[svn-r400] Changes since 19980513

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

./html/Datasets.html
	Fixed a couple of typos.

./src/H5.c
	Added the `Z' modifier to HDfprintf() for `size_t' sizes.  Use
	it like this:
	   HDfprintf(stderr,"size is %Zd\n", (size_t)x);

./src/H5AC.c
./src/H5F.c
./src/H5Fprivate.h
	The maximum number of meta data objects that can be cached can
	be set from the application (but the library might not honor
	it every time; it's a hint).

./src/H5D.c
	Changed a warning message so it's not so alarming.

./src/H5Fistore.c
	Chunks can be cached.

./src/H5O.c
./src/H5Oprivate.h
	Added H5O_copy() and H5O_free() to copy and free messages.

./src/H5P.c
./src/H5Ppublic.h
	Added H5Pset_cache() and H5Pget_cache() and changed lots of
	"template" to "property list".

./src/H5Z.c
./src/H5Zpublic.h
	Miscellaneous little things to clean up.  Mostly just removed
	H5Z_MAXVAL and added H5Z_USERDEF_MIN and H5Z_USERDEF_MAX.

./MANIFEST
./test/Makefile.in
./test/chunk.c		[NEW]
	Added a performance test for chunk caching.  It looks at the
	amount of I/O instead of timing because timing is partly
	dependent on the chunk size and I wanted a measurement that
	was a function of only the cache size.  Run `chunk' with no
	arguments and then say `gnuplot x-gnuplot' to see the plots
	(press return between plots). Postscript files are created for
	each plot.

./test/big.c
./test/cmpd_dset.c
./test/extend.c
./test/external.c
./test/gheap.c
	Added H5F_ACC_DEBUG so we can see cache performance
	statistics.

24 files changed, 2520 insertions, 652 deletions

diff --git a/MANIFEST b/MANIFEST
index 7742101..4760bee 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -206,6 +206,7 @@
 ./test/.distdep
 ./test/Makefile.in
 ./test/big.c
+./test/chunk.c
 ./test/cmpd_dset.c
 ./test/dsets.c
 ./test/dtypes.c
diff --git a/src/H5.c b/src/H5.c
index 4e48221..68838b2 100644
--- a/src/H5.c
+++ b/src/H5.c
@@ -535,7 +535,7 @@ HDfprintf (FILE *stream, const char *fmt, ...)
 	    }
 
 	    /* Type modifier */
-	    if (strchr ("Hhlq", *s)) {
+	    if (strchr ("ZHhlq", *s)) {
 		switch (*s) {
 		case 'H':
 		    if (sizeof(hsize_t)==sizeof(long)) {
@@ -544,6 +544,16 @@ HDfprintf (FILE *stream, const char *fmt, ...)
 			strcpy (modifier, PRINTF_LL_WIDTH);
 		    }
 		    break;
+		case 'Z':
+		    if (sizeof(size_t)==sizeof(long)) {
+			strcpy (modifier, "l");
+		    } else if (sizeof(size_t)==sizeof(long long)) {
+			strcpy (modifier, PRINTF_LL_WIDTH);
+		    } else if (sizeof(size_t)==sizeof(int)) {
+			modifier[0] = '\0';
+		    }
+		    break;
+		    
 		default:
 		    modifier[0] = *s;
 		    modifier[1] = '\0';
diff --git a/src/H5AC.c b/src/H5AC.c
index 98e7dfa..986b35b 100644
--- a/src/H5AC.c
+++ b/src/H5AC.c
@@ -50,7 +50,7 @@ static H5AC_t          *current_cache_g = NULL;         /*for sorting */
  *              pass an invalid value then H5AC_NSLOTS is used.  You can
  *              turn off caching by using 1 for the SIZE_HINT value.
  *
- * Return:      Success:        SUCCEED
+ * Return:      Success:        Number of slots actually used.
  *
  *              Failure:        FAIL
  *
@@ -62,7 +62,7 @@ static H5AC_t          *current_cache_g = NULL;         /*for sorting */
  *
  *-------------------------------------------------------------------------
  */
-herr_t
+intn
 H5AC_create(H5F_t *f, intn size_hint)
 {
     H5AC_t                 *cache = NULL;
@@ -70,14 +70,13 @@ H5AC_create(H5F_t *f, intn size_hint)
 
     assert(f);
     assert(NULL == f->shared->cache);
-    if (size_hint < 1)
-        size_hint = H5AC_NSLOTS;
+    if (size_hint < 1) size_hint = H5AC_NSLOTS;
 
     f->shared->cache = cache = H5MM_xcalloc(1, sizeof(H5AC_t));
     cache->nslots = size_hint;
     cache->slot = H5MM_xcalloc((intn)(cache->nslots), sizeof(H5AC_slot_t));
 
-    FUNC_LEAVE(SUCCEED);
+    FUNC_LEAVE(size_hint);
 }
 
 /*-------------------------------------------------------------------------
@@ -838,7 +837,7 @@ H5AC_debug(H5F_t *f)
 
     FUNC_ENTER(H5AC_debug, FAIL);
 
-    fprintf(stderr, "H5AC: cache statistics for file %s\n", f->name);
+    fprintf(stderr, "H5AC: meta data cache statistics for file %s\n", f->name);
     fprintf(stderr, "   %-18s %8s %8s %8s %8s+%-8s\n",
             "Layer", "Hits", "Misses", "MissRate", "Inits", "Flushes");
     fprintf(stderr, "   %-18s %8s %8s %8s %8s-%-8s\n",
@@ -866,10 +865,12 @@ H5AC_debug(H5F_t *f)
             sprintf(s, "unknown id %d", i);
         }
 
-        if (cache->diagnostics[i].nhits) {
+        if (cache->diagnostics[i].nhits>0 ||
+	    cache->diagnostics[i].nmisses>0) {
             miss_rate = 100.0 * cache->diagnostics[i].nmisses /
-                cache->diagnostics[i].nhits;
-        } else {
+			(cache->diagnostics[i].nhits+
+			 cache->diagnostics[i].nmisses);
+	} else {
             miss_rate = 0.0;
         }
 
diff --git a/src/H5D.c b/src/H5D.c
index 90ed3d0..f07efd8 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -1252,8 +1252,8 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
 				    mem_space, buf/*out*/);
 	if (status>=0) goto succeed;
 #ifdef H5D_DEBUG
-	fprintf (stderr, "H5D: input pipe optimization failed "
-		 "(falling through)\n");
+	fprintf (stderr, "H5D: data space conversion could not be optimized "
+		 "for this case (using general method instead)\n");
 #endif
 	H5E_clear ();
     }
@@ -1547,8 +1547,8 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
 				     mem_space, buf);
 	if (status>=0) goto succeed;
 #ifdef H5D_DEBUG
-	fprintf (stderr, "H5D: output pipe optimization failed "
-		 "(falling through)\n");
+	fprintf (stderr, "H5D: data space conversion could not be optimized "
+		 "for this case (using general method instead)\n");
 #endif
 	H5E_clear ();
     }
diff --git a/src/H5Distore.c b/src/H5Distore.c
index 7e80f1a..91c4e9d 100644
--- a/src/H5Distore.c
+++ b/src/H5Distore.c
@@ -2,8 +2,17 @@
  * Copyright (C) 1997 NCSA
  *		      All rights reserved.
  *
- * Programmer: Robb Matzke <matzke@llnl.gov>
- *	       Wednesday, October  8, 1997
+ * Programmer: 	Robb Matzke <matzke@llnl.gov>
+ *	       	Wednesday, October  8, 1997
+ *
+ * Purpose:	Indexed (chunked) I/O functions.  The logical
+ *		multi-dimensional data space is regularly partitioned into
+ *		same-sized "chunks", the first of which is aligned with the
+ *		logical origin.  The chunks are given a multi-dimensional
+ *		index which is used as a lookup key in a B-tree that maps
+ *		chunk index to disk address.  Each chunk can be compressed
+ *		independently and the chunks may move around in the file as
+ *		their storage requirements change.
  */
 #include <H5private.h>
 #include <H5Dprivate.h>
@@ -14,13 +23,25 @@
 #include <H5Oprivate.h>
 #include <H5Vprivate.h>
 
-
 /* Interface initialization */
 #define PABLO_MASK	H5F_istore_mask
 static hbool_t		interface_initialize_g = FALSE;
 #define INTERFACE_INIT NULL
 
-/* PRIVATE PROTOTYPES */
+/* Raw data chunks are cached.  Each entry in the cache is: */
+typedef struct H5F_rdcc_ent_t {
+    hbool_t	locked;		/*entry is locked in cache		*/
+    hbool_t	dirty;		/*needs to be written to disk?		*/
+    H5O_layout_t *layout;	/*the layout message			*/
+    H5O_compress_t *comp;	/*compression message			*/
+    hssize_t	offset[H5O_LAYOUT_NDIMS]; /*chunk name			*/
+    size_t	chunk_size;	/*size of a chunk			*/
+    size_t	rd_count;	/*bytes remaining to be read		*/
+    size_t	wr_count;	/*bytes remaining to be written		*/
+    uint8	*chunk;		/*the uncompressed chunk data		*/
+} H5F_rdcc_ent_t;
+
+/* Private prototypes */
 static size_t H5F_istore_sizeof_rkey(H5F_t *f, const void *_udata);
 static herr_t H5F_istore_new_node(H5F_t *f, H5B_ins_t, void *_lt_key,
 				  void *_udata, void *_rt_key, haddr_t *);
@@ -546,7 +567,6 @@ H5F_istore_insert(H5F_t *f, const haddr_t *addr, void *_lt_key,
 	 * Already exists.  If the new size is not the same as the old size
 	 * then we should reallocate storage.
 	 */
-#if 1
 	if (lt_key->nbytes != udata->key.nbytes) {
 	    if (H5MF_realloc (f, H5MF_RAW, lt_key->nbytes, addr,
 			      udata->key.nbytes, new_node/*out*/)<0) {
@@ -561,13 +581,6 @@ H5F_istore_insert(H5F_t *f, const haddr_t *addr, void *_lt_key,
 	    udata->addr = *addr;
 	    ret_value = H5B_INS_NOOP;
 	}
-#else
-	assert (lt_key->nbytes == udata->key.nbytes);
-	assert (!H5F_addr_defined (&(udata->addr)) ||
-		H5F_addr_eq (&(udata->addr), addr));
-	udata->addr = *addr;
-	ret_value = H5B_INS_NOOP;
-#endif
 
     } else if (H5V_hyper_disjointp(udata->mesg.ndims,
 				   lt_key->offset, udata->mesg.dim,
@@ -606,6 +619,596 @@ H5F_istore_insert(H5F_t *f, const haddr_t *addr, void *_lt_key,
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5F_istore_init
+ *
+ * Purpose:	Initialize the raw data chunk cache for a file.  This is
+ *		called when the file handle is initialized.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Monday, May 18, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_init (H5F_t *f)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    
+    FUNC_ENTER (H5F_istore_init, FAIL);
+
+    HDmemset (rdcc, 0, sizeof(H5F_rdcc_t));
+    if (f->shared->access_parms->rdcc_nbytes>0) {
+	rdcc->nslots = 25; /*some initial number of slots*/
+	rdcc->slot = H5MM_xcalloc (rdcc->nslots, sizeof(H5F_rdcc_ent_t));
+    }
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_flush_entry
+ *
+ * Purpose:	Writes a chunk to disk.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_flush_entry (H5F_t *f, H5F_rdcc_ent_t *ent)
+{
+    void	*c_buf = NULL;		/*temp compression buffer	*/
+    void	*out_ptr = NULL;	/*ptr to output buffer		*/
+    size_t	nbytes;			/*size of output buffer		*/
+    herr_t	ret_value = FAIL;	/*return value			*/
+    H5F_istore_ud1_t udata;		/*pass through B-tree		*/
+    intn	i;
+    
+    FUNC_ENTER (H5F_istore_flush_entry, FAIL);
+    assert (ent);
+    assert (!ent->locked);
+    if (!ent->dirty) HRETURN (SUCCEED);
+
+    /* Should the chunk be compressed before writing it to disk? */
+    if (ent->comp && H5Z_NONE!=ent->comp->method) {
+	c_buf = H5MM_xmalloc (ent->chunk_size);
+	nbytes = H5Z_compress (ent->comp, ent->chunk_size, ent->chunk, c_buf);
+	if (nbytes && nbytes<ent->chunk_size) {
+	    out_ptr = c_buf;
+	} else {
+	    out_ptr = ent->chunk;
+	    nbytes = ent->chunk_size;
+	}
+    } else {
+	out_ptr = ent->chunk;
+	nbytes = ent->chunk_size;
+    }
+    
+    /*
+     * Create the chunk it if it doesn't exist, or reallocate the chunk if its
+     * size changed.  Then write the data into the file.
+     */
+    udata.mesg = *(ent->layout);
+    H5F_addr_undef(&(udata.addr));
+    udata.key.nbytes = nbytes;
+    for (i=0; i<ent->layout->ndims; i++) {
+	udata.key.offset[i] = ent->offset[i];
+    }
+    
+    if (H5B_insert(f, H5B_ISTORE, &(ent->layout->addr), &udata)<0) {
+	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+		     "unable to allocate chunk");
+    }
+    if (H5F_block_write (f, &(udata.addr), nbytes, out_ptr)<0) {
+	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+		     "unable to write raw data to file");
+    }
+
+    /* Mark cache entry as clean */
+    ent->dirty = FALSE;
+    f->shared->rdcc.nflushes++;
+    ret_value = SUCCEED;
+
+ done:
+    H5MM_xfree (c_buf);
+    FUNC_LEAVE (ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_flush
+ *
+ * Purpose:	Writes all dirty chunks to disk but does not remove them from
+ *		the cache.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_flush (H5F_t *f)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    intn	i, nerrors=0;
+    
+    FUNC_ENTER (H5F_istore_flush, FAIL);
+
+    for (i=0; i<rdcc->nused; i++) {
+	if (H5F_istore_flush_entry (f, rdcc->slot+i)<0) {
+	    nerrors++;
+	}
+    }
+    if (nerrors) {
+	HRETURN_ERROR (H5E_IO, H5E_CANTFLUSH, FAIL,
+		       "unable to flush one or more raw data chunks");
+    }
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_preempt
+ *
+ * Purpose:	Preempts the specified entry from the cache, flushing it to
+ *		disk if necessary.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_preempt (H5F_t *f, intn idx)
+{
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent = rdcc->slot + idx;
+    
+    FUNC_ENTER (H5F_istore_preempt, FAIL);
+    assert (idx>=0 && idx<rdcc->nused);
+    assert (!ent->locked);
+
+    if (ent->dirty) H5F_istore_flush_entry (f, ent);
+    H5O_free (H5O_LAYOUT, ent->layout);
+    H5O_free (H5O_COMPRESS, ent->comp);
+    H5MM_xfree (ent->chunk);
+    rdcc->nused -= 1;
+    rdcc->nbytes -= ent->chunk_size;
+    HDmemmove (rdcc->slot+idx, rdcc->slot+idx+1,
+	       (rdcc->nused-idx) * sizeof(H5F_rdcc_ent_t));
+    
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_dest
+ *
+ * Purpose:	Destroy the entire chunk cache by flushing dirty entries,
+ *		preempting all entries, and freeing the cache itself.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_dest (H5F_t *f)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    intn	i, nerrors=0;
+    
+    FUNC_ENTER (H5F_istore_dest, FAIL);
+
+    for (i=rdcc->nused-1; i>=0; --i) {
+	if (H5F_istore_flush_entry (f, rdcc->slot+i)<0) {
+	    nerrors++;
+	}
+	if (H5F_istore_preempt (f, i)<0) {
+	    nerrors++;
+	}
+    }
+    if (nerrors) {
+	HRETURN_ERROR (H5E_IO, H5E_CANTFLUSH, FAIL,
+		       "unable to flush one or more raw data chunks");
+    }
+
+    H5MM_xfree (rdcc->slot);
+    HDmemset (rdcc, 0, sizeof(H5F_rdcc_t));
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_prune
+ *
+ * Purpose:	Prune the cache by preempting some things until the cache has
+ *		room for something which is SIZE bytes.  Only unlocked
+ *		entries are considered for preemption.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_prune (H5F_t *f, size_t size)
+{
+    intn		i, meth0, meth1, nerrors=0;
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent0, *ent1;
+    double		w0 = f->shared->access_parms->rdcc_w0;
+    size_t		total = f->shared->access_parms->rdcc_nbytes;
+
+    FUNC_ENTER (H5F_istore_prune, FAIL);
+
+    /*
+     * We have two pointers that slide down the cache beginning at the least
+     * recently used entry.  The distance between the pointers represents the
+     * relative weight.  A weight of 50% for the first pointer means that the
+     * second pointer is half the cache length behind the first pointer.
+     */
+    meth0 = rdcc->nused;
+    meth1 = rdcc->nused * (1.0+w0);
+    for (i=MAX(meth0, meth1)-1;
+	 rdcc->nbytes+size>total && i>=0;
+	 --i, --meth0, --meth1) {
+
+	ent0 = rdcc->slot+meth0; /*might be a bad pointer!*/
+	ent1 = rdcc->slot+meth1; /*might be a bad pointer!*/
+	
+	if (meth0>=0 && meth0<rdcc->nused && !ent0->locked &&
+	    (0==ent0->rd_count || ent0->chunk_size==ent0->rd_count) &&
+	    (0==ent0->wr_count || ent0->chunk_size==ent0->wr_count)) {
+	    /*
+	     * Method 0: Preempt entries that have a zero rd_count.  If the
+	     * application is accessing a dataset with a set of
+	     * non-overlapping partial I/O requests then chunks with a zero
+	     * rd_count will probably not be accessed in the near future.
+	     */
+	    if (H5F_istore_preempt (f, meth0)<0) nerrors++;
+	    
+	} else if (meth1>=0 && meth1<rdcc->nused && !ent1->locked) {
+	    /*
+	     * Method 1: Discard the least recently used members from the
+	     * cache.  This is a catch-all.
+	     */
+	    if (H5F_istore_preempt (f, meth1)<0) nerrors++;
+	}
+    }
+    if (nerrors) {
+	HRETURN_ERROR (H5E_IO, H5E_CANTFLUSH, FAIL,
+		       "unable to preempt one or more raw data cache entry");
+    }
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_lock
+ *
+ * Purpose:	Return a pointer to an uncompressed chunk.  The pointer
+ *		points directly into the chunk cache and should not be freed
+ *		by the caller but will be valid until it is unlocked.  The
+ *		input value IDX_HINT is used to speed up cache lookups and
+ *		it's output value should be given to H5F_rdcc_unlock().
+ *
+ *		If RELAX is non-zero and the chunk isn't in the cache then
+ *		don't try to read it from the file, but just allocate an
+ *		uninitialized buffer to hold the result.  This is indented
+ *		for output functions that are about to overwrite the entire
+ *		chunk.
+ *
+ * Return:	Success:	Ptr to an uncompressed chunk.
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5F_istore_lock (H5F_t *f, const H5O_layout_t *layout,
+		 const H5O_compress_t *comp, const hssize_t offset[],
+		 hbool_t relax, intn *idx_hint/*in,out*/)
+{
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent = NULL;
+    intn		i, j, found = -1;
+    H5F_istore_ud1_t	udata;			/*B-tree pass-through	*/
+    size_t		chunk_size;		/*size of a chunk	*/
+    herr_t		status;			/*func return status	*/
+    void		*chunk=NULL;		/*the uncompressed chunk*/
+    void		*temp=NULL;		/*temporary chunk buffer*/
+    void		*ret_value=NULL;	/*return value		*/
+    
+    FUNC_ENTER (H5F_istore_lock, NULL);
+
+    /* First use the hint */
+    if (idx_hint && *idx_hint>=0 && *idx_hint<rdcc->nused) {
+	ent = rdcc->slot + *idx_hint;
+	if (layout->ndims==ent->layout->ndims) {
+	    for (i=0, found=*idx_hint; found>=0 && i<ent->layout->ndims; i++) {
+		if (offset[i]!=ent->offset[i]) found = -1;
+	    }
+	}
+    }
+
+    /* Then look at all the entries */
+    for (i=0; found<0 && i<rdcc->nused; i++) {
+	ent = rdcc->slot + i;
+	if (layout->ndims==ent->layout->ndims) {
+	    for (j=0, found=i; found>=0 && j<ent->layout->ndims; j++) {
+		if (offset[j]!=ent->offset[j]) found = -1;
+	    }
+	}
+    }
+
+
+    if (found>=0) {
+	/*
+	 * Already in the cache.  Count a hit.
+	 */
+	rdcc->nhits++;
+	
+    } else if (found<0 && relax) {
+	/*
+	 * Not in the cache, but we're about to overwrite the whole thing
+	 * anyway, so just allocate a buffer for it but don't initialize that
+	 * buffer with the file contents. Count this as a hit instead of a
+	 * miss because we saved ourselves lots of work.
+	 */
+	rdcc->nhits++;
+	for (i=0, chunk_size=1; i<layout->ndims; i++) {
+	    chunk_size *= layout->dim[i];
+	}
+	chunk = H5MM_xmalloc (chunk_size);
+	
+    } else {
+	/*
+	 * Not in the cache.  Read it from the file and count this as a miss
+	 * if it's in the file or an init if it isn't.
+	 */
+	for (i=0, chunk_size=1; i<layout->ndims; i++) {
+	    udata.key.offset[i] = offset[i];
+	    chunk_size *= layout->dim[i];
+	}
+	udata.mesg = *layout;
+	H5F_addr_undef (&(udata.addr));
+	status = H5B_find (f, H5B_ISTORE, &(layout->addr), &udata);
+	chunk = H5MM_xmalloc (chunk_size);
+	if (status>=0 && H5F_addr_defined (&(udata.addr))) {
+	    /*
+	     * The chunk exists on disk but might be compressed.  Instead of
+	     * allocating the exact size for the compressed chunk we allocate
+	     * the entire chunk size -- it reduces strain on the malloc()
+	     * subsystem.
+	     */
+	    if (H5F_block_read (f, &(udata.addr), udata.key.nbytes, chunk)<0) {
+		HGOTO_ERROR (H5E_IO, H5E_READERROR, NULL,
+			     "unable to read raw data chunk");
+	    }
+	    if (udata.key.nbytes<chunk_size) {
+		temp = H5MM_xmalloc (chunk_size);
+		if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
+						chunk, chunk_size, temp)) {
+		    HGOTO_ERROR (H5E_IO, H5E_READERROR, NULL,
+				 "unable to uncompress raw data chunk"); 
+		}
+		H5MM_xfree (chunk);
+		chunk = temp;
+		temp = NULL;
+	    }
+	    rdcc->nmisses++;
+	} else {
+	    /*
+	     * The chunk doesn't exist in the file.  Assume all zeros.
+	     */
+	    HDmemset (chunk, 0, chunk_size);
+	    rdcc->ninits++;
+	}
+    }
+
+    if (found<0 && chunk_size<=f->shared->access_parms->rdcc_nbytes) {
+	/*
+	 * Add the chunk to the beginning of the cache after pruning the cache
+	 * to make room.
+	 */
+	if (H5F_istore_prune (f, chunk_size)<0) {
+	    H5E_clear ();
+	}
+	if (rdcc->nused>=rdcc->nslots) {
+	    rdcc->nslots = MAX (25, 2*rdcc->nslots);
+	    rdcc->slot = H5MM_xrealloc (rdcc->slot,
+					(rdcc->nslots*
+					 sizeof(H5F_rdcc_ent_t)));
+	}
+	HDmemmove (rdcc->slot+1, rdcc->slot,
+		   rdcc->nused*sizeof(H5F_rdcc_ent_t));
+	rdcc->nused++;
+	rdcc->nbytes += chunk_size;
+	ent = rdcc->slot;
+	ent->locked = 0;
+	ent->dirty = FALSE;
+	ent->chunk_size = chunk_size;
+	ent->layout = H5O_copy (H5O_LAYOUT, layout);
+	ent->comp = H5O_copy (H5O_COMPRESS, comp);
+	for (i=0; i<layout->ndims; i++) {
+	    ent->offset[i] = offset[i];
+	}
+	ent->rd_count = chunk_size;
+	ent->wr_count = chunk_size;
+	ent->chunk = chunk;
+	found = 0;
+	    
+    } else if (found<0) {
+	/*
+	 * The chunk is larger than the entire cache so we don't cache it.
+	 * This is the reason all those arguments have to be repeated for the
+	 * unlock function.
+	 */
+	ent = NULL;
+	found = -999;
+	
+    } else if (found>0) {
+	/*
+	 * The chunk is not at the beginning of the cache; move it forward by
+	 * one slot.  This is how we implement the LRU preemption algorithm.
+	 */
+	H5F_rdcc_ent_t x = rdcc->slot[found];
+	rdcc->slot[found] = rdcc->slot[found-1];
+	rdcc->slot[found-1] = x;
+	ent = rdcc->slot + --found;
+    }
+
+    /* Lock the chunk into the cache */
+    if (ent) {
+	assert (!ent->locked);
+	ent->locked = TRUE;
+	if (idx_hint) *idx_hint = found;
+	chunk = ent->chunk;
+    }
+
+    ret_value = chunk;
+ done:
+    if (!ret_value) H5MM_xfree (chunk);
+    H5MM_xfree (temp);
+    FUNC_LEAVE (ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_unlock
+ *
+ * Purpose:	Unlocks a previously locked chunk. The LAYOUT, COMP, and
+ *		OFFSET arguments should be the same as for H5F_rdcc_lock().
+ *		The DIRTY argument should be set to non-zero if the chunk has
+ *		been modified since it was locked. The IDX_HINT argument is
+ *		the returned index hint from the lock operation and BUF is
+ *		the return value from the lock.
+ *
+ *		The NACCESSED argument should be the number of bytes accessed
+ *		for reading or writing (depending on the value of DIRTY).
+ *		It's only purpose is to provide additional information to the
+ *		preemption policy.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_unlock (H5F_t *f, const H5O_layout_t *layout,
+		   const H5O_compress_t *comp, hbool_t dirty,
+		   const hssize_t offset[], intn *idx_hint,
+		   uint8 *chunk, size_t naccessed)
+{
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent = NULL;
+    intn		i, found = -1;
+    
+    FUNC_ENTER (H5F_istore_unlock, FAIL);
+
+    /* First look at the hint */
+    if (idx_hint && *idx_hint>=0 && *idx_hint<rdcc->nused) {
+	if (rdcc->slot[*idx_hint].chunk==chunk) found = *idx_hint;
+    }
+
+    /* Then look at all the entries */
+    for (i=0; found<0 && i<rdcc->nused; i++) {
+	if (rdcc->slot[i].chunk==chunk) found = i;
+    }
+
+    if (found<0) {
+	/*
+	 * It's not in the cache, probably because it's too big.  If it's
+	 * dirty then flush it to disk.  In any case, free the chunk.
+	 * Note: we have to copy the layout and compression messages so we
+	 *	 don't discard the `const' qualifier.
+	 */
+	if (dirty) {
+	    H5F_rdcc_ent_t x;
+	    HDmemset (&x, 0, sizeof x);
+	    x.dirty = TRUE;
+	    x.layout = H5O_copy (H5O_LAYOUT, layout);
+	    x.comp = H5O_copy (H5O_COMPRESS, comp);
+	    for (i=0; i<layout->ndims; i++) {
+		x.offset[i] = offset[i];
+	    }
+	    x.chunk = chunk;
+	    H5F_istore_flush_entry (f, &x);
+	    H5O_free (H5O_LAYOUT, x.layout);
+	    H5O_free (H5O_COMPRESS, x.comp);
+	}
+	H5MM_xfree (chunk);
+    } else {
+	/*
+	 * It's in the cache so unlock it.
+	 */
+	ent = rdcc->slot + found;
+	assert (ent->locked);
+	if (dirty) {
+	    ent->dirty = TRUE;
+	    ent->wr_count -= MIN (ent->wr_count, naccessed);
+	} else {
+	    ent->rd_count -= MIN (ent->rd_count, naccessed);
+	}
+	ent->locked = FALSE;
+    }
+    
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F_istore_read
  *
  * Purpose:	Reads a multi-dimensional buffer from (part of) an indexed raw
@@ -629,18 +1232,17 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
 {
     hssize_t		offset_m[H5O_LAYOUT_NDIMS];
     hsize_t		size_m[H5O_LAYOUT_NDIMS];
-    intn		i, carry;
     hsize_t		idx_cur[H5O_LAYOUT_NDIMS];
     hsize_t		idx_min[H5O_LAYOUT_NDIMS];
     hsize_t		idx_max[H5O_LAYOUT_NDIMS];
     hsize_t		sub_size[H5O_LAYOUT_NDIMS];
     hssize_t		offset_wrt_chunk[H5O_LAYOUT_NDIMS];
     hssize_t		sub_offset_m[H5O_LAYOUT_NDIMS];
-    size_t		chunk_size;
-    uint8		*chunk=NULL, *compressed=NULL;
-    H5F_istore_ud1_t	udata;
-    herr_t		status;
-    herr_t		ret_value = FAIL;
+    hssize_t		chunk_offset[H5O_LAYOUT_NDIMS];
+    intn		i, carry;
+    size_t		naccessed;		/*bytes accessed in chnk*/
+    uint8		*chunk=NULL;		/*ptr to a chunk buffer	*/
+    intn		idx_hint=0;		/*cache index hint	*/
 
     FUNC_ENTER(H5F_istore_read, FAIL);
 
@@ -672,61 +1274,10 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
     }
 #endif
 
-    /* Determine the chunk size and allocate buffers */
-    for (i=0, chunk_size=1; i<layout->ndims; i++) {
-	chunk_size *= layout->dim[i];
-    }
-    chunk = H5MM_xmalloc(chunk_size);
-    if (comp && H5Z_NONE!=comp->method) {
-	compressed = H5MM_xmalloc (chunk_size);
-    }
-    
-    /*
-     * As a special case if the source is aligned on a chunk boundary and is
-     * the same size as a chunk, and the destination is the same size as a
-     * chunk, then instead of reading into a temporary buffer and then into
-     * the destination, we read directly into the destination.
-     */
-    for (i=0; i<layout->ndims; i++) {
-	if (offset_f[i] % layout->dim[i]) break; /*src not aligned*/
-	if (size[i]!=layout->dim[i]) break; /*src not a chunk*/
-	if (size_m[i]!=layout->dim[i]) break; /*dst not a chunk*/
-	udata.key.offset[i] = offset_f[i];
-    }
-    if (i==layout->ndims) {
-	udata.mesg = *layout;
-	H5F_addr_undef (&(udata.addr));
-	status = H5B_find (f, H5B_ISTORE, &(layout->addr), &udata);
-	if (status>=0 && H5F_addr_defined (&(udata.addr))) {
-	    if (compressed && udata.key.nbytes<chunk_size) {
-		if (H5F_block_read (f, &(udata.addr), udata.key.nbytes,
-				    compressed)<0) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to read raw storage chunk");
-		}
-		if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
-						compressed, chunk_size, buf)) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to uncompress raw storage chunk");
-		}
-	    } else {
-		assert (udata.key.nbytes==chunk_size);
-		if (H5F_block_read (f, &(udata.addr), chunk_size, buf)<0) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to read raw storage chunk");
-		}
-	    }
-	} else {
-	    HDmemset (buf, 0, chunk_size);
-	}
-	HGOTO_DONE (SUCCEED);
-    }
-
     /*
-     * This is the general case.  We set up multi-dimensional counters
-     * (idx_min, idx_max, and idx_cur) and loop through the chunks compressing
-     * or copying each chunk into a temporary buffer, and then copying it to
-     * it's destination.
+     * Set up multi-dimensional counters (idx_min, idx_max, and idx_cur) and
+     * loop through the chunks copying each to its final destination in the
+     * application buffer.
      */
     for (i=0; i<layout->ndims; i++) {
 	idx_min[i] = offset_f[i] / layout->dim[i];
@@ -734,59 +1285,42 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
 	idx_cur[i] = idx_min[i];
     }
 
-    /* Initialize non-changing part of udata */
-    udata.mesg = *layout;
-
     /* Loop over all chunks */
     while (1) {
-
-	for (i=0; i<layout->ndims; i++) {
+	for (i=0, naccessed=1; i<layout->ndims; i++) {
 	    /* The location and size of the chunk being accessed */
 	    assert (layout->dim[i] < MAX_HSSIZET);
-	    udata.key.offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
+	    chunk_offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
 
 	    /* The offset and size wrt the chunk */
-	    offset_wrt_chunk[i] = MAX(offset_f[i], udata.key.offset[i]) -
-				  udata.key.offset[i];
+	    offset_wrt_chunk[i] = MAX(offset_f[i], chunk_offset[i]) -
+				  chunk_offset[i];
 	    sub_size[i] = MIN((idx_cur[i]+1)*layout->dim[i],
 			      offset_f[i]+size[i]) -
-			  (udata.key.offset[i] + offset_wrt_chunk[i]);
+			  (chunk_offset[i] + offset_wrt_chunk[i]);
+	    naccessed *= sub_size[i];
 	    
 	    /* Offset into mem buffer */
-	    sub_offset_m[i] = udata.key.offset[i] + offset_wrt_chunk[i] +
+	    sub_offset_m[i] = chunk_offset[i] + offset_wrt_chunk[i] +
 			      offset_m[i] - offset_f[i];
 	}
 
-	/* Read chunk */
-	H5F_addr_undef(&(udata.addr));
-	status = H5B_find(f, H5B_ISTORE, &(layout->addr), &udata);
-	if (status>=0 && H5F_addr_defined(&(udata.addr))) {
-	    if (compressed && udata.key.nbytes<chunk_size) {
-		if (H5F_block_read (f, &(udata.addr), udata.key.nbytes,
-				    compressed)<0) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to read raw storage chunk");
-		}
-		if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
-						compressed, chunk_size,
-						chunk)) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to uncompress data");
-		}
-	    } else {
-		assert (udata.key.nbytes == chunk_size);
-		if (H5F_block_read(f, &(udata.addr), chunk_size, chunk) < 0) {
-		    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL,
-				"unable to read raw storage chunk");
-		}
-	    }
-	} else {
-	    HDmemset(chunk, 0, chunk_size);
+	/*
+	 * Lock the chunk, transfer data to the application, then unlock the
+	 * chunk.
+	 */
+	if (NULL==(chunk=H5F_istore_lock (f, layout, comp, chunk_offset,
+					  FALSE, &idx_hint))) {
+	    HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
+			   "unable to read raw data chunk");
 	}
-	
-	/* Transfer data from the chunk buffer to the application */
 	H5V_hyper_copy(layout->ndims, sub_size, size_m, sub_offset_m,
-		       (void *)buf, layout->dim, offset_wrt_chunk, chunk);
+		       (void*)buf, layout->dim, offset_wrt_chunk, chunk);
+	if (H5F_istore_unlock (f, layout, comp, FALSE, chunk_offset, &idx_hint,
+			       chunk, naccessed)<0) {
+	    HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
+			   "unable to unlock raw data chunk");
+	}
 
 	/* Increment indices */
 	for (i=layout->ndims-1, carry=1; i>=0 && carry; --i) {
@@ -795,12 +1329,7 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
 	}
 	if (carry) break;
     }
-    ret_value = SUCCEED;
-
-  done:
-    H5MM_xfree(chunk);
-    H5MM_xfree (compressed);
-    FUNC_LEAVE(ret_value);
+    FUNC_LEAVE(SUCCEED);
 }
 
 
@@ -833,12 +1362,12 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
     hsize_t		idx_min[H5O_LAYOUT_NDIMS];
     hsize_t		idx_max[H5O_LAYOUT_NDIMS];
     hsize_t		sub_size[H5O_LAYOUT_NDIMS];
+    hssize_t		chunk_offset[H5O_LAYOUT_NDIMS];
     hssize_t		offset_wrt_chunk[H5O_LAYOUT_NDIMS];
     hssize_t		sub_offset_m[H5O_LAYOUT_NDIMS];
-    hsize_t		chunk_size, nbytes;
-    uint8		*chunk=NULL, *compressed=NULL, *outbuf;
-    H5F_istore_ud1_t	udata;
-    herr_t		ret_value = FAIL;
+    uint8		*chunk=NULL;
+    intn		idx_hint=0;
+    size_t		chunk_size, naccessed;
     
     FUNC_ENTER(H5F_istore_write, FAIL);
 
@@ -855,9 +1384,10 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
      * For now the source must not be a hyperslab.  It must be an entire
      * memory buffer.
      */
-    for (i=0; i<layout->ndims; i++) {
+    for (i=0, chunk_size=1; i<layout->ndims; i++) {
 	offset_m[i] = 0;
 	size_m[i] = size[i];
+	chunk_size *= layout->dim[i];
     }
 
 #ifndef NDEBUG
@@ -871,10 +1401,9 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
 #endif
 
     /*
-     * This is the general case.  We set up multi-dimensional counters
-     * (idx_min, idx_max, and idx_cur) and loop through the chunks copying
-     * each chunk into a temporary buffer, compressing or decompressing, and
-     * then copying it to it's destination.
+     * Set up multi-dimensional counters (idx_min, idx_max, and idx_cur) and
+     * loop through the chunks copying each chunk from the application to the
+     * chunk cache.
      */
     for (i=0; i<layout->ndims; i++) {
 	idx_min[i] = offset_f[i] / layout->dim[i];
@@ -882,102 +1411,46 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
 	idx_cur[i] = idx_min[i];
     }
 
-    /* Allocate buffers */
-    for (i=0, chunk_size=1; i<layout->ndims; i++) {
-	chunk_size *= layout->dim[i];
-    }
-    chunk = H5MM_xmalloc(chunk_size);
-    if (comp && H5Z_NONE!=comp->method) {
-	compressed = H5MM_xmalloc (chunk_size);
-    }
-
-    /* Initialize non-changing part of udata */
-    udata.mesg = *layout;
 
     /* Loop over all chunks */
     while (1) {
-
-	for (i=0; i<layout->ndims; i++) {
+	
+	for (i=0, naccessed=1; i<layout->ndims; i++) {
 	    /* The location and size of the chunk being accessed */
 	    assert (layout->dim[i] < MAX_HSSIZET);
-	    udata.key.offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
+	    chunk_offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
 
 	    /* The offset and size wrt the chunk */
-	    offset_wrt_chunk[i] = MAX(offset_f[i], udata.key.offset[i]) -
-				  udata.key.offset[i];
+	    offset_wrt_chunk[i] = MAX(offset_f[i], chunk_offset[i]) -
+				  chunk_offset[i];
 	    sub_size[i] = MIN((idx_cur[i]+1)*layout->dim[i],
 			      offset_f[i]+size[i]) -
-			  (udata.key.offset[i] + offset_wrt_chunk[i]);
+			  (chunk_offset[i] + offset_wrt_chunk[i]);
+	    naccessed *= sub_size[i];
 	    
 	    /* Offset into mem buffer */
-	    sub_offset_m[i] = udata.key.offset[i] + offset_wrt_chunk[i] +
+	    sub_offset_m[i] = chunk_offset[i] + offset_wrt_chunk[i] +
 			      offset_m[i] - offset_f[i];
 	}
-	
+
 	/*
-	 * If we are writing a partial chunk then load the chunk from disk
-	 * and uncompress it if it exists.
+	 * Lock the chunk, copy from application to chunk, then unlock the
+	 * chunk.
 	 */
-	if (!H5V_vector_zerop_s(layout->ndims, offset_wrt_chunk) ||
-	    !H5V_vector_eq_u(layout->ndims, sub_size, layout->dim)) {
-	    if (H5B_find (f, H5B_ISTORE, &(layout->addr), &udata)>=0 &&
-		H5F_addr_defined (&(udata.addr))) {
-
-		if (compressed && udata.key.nbytes<chunk_size) {
-		    if (H5F_block_read(f, &(udata.addr), udata.key.nbytes,
-				       compressed)<0) {
-			HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL,
-				    "unable to read raw storage chunk");
-		    }
-		    if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
-						    compressed, chunk_size,
-						    chunk)) {
-			HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				     "unable to uncompress data");
-		    }
-		} else {
-		    assert (chunk_size==udata.key.nbytes);
-		    if (H5F_block_read(f, &(udata.addr), udata.key.nbytes,
-				       chunk)<0) {
-			HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL,
-				    "unable to read raw storage chunk");
-		    }
-		}
-	    } else {
-		HDmemset(chunk, 0, chunk_size);
-	    }
+	if (NULL==(chunk=H5F_istore_lock (f, layout, comp, chunk_offset,
+					  naccessed==chunk_size, &idx_hint))) {
+	    HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+			   "unable to read raw data chunk");
 	}
-	
-	/* Transfer data to the chunk */
 	H5V_hyper_copy(layout->ndims, sub_size,
 		       layout->dim, offset_wrt_chunk, chunk,
 		       size_m, sub_offset_m, buf);
-
-	/* Compress the chunk */
-	if (compressed &&
-	    (nbytes=H5Z_compress (comp, chunk_size, chunk, compressed)) &&
-	    nbytes<chunk_size) {
-	    outbuf = compressed;
-	} else {
-	    outbuf = chunk;
-	    nbytes = chunk_size;
+	if (H5F_istore_unlock (f, layout, comp, TRUE, chunk_offset, &idx_hint,
+			       chunk, naccessed)<0) {
+	    HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+			   "uanble to unlock raw data chunk");
 	}
 	
-	/*
-	 * Create the chunk it if it doesn't exist, or reallocate the chunk
-	 * if its size changed.  Then write the data into the file.
-	 */
-	H5F_addr_undef(&(udata.addr));
-	udata.key.nbytes = nbytes;
-	if (H5B_insert(f, H5B_ISTORE, &(layout->addr), &udata)<0) {
-	    HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
-			 "unable to allocate chunk");
-	}
-	if (H5F_block_write(f, &(udata.addr), nbytes, outbuf) < 0) {
-	    HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
-			"unable to write raw storage chunk");
-	}
-
 	/* Increment indices */
 	for (i=layout->ndims-1, carry=1; i>=0 && carry; --i) {
 	    if (++idx_cur[i]>=idx_max[i]) idx_cur[i] = idx_min[i];
@@ -985,12 +1458,8 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
 	}
 	if (carry) break;
     }
-    ret_value = SUCCEED;
 
-  done:
-    H5MM_xfree(chunk);
-    H5MM_xfree (compressed);
-    FUNC_LEAVE(ret_value);
+    FUNC_LEAVE(SUCCEED);
 }
 
 
@@ -1046,6 +1515,61 @@ H5F_istore_create(H5F_t *f, H5O_layout_t *layout /*out */ )
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5F_istore_stats
+ *
+ * Purpose:	Print raw data cache statistics to the stderr stream.  If
+ *		HEADERS is non-zero then print table column headers,
+ *		otherwise assume that the H5AC layer has already printed them.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_stats (H5F_t *f, hbool_t headers)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    double	miss_rate;
+    char	ascii[32];
+    
+    FUNC_ENTER (H5F_istore_stats, FAIL);
+
+    if (headers) {
+	fprintf(stderr, "H5F: raw data cache statistics for file %s\n",
+		f->name);
+	fprintf(stderr, "   %-18s %8s %8s %8s %8s+%-8s\n",
+		"Layer", "Hits", "Misses", "MissRate", "Inits", "Flushes");
+	fprintf(stderr, "   %-18s %8s %8s %8s %8s-%-8s\n",
+		"-----", "----", "------", "--------", "-----", "-------");
+    }
+
+    if (rdcc->nhits>0 || rdcc->nmisses>0) {
+	miss_rate = 100.0 * rdcc->nmisses /
+			(rdcc->nhits + rdcc->nmisses);
+    } else {
+	miss_rate = 0.0;
+    }
+    if (miss_rate > 100) {
+	sprintf(ascii, "%7d%%", (int) (miss_rate + 0.5));
+    } else {
+	sprintf(ascii, "%7.2f%%", miss_rate);
+    }
+    
+    fprintf(stderr, "   %-18s %8u %8u %7s %8d+%-9ld\n",
+	    "raw data chunks", rdcc->nhits, rdcc->nmisses, ascii,
+	    rdcc->ninits, (long)(rdcc->nflushes)-(long)(rdcc->ninits));
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F_istore_debug
  *
  * Purpose:	Debugs a B-tree node for indexed raw data storage.
diff --git a/src/H5F.c b/src/H5F.c
index 972ffc9..78d70b3 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -97,7 +97,8 @@ static intn interface_initialize_g = FALSE;
 static void H5F_term_interface(void);
 
 /* PRIVATE PROTOTYPES */
-static H5F_t *H5F_new(H5F_file_t *shared);
+static H5F_t *H5F_new(H5F_file_t *shared, const H5F_create_t *fcpl,
+		      const H5F_access_t *fapl);
 static herr_t H5F_dest(H5F_t *f);
 static herr_t H5F_flush(H5F_t *f, hbool_t invalidate);
 static herr_t H5F_locate_signature(H5F_low_t *f_handle,
@@ -141,6 +142,9 @@ H5F_init_interface(void)
     }
 
     /* Initialize the default file access property list */
+    H5F_access_dflt.mdc_nelmts = H5AC_NSLOTS;
+    H5F_access_dflt.rdcc_nbytes = 1024*1024; /*1MB*/
+    H5F_access_dflt.rdcc_w0 = 0.75; /*preempt fully read chunks*/
     H5F_access_dflt.driver = H5F_LOW_DFLT;
 #if (H5F_LOW_DFLT == H5F_LOW_SEC2)
     /* Nothing to initialize */
@@ -468,7 +472,8 @@ H5Fis_hdf5(const char *filename)
  *		H5Fopen and H5Fcreate functions then fill in various
  *		fields.	 If SHARED is a non-null pointer then the shared info
  *		to which it points has the reference count incremented.
- *		Otherwise a new, empty shared info struct is created.
+ *		Otherwise a new, empty shared info struct is created and
+ *		initialized with the specified file access property list.
  *
  * Errors:
  *
@@ -485,9 +490,11 @@ H5Fis_hdf5(const char *filename)
  *-------------------------------------------------------------------------
  */
 static H5F_t *
-H5F_new(H5F_file_t *shared)
+H5F_new(H5F_file_t *shared, const H5F_create_t *fcpl, const H5F_access_t *fapl)
 {
-    H5F_t		   *f = NULL;
+    H5F_t		*f = NULL;
+    intn		n;
+    
     FUNC_ENTER(H5F_new, NULL);
 
     f = H5MM_xcalloc(1, sizeof(H5F_t));
@@ -500,13 +507,39 @@ H5F_new(H5F_file_t *shared)
 	H5F_addr_undef(&(f->shared->freespace_addr));
 	H5F_addr_undef(&(f->shared->hdf5_eof));
 
-	/* Create a main cache */
-	H5AC_create(f, H5AC_NSLOTS);
+	/*
+	 * Deep-copy the file creation and file access property lists into
+	 * the new file handle.  We do this early because some values might
+	 * need to change as the file is being opened.
+	 */
+	if (NULL==(f->shared->create_parms=H5P_copy(H5P_FILE_CREATE, fcpl))) {
+	    HRETURN_ERROR (H5E_FILE, H5E_CANTINIT, NULL,
+			   "unable to copy file creation property list");
+	}
+	if (NULL==(f->shared->access_parms=H5P_copy(H5P_FILE_ACCESS, fapl))) {
+	    HRETURN_ERROR (H5E_FILE, H5E_CANTINIT, NULL,
+			   "unable to copy file access property list");
+	}
+
+	/*
+	 * Create a meta data cache with the specified number of elements.
+	 * The cache might be created with a different number of elements and
+	 * the access property list should be updated to reflect that.
+	 */
+	if ((n=H5AC_create(f, f->shared->access_parms->mdc_nelmts))<0) {
+	    HRETURN_ERROR (H5E_FILE, H5E_CANTINIT, NULL,
+			   "unable to create meta data cache");
+	}
+	f->shared->access_parms->mdc_nelmts = n;
+	
+	/* Create the chunk cache */
+	H5F_istore_init (f);
     }
     f->shared->nrefs++;
 
     FUNC_LEAVE(f);
 }
+
 
 /*-------------------------------------------------------------------------
  * Function:	H5F_dest
@@ -547,6 +580,10 @@ H5F_dest(H5F_t *f)
 		HERROR (H5E_FILE, H5E_CANTINIT, "problems closing file");
 		ret_value = FAIL; /*but keep going*/
 	    }
+	    if (H5F_istore_dest (f)<0) {
+		HERROR (H5E_FILE, H5E_CANTINIT, "problems closing file");
+		ret_value = FAIL; /*but keep going*/
+	    }
 	    f->shared->cwfs = H5MM_xfree (f->shared->cwfs);
 	    H5P_close (H5P_FILE_CREATE, f->shared->create_parms);
 	    H5P_close (H5P_FILE_ACCESS, f->shared->access_parms);
@@ -735,7 +772,7 @@ H5F_open(const char *name, uintn flags,
 		old->shared->flags |= H5F_ACC_RDWR;
 		fd = NULL;	/*so we don't close it during error */
 	    }
-	    f = H5F_new(old->shared);
+	    f = H5F_new(old->shared, NULL, NULL);
 
 	} else if (flags & H5F_ACC_TRUNC) {
 	    /* Truncate existing file */
@@ -749,7 +786,7 @@ H5F_open(const char *name, uintn flags,
 		HRETURN_ERROR(H5E_FILE, H5E_CANTCREATE, NULL,
 			      "can't truncate file");
 	    }
-	    f = H5F_new(NULL);
+	    f = H5F_new(NULL, create_parms, access_parms);
 	    f->shared->key = search;
 	    f->shared->flags = flags;
 	    f->shared->lf = fd;
@@ -762,7 +799,7 @@ H5F_open(const char *name, uintn flags,
 		HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
 			      "cannot open existing file");
 	    }
-	    f = H5F_new(NULL);
+	    f = H5F_new(NULL, create_parms, access_parms);
 	    f->shared->key = search;
 	    f->shared->flags = flags;
 	    f->shared->lf = fd;
@@ -794,7 +831,7 @@ H5F_open(const char *name, uintn flags,
 	    HRETURN_ERROR(H5E_FILE, H5E_CANTCREATE, NULL,
 			  "can't create file");
 	}
-	f = H5F_new(NULL);
+	f = H5F_new(NULL, create_parms, access_parms);
 	f->shared->key = search;
 	f->shared->flags = flags;
 	f->shared->lf = fd;
@@ -816,13 +853,10 @@ H5F_open(const char *name, uintn flags,
     f->name = H5MM_xstrdup(name);
 
     /*
-     * Update the file creation parameters and file access parameters with
-     * default values if this is the first time this file is opened.  Some of
-     * the properties may need to be updated.
+     * Some of the properties may need to be updated. We would like to
+     * eventually get rid of this step by not having redundant data!
      */
     if (1 == f->shared->nrefs) {
-	f->shared->create_parms = H5P_copy (H5P_FILE_CREATE, create_parms);
-	f->shared->access_parms = H5P_copy (H5P_FILE_ACCESS, access_parms);
 	if (H5F_LOW_FAMILY==f->shared->access_parms->driver) {
 	    haddr_t x = f->shared->lf->u.fam.memb_size;
 	    f->shared->access_parms->u.fam.memb_size = x;
@@ -1255,12 +1289,20 @@ H5F_flush(H5F_t *f, hbool_t invalidate)
      * once for read-only and once for read-write, and then calling
      * H5F_flush() with the read-only handle, still causes data to be flushed.
      */
-    if (0 == (H5F_ACC_RDWR & f->shared->flags))
+    if (0 == (H5F_ACC_RDWR & f->shared->flags)) {
 	HRETURN(SUCCEED);
+    }
 
-    /* flush (and invalidate) the entire cache */
+    /* flush the entire raw data cache */
+    if (H5F_istore_flush (f)<0) {
+	HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL,
+		      "unable to flush raw data cache");
+    }
+    
+    /* flush (and invalidate) the entire meta data cache */
     if (H5AC_flush(f, NULL, 0, invalidate) < 0) {
-	HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush cache");
+	HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL,
+		      "unable to flush meta data cache");
     }
 
     /* encode the file boot block */
@@ -1371,7 +1413,10 @@ H5F_close(H5F_t *f)
 	}
 
 	/* Dump debugging info */
-	if (f->intent & H5F_ACC_DEBUG) H5AC_debug(f);
+	if (f->intent & H5F_ACC_DEBUG) {
+	    H5AC_debug(f);
+	    H5F_istore_stats (f, FALSE);
+	}
 
 	/* Close files and release resources */
 	H5F_low_close(f->shared->lf, f->shared->access_parms);
diff --git a/src/H5Fistore.c b/src/H5Fistore.c
index 7e80f1a..91c4e9d 100644
--- a/src/H5Fistore.c
+++ b/src/H5Fistore.c
@@ -2,8 +2,17 @@
  * Copyright (C) 1997 NCSA
  *		      All rights reserved.
  *
- * Programmer: Robb Matzke <matzke@llnl.gov>
- *	       Wednesday, October  8, 1997
+ * Programmer: 	Robb Matzke <matzke@llnl.gov>
+ *	       	Wednesday, October  8, 1997
+ *
+ * Purpose:	Indexed (chunked) I/O functions.  The logical
+ *		multi-dimensional data space is regularly partitioned into
+ *		same-sized "chunks", the first of which is aligned with the
+ *		logical origin.  The chunks are given a multi-dimensional
+ *		index which is used as a lookup key in a B-tree that maps
+ *		chunk index to disk address.  Each chunk can be compressed
+ *		independently and the chunks may move around in the file as
+ *		their storage requirements change.
  */
 #include <H5private.h>
 #include <H5Dprivate.h>
@@ -14,13 +23,25 @@
 #include <H5Oprivate.h>
 #include <H5Vprivate.h>
 
-
 /* Interface initialization */
 #define PABLO_MASK	H5F_istore_mask
 static hbool_t		interface_initialize_g = FALSE;
 #define INTERFACE_INIT NULL
 
-/* PRIVATE PROTOTYPES */
+/* Raw data chunks are cached.  Each entry in the cache is: */
+typedef struct H5F_rdcc_ent_t {
+    hbool_t	locked;		/*entry is locked in cache		*/
+    hbool_t	dirty;		/*needs to be written to disk?		*/
+    H5O_layout_t *layout;	/*the layout message			*/
+    H5O_compress_t *comp;	/*compression message			*/
+    hssize_t	offset[H5O_LAYOUT_NDIMS]; /*chunk name			*/
+    size_t	chunk_size;	/*size of a chunk			*/
+    size_t	rd_count;	/*bytes remaining to be read		*/
+    size_t	wr_count;	/*bytes remaining to be written		*/
+    uint8	*chunk;		/*the uncompressed chunk data		*/
+} H5F_rdcc_ent_t;
+
+/* Private prototypes */
 static size_t H5F_istore_sizeof_rkey(H5F_t *f, const void *_udata);
 static herr_t H5F_istore_new_node(H5F_t *f, H5B_ins_t, void *_lt_key,
 				  void *_udata, void *_rt_key, haddr_t *);
@@ -546,7 +567,6 @@ H5F_istore_insert(H5F_t *f, const haddr_t *addr, void *_lt_key,
 	 * Already exists.  If the new size is not the same as the old size
 	 * then we should reallocate storage.
 	 */
-#if 1
 	if (lt_key->nbytes != udata->key.nbytes) {
 	    if (H5MF_realloc (f, H5MF_RAW, lt_key->nbytes, addr,
 			      udata->key.nbytes, new_node/*out*/)<0) {
@@ -561,13 +581,6 @@ H5F_istore_insert(H5F_t *f, const haddr_t *addr, void *_lt_key,
 	    udata->addr = *addr;
 	    ret_value = H5B_INS_NOOP;
 	}
-#else
-	assert (lt_key->nbytes == udata->key.nbytes);
-	assert (!H5F_addr_defined (&(udata->addr)) ||
-		H5F_addr_eq (&(udata->addr), addr));
-	udata->addr = *addr;
-	ret_value = H5B_INS_NOOP;
-#endif
 
     } else if (H5V_hyper_disjointp(udata->mesg.ndims,
 				   lt_key->offset, udata->mesg.dim,
@@ -606,6 +619,596 @@ H5F_istore_insert(H5F_t *f, const haddr_t *addr, void *_lt_key,
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5F_istore_init
+ *
+ * Purpose:	Initialize the raw data chunk cache for a file.  This is
+ *		called when the file handle is initialized.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Monday, May 18, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_init (H5F_t *f)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    
+    FUNC_ENTER (H5F_istore_init, FAIL);
+
+    HDmemset (rdcc, 0, sizeof(H5F_rdcc_t));
+    if (f->shared->access_parms->rdcc_nbytes>0) {
+	rdcc->nslots = 25; /*some initial number of slots*/
+	rdcc->slot = H5MM_xcalloc (rdcc->nslots, sizeof(H5F_rdcc_ent_t));
+    }
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_flush_entry
+ *
+ * Purpose:	Writes a chunk to disk.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_flush_entry (H5F_t *f, H5F_rdcc_ent_t *ent)
+{
+    void	*c_buf = NULL;		/*temp compression buffer	*/
+    void	*out_ptr = NULL;	/*ptr to output buffer		*/
+    size_t	nbytes;			/*size of output buffer		*/
+    herr_t	ret_value = FAIL;	/*return value			*/
+    H5F_istore_ud1_t udata;		/*pass through B-tree		*/
+    intn	i;
+    
+    FUNC_ENTER (H5F_istore_flush_entry, FAIL);
+    assert (ent);
+    assert (!ent->locked);
+    if (!ent->dirty) HRETURN (SUCCEED);
+
+    /* Should the chunk be compressed before writing it to disk? */
+    if (ent->comp && H5Z_NONE!=ent->comp->method) {
+	c_buf = H5MM_xmalloc (ent->chunk_size);
+	nbytes = H5Z_compress (ent->comp, ent->chunk_size, ent->chunk, c_buf);
+	if (nbytes && nbytes<ent->chunk_size) {
+	    out_ptr = c_buf;
+	} else {
+	    out_ptr = ent->chunk;
+	    nbytes = ent->chunk_size;
+	}
+    } else {
+	out_ptr = ent->chunk;
+	nbytes = ent->chunk_size;
+    }
+    
+    /*
+     * Create the chunk it if it doesn't exist, or reallocate the chunk if its
+     * size changed.  Then write the data into the file.
+     */
+    udata.mesg = *(ent->layout);
+    H5F_addr_undef(&(udata.addr));
+    udata.key.nbytes = nbytes;
+    for (i=0; i<ent->layout->ndims; i++) {
+	udata.key.offset[i] = ent->offset[i];
+    }
+    
+    if (H5B_insert(f, H5B_ISTORE, &(ent->layout->addr), &udata)<0) {
+	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+		     "unable to allocate chunk");
+    }
+    if (H5F_block_write (f, &(udata.addr), nbytes, out_ptr)<0) {
+	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+		     "unable to write raw data to file");
+    }
+
+    /* Mark cache entry as clean */
+    ent->dirty = FALSE;
+    f->shared->rdcc.nflushes++;
+    ret_value = SUCCEED;
+
+ done:
+    H5MM_xfree (c_buf);
+    FUNC_LEAVE (ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_flush
+ *
+ * Purpose:	Writes all dirty chunks to disk but does not remove them from
+ *		the cache.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_flush (H5F_t *f)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    intn	i, nerrors=0;
+    
+    FUNC_ENTER (H5F_istore_flush, FAIL);
+
+    for (i=0; i<rdcc->nused; i++) {
+	if (H5F_istore_flush_entry (f, rdcc->slot+i)<0) {
+	    nerrors++;
+	}
+    }
+    if (nerrors) {
+	HRETURN_ERROR (H5E_IO, H5E_CANTFLUSH, FAIL,
+		       "unable to flush one or more raw data chunks");
+    }
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_preempt
+ *
+ * Purpose:	Preempts the specified entry from the cache, flushing it to
+ *		disk if necessary.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_preempt (H5F_t *f, intn idx)
+{
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent = rdcc->slot + idx;
+    
+    FUNC_ENTER (H5F_istore_preempt, FAIL);
+    assert (idx>=0 && idx<rdcc->nused);
+    assert (!ent->locked);
+
+    if (ent->dirty) H5F_istore_flush_entry (f, ent);
+    H5O_free (H5O_LAYOUT, ent->layout);
+    H5O_free (H5O_COMPRESS, ent->comp);
+    H5MM_xfree (ent->chunk);
+    rdcc->nused -= 1;
+    rdcc->nbytes -= ent->chunk_size;
+    HDmemmove (rdcc->slot+idx, rdcc->slot+idx+1,
+	       (rdcc->nused-idx) * sizeof(H5F_rdcc_ent_t));
+    
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_dest
+ *
+ * Purpose:	Destroy the entire chunk cache by flushing dirty entries,
+ *		preempting all entries, and freeing the cache itself.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_dest (H5F_t *f)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    intn	i, nerrors=0;
+    
+    FUNC_ENTER (H5F_istore_dest, FAIL);
+
+    for (i=rdcc->nused-1; i>=0; --i) {
+	if (H5F_istore_flush_entry (f, rdcc->slot+i)<0) {
+	    nerrors++;
+	}
+	if (H5F_istore_preempt (f, i)<0) {
+	    nerrors++;
+	}
+    }
+    if (nerrors) {
+	HRETURN_ERROR (H5E_IO, H5E_CANTFLUSH, FAIL,
+		       "unable to flush one or more raw data chunks");
+    }
+
+    H5MM_xfree (rdcc->slot);
+    HDmemset (rdcc, 0, sizeof(H5F_rdcc_t));
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_prune
+ *
+ * Purpose:	Prune the cache by preempting some things until the cache has
+ *		room for something which is SIZE bytes.  Only unlocked
+ *		entries are considered for preemption.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_prune (H5F_t *f, size_t size)
+{
+    intn		i, meth0, meth1, nerrors=0;
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent0, *ent1;
+    double		w0 = f->shared->access_parms->rdcc_w0;
+    size_t		total = f->shared->access_parms->rdcc_nbytes;
+
+    FUNC_ENTER (H5F_istore_prune, FAIL);
+
+    /*
+     * We have two pointers that slide down the cache beginning at the least
+     * recently used entry.  The distance between the pointers represents the
+     * relative weight.  A weight of 50% for the first pointer means that the
+     * second pointer is half the cache length behind the first pointer.
+     */
+    meth0 = rdcc->nused;
+    meth1 = rdcc->nused * (1.0+w0);
+    for (i=MAX(meth0, meth1)-1;
+	 rdcc->nbytes+size>total && i>=0;
+	 --i, --meth0, --meth1) {
+
+	ent0 = rdcc->slot+meth0; /*might be a bad pointer!*/
+	ent1 = rdcc->slot+meth1; /*might be a bad pointer!*/
+	
+	if (meth0>=0 && meth0<rdcc->nused && !ent0->locked &&
+	    (0==ent0->rd_count || ent0->chunk_size==ent0->rd_count) &&
+	    (0==ent0->wr_count || ent0->chunk_size==ent0->wr_count)) {
+	    /*
+	     * Method 0: Preempt entries that have a zero rd_count.  If the
+	     * application is accessing a dataset with a set of
+	     * non-overlapping partial I/O requests then chunks with a zero
+	     * rd_count will probably not be accessed in the near future.
+	     */
+	    if (H5F_istore_preempt (f, meth0)<0) nerrors++;
+	    
+	} else if (meth1>=0 && meth1<rdcc->nused && !ent1->locked) {
+	    /*
+	     * Method 1: Discard the least recently used members from the
+	     * cache.  This is a catch-all.
+	     */
+	    if (H5F_istore_preempt (f, meth1)<0) nerrors++;
+	}
+    }
+    if (nerrors) {
+	HRETURN_ERROR (H5E_IO, H5E_CANTFLUSH, FAIL,
+		       "unable to preempt one or more raw data cache entry");
+    }
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_lock
+ *
+ * Purpose:	Return a pointer to an uncompressed chunk.  The pointer
+ *		points directly into the chunk cache and should not be freed
+ *		by the caller but will be valid until it is unlocked.  The
+ *		input value IDX_HINT is used to speed up cache lookups and
+ *		it's output value should be given to H5F_rdcc_unlock().
+ *
+ *		If RELAX is non-zero and the chunk isn't in the cache then
+ *		don't try to read it from the file, but just allocate an
+ *		uninitialized buffer to hold the result.  This is indented
+ *		for output functions that are about to overwrite the entire
+ *		chunk.
+ *
+ * Return:	Success:	Ptr to an uncompressed chunk.
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5F_istore_lock (H5F_t *f, const H5O_layout_t *layout,
+		 const H5O_compress_t *comp, const hssize_t offset[],
+		 hbool_t relax, intn *idx_hint/*in,out*/)
+{
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent = NULL;
+    intn		i, j, found = -1;
+    H5F_istore_ud1_t	udata;			/*B-tree pass-through	*/
+    size_t		chunk_size;		/*size of a chunk	*/
+    herr_t		status;			/*func return status	*/
+    void		*chunk=NULL;		/*the uncompressed chunk*/
+    void		*temp=NULL;		/*temporary chunk buffer*/
+    void		*ret_value=NULL;	/*return value		*/
+    
+    FUNC_ENTER (H5F_istore_lock, NULL);
+
+    /* First use the hint */
+    if (idx_hint && *idx_hint>=0 && *idx_hint<rdcc->nused) {
+	ent = rdcc->slot + *idx_hint;
+	if (layout->ndims==ent->layout->ndims) {
+	    for (i=0, found=*idx_hint; found>=0 && i<ent->layout->ndims; i++) {
+		if (offset[i]!=ent->offset[i]) found = -1;
+	    }
+	}
+    }
+
+    /* Then look at all the entries */
+    for (i=0; found<0 && i<rdcc->nused; i++) {
+	ent = rdcc->slot + i;
+	if (layout->ndims==ent->layout->ndims) {
+	    for (j=0, found=i; found>=0 && j<ent->layout->ndims; j++) {
+		if (offset[j]!=ent->offset[j]) found = -1;
+	    }
+	}
+    }
+
+
+    if (found>=0) {
+	/*
+	 * Already in the cache.  Count a hit.
+	 */
+	rdcc->nhits++;
+	
+    } else if (found<0 && relax) {
+	/*
+	 * Not in the cache, but we're about to overwrite the whole thing
+	 * anyway, so just allocate a buffer for it but don't initialize that
+	 * buffer with the file contents. Count this as a hit instead of a
+	 * miss because we saved ourselves lots of work.
+	 */
+	rdcc->nhits++;
+	for (i=0, chunk_size=1; i<layout->ndims; i++) {
+	    chunk_size *= layout->dim[i];
+	}
+	chunk = H5MM_xmalloc (chunk_size);
+	
+    } else {
+	/*
+	 * Not in the cache.  Read it from the file and count this as a miss
+	 * if it's in the file or an init if it isn't.
+	 */
+	for (i=0, chunk_size=1; i<layout->ndims; i++) {
+	    udata.key.offset[i] = offset[i];
+	    chunk_size *= layout->dim[i];
+	}
+	udata.mesg = *layout;
+	H5F_addr_undef (&(udata.addr));
+	status = H5B_find (f, H5B_ISTORE, &(layout->addr), &udata);
+	chunk = H5MM_xmalloc (chunk_size);
+	if (status>=0 && H5F_addr_defined (&(udata.addr))) {
+	    /*
+	     * The chunk exists on disk but might be compressed.  Instead of
+	     * allocating the exact size for the compressed chunk we allocate
+	     * the entire chunk size -- it reduces strain on the malloc()
+	     * subsystem.
+	     */
+	    if (H5F_block_read (f, &(udata.addr), udata.key.nbytes, chunk)<0) {
+		HGOTO_ERROR (H5E_IO, H5E_READERROR, NULL,
+			     "unable to read raw data chunk");
+	    }
+	    if (udata.key.nbytes<chunk_size) {
+		temp = H5MM_xmalloc (chunk_size);
+		if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
+						chunk, chunk_size, temp)) {
+		    HGOTO_ERROR (H5E_IO, H5E_READERROR, NULL,
+				 "unable to uncompress raw data chunk"); 
+		}
+		H5MM_xfree (chunk);
+		chunk = temp;
+		temp = NULL;
+	    }
+	    rdcc->nmisses++;
+	} else {
+	    /*
+	     * The chunk doesn't exist in the file.  Assume all zeros.
+	     */
+	    HDmemset (chunk, 0, chunk_size);
+	    rdcc->ninits++;
+	}
+    }
+
+    if (found<0 && chunk_size<=f->shared->access_parms->rdcc_nbytes) {
+	/*
+	 * Add the chunk to the beginning of the cache after pruning the cache
+	 * to make room.
+	 */
+	if (H5F_istore_prune (f, chunk_size)<0) {
+	    H5E_clear ();
+	}
+	if (rdcc->nused>=rdcc->nslots) {
+	    rdcc->nslots = MAX (25, 2*rdcc->nslots);
+	    rdcc->slot = H5MM_xrealloc (rdcc->slot,
+					(rdcc->nslots*
+					 sizeof(H5F_rdcc_ent_t)));
+	}
+	HDmemmove (rdcc->slot+1, rdcc->slot,
+		   rdcc->nused*sizeof(H5F_rdcc_ent_t));
+	rdcc->nused++;
+	rdcc->nbytes += chunk_size;
+	ent = rdcc->slot;
+	ent->locked = 0;
+	ent->dirty = FALSE;
+	ent->chunk_size = chunk_size;
+	ent->layout = H5O_copy (H5O_LAYOUT, layout);
+	ent->comp = H5O_copy (H5O_COMPRESS, comp);
+	for (i=0; i<layout->ndims; i++) {
+	    ent->offset[i] = offset[i];
+	}
+	ent->rd_count = chunk_size;
+	ent->wr_count = chunk_size;
+	ent->chunk = chunk;
+	found = 0;
+	    
+    } else if (found<0) {
+	/*
+	 * The chunk is larger than the entire cache so we don't cache it.
+	 * This is the reason all those arguments have to be repeated for the
+	 * unlock function.
+	 */
+	ent = NULL;
+	found = -999;
+	
+    } else if (found>0) {
+	/*
+	 * The chunk is not at the beginning of the cache; move it forward by
+	 * one slot.  This is how we implement the LRU preemption algorithm.
+	 */
+	H5F_rdcc_ent_t x = rdcc->slot[found];
+	rdcc->slot[found] = rdcc->slot[found-1];
+	rdcc->slot[found-1] = x;
+	ent = rdcc->slot + --found;
+    }
+
+    /* Lock the chunk into the cache */
+    if (ent) {
+	assert (!ent->locked);
+	ent->locked = TRUE;
+	if (idx_hint) *idx_hint = found;
+	chunk = ent->chunk;
+    }
+
+    ret_value = chunk;
+ done:
+    if (!ret_value) H5MM_xfree (chunk);
+    H5MM_xfree (temp);
+    FUNC_LEAVE (ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_istore_unlock
+ *
+ * Purpose:	Unlocks a previously locked chunk. The LAYOUT, COMP, and
+ *		OFFSET arguments should be the same as for H5F_rdcc_lock().
+ *		The DIRTY argument should be set to non-zero if the chunk has
+ *		been modified since it was locked. The IDX_HINT argument is
+ *		the returned index hint from the lock operation and BUF is
+ *		the return value from the lock.
+ *
+ *		The NACCESSED argument should be the number of bytes accessed
+ *		for reading or writing (depending on the value of DIRTY).
+ *		It's only purpose is to provide additional information to the
+ *		preemption policy.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_istore_unlock (H5F_t *f, const H5O_layout_t *layout,
+		   const H5O_compress_t *comp, hbool_t dirty,
+		   const hssize_t offset[], intn *idx_hint,
+		   uint8 *chunk, size_t naccessed)
+{
+    H5F_rdcc_t		*rdcc = &(f->shared->rdcc);
+    H5F_rdcc_ent_t	*ent = NULL;
+    intn		i, found = -1;
+    
+    FUNC_ENTER (H5F_istore_unlock, FAIL);
+
+    /* First look at the hint */
+    if (idx_hint && *idx_hint>=0 && *idx_hint<rdcc->nused) {
+	if (rdcc->slot[*idx_hint].chunk==chunk) found = *idx_hint;
+    }
+
+    /* Then look at all the entries */
+    for (i=0; found<0 && i<rdcc->nused; i++) {
+	if (rdcc->slot[i].chunk==chunk) found = i;
+    }
+
+    if (found<0) {
+	/*
+	 * It's not in the cache, probably because it's too big.  If it's
+	 * dirty then flush it to disk.  In any case, free the chunk.
+	 * Note: we have to copy the layout and compression messages so we
+	 *	 don't discard the `const' qualifier.
+	 */
+	if (dirty) {
+	    H5F_rdcc_ent_t x;
+	    HDmemset (&x, 0, sizeof x);
+	    x.dirty = TRUE;
+	    x.layout = H5O_copy (H5O_LAYOUT, layout);
+	    x.comp = H5O_copy (H5O_COMPRESS, comp);
+	    for (i=0; i<layout->ndims; i++) {
+		x.offset[i] = offset[i];
+	    }
+	    x.chunk = chunk;
+	    H5F_istore_flush_entry (f, &x);
+	    H5O_free (H5O_LAYOUT, x.layout);
+	    H5O_free (H5O_COMPRESS, x.comp);
+	}
+	H5MM_xfree (chunk);
+    } else {
+	/*
+	 * It's in the cache so unlock it.
+	 */
+	ent = rdcc->slot + found;
+	assert (ent->locked);
+	if (dirty) {
+	    ent->dirty = TRUE;
+	    ent->wr_count -= MIN (ent->wr_count, naccessed);
+	} else {
+	    ent->rd_count -= MIN (ent->rd_count, naccessed);
+	}
+	ent->locked = FALSE;
+    }
+    
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F_istore_read
  *
  * Purpose:	Reads a multi-dimensional buffer from (part of) an indexed raw
@@ -629,18 +1232,17 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
 {
     hssize_t		offset_m[H5O_LAYOUT_NDIMS];
     hsize_t		size_m[H5O_LAYOUT_NDIMS];
-    intn		i, carry;
     hsize_t		idx_cur[H5O_LAYOUT_NDIMS];
     hsize_t		idx_min[H5O_LAYOUT_NDIMS];
     hsize_t		idx_max[H5O_LAYOUT_NDIMS];
     hsize_t		sub_size[H5O_LAYOUT_NDIMS];
     hssize_t		offset_wrt_chunk[H5O_LAYOUT_NDIMS];
     hssize_t		sub_offset_m[H5O_LAYOUT_NDIMS];
-    size_t		chunk_size;
-    uint8		*chunk=NULL, *compressed=NULL;
-    H5F_istore_ud1_t	udata;
-    herr_t		status;
-    herr_t		ret_value = FAIL;
+    hssize_t		chunk_offset[H5O_LAYOUT_NDIMS];
+    intn		i, carry;
+    size_t		naccessed;		/*bytes accessed in chnk*/
+    uint8		*chunk=NULL;		/*ptr to a chunk buffer	*/
+    intn		idx_hint=0;		/*cache index hint	*/
 
     FUNC_ENTER(H5F_istore_read, FAIL);
 
@@ -672,61 +1274,10 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
     }
 #endif
 
-    /* Determine the chunk size and allocate buffers */
-    for (i=0, chunk_size=1; i<layout->ndims; i++) {
-	chunk_size *= layout->dim[i];
-    }
-    chunk = H5MM_xmalloc(chunk_size);
-    if (comp && H5Z_NONE!=comp->method) {
-	compressed = H5MM_xmalloc (chunk_size);
-    }
-    
-    /*
-     * As a special case if the source is aligned on a chunk boundary and is
-     * the same size as a chunk, and the destination is the same size as a
-     * chunk, then instead of reading into a temporary buffer and then into
-     * the destination, we read directly into the destination.
-     */
-    for (i=0; i<layout->ndims; i++) {
-	if (offset_f[i] % layout->dim[i]) break; /*src not aligned*/
-	if (size[i]!=layout->dim[i]) break; /*src not a chunk*/
-	if (size_m[i]!=layout->dim[i]) break; /*dst not a chunk*/
-	udata.key.offset[i] = offset_f[i];
-    }
-    if (i==layout->ndims) {
-	udata.mesg = *layout;
-	H5F_addr_undef (&(udata.addr));
-	status = H5B_find (f, H5B_ISTORE, &(layout->addr), &udata);
-	if (status>=0 && H5F_addr_defined (&(udata.addr))) {
-	    if (compressed && udata.key.nbytes<chunk_size) {
-		if (H5F_block_read (f, &(udata.addr), udata.key.nbytes,
-				    compressed)<0) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to read raw storage chunk");
-		}
-		if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
-						compressed, chunk_size, buf)) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to uncompress raw storage chunk");
-		}
-	    } else {
-		assert (udata.key.nbytes==chunk_size);
-		if (H5F_block_read (f, &(udata.addr), chunk_size, buf)<0) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to read raw storage chunk");
-		}
-	    }
-	} else {
-	    HDmemset (buf, 0, chunk_size);
-	}
-	HGOTO_DONE (SUCCEED);
-    }
-
     /*
-     * This is the general case.  We set up multi-dimensional counters
-     * (idx_min, idx_max, and idx_cur) and loop through the chunks compressing
-     * or copying each chunk into a temporary buffer, and then copying it to
-     * it's destination.
+     * Set up multi-dimensional counters (idx_min, idx_max, and idx_cur) and
+     * loop through the chunks copying each to its final destination in the
+     * application buffer.
      */
     for (i=0; i<layout->ndims; i++) {
 	idx_min[i] = offset_f[i] / layout->dim[i];
@@ -734,59 +1285,42 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
 	idx_cur[i] = idx_min[i];
     }
 
-    /* Initialize non-changing part of udata */
-    udata.mesg = *layout;
-
     /* Loop over all chunks */
     while (1) {
-
-	for (i=0; i<layout->ndims; i++) {
+	for (i=0, naccessed=1; i<layout->ndims; i++) {
 	    /* The location and size of the chunk being accessed */
 	    assert (layout->dim[i] < MAX_HSSIZET);
-	    udata.key.offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
+	    chunk_offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
 
 	    /* The offset and size wrt the chunk */
-	    offset_wrt_chunk[i] = MAX(offset_f[i], udata.key.offset[i]) -
-				  udata.key.offset[i];
+	    offset_wrt_chunk[i] = MAX(offset_f[i], chunk_offset[i]) -
+				  chunk_offset[i];
 	    sub_size[i] = MIN((idx_cur[i]+1)*layout->dim[i],
 			      offset_f[i]+size[i]) -
-			  (udata.key.offset[i] + offset_wrt_chunk[i]);
+			  (chunk_offset[i] + offset_wrt_chunk[i]);
+	    naccessed *= sub_size[i];
 	    
 	    /* Offset into mem buffer */
-	    sub_offset_m[i] = udata.key.offset[i] + offset_wrt_chunk[i] +
+	    sub_offset_m[i] = chunk_offset[i] + offset_wrt_chunk[i] +
 			      offset_m[i] - offset_f[i];
 	}
 
-	/* Read chunk */
-	H5F_addr_undef(&(udata.addr));
-	status = H5B_find(f, H5B_ISTORE, &(layout->addr), &udata);
-	if (status>=0 && H5F_addr_defined(&(udata.addr))) {
-	    if (compressed && udata.key.nbytes<chunk_size) {
-		if (H5F_block_read (f, &(udata.addr), udata.key.nbytes,
-				    compressed)<0) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to read raw storage chunk");
-		}
-		if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
-						compressed, chunk_size,
-						chunk)) {
-		    HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				 "unable to uncompress data");
-		}
-	    } else {
-		assert (udata.key.nbytes == chunk_size);
-		if (H5F_block_read(f, &(udata.addr), chunk_size, chunk) < 0) {
-		    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL,
-				"unable to read raw storage chunk");
-		}
-	    }
-	} else {
-	    HDmemset(chunk, 0, chunk_size);
+	/*
+	 * Lock the chunk, transfer data to the application, then unlock the
+	 * chunk.
+	 */
+	if (NULL==(chunk=H5F_istore_lock (f, layout, comp, chunk_offset,
+					  FALSE, &idx_hint))) {
+	    HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
+			   "unable to read raw data chunk");
 	}
-	
-	/* Transfer data from the chunk buffer to the application */
 	H5V_hyper_copy(layout->ndims, sub_size, size_m, sub_offset_m,
-		       (void *)buf, layout->dim, offset_wrt_chunk, chunk);
+		       (void*)buf, layout->dim, offset_wrt_chunk, chunk);
+	if (H5F_istore_unlock (f, layout, comp, FALSE, chunk_offset, &idx_hint,
+			       chunk, naccessed)<0) {
+	    HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL,
+			   "unable to unlock raw data chunk");
+	}
 
 	/* Increment indices */
 	for (i=layout->ndims-1, carry=1; i>=0 && carry; --i) {
@@ -795,12 +1329,7 @@ H5F_istore_read(H5F_t *f, const H5O_layout_t *layout,
 	}
 	if (carry) break;
     }
-    ret_value = SUCCEED;
-
-  done:
-    H5MM_xfree(chunk);
-    H5MM_xfree (compressed);
-    FUNC_LEAVE(ret_value);
+    FUNC_LEAVE(SUCCEED);
 }
 
 
@@ -833,12 +1362,12 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
     hsize_t		idx_min[H5O_LAYOUT_NDIMS];
     hsize_t		idx_max[H5O_LAYOUT_NDIMS];
     hsize_t		sub_size[H5O_LAYOUT_NDIMS];
+    hssize_t		chunk_offset[H5O_LAYOUT_NDIMS];
     hssize_t		offset_wrt_chunk[H5O_LAYOUT_NDIMS];
     hssize_t		sub_offset_m[H5O_LAYOUT_NDIMS];
-    hsize_t		chunk_size, nbytes;
-    uint8		*chunk=NULL, *compressed=NULL, *outbuf;
-    H5F_istore_ud1_t	udata;
-    herr_t		ret_value = FAIL;
+    uint8		*chunk=NULL;
+    intn		idx_hint=0;
+    size_t		chunk_size, naccessed;
     
     FUNC_ENTER(H5F_istore_write, FAIL);
 
@@ -855,9 +1384,10 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
      * For now the source must not be a hyperslab.  It must be an entire
      * memory buffer.
      */
-    for (i=0; i<layout->ndims; i++) {
+    for (i=0, chunk_size=1; i<layout->ndims; i++) {
 	offset_m[i] = 0;
 	size_m[i] = size[i];
+	chunk_size *= layout->dim[i];
     }
 
 #ifndef NDEBUG
@@ -871,10 +1401,9 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
 #endif
 
     /*
-     * This is the general case.  We set up multi-dimensional counters
-     * (idx_min, idx_max, and idx_cur) and loop through the chunks copying
-     * each chunk into a temporary buffer, compressing or decompressing, and
-     * then copying it to it's destination.
+     * Set up multi-dimensional counters (idx_min, idx_max, and idx_cur) and
+     * loop through the chunks copying each chunk from the application to the
+     * chunk cache.
      */
     for (i=0; i<layout->ndims; i++) {
 	idx_min[i] = offset_f[i] / layout->dim[i];
@@ -882,102 +1411,46 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
 	idx_cur[i] = idx_min[i];
     }
 
-    /* Allocate buffers */
-    for (i=0, chunk_size=1; i<layout->ndims; i++) {
-	chunk_size *= layout->dim[i];
-    }
-    chunk = H5MM_xmalloc(chunk_size);
-    if (comp && H5Z_NONE!=comp->method) {
-	compressed = H5MM_xmalloc (chunk_size);
-    }
-
-    /* Initialize non-changing part of udata */
-    udata.mesg = *layout;
 
     /* Loop over all chunks */
     while (1) {
-
-	for (i=0; i<layout->ndims; i++) {
+	
+	for (i=0, naccessed=1; i<layout->ndims; i++) {
 	    /* The location and size of the chunk being accessed */
 	    assert (layout->dim[i] < MAX_HSSIZET);
-	    udata.key.offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
+	    chunk_offset[i] = idx_cur[i] * (hssize_t)(layout->dim[i]);
 
 	    /* The offset and size wrt the chunk */
-	    offset_wrt_chunk[i] = MAX(offset_f[i], udata.key.offset[i]) -
-				  udata.key.offset[i];
+	    offset_wrt_chunk[i] = MAX(offset_f[i], chunk_offset[i]) -
+				  chunk_offset[i];
 	    sub_size[i] = MIN((idx_cur[i]+1)*layout->dim[i],
 			      offset_f[i]+size[i]) -
-			  (udata.key.offset[i] + offset_wrt_chunk[i]);
+			  (chunk_offset[i] + offset_wrt_chunk[i]);
+	    naccessed *= sub_size[i];
 	    
 	    /* Offset into mem buffer */
-	    sub_offset_m[i] = udata.key.offset[i] + offset_wrt_chunk[i] +
+	    sub_offset_m[i] = chunk_offset[i] + offset_wrt_chunk[i] +
 			      offset_m[i] - offset_f[i];
 	}
-	
+
 	/*
-	 * If we are writing a partial chunk then load the chunk from disk
-	 * and uncompress it if it exists.
+	 * Lock the chunk, copy from application to chunk, then unlock the
+	 * chunk.
 	 */
-	if (!H5V_vector_zerop_s(layout->ndims, offset_wrt_chunk) ||
-	    !H5V_vector_eq_u(layout->ndims, sub_size, layout->dim)) {
-	    if (H5B_find (f, H5B_ISTORE, &(layout->addr), &udata)>=0 &&
-		H5F_addr_defined (&(udata.addr))) {
-
-		if (compressed && udata.key.nbytes<chunk_size) {
-		    if (H5F_block_read(f, &(udata.addr), udata.key.nbytes,
-				       compressed)<0) {
-			HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL,
-				    "unable to read raw storage chunk");
-		    }
-		    if (chunk_size!=H5Z_uncompress (comp, udata.key.nbytes,
-						    compressed, chunk_size,
-						    chunk)) {
-			HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL,
-				     "unable to uncompress data");
-		    }
-		} else {
-		    assert (chunk_size==udata.key.nbytes);
-		    if (H5F_block_read(f, &(udata.addr), udata.key.nbytes,
-				       chunk)<0) {
-			HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL,
-				    "unable to read raw storage chunk");
-		    }
-		}
-	    } else {
-		HDmemset(chunk, 0, chunk_size);
-	    }
+	if (NULL==(chunk=H5F_istore_lock (f, layout, comp, chunk_offset,
+					  naccessed==chunk_size, &idx_hint))) {
+	    HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+			   "unable to read raw data chunk");
 	}
-	
-	/* Transfer data to the chunk */
 	H5V_hyper_copy(layout->ndims, sub_size,
 		       layout->dim, offset_wrt_chunk, chunk,
 		       size_m, sub_offset_m, buf);
-
-	/* Compress the chunk */
-	if (compressed &&
-	    (nbytes=H5Z_compress (comp, chunk_size, chunk, compressed)) &&
-	    nbytes<chunk_size) {
-	    outbuf = compressed;
-	} else {
-	    outbuf = chunk;
-	    nbytes = chunk_size;
+	if (H5F_istore_unlock (f, layout, comp, TRUE, chunk_offset, &idx_hint,
+			       chunk, naccessed)<0) {
+	    HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
+			   "uanble to unlock raw data chunk");
 	}
 	
-	/*
-	 * Create the chunk it if it doesn't exist, or reallocate the chunk
-	 * if its size changed.  Then write the data into the file.
-	 */
-	H5F_addr_undef(&(udata.addr));
-	udata.key.nbytes = nbytes;
-	if (H5B_insert(f, H5B_ISTORE, &(layout->addr), &udata)<0) {
-	    HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL,
-			 "unable to allocate chunk");
-	}
-	if (H5F_block_write(f, &(udata.addr), nbytes, outbuf) < 0) {
-	    HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
-			"unable to write raw storage chunk");
-	}
-
 	/* Increment indices */
 	for (i=layout->ndims-1, carry=1; i>=0 && carry; --i) {
 	    if (++idx_cur[i]>=idx_max[i]) idx_cur[i] = idx_min[i];
@@ -985,12 +1458,8 @@ H5F_istore_write(H5F_t *f, const H5O_layout_t *layout,
 	}
 	if (carry) break;
     }
-    ret_value = SUCCEED;
 
-  done:
-    H5MM_xfree(chunk);
-    H5MM_xfree (compressed);
-    FUNC_LEAVE(ret_value);
+    FUNC_LEAVE(SUCCEED);
 }
 
 
@@ -1046,6 +1515,61 @@ H5F_istore_create(H5F_t *f, H5O_layout_t *layout /*out */ )
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5F_istore_stats
+ *
+ * Purpose:	Print raw data cache statistics to the stderr stream.  If
+ *		HEADERS is non-zero then print table column headers,
+ *		otherwise assume that the H5AC layer has already printed them.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_istore_stats (H5F_t *f, hbool_t headers)
+{
+    H5F_rdcc_t	*rdcc = &(f->shared->rdcc);
+    double	miss_rate;
+    char	ascii[32];
+    
+    FUNC_ENTER (H5F_istore_stats, FAIL);
+
+    if (headers) {
+	fprintf(stderr, "H5F: raw data cache statistics for file %s\n",
+		f->name);
+	fprintf(stderr, "   %-18s %8s %8s %8s %8s+%-8s\n",
+		"Layer", "Hits", "Misses", "MissRate", "Inits", "Flushes");
+	fprintf(stderr, "   %-18s %8s %8s %8s %8s-%-8s\n",
+		"-----", "----", "------", "--------", "-----", "-------");
+    }
+
+    if (rdcc->nhits>0 || rdcc->nmisses>0) {
+	miss_rate = 100.0 * rdcc->nmisses /
+			(rdcc->nhits + rdcc->nmisses);
+    } else {
+	miss_rate = 0.0;
+    }
+    if (miss_rate > 100) {
+	sprintf(ascii, "%7d%%", (int) (miss_rate + 0.5));
+    } else {
+	sprintf(ascii, "%7.2f%%", miss_rate);
+    }
+    
+    fprintf(stderr, "   %-18s %8u %8u %7s %8d+%-9ld\n",
+	    "raw data chunks", rdcc->nhits, rdcc->nmisses, ascii,
+	    rdcc->ninits, (long)(rdcc->nflushes)-(long)(rdcc->ninits));
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F_istore_debug
  *
  * Purpose:	Debugs a B-tree node for indexed raw data storage.
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index cce26e1..26942ce 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -238,6 +238,9 @@ typedef struct H5F_create_t {
  * File-access property list.
  */
 typedef struct H5F_access_t {
+    intn	mdc_nelmts;	/* Size of meta data cache (nelmts)	*/
+    size_t	rdcc_nbytes;	/* Size of raw data chunk cache	(bytes)	*/
+    double	rdcc_w0;	/* Preempt read chunks first? [0.0..1.0]*/
     H5F_driver_t driver;	/* Low level file driver		*/
     union {
 
@@ -386,6 +389,18 @@ extern const H5F_low_class_t H5F_LOW_SPLIT_g[];	/* Split meta/raw data	*/
 extern const H5F_low_class_t H5F_LOW_MPIO_g[];	/* MPI-IO		*/
 #endif
 
+/* The raw data chunk cache */
+typedef struct H5F_rdcc_t {
+    uintn		ninits;	/* Number of chunk creations		*/
+    uintn		nhits;	/* Number of cache hits			*/
+    uintn		nmisses;/* Number of cache misses		*/
+    uintn		nflushes;/* Number of cache flushes		*/
+    size_t		nbytes;	/* Current cached raw data in bytes	*/
+    intn		nslots;	/* Number of chunk slots allocated	*/
+    intn		nused;	/* Number of chunk slots in use		*/
+    struct H5F_rdcc_ent_t *slot; /* Chunk slots, each points to a chunk	*/
+} H5F_rdcc_t;
+
 /*
  * Define the structure to store the file information for HDF5 files. One of
  * these structures is allocated per file, not per H5Fopen().
@@ -406,6 +421,7 @@ typedef struct H5F_file_t {
     struct H5G_t *root_grp;	/* Open root group			*/
     intn	ncwfs;		/* Num entries on cwfs list		*/
     struct H5HG_heap_t **cwfs;	/* Global heap cache			*/
+    H5F_rdcc_t	rdcc;		/* Raw data chunk cache			*/
 } H5F_file_t;
 
 /*
@@ -494,6 +510,10 @@ herr_t H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
 		      const hssize_t file_offset[], const void *_buf);
 
 /* Functions that operate on indexed storage */
+herr_t H5F_istore_init (H5F_t *f);
+herr_t H5F_istore_flush (H5F_t *f);
+herr_t H5F_istore_dest (H5F_t *f);
+herr_t H5F_istore_stats (H5F_t *f, hbool_t headers);
 herr_t H5F_istore_create(H5F_t *f, struct H5O_layout_t *layout /*in,out*/);
 herr_t H5F_istore_read(H5F_t *f, const struct H5O_layout_t *layout,
 		       const struct H5O_compress_t *comp,
diff --git a/src/H5MM.c b/src/H5MM.c
index 329a4f0..5a02f41 100644
--- a/src/H5MM.c
+++ b/src/H5MM.c
@@ -1,59 +1,61 @@
 /*-------------------------------------------------------------------------
- * Copyright (C) 1997   National Center for Supercomputing Applications.
- *                      All rights reserved.
+ * Copyright (C) 1997	National Center for Supercomputing Applications.
+ *			All rights reserved.
  *
  *-------------------------------------------------------------------------
  *
- * Created:             H5MM.c
- *                      Jul 10 1997
- *                      Robb Matzke <matzke@llnl.gov>
+ * Created:		H5MM.c
+ *			Jul 10 1997
+ *			Robb Matzke <matzke@llnl.gov>
  *
- * Purpose:             Memory management functions.
+ * Purpose:		Memory management functions.
  *
- * Modifications:       
+ * Modifications:	
  *
  *-------------------------------------------------------------------------
  */
 #include <H5private.h>
 #include <H5MMprivate.h>
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5MM_xmalloc
+ * Function:	H5MM_xmalloc
  *
- * Purpose:     Just like malloc(3) except it aborts on an error.
+ * Purpose:	Just like malloc(3) except it aborts on an error.
  *
- * Return:      Success:        Ptr to new memory.
+ * Return:	Success:	Ptr to new memory.
  *
- *              Failure:        abort()
+ *		Failure:	abort()
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-void                   *
+void *
 H5MM_xmalloc(size_t size)
 {
-    void                   *mem = HDmalloc(size);
+    void *mem = HDmalloc(size);
     assert(mem);
     return mem;
 }
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5MM_xcalloc
+ * Function:	H5MM_xcalloc
  *
- * Purpose:     Just like calloc(3) except it aborts on an error.
+ * Purpose:	Just like calloc(3) except it aborts on an error.
  *
- * Return:      Success:        Ptr to memory.
+ * Return:	Success:	Ptr to memory.
  *
- *              Failure:        abort()
+ *		Failure:	abort()
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
@@ -73,64 +75,65 @@ H5MM_xcalloc(intn n, size_t size)
     
     return mem;
 }
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5MM_xrealloc
+ * Function:	H5MM_xrealloc
  *
- * Purpose:     Just like the POSIX version of realloc(3) exept it aborts
- *              on an error.  Specifically, the following calls are
- *              equivalent
+ * Purpose:	Just like the POSIX version of realloc(3) exept it aborts
+ *		on an error.  Specifically, the following calls are
+ *		equivalent
  *
- *              H5MM_xrealloc (NULL, size) <==> H5MM_xmalloc (size)
- *              H5MM_xrealloc (ptr, 0)     <==> H5MM_xfree (ptr)
- *              H5MM_xrealloc (NULL, 0)    <==> NULL
+ *		H5MM_xrealloc (NULL, size) <==> H5MM_xmalloc (size)
+ *		H5MM_xrealloc (ptr, 0)	   <==> H5MM_xfree (ptr)
+ *		H5MM_xrealloc (NULL, 0)	   <==> NULL
  *
- * Return:      Success:        Ptr to new memory or NULL if the memory
- *                              was freed.
+ * Return:	Success:	Ptr to new memory or NULL if the memory
+ *				was freed.
  *
- *              Failure:        abort()
+ *		Failure:	abort()
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-void                   *
+void *
 H5MM_xrealloc(void *mem, size_t size)
 {
     if (!mem) {
-        if (0 == size)
-            return NULL;
-        mem = H5MM_xmalloc(size);
+	if (0 == size) return NULL;
+	mem = H5MM_xmalloc(size);
 
     } else if (0 == size) {
-        mem = H5MM_xfree(mem);
+	mem = H5MM_xfree(mem);
 
     } else {
-        mem = HDrealloc(mem, size);
-        assert(mem);
+	mem = HDrealloc(mem, size);
+	assert(mem);
     }
 
     return mem;
 }
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5MM_strdup
+ * Function:	H5MM_strdup
  *
- * Purpose:     Duplicates a string.  If the string to be duplicated is the
- *              null pointer, then return null.  If the string to be duplicated
- *              is the empty string then return a new empty string.
+ * Purpose:	Duplicates a string.  If the string to be duplicated is the
+ *		null pointer, then return null.	 If the string to be duplicated
+ *		is the empty string then return a new empty string.
  *
- * Return:      Success:        Ptr to a new string (or null if no string).
+ * Return:	Success:	Ptr to a new string (or null if no string).
  *
- *              Failure:        abort()
+ *		Failure:	abort()
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
@@ -139,30 +142,31 @@ H5MM_xrealloc(void *mem, size_t size)
 char *
 H5MM_xstrdup(const char *s)
 {
-    char                   *mem;
+    char	*mem;
 
     if (!s) return NULL;
     mem = H5MM_xmalloc(HDstrlen(s) + 1);
     HDstrcpy(mem, s);
     return mem;
 }
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5MM_xfree
+ * Function:	H5MM_xfree
  *
- * Purpose:     Just like free(3) except null pointers are allowed as
- *              arguments, and the return value (always NULL) can be
- *              assigned to the pointer whose memory was just freed:
+ * Purpose:	Just like free(3) except null pointers are allowed as
+ *		arguments, and the return value (always NULL) can be
+ *		assigned to the pointer whose memory was just freed:
  *
- *                      thing = H5MM_xfree (thing);
+ *			thing = H5MM_xfree (thing);
  *
- * Return:      Success:        NULL
+ * Return:	Success:	NULL
  *
- *              Failure:        never fails
+ *		Failure:	never fails
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
diff --git a/src/H5O.c b/src/H5O.c
index 35dbe79..ce369cf 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -667,6 +667,76 @@ H5O_reset(const H5O_class_t *type, void *native)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5O_free
+ *
+ * Purpose:	Similar to H5O_reset() except it also frees the message
+ *		pointer.
+ *
+ * Return:	Success:	NULL
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5O_free (const H5O_class_t *type, void *mesg)
+{
+    FUNC_ENTER (H5O_free, NULL);
+    
+    if (mesg) {
+	H5O_reset (type, mesg);
+	H5MM_xfree (mesg);
+    }
+
+    FUNC_LEAVE (NULL);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_copy
+ *
+ * Purpose:	Copies a message.  If MESG is is the null pointer then a null
+ *		pointer is returned with no error.
+ *
+ * Return:	Success:	Ptr to the new message
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 21, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5O_copy (const H5O_class_t *type, const void *mesg)
+{
+    void	*ret_value = NULL;
+    
+    FUNC_ENTER (H5O_copy, NULL);
+
+    assert (type);
+    assert (type->copy);
+
+    if (mesg) {
+	if (NULL==(ret_value=(type->copy)(mesg, NULL))) {
+	    HRETURN_ERROR (H5E_OHDR, H5E_CANTINIT, NULL,
+			   "unable to copy object header message");
+	}
+    }
+
+    FUNC_LEAVE (ret_value);
+}
+
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5O_link
  *
  * Purpose:	Adjust the link count for an object header by adding
@@ -1209,9 +1279,7 @@ H5O_remove(H5G_entry_t *ent, const H5O_class_t *type, intn sequence)
 	    /* change message type to nil and zero it */
 	    oh->mesg[i].type = H5O_NULL;
 	    HDmemset(oh->mesg[i].raw, 0, oh->mesg[i].raw_size);
-	    H5O_reset(type, oh->mesg[i].native);
-	    oh->mesg[i].native = H5MM_xfree(oh->mesg[i].native);
-
+	    oh->mesg[i].native = H5O_free (type, oh->mesg[i].native);
 	    oh->mesg[i].dirty = TRUE;
 	    oh->dirty = TRUE;
 	}
@@ -1850,8 +1918,7 @@ H5O_debug(H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
 		(oh->mesg[i].type->debug)(f, mesg, stream, indent+3,
 					  MAX (0, fwidth-3));
 	    }
-	    H5O_reset (oh->mesg[i].type, mesg);
-	    H5MM_xfree (mesg);
+	    H5O_free (oh->mesg[i].type, mesg);
 	    H5MM_xfree (p);
 	}
     }
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index b6e340b..7db9313 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -247,6 +247,8 @@ intn H5O_modify (H5G_entry_t *ent, const H5O_class_t *type, intn overwrite,
 		 uintn flags, const void *mesg);
 herr_t H5O_remove (H5G_entry_t *ent, const H5O_class_t *type, intn sequence);
 herr_t H5O_reset (const H5O_class_t *type, void *native);
+void *H5O_free (const H5O_class_t *type, void *mesg);
+void *H5O_copy (const H5O_class_t *type, const void *mesg);
 herr_t H5O_share (H5F_t *f, const H5O_class_t *type, const void *mesg,
 		  H5HG_t *hobj/*out*/);
 herr_t H5O_debug (H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
diff --git a/src/H5P.c b/src/H5P.c
index 6e8c337..09ed1a6 100644
--- a/src/H5P.c
+++ b/src/H5P.c
@@ -59,7 +59,7 @@ H5P_init_interface(void)
     FUNC_ENTER(H5P_init_interface, FAIL);
 
     /*
-     * Make sure the file creation and file access default templates are
+     * Make sure the file creation and file access default property lists are
      * initialized since this might be done at run-time instead of compile
      * time.
      */
@@ -71,9 +71,9 @@ H5P_init_interface(void)
     assert(H5P_NCLASSES <= H5_TEMPLATE_MAX - H5_TEMPLATE_0);
 
     /*
-     * Initialize the mappings between template classes and atom groups. We
-     * keep the two separate because template classes are publicly visible but
-     * atom groups aren't.
+     * Initialize the mappings between property list classes and atom
+     * groups. We keep the two separate because property list classes are
+     * publicly visible but atom groups aren't.
      */
     for (i = 0; i < H5P_NCLASSES; i++) {
 	status = H5I_init_group((H5I_group_t)(H5_TEMPLATE_0 +i),
@@ -127,20 +127,23 @@ H5P_term_interface(void)
  NAME
     H5Pcreate
  PURPOSE
-    Returns a copy of the default template for some class of templates.
+    Returns a copy of the default property list for some class of property
+ *  lists.
  USAGE
     herr_t H5Pcreate (type)
-	H5P_class_t type;	IN: Template class whose default is desired.
+	H5P_class_t type;	IN: Property list class whose default is
+ *				    desired.
  RETURNS
-    Template ID or FAIL
+    Property list ID or FAIL
  
  ERRORS
-    ARGS      BADVALUE	    Unknown template class. 
-    ATOM      CANTINIT	    Can't register template. 
+    ARGS      BADVALUE	    Unknown property list class. 
+    ATOM      CANTINIT	    Can't register property list. 
     INTERNAL  UNSUPPORTED   Not implemented yet. 
 
  DESCRIPTION
-    Returns a copy of the default template for some class of templates.
+    Returns a copy of the default property list for some class of property
+ *  lists.
 --------------------------------------------------------------------------*/
 hid_t
 H5Pcreate(H5P_class_t type)
@@ -150,7 +153,7 @@ H5Pcreate(H5P_class_t type)
 
     FUNC_ENTER(H5Pcreate, FAIL);
 
-    /* Allocate a new template and initialize it with default values */
+    /* Allocate a new property list and initialize it with default values */
     switch (type) {
     case H5P_FILE_CREATE:
 	tmpl = H5MM_xmalloc(sizeof(H5F_create_t));
@@ -174,13 +177,13 @@ H5Pcreate(H5P_class_t type)
 
     default:
 	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
-		      "unknown template class");
+		      "unknown property list class");
     }
 
-    /* Atomize the new template */
+    /* Atomize the new property list */
     if ((ret_value = H5P_create(type, tmpl)) < 0) {
 	HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
-		      "can't register template");
+		      "unable to register property list");
     }
     FUNC_LEAVE(ret_value);
 }
@@ -188,11 +191,12 @@ H5Pcreate(H5P_class_t type)
 /*-------------------------------------------------------------------------
  * Function:	H5P_create
  *
- * Purpose:	Given a pointer to some template struct, atomize the template
- *		and return its ID. The template memory is not copied, so the
- *		caller should not free it; it will be freed by H5P_release().
+ * Purpose:	Given a pointer to some property list struct, atomize the
+ *		property list and return its ID. The property list memory is
+ *		not copied, so the caller should not free it; it will be
+ *		freed by H5P_release().
  *
- * Return:	Success:	A new template ID.
+ * Return:	Success:	A new property list ID.
  *
  *		Failure:	FAIL
  *
@@ -214,10 +218,10 @@ H5P_create(H5P_class_t type, void *tmpl)
     assert(type >= 0 && type < H5P_NCLASSES);
     assert(tmpl);
 
-    /* Atomize the new template */
+    /* Atomize the new property list */
     if ((ret_value=H5I_register((H5I_group_t)(H5_TEMPLATE_0+type), tmpl)) < 0) {
 	HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
-		      "can't register template");
+		      "unable to register property list");
     }
     
     FUNC_LEAVE(ret_value);
@@ -227,14 +231,14 @@ H5P_create(H5P_class_t type, void *tmpl)
  NAME
     H5Pclose
  PURPOSE
-    Release access to a template object.
+    Release access to a property list object.
  USAGE
     herr_t H5Pclose(oid)
-	hid_t oid;	 IN: Template object to release access to
+	hid_t oid;	 IN: property list object to release access to
  RETURNS
     SUCCEED/FAIL
  DESCRIPTION
-	This function releases access to a template object
+	This function releases access to a property list object
 --------------------------------------------------------------------------*/
 herr_t
 H5Pclose(hid_t tid)
@@ -265,8 +269,8 @@ H5Pclose(hid_t tid)
 /*-------------------------------------------------------------------------
  * Function:	H5P_close
  *
- * Purpose:	Closes a template and frees the memory associated with the
- *		template.
+ * Purpose:	Closes a property list and frees the memory associated with
+ *		the property list.
  *
  * Return:	Success:	SUCCEED
  *
@@ -290,7 +294,7 @@ H5P_close (H5P_class_t type, void *tmpl)
     /* Check args */
     if (!tmpl) HRETURN (SUCCEED);
 
-    /* Some templates may need to do special things */
+    /* Some property lists may need to do special things */
     switch (type) {
     case H5P_FILE_ACCESS:
 	switch (fa_list->driver) {
@@ -340,7 +344,7 @@ H5P_close (H5P_class_t type, void *tmpl)
 		       "unknown property list class");
     }
 
-    /* Free the template struct and return */
+    /* Free the property list struct and return */
     H5MM_xfree(tmpl);
     FUNC_LEAVE(SUCCEED);
 }
@@ -349,9 +353,9 @@ H5P_close (H5P_class_t type, void *tmpl)
 /*-------------------------------------------------------------------------
  * Function:	H5Pget_class
  *
- * Purpose:	Returns the class identifier for a template.
+ * Purpose:	Returns the class identifier for a property list.
  *
- * Return:	Success:	A template class
+ * Return:	Success:	A property list class
  *
  *		Failure:	H5P_NO_CLASS (-1)
  *
@@ -375,7 +379,8 @@ H5Pget_class(hid_t tid)
 	group >= H5_TEMPLATE_MAX ||
 #endif
 	group < H5_TEMPLATE_0) {
-	HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, H5P_NO_CLASS, "not a template");
+	HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, H5P_NO_CLASS,
+		      "not a property list");
     }
     ret_value = (H5P_class_t)(group - H5_TEMPLATE_0);
     FUNC_LEAVE(ret_value);
@@ -419,7 +424,7 @@ H5Pget_version(hid_t tid, int *boot/*out*/, int *freelist/*out*/,
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     /* Get values */
     if (boot) *boot = tmpl->bootblock_ver;
@@ -433,7 +438,8 @@ H5Pget_version(hid_t tid, int *boot/*out*/, int *freelist/*out*/,
 /*-------------------------------------------------------------------------
  * Function:	H5Pset_userblock
  *
- * Purpose:	Sets the userblock size field of a file creation template.
+ * Purpose:	Sets the userblock size field of a file creation property
+ *		list.
  *
  * Return:	Success:	SUCCEED
  *
@@ -458,7 +464,7 @@ H5Pset_userblock(hid_t tid, hsize_t size)
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     for (i=8; i<8*sizeof(hsize_t); i++) {
 	hsize_t p2 = 8==i ? 0 : ((hsize_t)1<<i);
@@ -477,7 +483,8 @@ H5Pset_userblock(hid_t tid, hsize_t size)
 /*-------------------------------------------------------------------------
  * Function:	H5Pget_userblock
  *
- * Purpose:	Queries the size of a user block in a file creation template.
+ * Purpose:	Queries the size of a user block in a file creation property
+ *		list.
  *
  * Return:	Success:	SUCCEED, size returned through SIZE argument.
  *
@@ -501,7 +508,7 @@ H5Pget_userblock(hid_t tid, hsize_t *size)
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     /* Get value */
     if (size) *size = tmpl->userblock_size;
@@ -512,9 +519,9 @@ H5Pget_userblock(hid_t tid, hsize_t *size)
 /*-------------------------------------------------------------------------
  * Function:	H5Pset_sizes
  *
- * Purpose:	Sets file size-of addresses and sizes.	TEMPLATE
- *		should be a file creation template.  A value of zero causes
- *		the property to not change.
+ * Purpose:	Sets file size-of addresses and sizes.	TID should be a file
+ *		creation property list.  A value of zero causes the property
+ *		to not change.
  *
  * Return:	Success:	SUCCEED
  *
@@ -538,7 +545,7 @@ H5Pset_sizes(hid_t tid, size_t sizeof_addr, size_t sizeof_size)
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     if (sizeof_addr) {
 	if (sizeof_addr != 2 && sizeof_addr != 4 &&
@@ -567,8 +574,8 @@ H5Pset_sizes(hid_t tid, size_t sizeof_addr, size_t sizeof_size)
  * Function:	H5Pget_sizes
  *
  * Purpose:	Returns the size of address and size quantities stored in a
- *		file according to a file creation template.  Either (or even
- *		both) SIZEOF_ADDR and SIZEOF_SIZE may be null pointers.
+ *		file according to a file creation property list.  Either (or
+ *		even both) SIZEOF_ADDR and SIZEOF_SIZE may be null pointers.
  *
  * Return:	Success:	SUCCEED, sizes returned through arguments.
  *
@@ -593,7 +600,7 @@ H5Pget_sizes(hid_t tid,
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     /* Get values */
     if (sizeof_addr)
@@ -644,7 +651,7 @@ H5Pset_sym_k(hid_t tid, int ik, int lk)
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     /* Set values */
     if (ik > 0) {
@@ -686,7 +693,7 @@ H5Pget_sym_k(hid_t tid, int *ik /*out */ , int *lk /*out */ )
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     /* Get values */
     if (ik)
@@ -726,7 +733,7 @@ H5Pset_istore_k(hid_t tid, int ik)
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     if (ik <= 0) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
@@ -767,7 +774,7 @@ H5Pget_istore_k(hid_t tid, int *ik /*out */ )
     if (H5P_FILE_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file creation template");
+		      "not a file creation property list");
     }
     /* Get value */
     if (ik)
@@ -803,7 +810,7 @@ H5Pset_layout(hid_t tid, H5D_layout_t layout)
     if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a dataset creation template");
+		      "not a dataset creation property list");
     }
     if (layout < 0 || layout >= H5D_NLAYOUTS) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL,
@@ -818,7 +825,7 @@ H5Pset_layout(hid_t tid, H5D_layout_t layout)
 /*-------------------------------------------------------------------------
  * Function:	H5Pget_layout
  *
- * Purpose:	Retrieves layout type of a dataset creation template.
+ * Purpose:	Retrieves layout type of a dataset creation property list.
  *
  * Return:	Success:	The layout type
  *
@@ -842,7 +849,7 @@ H5Pget_layout(hid_t tid)
     if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, H5D_LAYOUT_ERROR,
-		      "not a dataset creation template");
+		      "not a dataset creation property list");
     }
     FUNC_LEAVE(tmpl->layout);
 }
@@ -880,7 +887,7 @@ H5Pset_chunk(hid_t tid, int ndims, const hsize_t dim[])
     if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a dataset creation template");
+		      "not a dataset creation property list");
     }
     if (ndims <= 0) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL,
@@ -1200,7 +1207,7 @@ H5Pset_stdio (hid_t tid)
     if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
 
     /* Set driver */
@@ -1280,7 +1287,7 @@ H5Pset_sec2 (hid_t tid)
     if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
 
     /* Set driver */
@@ -1364,7 +1371,7 @@ H5Pset_core (hid_t tid, size_t increment)
     if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
     if (increment<1) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
@@ -1458,19 +1465,19 @@ H5Pset_split (hid_t tid, const char *meta_ext, hid_t meta_tid,
     if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
     if (H5P_DEFAULT!=meta_tid &&
 	(H5P_FILE_ACCESS != H5Pget_class(meta_tid) ||
 	 NULL == (meta_tmpl = H5I_object(meta_tid)))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
     if (H5P_DEFAULT!=raw_tid &&
 	(H5P_FILE_ACCESS != H5Pget_class(raw_tid) ||
 	 NULL == (raw_tmpl = H5I_object(raw_tid)))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
 
     /* Set driver */
@@ -1603,7 +1610,7 @@ H5Pset_family (hid_t tid, hsize_t memb_size, hid_t memb_tid)
     if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
     if (memb_size && memb_size<1024) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADRANGE, FAIL,
@@ -1613,7 +1620,7 @@ H5Pset_family (hid_t tid, hsize_t memb_size, hid_t memb_tid)
 	(H5P_FILE_ACCESS != H5Pget_class(memb_tid) ||
 	 NULL == (tmpl = H5I_object(memb_tid)))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
 
     /* Set driver */
@@ -1682,6 +1689,106 @@ H5Pget_family (hid_t tid, hsize_t *memb_size/*out*/, hid_t *memb_tid/*out*/)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Pset_cache
+ *
+ * Purpose:	Set the number of objects in the meta data cache and the
+ *		total number of bytes in the raw data chunk cache.
+ *
+ * 		The RDCC_W0 value should be between 0 and 1 inclusive and
+ *		indicates how much chunks that have been fully read are
+ *		favored for preemption.  A value of zero means fully read
+ *		chunks are treated no differently than other chunks (the
+ *		preemption is strictly LRU) while a value of one means fully
+ *		read chunks are always preempted before other chunks.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, May 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_cache (hid_t tid, int mdc_nelmts, size_t rdcc_nbytes,
+	      double rdcc_w0)
+{
+    H5F_access_t	*fapl = NULL;
+    
+    FUNC_ENTER (H5Pset_cache, FAIL);
+
+    /* Check arguments */
+    if (H5P_FILE_ACCESS!=H5Pget_class (tid) ||
+	NULL==(fapl=H5I_object (tid))) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "not a file access property list");
+    }
+    if (mdc_nelmts<0) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
+		       "meta data cache size must be non-negative");
+    }
+    if (rdcc_w0<0.0 || rdcc_w0>1.0) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
+		       "raw data cache w0 value must be between 0.0 and 1.0 "
+		       "inclusive");
+    }
+
+    /* Set sizes */
+    fapl->mdc_nelmts = mdc_nelmts;
+    fapl->rdcc_nbytes = rdcc_nbytes;
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pget_cache
+ *
+ * Purpose:	Retrieves the maximum possible number of elements in the meta
+ *		data cache and the maximum possible number of bytes in the
+ *		raw data chunk cache.  Any (or all) arguments may be null
+ *		pointers in which case the corresponding datum is not
+ *		returned.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, May 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_cache (hid_t tid, int *mdc_nelmts, size_t *rdcc_nbytes,
+	      double *rdcc_w0)
+{
+    H5F_access_t	*fapl = NULL;
+    
+    FUNC_ENTER (H5Pget_cache, FAIL);
+
+    /* Check arguments */
+    if (H5P_FILE_ACCESS!=H5Pget_class (tid) ||
+	NULL==(fapl=H5I_object (tid))) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "not a file access property list");
+    }
+
+    /* Get sizes */
+    if (mdc_nelmts) *mdc_nelmts = fapl->mdc_nelmts;
+    if (rdcc_nbytes) *rdcc_nbytes = fapl->rdcc_nbytes;
+    if (rdcc_w0) *rdcc_w0 = fapl->rdcc_w0;
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Pset_buffer
  *
  * Purpose:	Given a dataset transfer property list, set the maximum size
@@ -1889,7 +1996,7 @@ H5Pset_compression (hid_t plist_id, H5Z_method_t method, unsigned int flags,
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset creation property list");
     }
-    if (method<0 || method>H5Z_MAXVAL) {
+    if (method<0 || method>H5Z_USERDEF_MAX) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
 		       "invalid compression method");
     }
@@ -2054,27 +2161,28 @@ H5Pget_deflate (hid_t plist_id)
  * Signature:	herr_t H5Pset_mpi(hid_t tid, MPI_Comm comm, MPI_Info info)
  *
  * Purpose:	Store the access mode for MPIO call and the user supplied
- *		communicator and info in the access template which can then
- *		be used to open file.  This function is available only in the
- *		parallel HDF5 library and is not a collective function.
+ *		communicator and info in the access property list which can
+ *		then be used to open file.  This function is available only
+ *		in the parallel HDF5 library and is not a collective
+ *		function.
  *
  * Parameters:
  *		hid_t tid 
- *		    ID of template to modify 
+ *		    ID of property list to modify 
  *		MPI_Comm comm 
  *		    MPI communicator to be used for file open as defined in
  *		    MPI_FILE_OPEN of MPI-2.  This function  does not make a
  *		    duplicated communicator. Any modification to comm after
  *		    this function call returns may have undetermined effect
- *		    to the access template.  Users should call this function
- *		    again to setup the template.
+ *		    to the access property list.  Users should call this
+ *		    function again to setup the property list.
  *		MPI_Info info 
  *		    MPI info object to be used for file open as defined in
  *		    MPI_FILE_OPEN of MPI-2.  This function  does not make a
  *		    duplicated info. Any modification to info after
  *		    this function call returns may have undetermined effect
- *		    to the access template.  Users should call this function
- *		    again to setup the template.
+ *		    to the access property list.  Users should call this
+ *		    function again to setup the property list.
  *	     
  * Return:	Success:	SUCCEED
  *
@@ -2086,11 +2194,11 @@ H5Pget_deflate (hid_t plist_id)
  * Modifications:
  *
  *	Robb Matzke, 18 Feb 1998
- *	Check all arguments before the template is updated so we don't leave
- *	the template in a bad state if something goes wrong.  Also, the
- *	template data type changed to allow more generality so all the
- *	mpi-related stuff is in the `u.mpi' member.  The `access_mode' will
- *	contain only mpi-related flags defined in H5Fpublic.h.
+ *	Check all arguments before the property list is updated so we don't
+ *	leave the property list in a bad state if something goes wrong.  Also,
+ *	the property list data type changed to allow more generality so all
+ *	the mpi-related stuff is in the `u.mpi' member.  The `access_mode'
+ *	will contain only mpi-related flags defined in H5Fpublic.h.
  *
  *	Albert Cheng, Apr 16, 1998
  *	Removed the access_mode argument.  The access_mode is changed
@@ -2112,7 +2220,7 @@ H5Pset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info)
     if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-		      "not a file access template");
+		      "not a file access property list");
     }
     
 #ifdef LATER
@@ -2286,24 +2394,24 @@ H5Pget_xfer (hid_t tid, H5D_transfer_t *data_xfer_mode)
  NAME
     H5Pcopy
  PURPOSE
-    Copy a template
+    Copy a property list
  USAGE
     hid_t H5P_copy(tid)
-	hid_t tid;	  IN: Template object to copy
+	hid_t tid;	  IN: property list object to copy
  RETURNS
-    Returns template ID (atom) on success, FAIL on failure
+    Returns property list ID (atom) on success, FAIL on failure
 
  ERRORS
-    ARGS      BADRANGE	    Unknown template class. 
-    ATOM      BADATOM	    Can't unatomize template. 
-    ATOM      CANTREGISTER  Register the atom for the new template. 
+    ARGS      BADRANGE	    Unknown property list class. 
+    ATOM      BADATOM	    Can't unatomize property list. 
+    ATOM      CANTREGISTER  Register the atom for the new property list. 
     INTERNAL  UNSUPPORTED   Dataset transfer properties are not implemented
 			    yet. 
     INTERNAL  UNSUPPORTED   File access properties are not implemented yet. 
 
  DESCRIPTION
-    This function creates a new copy of a template with all the same parameter
-    settings.
+ * This function creates a new copy of a property list with all the same
+ * parameter settings.
 --------------------------------------------------------------------------*/
 hid_t
 H5Pcopy(hid_t tid)
@@ -2321,19 +2429,19 @@ H5Pcopy(hid_t tid)
 	(type = H5Pget_class(tid)) < 0 ||
 	(group = H5I_group(tid)) < 0) {
 	HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, FAIL,
-		      "can't unatomize template");
+		      "unable to unatomize property list");
     }
 
     /* Copy it */
     if (NULL==(new_tmpl=H5P_copy (type, tmpl))) {
 	HRETURN_ERROR (H5E_INTERNAL, H5E_CANTINIT, FAIL,
-		       "unable to copy template");
+		       "unable to copy property list");
     }
 
-    /* Register the atom for the new template */
+    /* Register the atom for the new property list */
     if ((ret_value = H5I_register(group, new_tmpl)) < 0) {
 	HRETURN_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL,
-		      "unable to atomize template pointer");
+		      "unable to atomize property list pointer");
     }
     FUNC_LEAVE(ret_value);
 }
@@ -2341,10 +2449,10 @@ H5Pcopy(hid_t tid)
 /*-------------------------------------------------------------------------
  * Function:	H5P_copy
  *
- * Purpose:	Creates a new template and initializes it with some other
- *		template.
+ * Purpose:	Creates a new property list and initializes it with some
+ *		other property list.
  *
- * Return:	Success:	Ptr to new template
+ * Return:	Success:	Ptr to new property list
  *
  *		Failure:	NULL
  *
@@ -2368,7 +2476,7 @@ H5P_copy (H5P_class_t type, const void *src)
     
     FUNC_ENTER (H5P_copy, NULL);
     
-    /* How big is the template */
+    /* How big is the property list */
     switch (type) {
     case H5P_FILE_CREATE:
 	size = sizeof(H5F_create_t);
@@ -2388,10 +2496,10 @@ H5P_copy (H5P_class_t type, const void *src)
 
     default:
 	HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, NULL,
-		      "unknown template class");
+		      "unknown property list class");
     }
 
-    /* Create the new template */
+    /* Create the new property list */
     dst = H5MM_xmalloc(size);
     HDmemcpy(dst, src, size);
 
@@ -2446,7 +2554,7 @@ H5P_copy (H5P_class_t type, const void *src)
 
     default:
 	HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, NULL,
-		      "unknown template class");
+		      "unknown property list class");
     }
 
     FUNC_LEAVE (dst);
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index e9717d1..9a3cda2 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -96,6 +96,10 @@ H5Z_method_t H5Pget_compression (hid_t plist_id, unsigned int *flags/*out*/,
 				 void *client_data/*out*/);
 herr_t H5Pset_deflate (hid_t plist_id, int level);
 int H5Pget_deflate (hid_t plist_id);
+herr_t H5Pset_cache (hid_t plist_id, int mdc_nelmts, size_t rdcc_nbytes,
+		     double rdcc_w0);
+herr_t H5Pget_cache (hid_t plist_id, int *mdc_nelmts, size_t *rdcc_nbytes,
+		     double *rdcc_w0);
 
 #ifdef HAVE_PARALLEL
 herr_t H5Pset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info);
diff --git a/src/H5Z.c b/src/H5Z.c
index 8a28f54..227d7d8 100644
--- a/src/H5Z.c
+++ b/src/H5Z.c
@@ -50,7 +50,7 @@ typedef struct H5Z_class_t {
     } uncomp;
 #endif
 } H5Z_class_t;
-static H5Z_class_t	H5Z_g[H5Z_MAXVAL+1];
+static H5Z_class_t	H5Z_g[H5Z_USERDEF_MAX+1];
 
 /* Compression and uncompression methods */
 static size_t H5Z_zlib_c (unsigned int flags, size_t __unused__ cd_size,
@@ -114,21 +114,21 @@ H5Z_term_interface (void)
     int		i, nprint=0;
     char	name[16];
 
-    for (i=0; i<=H5Z_MAXVAL; i++) {
+    for (i=0; i<=H5Z_USERDEF_MAX; i++) {
 	if (H5Z_g[i].comp.nbytes || H5Z_g[i].uncomp.nbytes) {
 	    if (0==nprint++) {
 		HDfprintf (stderr, "H5Z: compression statistics accumulated "
 			   "over life of library:\n");
-		HDfprintf (stderr, "   %-10s   %8s %8s %8s %8s %8s %8s %9s\n",
+		HDfprintf (stderr, "   %-10s   %10s %7s %7s %8s %8s %8s %9s\n",
 			   "Method", "Total", "Overrun", "Errors", "User",
 			   "System", "Elapsed", "Bandwidth");
-		HDfprintf (stderr, "   %-10s   %8s %8s %8s %8s %8s %8s %9s\n",
+		HDfprintf (stderr, "   %-10s   %10s %7s %7s %8s %8s %8s %9s\n",
 			   "------", "-----", "-------", "------", "----",
 			   "------", "-------", "---------");
 	    }
 	    sprintf (name, "%s-c", H5Z_g[i].name);
 	    HDfprintf (stderr,
-		       "   %-12s %8Hd %8Hd %8Hd %8.2f %8.2f %8.2f ",
+		       "   %-12s %10Hd %7Hd %7Hd %8.2f %8.2f %8.2f ",
 		       name,
 		       H5Z_g[i].comp.nbytes,
 		       H5Z_g[i].comp.over,
@@ -145,7 +145,7 @@ H5Z_term_interface (void)
 	    
 	    sprintf (name, "%s-u", H5Z_g[i].name);
 	    HDfprintf (stderr,
-		       "   %-12s %8Hd %8Hd %8Hd %8.2f %8.2f %8.2f ",
+		       "   %-12s %10Hd %7Hd %7Hd %8.2f %8.2f %8.2f ",
 		       name,
 		       H5Z_g[i].uncomp.nbytes,
 		       H5Z_g[i].uncomp.over,
@@ -198,7 +198,7 @@ H5Zregister (H5Z_method_t method, const char *name, H5Z_func_t cfunc,
     FUNC_ENTER (H5Zregister, FAIL);
 
     /* Check args */
-    if (method<0 || method>H5Z_MAXVAL) {
+    if (method<0 || method>H5Z_USERDEF_MAX) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
 		       "invalid data compression method number");
     }
@@ -381,7 +381,7 @@ H5Z_register (H5Z_method_t method, const char *name, H5Z_func_t cfunc,
 {
     FUNC_ENTER (H5Z_register, FAIL);
 
-    assert (method>=0 && method<=H5Z_MAXVAL);
+    assert (method>=0 && method<=H5Z_USERDEF_MAX);
     H5MM_xfree (H5Z_g[method].name);
     H5Z_g[method].name = H5MM_xstrdup (name);
     H5Z_g[method].compress = cfunc;
diff --git a/src/H5Zpublic.h b/src/H5Zpublic.h
index daebf89..2ce1326 100644
--- a/src/H5Zpublic.h
+++ b/src/H5Zpublic.h
@@ -13,24 +13,25 @@
  * 15 are defined by the library.  Methods 16-255 are user-defined.
  */
 typedef int H5Z_method_t;
-#define H5Z_NONE	0	/*no compression, must be zero	     */
-#define H5Z_DEFLATE	1	/*deflation like gzip		     */
-#define H5Z_RES_2	2	/*reserved for internal use	     */
-#define H5Z_RES_3	3	/*reserved for internal use	     */
-#define H5Z_RES_4	4	/*reserved for internal use	     */
-#define H5Z_RES_5	5	/*reserved for internal use	     */
-#define H5Z_RES_6	6	/*reserved for internal use	     */
-#define H5Z_RES_7	7	/*reserved for internal use	     */
-#define H5Z_RES_8	8	/*reserved for internal use	     */
-#define H5Z_RES_9	9	/*reserved for internal use	     */
-#define H5Z_RES_10	10	/*reserved for internal use	     */
-#define H5Z_RES_11	11	/*reserved for internal use	     */
-#define H5Z_RES_12	12	/*reserved for internal use	     */
-#define H5Z_RES_13	13	/*reserved for internal use	     */
-#define H5Z_RES_14	14	/*reserved for internal use	     */
-#define H5Z_RES_15	15	/*reserved for internal use	     */
+#define H5Z_NONE	0	/*no compression, must be zero	    	*/
+#define H5Z_DEFLATE	1	/*deflation like gzip		     	*/
+#define H5Z_RES_2	2	/*reserved for internal use	     	*/
+#define H5Z_RES_3	3	/*reserved for internal use	     	*/
+#define H5Z_RES_4	4	/*reserved for internal use	     	*/
+#define H5Z_RES_5	5	/*reserved for internal use	     	*/
+#define H5Z_RES_6	6	/*reserved for internal use	     	*/
+#define H5Z_RES_7	7	/*reserved for internal use	     	*/
+#define H5Z_RES_8	8	/*reserved for internal use	     	*/
+#define H5Z_RES_9	9	/*reserved for internal use	     	*/
+#define H5Z_RES_10	10	/*reserved for internal use	     	*/
+#define H5Z_RES_11	11	/*reserved for internal use	     	*/
+#define H5Z_RES_12	12	/*reserved for internal use	     	*/
+#define H5Z_RES_13	13	/*reserved for internal use	     	*/
+#define H5Z_RES_14	14	/*reserved for internal use	     	*/
+#define H5Z_RES_15	15	/*reserved for internal use	     	*/
 /* user-defined 16-255 */
-#define H5Z_MAXVAL	255	/*maximum compression method ID	     */
+#define H5Z_USERDEF_MIN	16	/*first user-defined method		*/
+#define H5Z_USERDEF_MAX	255	/*last user-defined method		*/
 
 /*
  * A compression function takes some configuration data which comes from the
diff --git a/src/Makefile.in b/src/Makefile.in
index 0f7db53..1cffe5a 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -18,10 +18,10 @@ PARALLEL_SRC=H5Fmpio.c
 
 LIB_SRC=H5.c H5A.c H5AC.c H5B.c H5D.c H5E.c H5F.c H5Farray.c H5Fcore.c \
     H5Ffamily.c H5Fistore.c H5Flow.c H5Fsec2.c H5Fsplit.c H5Fstdio.c H5G.c \
-    H5Gent.c H5Gnode.c H5Gstab.c H5HG.c H5HL.c H5I.c H5MF.c H5MM.c \
-    H5O.c H5Oattr.c H5Ocomp.c H5Ocont.c H5Odtype.c H5Oefl.c H5Olayout.c \
-    H5Oname.c H5Onull.c H5Osdspace.c H5Oshared.c H5Ostab.c H5P.c H5S.c \
-    H5Ssimp.c H5T.c H5Tconv.c H5Tinit.c H5V.c H5Z.c @PARALLEL_SRC@
+    H5Gent.c H5Gnode.c H5Gstab.c H5HG.c H5HL.c H5I.c H5MF.c H5MM.c H5O.c \
+    H5Oattr.c H5Ocomp.c H5Ocont.c H5Odtype.c H5Oefl.c H5Olayout.c H5Oname.c \
+    H5Onull.c H5Osdspace.c H5Oshared.c H5Ostab.c H5P.c H5S.c H5Ssimp.c H5T.c \
+    H5Tconv.c H5Tinit.c H5V.c H5Z.c @PARALLEL_SRC@
 
 LIB_OBJ=$(LIB_SRC:.c=.o)
 
diff --git a/test/.distdep b/test/.distdep
index bb1cb84..f2e23cd 100644
--- a/test/.distdep
+++ b/test/.distdep
@@ -403,3 +403,25 @@ links.o: \
    ../src/H5MMpublic.h \
    ../src/H5Opublic.h \
    ../src/H5Ppublic.h
+chunk.o: \
+   chunk.c \
+   ../src/hdf5.h \
+   ../src/H5public.h \
+   ../src/H5config.h \
+   ../src/H5Ipublic.h \
+   ../src/H5Apublic.h \
+   ../src/H5ACpublic.h \
+   ../src/H5Bpublic.h \
+   ../src/H5Dpublic.h \
+   ../src/H5Epublic.h \
+   ../src/H5Fpublic.h \
+   ../src/H5Gpublic.h \
+   ../src/H5HGpublic.h \
+   ../src/H5HLpublic.h \
+   ../src/H5MFpublic.h \
+   ../src/H5MMpublic.h \
+   ../src/H5Opublic.h \
+   ../src/H5Ppublic.h \
+   ../src/H5Zpublic.h \
+   ../src/H5Spublic.h \
+   ../src/H5Tpublic.h
diff --git a/test/Makefile.in b/test/Makefile.in
index aab4e6c..37a01ac 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -12,10 +12,10 @@ CPPFLAGS=-I. -I../src @CPPFLAGS@
 # These are our main targets. They should be listed in the order to be
 # executed, generally most specific tests to least specific tests.
 PROGS=testhdf5 gheap hyperslab istore dtypes dsets cmpd_dset extend external \
-      shtype iopipe big links
+      shtype iopipe big links chunk
 TESTS=testhdf5 gheap hyperslab istore dtypes dsets cmpd_dset extend external \
       shtype links
-TIMINGS=iopipe
+TIMINGS=iopipe chunk
 
 # Temporary files
 MOSTLYCLEAN=cmpd_dset.h5 dataset.h5 extend.h5 istore.h5 tfile1.h5 tfile2.h5  \
@@ -24,15 +24,15 @@ MOSTLYCLEAN=cmpd_dset.h5 dataset.h5 extend.h5 istore.h5 tfile1.h5 tfile2.h5  \
 	    extern_2.raw extern_2b.raw extern_3.raw extern_3b.raw            \
 	    extern_4.raw extern_4b.raw iopipe.raw iopipe.h5 gheap0.h5        \
 	    gheap1.h5 gheap2.h5 gheap3.h5 gheap4.h5 shtype0.h5 shtype1.h5    \
-	    shtype2a.h5 shtype2b.h5 shtype3.h5 links.h5
+	    shtype2a.h5 shtype2b.h5 shtype3.h5 links.h5 chunk.h5
 
 # Source and object files for programs...  The PROG_SRC list contains all the
 # source files and is used for things like dependencies, archiving, etc.  The
 # other source lists are for the individual tests, the files of which may
 # overlap with other tests.
 PROG_SRC=testhdf5.c tattr.c tfile.c theap.c tmeta.c tohdr.c tstab.c th5s.c \
-    dtypes.c hyperslab.c istore.c dsets.c cmpd_dset.c extend.c external.c \
-	iopipe.c gheap.c shtype.c big.c links.c
+	dtypes.c hyperslab.c istore.c dsets.c cmpd_dset.c extend.c external.c \
+	iopipe.c gheap.c shtype.c big.c links.c chunk.c
 PROG_OBJ=$(PROG_SRC:.c=.o)
 
 TESTHDF5_SRC=testhdf5.c tattr.c tfile.c theap.c tmeta.c tohdr.c tstab.c th5s.c
@@ -77,6 +77,9 @@ BIG_OBJ=$(BIG_SRC:.c=.o)
 LINKS_SRC=links.c
 LINKS_OBJ=$(LINKS_SRC:.c=.o)
 
+CHUNK_SRC=chunk.c
+CHUNK_OBJ=$(CHUNK_SRC:.c=.o)
+
 # Private header files (not to be installed)...
 PRIVATE_HDR=testhdf5.h
 
@@ -133,4 +136,7 @@ big: $(BIG_OBJ) ../src/libhdf5.a
 links: $(LINKS_OBJ) ../src/libhdf5.a
 	$(CC) $(CFLAGS) -o $@ $(LINKS_OBJ) ../src/libhdf5.a $(LIBS)
 
+chunk: $(CHUNK_OBJ) ../src/libhdf5.a
+	$(CC) $(CFLAGS) -o $@ $(CHUNK_OBJ) ../src/libhdf5.a $(LIBS)
+
 @CONCLUDE@
diff --git a/test/big.c b/test/big.c
index 226eeb0..c45690a 100644
--- a/test/big.c
+++ b/test/big.c
@@ -68,7 +68,7 @@ writer (int wrt_n)
      */
     plist = H5Pcreate (H5P_FILE_ACCESS);
     H5Pset_family (plist, FAMILY_SIZE, H5P_DEFAULT);
-    file = H5Fcreate (FNAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist);
+    file = H5Fcreate (FNAME, H5F_ACC_TRUNC|H5F_ACC_DEBUG, H5P_DEFAULT, plist);
     H5Pclose (plist);
 
     /* Create simple data spaces according to the size specified above. */
@@ -133,7 +133,7 @@ reader (const char *script_name)
     /* Open HDF5 file */
     plist = H5Pcreate (H5P_FILE_ACCESS);
     H5Pset_family (plist, FAMILY_SIZE, H5P_DEFAULT);
-    file = H5Fopen (FNAME, H5F_ACC_RDONLY, plist);
+    file = H5Fopen (FNAME, H5F_ACC_RDONLY|H5F_ACC_DEBUG, plist);
     H5Pclose (plist);
 
     /* Open the dataset */
diff --git a/test/chunk.c b/test/chunk.c
new file mode 100644
index 0000000..35b5b85
--- /dev/null
+++ b/test/chunk.c
@@ -0,0 +1,521 @@
+/*
+ * Copyright (C) 1998 NCSA
+ *                    All rights reserved.
+ *
+ * Programmer:  Robb Matzke <robb@arborea.spizella.com>
+ *              Thursday, May 14, 1998
+ *
+ * Purpose:	Checks the effect of various I/O request sizes and raw data
+ *		cache sizes.  Performance depends on the amount of data read
+ *		from disk, and we use a trick to get that number: a
+ *		compress/uncompress pair that counts the amount of data read.
+ *		Since the data itself is not important, the compression just
+ *		removes a byte and uncompression adds some byte of arbitrary
+ *		value.  The change in size is necessary or the library will
+ *		not store the data as compressed and thus not call the
+ *		uncompression method.
+ */
+#include <assert.h>
+#include <hdf5.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <H5config.h>
+#ifndef HAVE_ATTRIBUTE
+#   undef __attribute__
+#   define __attribute__(X) /*void*/
+#   define __unused__ /*void*/
+#else
+#   define __unused__ __attribute__((unused))
+#endif
+
+#define FILE_NAME	"chunk.h5"
+#define LINESPOINTS	"lines"
+#define CH_SIZE		100		/*squared in terms of bytes    	*/
+#define DS_SIZE		20		/*squared in terms of chunks	*/
+#define ZMETHNO		H5Z_USERDEF_MIN
+#define READ		0
+#define WRITE		1
+#define MIN(X,Y)	((X)<(Y)?(X):(Y))
+#define MAX(X,Y)	((X)>(Y)?(X):(Y))
+#define SQUARE(X)	((X)*(X))
+
+/* The row-major test */
+#define RM_CACHE_STRT	25
+#define RM_CACHE_END	25
+#define RM_CACHE_DELT	5
+#define RM_START	0.20
+#define RM_END	        5.00
+#define RM_DELTA	0.0025
+
+/* Diagonal test */
+#define DIAG_CACHE_STRT	25
+#define DIAG_CACHE_END	25
+#define DIAG_CACHE_DELT	5
+#define DIAG_START	0.20
+#define DIAG_END	5.00
+#define DIAG_DELTA	0.0025
+
+static size_t	nio_g;
+static hid_t	fapl_g = -1;
+
+
+/*-------------------------------------------------------------------------
+ * Function:	count_c
+ *
+ * Purpose:	A bogus compression method that just removes the last byte.
+ *
+ * Return:	Success:	src_nbytes-1
+ *
+ *		Failure:	never fails
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 14, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static size_t
+count_c (unsigned int __unused__ flags, size_t __unused__ cd_size,
+	 const void __unused__ *client_data, size_t src_nbytes,
+	 const void *src, size_t __unused__ dst_nbytes, void *dst/*out*/)
+{
+    memcpy (dst, src, src_nbytes-1);
+    nio_g += src_nbytes;
+    return src_nbytes-1;
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	count_u
+ *
+ * Purpose:	A bogus unompress method that just adds a zero to the end.
+ *
+ * Return:	Success:	src_nbytes+1
+ *
+ *		Failure:	never fails
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 14, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static size_t
+count_u (unsigned int __unused__ flags, size_t __unused__ cd_size,
+	 const void __unused__ *client_data, size_t src_nbytes,
+	 const void *src, size_t __unused__ dst_nbytes, void *dst/*out*/)
+{
+    memcpy (dst, src, src_nbytes);
+    ((char*)dst)[src_nbytes] = 0;
+    nio_g += src_nbytes+1;
+    return src_nbytes+1;
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	create_dataset
+ *
+ * Purpose:	Creates a square dataset with square chunks, registers a
+ *		stupid compress/uncompress pair for counting I/O, and
+ *		initializes the dataset.  The chunk size is in bytes, the
+ *		dataset size is in terms of chunks.
+ *
+ * Return:	void
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 14, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void
+create_dataset (void)
+{
+    hid_t	file, space, dcpl, dset;
+    hsize_t	size[2];
+    char	*buf;
+
+    /* The file */
+    file = H5Fcreate (FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_g);
+
+    /* The data space */
+    size[0] = size[1] = DS_SIZE * CH_SIZE;
+    space = H5Screate_simple (2, size, size);
+
+    /* The storage layout and compression */
+    dcpl = H5Pcreate (H5P_DATASET_CREATE);
+    size[0] = size[1] = CH_SIZE;
+    H5Pset_chunk (dcpl, 2, size);
+    H5Zregister (ZMETHNO, "counter", count_c, count_u);
+    H5Pset_compression (dcpl, ZMETHNO, 0, 0, NULL);
+        
+    /* The dataset */
+    dset = H5Dcreate (file, "dset", H5T_NATIVE_CHAR, space, dcpl);
+    assert (dset>=0);
+
+    /* The data */
+    buf = calloc (1, SQUARE (DS_SIZE*CH_SIZE));
+    H5Dwrite (dset, H5T_NATIVE_CHAR, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf);
+    free (buf);
+
+    /* Close */
+    H5Dclose (dset);
+    H5Sclose (space);
+    H5Pclose (dcpl);
+    H5Fclose (file);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	test_rowmaj
+ *
+ * Purpose:	Reads the entire dataset using the specified size-squared
+ *		I/O requests in row major order.
+ *
+ * Return:	Efficiency: data requested divided by data actually read.
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 14, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static double
+test_rowmaj (int op, hsize_t cache_size, hsize_t io_size)
+{
+    hid_t	file, dset, mem_space, file_space;
+    char	*buf = calloc (1, SQUARE(io_size));
+    hsize_t	i, j, hs_size[2];
+    hssize_t	hs_offset[2];
+    int		mdc_nelmts;
+    double	w0;
+
+    H5Pget_cache (fapl_g, &mdc_nelmts, NULL, &w0);
+    H5Pset_cache (fapl_g, mdc_nelmts, cache_size*SQUARE (CH_SIZE), w0);
+    file = H5Fopen (FILE_NAME, H5F_ACC_RDWR, fapl_g);
+    dset = H5Dopen (file, "dset");
+    file_space = H5Dget_space (dset);
+    nio_g = 0;
+
+    for (i=0; i<CH_SIZE*DS_SIZE; i+=io_size) {
+#if 0
+	fprintf (stderr, "%5d\b\b\b\b\b", (int)i);
+	fflush (stderr);
+#endif
+	for (j=0; j<CH_SIZE*DS_SIZE; j+=io_size) {
+	    hs_offset[0] = i;
+	    hs_size[0] = MIN (io_size, CH_SIZE*DS_SIZE-i);
+	    hs_offset[1] = j;
+	    hs_size[1] = MIN (io_size, CH_SIZE*DS_SIZE-j);
+	    mem_space = H5Screate_simple (2, hs_size, hs_size);
+	    H5Sset_hyperslab (file_space, hs_offset, hs_size, NULL);
+
+	    if (READ==op) {
+		H5Dread (dset, H5T_NATIVE_CHAR, mem_space, file_space,
+			 H5P_DEFAULT, buf);
+	    } else {
+		H5Dwrite (dset, H5T_NATIVE_CHAR, mem_space, file_space,
+			  H5P_DEFAULT, buf);
+	    }
+	    H5Sclose (mem_space);
+	}
+    }
+    
+    free (buf); 
+    H5Sclose (file_space);
+    H5Dclose (dset);
+    H5Fclose (file);
+
+    return (double)SQUARE(CH_SIZE*DS_SIZE)/nio_g;
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	test_diag
+ *
+ * Purpose:	Reads windows diagonally across the dataset.  Each window is
+ *		offset from the previous window by OFFSET in the x and y
+ *		directions.  The reading ends after the (k,k) value is read
+ *		where k is the maximum index in the dataset.
+ *
+ * Return:	Efficiency.
+ *
+ * Programmer:	Robb Matzke
+ *              Friday, May 15, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static double
+test_diag (int op, hsize_t cache_size, hsize_t io_size, hsize_t offset)
+{
+    hid_t	file, dset, mem_space, file_space;
+    hsize_t	i, hs_size[2], nio=0;
+    hssize_t	hs_offset[2];
+    char	*buf = calloc (1, SQUARE (io_size));
+    int		mdc_nelmts;
+    double	w0;
+
+    H5Pget_cache (fapl_g, &mdc_nelmts, NULL, &w0);
+    H5Pset_cache (fapl_g, mdc_nelmts, cache_size*SQUARE (CH_SIZE), w0);
+    file = H5Fopen (FILE_NAME, H5F_ACC_RDWR, fapl_g);
+    dset = H5Dopen (file, "dset");
+    file_space = H5Dget_space (dset);
+    nio_g = 0;
+    
+    for (i=0, hs_size[0]=io_size; hs_size[0]==io_size; i+=offset) {
+	hs_offset[0] = hs_offset[1] = i;
+	hs_size[0] = hs_size[1] = MIN (io_size, CH_SIZE*DS_SIZE-i);
+	mem_space = H5Screate_simple (2, hs_size, hs_size);
+	H5Sset_hyperslab (file_space, hs_offset, hs_size, NULL);
+	if (READ==op) {
+	    H5Dread (dset, H5T_NATIVE_CHAR, mem_space, file_space,
+		     H5P_DEFAULT, buf);
+	} else {
+	    H5Dwrite (dset, H5T_NATIVE_CHAR, mem_space, file_space,
+		      H5P_DEFAULT, buf);
+	}
+	H5Sclose (mem_space);
+	nio += hs_size[0]*hs_size[1];
+	if (i>0) nio -= SQUARE (io_size-offset);
+    }
+
+    free (buf);
+    H5Sclose (file_space);
+    H5Dclose (dset);
+    H5Fclose (file);
+
+    return (double)nio/nio_g;
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	main
+ *
+ * Purpose:	See file prologue.
+ *
+ * Return:	Success:	
+ *
+ *		Failure:	
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, May 14, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+main (void)
+{
+    hsize_t	io_size;
+    double	effic, io_percent;
+    FILE	*f, *d;
+    int		cache_size;
+    double	w0;
+
+    /*
+     * Create a global file access property list.
+     */
+    fapl_g = H5Pcreate (H5P_FILE_ACCESS);
+    H5Pget_cache (fapl_g, NULL, NULL, &w0);
+
+    /* Create the file */
+    create_dataset ();
+    f = fopen ("x-gnuplot", "w");
+
+
+#if 1
+    /*
+     * Test row-major reading of the dataset with various sizes of request
+     * windows.
+     */
+    if (RM_CACHE_STRT==RM_CACHE_END) {
+	fprintf (f, "set yrange [0:1.2]\n");
+	fprintf (f, "set ytics 0, 0.1, 1\n");
+	fprintf (f, "set xlabel \"%s\"\n",
+		 "Request size as a fraction of chunk size");
+	fprintf (f, "set ylabel \"Efficiency\"\n");
+	fprintf (f, "set title \"Cache %d chunks, w0=%g, "
+		 "Size=(total=%d, chunk=%d)\"\n",
+		 RM_CACHE_STRT, w0, DS_SIZE*CH_SIZE, CH_SIZE);
+    } else {
+	fprintf (f, "set autoscale\n");
+	fprintf (f, "set hidden3d\n");
+    }
+
+    fprintf (f, "set terminal postscript\nset output \"x-rowmaj-rd.ps\"\n");
+    fprintf (f, "%s \"x-rowmaj-rd.dat\" title \"RowMaj-Read\" with %s\n",
+	     RM_CACHE_STRT==RM_CACHE_END?"plot":"splot",
+	     LINESPOINTS);
+    fprintf (f, "set terminal x11\nreplot\n");
+    d = fopen ("x-rowmaj-rd.dat", "w");
+    for (cache_size=RM_CACHE_STRT;
+	 cache_size<=RM_CACHE_END;
+	 cache_size+=RM_CACHE_DELT) {
+	for (io_percent=RM_START; io_percent<=RM_END; io_percent+=RM_DELTA) {
+	    io_size = MAX (1, (int)(CH_SIZE*io_percent));
+	    printf ("Rowmaj-rd %8d %8.2f", cache_size, io_percent);
+	    fflush (stdout);
+	    effic = test_rowmaj (READ, cache_size, io_size);
+	    printf (" %8.2f\n", effic);
+	    if (RM_CACHE_STRT==RM_CACHE_END) {
+		fprintf (d, "%g %g\n", io_percent, effic);
+	    } else {
+		fprintf (d, "%g\n", effic);
+	    }
+	}
+	fprintf (d, "\n");
+    }
+    fclose (d);
+    fprintf (f, "pause -1\n");
+#endif
+
+#if 1
+    /*
+     * Test row-major writing of the dataset with various sizes of request
+     * windows.
+     */
+    if (RM_CACHE_STRT==RM_CACHE_END) {
+	fprintf (f, "set yrange [0:1.2]\n");
+	fprintf (f, "set ytics 0, 0.1, 1\n");
+	fprintf (f, "set xlabel \"%s\"\n",
+		 "Request size as a fraction of chunk size");
+	fprintf (f, "set ylabel \"Efficiency\"\n");
+	fprintf (f, "set title \"Cache %d chunks,w0=%g, "
+		 "Size=(total=%d, chunk=%d)\"\n",
+		 RM_CACHE_STRT, w0, DS_SIZE*CH_SIZE, CH_SIZE);
+    } else {
+	fprintf (f, "set autoscale\n");
+	fprintf (f, "set hidden3d\n");
+    }
+
+    fprintf (f, "set terminal postscript\nset output \"x-rowmaj-wr.ps\"\n");
+    fprintf (f, "%s \"x-rowmaj-wr.dat\" title \"RowMaj-Write\" with %s\n",
+	     RM_CACHE_STRT==RM_CACHE_END?"plot":"splot",
+	     LINESPOINTS);
+    fprintf (f, "set terminal x11\nreplot\n");
+    d = fopen ("x-rowmaj-wr.dat", "w");
+    for (cache_size=RM_CACHE_STRT;
+	 cache_size<=RM_CACHE_END;
+	 cache_size+=RM_CACHE_DELT) {
+	for (io_percent=RM_START; io_percent<=RM_END; io_percent+=RM_DELTA) {
+	    io_size = MAX (1, (int)(CH_SIZE*io_percent));
+	    printf ("Rowmaj-wr %8d %8.2f", cache_size, io_percent);
+	    fflush (stdout);
+	    effic = test_rowmaj (WRITE, cache_size, io_size);
+	    printf (" %8.2f\n", effic);
+	    if (RM_CACHE_STRT==RM_CACHE_END) {
+		fprintf (d, "%g %g\n", io_percent, effic);
+	    } else {
+		fprintf (d, "%g\n", effic);
+	    }
+	}
+	fprintf (d, "\n");
+    }
+    fclose (d);
+    fprintf (f, "pause -1\n");
+#endif
+
+#if 1
+    /*
+     * Test diagonal read
+     */
+    if (DIAG_CACHE_STRT==DIAG_CACHE_END) {
+	fprintf (f, "set yrange [0:1.2]\n");
+	fprintf (f, "set ytics 0, 0.1, 1\n");
+	fprintf (f, "set xlabel \"%s\"\n",
+		 "Request size as a fraction of chunk size");
+	fprintf (f, "set ylabel \"Efficiency\"\n");
+	fprintf (f, "set title \"Cache %d chunks,w0=%g, "
+		 "Size=(total=%d, chunk=%d)\"\n",
+		 DIAG_CACHE_STRT, w0, DS_SIZE*CH_SIZE, CH_SIZE);
+    } else {
+	fprintf (f, "set autoscale\n");
+	fprintf (f, "set hidden3d\n");
+    }
+    fprintf (f, "set terminal postscript\nset output \"x-diag-rd.ps\"\n");
+    fprintf (f, "%s \"x-diag-rd.dat\" title \"Diag-Read\" with %s\n",
+	     DIAG_CACHE_STRT==DIAG_CACHE_END?"plot":"splot", LINESPOINTS);
+    fprintf (f, "set terminal x11\nreplot\n");
+    d = fopen ("x-diag-rd.dat", "w");
+    for (cache_size=DIAG_CACHE_STRT;
+	 cache_size<=DIAG_CACHE_END;
+	 cache_size+=DIAG_CACHE_DELT) {
+	for (io_percent=DIAG_START;
+	     io_percent<=DIAG_END;
+	     io_percent+=DIAG_DELTA) {
+	    io_size = MAX (1, (int)(CH_SIZE*io_percent));
+	    printf ("Diag-rd   %8d %8.2f", cache_size, io_percent);
+	    fflush (stdout);
+	    effic = test_diag (READ, cache_size, io_size, MAX (1, io_size/2));
+	    printf (" %8.2f\n", effic);
+	    if (DIAG_CACHE_STRT==DIAG_CACHE_END) {
+		fprintf (d, "%g %g\n", io_percent, effic);
+	    } else {
+		fprintf (d, "%g\n", effic);
+	    }
+	}
+	fprintf (d, "\n");
+    }
+    fclose (d);
+    fprintf (f, "pause -1\n");
+#endif
+
+#if 1
+    /*
+     * Test diagonal write
+     */
+    if (DIAG_CACHE_STRT==DIAG_CACHE_END) {
+	fprintf (f, "set yrange [0:1.2]\n");
+	fprintf (f, "set ytics 0, 0.1, 1\n");
+	fprintf (f, "set xlabel \"%s\"\n",
+		 "Request size as a fraction of chunk size");
+	fprintf (f, "set ylabel \"Efficiency\"\n");
+	fprintf (f, "set title \"Cache %d chunks, w0=%g, "
+		 "Size=(total=%d, chunk=%d)\"\n",
+		 DIAG_CACHE_STRT, w0, DS_SIZE*CH_SIZE, CH_SIZE);
+    } else {
+	fprintf (f, "set autoscale\n");
+	fprintf (f, "set hidden3d\n");
+    }
+    fprintf (f, "set terminal postscript\nset output \"x-diag-wr.ps\"\n");
+    fprintf (f, "%s \"x-diag-wr.dat\" title \"Diag-Write\" with %s\n",
+	     DIAG_CACHE_STRT==DIAG_CACHE_END?"plot":"splot", LINESPOINTS);
+    fprintf (f, "set terminal x11\nreplot\n");
+    d = fopen ("x-diag-wr.dat", "w");
+    for (cache_size=DIAG_CACHE_STRT;
+	 cache_size<=DIAG_CACHE_END;
+	 cache_size+=DIAG_CACHE_DELT) {
+	for (io_percent=DIAG_START;
+	     io_percent<=DIAG_END;
+	     io_percent+=DIAG_DELTA) {
+	    io_size = MAX (1, (int)(CH_SIZE*io_percent));
+	    printf ("Diag-wr   %8d %8.2f", cache_size, io_percent);
+	    fflush (stdout);
+	    effic = test_diag (WRITE, cache_size, io_size, MAX (1, io_size/2));
+	    printf (" %8.2f\n", effic);
+	    if (DIAG_CACHE_STRT==DIAG_CACHE_END) {
+		fprintf (d, "%g %g\n", io_percent, effic);
+	    } else {
+		fprintf (d, "%g\n", effic);
+	    }
+	}
+	fprintf (d, "\n");
+    }
+    fclose (d);
+    fprintf (f, "pause -1\n");
+#endif
+
+
+    H5Pclose (fapl_g);
+    fclose (f);
+    return 0;
+}
+
diff --git a/test/cmpd_dset.c b/test/cmpd_dset.c
index edb3cdc..31492b9 100644
--- a/test/cmpd_dset.c
+++ b/test/cmpd_dset.c
@@ -131,7 +131,7 @@ main (void)
     hsize_t 		h_sample[2];	/*hyperslab sampling		*/
 
     /* Create the file */
-    file = H5Fcreate ("cmpd_dset.h5", H5F_ACC_TRUNC,
+    file = H5Fcreate ("cmpd_dset.h5", H5F_ACC_TRUNC|H5F_ACC_DEBUG,
 		      H5P_DEFAULT, H5P_DEFAULT);
     assert (file>=0);
 
diff --git a/test/extend.c b/test/extend.c
index 09ce489..7ead138 100644
--- a/test/extend.c
+++ b/test/extend.c
@@ -54,7 +54,8 @@ main (void)
     assert (mem_space>=0);
 
     /* Create the file */
-    file = H5Fcreate ("extend.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    file = H5Fcreate ("extend.h5", H5F_ACC_TRUNC|H5F_ACC_DEBUG,
+		      H5P_DEFAULT, H5P_DEFAULT);
     assert (file>=0);
 
     /* Create the dataset which is originally NX by NY */
diff --git a/test/external.c b/test/external.c
index 0694430..49e6d94 100644
--- a/test/external.c
+++ b/test/external.c
@@ -131,7 +131,8 @@ test_1 (void)
      * debugging to be emitted before we start playing games with what the
      * output looks like.
      */
-    file = H5Fcreate ("extern_1.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    file = H5Fcreate ("extern_1.h5", H5F_ACC_TRUNC|H5F_ACC_DEBUG,
+		      H5P_DEFAULT, H5P_DEFAULT);
     assert (file>=0);
     grp = H5Gcreate (file, "emit-diagnostics", 8);
     H5Gclose (grp);
@@ -520,7 +521,8 @@ test_2 (void)
      * debugging to be emitted before we start playing games with what the
      * output looks like.
      */
-    file = H5Fcreate ("extern_2.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    file = H5Fcreate ("extern_2.h5", H5F_ACC_TRUNC|H5F_ACC_DEBUG,
+		      H5P_DEFAULT, H5P_DEFAULT);
     assert (file>=0);
     grp = H5Gcreate (file, "emit-diagnostics", 8);
     H5Gclose (grp);
@@ -658,7 +660,8 @@ test_3 (void)
     /*
      * Create another file
      */
-    file = H5Fcreate ("extern_3.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    file = H5Fcreate ("extern_3.h5", H5F_ACC_TRUNC|H5F_ACC_DEBUG,
+		      H5P_DEFAULT, H5P_DEFAULT);
     assert (file>=0);
 
     /* Create the external file list */
diff --git a/test/gheap.c b/test/gheap.c
index 4183a84..c4a4420 100644
--- a/test/gheap.c
+++ b/test/gheap.c
@@ -91,7 +91,8 @@ test_1 (void)
 
     /* Open a clean file */
     H5Eclear ();
-    f = H5F_open ("gheap1.h5", H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC,
+    f = H5F_open ("gheap1.h5",
+		  H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC|H5F_ACC_DEBUG,
 		  NULL, NULL);
     if (!f) {
 	FAILED ("unable to create file");
@@ -133,8 +134,8 @@ test_1 (void)
 	}
     }
     
-    H5F_close (f);
     puts (" PASSED");
+    H5F_close (f);
     return retval;
 }
 
@@ -173,7 +174,8 @@ test_2 (void)
 
     /* Open a clean file */
     H5Eclear ();
-    f = H5F_open ("gheap2.h5", H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC,
+    f = H5F_open ("gheap2.h5",
+		  H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC|H5F_ACC_DEBUG,
 		  NULL, NULL);
     if (!f) {
 	FAILED ("unable to create file");
@@ -210,8 +212,8 @@ test_2 (void)
 	}
     }
     
-    H5F_close (f);
     puts (" PASSED");
+    H5F_close (f);
     return retval;
 }
 
@@ -249,7 +251,8 @@ test_3 (void)
 
     /* Open a clean file */
     H5Eclear ();
-    f = H5F_open ("gheap3.h5", H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC,
+    f = H5F_open ("gheap3.h5",
+		  H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC|H5F_ACC_DEBUG,
 		  NULL, NULL);
     if (!f) {
 	FAILED ("unable to create file");
@@ -277,8 +280,8 @@ test_3 (void)
 	}
     }
     
-    H5F_close (f);
     puts (" PASSED");
+    H5F_close (f);
     return retval;
 }
 
@@ -317,7 +320,8 @@ test_4 (void)
 
     /* Open a clean file */
     H5Eclear ();
-    f = H5F_open ("gheap4.h5", H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC,
+    f = H5F_open ("gheap4.h5",
+		  H5F_ACC_CREAT|H5F_ACC_RDWR|H5F_ACC_TRUNC|H5F_ACC_DEBUG,
 		  NULL, NULL);
     if (!f) {
 	FAILED ("unable to create file");
@@ -352,8 +356,8 @@ test_4 (void)
 	}
     }
 
-    H5F_close (f);
     puts (" PASSED");
+    H5F_close (f);
     return retval;
 }