[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.

1 files changed, 49 insertions, 0 deletions

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