November  2, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5T_isa(H5G_entry_t *ent)
+{
+    htri_t	exists;
+    
+    FUNC_ENTER(H5T_isa, FAIL);
+    assert(ent);
+
+    if ((exists=H5O_exists(ent, H5O_DTYPE, 0))<0) {
+	HRETURN_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL,
+		      "unable to read object header");
+    }
+    FUNC_LEAVE(exists);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5T_open
  *
  * Purpose:	Open a named data type.
diff --git a/src/H5Tprivate.h b/src/H5Tprivate.h
index 25d4f6d..3b602a1 100644
--- a/src/H5Tprivate.h
+++ b/src/H5Tprivate.h
@@ -44,6 +44,7 @@ typedef enum H5T_copy_t {
 /* Private functions */
 herr_t H5T_init (void);
 herr_t H5T_init_interface (void);
+htri_t H5T_isa(H5G_entry_t *ent);
 H5T_t *H5T_open (H5G_entry_t *loc, const char *name);
 H5T_t *H5T_create (H5T_class_t type, size_t size);
 H5T_t *H5T_copy (const H5T_t *old_dt, H5T_copy_t method);
diff --git a/src/H5config.h.in b/src/H5config.h.in
index 755ec7e..a08c7e2 100644
--- a/src/H5config.h.in
+++ b/src/H5config.h.in
@@ -44,7 +44,7 @@
 /* Define if it's safe to use `long long' for hsize_t and hssize_t */
 #undef HAVE_LARGE_HSIZET
 
-/* The width parameter for printf formats for type `long long', us. `ll' */
+/* Width for printf() for type `long long' or `__int64', us. `ll' */
 #undef PRINTF_LL_WIDTH
 
 /* Define if `tm_gmtoff' is a member of `struct tm' */
@@ -56,6 +56,9 @@
 /* Define if `struct timezone' is defined */
 #undef HAVE_STRUCT_TIMEZONE
 
+/* Define if `struct stat' has the `st_blocks' field */
+#undef HAVE_STAT_ST_BLOCKS
+
 /* The number of bytes in a __int64.  */
 #undef SIZEOF___INT64