[svn-r29738] Description:

    Bring "single" chunk index from revise_chunks branch to trunk.

Tested on:
    MacOSX/64 10.11.4 (amazon) w/serial, parallel & production (w/check-vfd)
    (h5committest forthcoming)

9 files changed, 650 insertions, 19 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 0acb385..08c671b 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -78,7 +78,8 @@
     HDassert((H5D_CHUNK_IDX_EARRAY == storage->idx_type && H5D_COPS_EARRAY == storage->ops) ||  \
              (H5D_CHUNK_IDX_FARRAY == storage->idx_type && H5D_COPS_FARRAY == storage->ops) ||  \
              (H5D_CHUNK_IDX_BT2 == storage->idx_type && H5D_COPS_BT2 == storage->ops) ||        \
-             (H5D_CHUNK_IDX_BTREE == storage->idx_type && H5D_COPS_BTREE == storage->ops));
+             (H5D_CHUNK_IDX_BTREE == storage->idx_type && H5D_COPS_BTREE == storage->ops) ||    \
+             (H5D_CHUNK_IDX_SINGLE == storage->idx_type && H5D_COPS_SINGLE == storage->ops));
 
 /*
  * Feature: If this constant is defined then every cache preemption and load
@@ -6232,7 +6233,6 @@ H5D__chunk_file_alloc(const H5D_chk_idx_info_t *idx_info, const H5F_block_t *old
     HDassert(idx_info->pline);
     HDassert(idx_info->layout);
     HDassert(idx_info->storage);
-    HDassert(H5F_addr_defined(idx_info->storage->idx_addr));
     HDassert(new_chunk);
     HDassert(need_insert);
 
@@ -6297,6 +6297,7 @@ H5D__chunk_file_alloc(const H5D_chk_idx_info_t *idx_info, const H5F_block_t *old
             case H5D_CHUNK_IDX_FARRAY:
             case H5D_CHUNK_IDX_BT2:
             case H5D_CHUNK_IDX_BTREE:
+            case H5D_CHUNK_IDX_SINGLE:
                 HDassert(new_chunk->length > 0);
                 H5_CHECK_OVERFLOW(new_chunk->length, /*From: */uint32_t, /*To: */hsize_t);
                 new_chunk->offset = H5MF_alloc(idx_info->f, H5FD_MEM_DRAW, idx_info->dxpl_id, (hsize_t)new_chunk->length);
diff --git a/src/H5Dlayout.c b/src/H5Dlayout.c
index bf99b9d..991ad95 100644
--- a/src/H5Dlayout.c
+++ b/src/H5Dlayout.c
@@ -101,6 +101,10 @@ H5D__layout_set_io_ops(const H5D_t *dataset)
                     dataset->shared->layout.storage.u.chunk.ops = H5D_COPS_BTREE;
                     break;
 
+                case H5D_CHUNK_IDX_SINGLE:
+                    dataset->shared->layout.storage.u.chunk.ops = H5D_COPS_SINGLE;
+                    break;
+
                 case H5D_CHUNK_IDX_FARRAY:
                     dataset->shared->layout.storage.u.chunk.ops = H5D_COPS_FARRAY;
                     break;
@@ -217,6 +221,14 @@ H5D__layout_meta_size(const H5F_t *f, const H5O_layout_t *layout, hbool_t includ
                     case H5D_CHUNK_IDX_BTREE:
                         HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, 0, "v1 B-tree index type found for layout message >v3")
 
+                    case H5D_CHUNK_IDX_SINGLE:
+                        /* Possible filter information */
+                        if(layout->u.chunk.flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
+                            ret_value += H5F_SIZEOF_SIZE(f);        /* Size of chunk (in file) */
+                            ret_value += 4;                         /* Filter mask for chunk */
+                        } /* end if */
+                        break;
+
                     case H5D_CHUNK_IDX_FARRAY:
                         /* Fixed array creation parameters */
                         ret_value += H5D_FARRAY_CREATE_PARAM_SIZE;
@@ -338,6 +350,7 @@ H5D__layout_set_latest_indexing(H5O_layout_t *layout, const H5S_t *space,
             hsize_t max_dims[H5O_LAYOUT_NDIMS]; /* Maximum dimension sizes */
             hsize_t cur_dims[H5O_LAYOUT_NDIMS]; /* Current dimension sizes */
             unsigned unlim_count = 0;          	/* Count of unlimited max. dimensions */
+            hbool_t single = TRUE;              /* Fulfill single chunk indexing */
             unsigned u;                     	/* Local index variable */
 
             /* Query the dataspace's dimensions */
@@ -348,6 +361,8 @@ H5D__layout_set_latest_indexing(H5O_layout_t *layout, const H5S_t *space,
             for(u = 0; u < ndims; u++) {
                 if(max_dims[u] == H5S_UNLIMITED)
                     unlim_count++;
+                if(cur_dims[u] != max_dims[u] || cur_dims[u] != layout->u.chunk.dim[u])
+                    single = FALSE;
             } /* end for */
 
             /* Chunked datasets with unlimited dimension(s) */
@@ -383,17 +398,25 @@ H5D__layout_set_latest_indexing(H5O_layout_t *layout, const H5S_t *space,
                     layout->u.chunk.u.btree2.cparam.merge_percent =  H5D_BT2_MERGE_PERC;
                 } /* end else */
             } /* end if */
-            else {
-                /* Set the chunk index type to Fixed Array */
-                layout->u.chunk.idx_type = H5D_CHUNK_IDX_FARRAY;
-                layout->storage.u.chunk.idx_type = H5D_CHUNK_IDX_FARRAY;
-                layout->storage.u.chunk.ops = H5D_COPS_FARRAY;
-
-                /* Set the fixed array creation parameters */
-                /* (use hard-coded defaults for now, until we give applications
-                 *          control over this with a property list - QAK)
-                 */
-                layout->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits = H5D_FARRAY_MAX_DBLK_PAGE_NELMTS_BITS;
+            else {      /* Chunked dataset with fixed dimensions */
+                /* Check for correct condition for using "single chunk" chunk index */
+                if(single) {
+                    layout->u.chunk.idx_type = H5D_CHUNK_IDX_SINGLE;
+                    layout->storage.u.chunk.idx_type = H5D_CHUNK_IDX_SINGLE;
+                    layout->storage.u.chunk.ops = H5D_COPS_SINGLE;
+                } /* end if */
+                else {
+                    /* Set the chunk index type to Fixed Array */
+                    layout->u.chunk.idx_type = H5D_CHUNK_IDX_FARRAY;
+                    layout->storage.u.chunk.idx_type = H5D_CHUNK_IDX_FARRAY;
+                    layout->storage.u.chunk.ops = H5D_COPS_FARRAY;
+
+                    /* Set the fixed array creation parameters */
+                    /* (use hard-coded defaults for now, until we give applications
+                     *          control over this with a property list - QAK)
+                     */
+                    layout->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits = H5D_FARRAY_MAX_DBLK_PAGE_NELMTS_BITS;
+                } /* end else */
             } /* end else */
         } /* end if */
     } /* end if */
@@ -422,6 +445,7 @@ H5D__layout_oh_create(H5F_t *file, hid_t dxpl_id, H5O_t *oh, H5D_t *dset,
 {
     H5O_layout_t        *layout;        /* Dataset's layout information */
     const H5O_fill_t    *fill_prop;     /* Pointer to dataset's fill value information */
+    unsigned layout_mesg_flags;         /* Flags for inserting layout message */
     hbool_t             layout_init = FALSE;    /* Flag to indicate that chunk information was initialized */
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -516,9 +540,14 @@ H5D__layout_oh_create(H5F_t *file, hid_t dxpl_id, H5O_t *oh, H5D_t *dset,
     } /* end if */
 
     /* Create layout message */
-    /* (Don't make layout message constant unless allocation time is early, since space may not be allocated) */
+    /* (Don't make layout message constant unless allocation time is early and non-filtered, since space may not be allocated) */
     /* (Note: this is relying on H5D__alloc_storage not calling H5O_msg_write during dataset creation) */
-    if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_LAYOUT_ID, ((fill_prop->alloc_time == H5D_ALLOC_TIME_EARLY && H5D_COMPACT != layout->type) ? H5O_MSG_FLAG_CONSTANT : 0), 0, layout) < 0)
+    if(fill_prop->alloc_time == H5D_ALLOC_TIME_EARLY && H5D_COMPACT != layout->type
+            && !dset->shared->dcpl_cache.pline.nused)
+        layout_mesg_flags = H5O_MSG_FLAG_CONSTANT;
+    else
+        layout_mesg_flags =  0;
+    if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_LAYOUT_ID, layout_mesg_flags, 0, layout) < 0)
          HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout")
 
 done:
@@ -636,6 +665,7 @@ done:
 herr_t
 H5D__layout_oh_write(H5D_t *dataset, hid_t dxpl_id, H5O_t *oh, unsigned update_flags)
 {
+    htri_t msg_exists;                  /* Whether the layout message exists */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_PACKAGE
@@ -644,9 +674,14 @@ H5D__layout_oh_write(H5D_t *dataset, hid_t dxpl_id, H5O_t *oh, unsigned update_f
     HDassert(dataset);
     HDassert(oh);
 
-    /* Write the layout message to the dataset's header */
-    if(H5O_msg_write_oh(dataset->oloc.file, dxpl_id, oh, H5O_LAYOUT_ID, H5O_MSG_FLAG_CONSTANT, update_flags, &dataset->shared->layout) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update layout message")
+    /* Check if the layout message has been added to the dataset's header */
+    if((msg_exists = H5O_msg_exists_oh(oh, H5O_LAYOUT_ID)) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "unable to check if layout message exists")
+    if(msg_exists) {
+        /* Write the layout message to the dataset's header */
+        if(H5O_msg_write_oh(dataset->oloc.file, dxpl_id, oh, H5O_LAYOUT_ID, 0, update_flags, &dataset->shared->layout) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update layout message")
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index 2609412..0fb0d12 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -541,6 +541,7 @@ H5_DLLVAR const H5D_layout_ops_t H5D_LOPS_VIRTUAL[1];
 
 /* Chunked layout operations */
 H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_BTREE[1];
+H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_SINGLE[1];
 H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_EARRAY[1];
 H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_FARRAY[1];
 H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_BT2[1];
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index 07f8dbe..361174a 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -61,6 +61,7 @@ typedef enum H5D_layout_t {
 /* Types of chunk index data structures */
 typedef enum H5D_chunk_index_t {
     H5D_CHUNK_IDX_BTREE	= 0,    /* v1 B-tree index (default)                */
+    H5D_CHUNK_IDX_SINGLE = 1,   /* Single Chunk index (cur dims[]=max dims[]=chunk dims[]; filtered & non-filtered) */
     H5D_CHUNK_IDX_FARRAY = 3,   /* Fixed array (for 0 unlimited dims)       */
     H5D_CHUNK_IDX_EARRAY = 4,   /* Extensible array (for 1 unlimited dim)   */
     H5D_CHUNK_IDX_BT2 = 5,      /* v2 B-tree index (for >1 unlimited dims)  */
diff --git a/src/H5Dsingle.c b/src/H5Dsingle.c
new file mode 100644
index 0000000..e09a5cf
--- /dev/null
+++ b/src/H5Dsingle.c
@@ -0,0 +1,556 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Programmer: 	Vailin Choi <vchoi@hdfgroup.org>
+ *	       	May 2011; updated 10/2015
+ *
+ * Purpose:	Single Chunk I/O functions.  
+ *		This is used when the dataset has only 1 chunk (with or without filter):
+ *			cur_dims[] is equal to max_dims[] is equal to the chunk dims[]
+ *		non-filter chunk record: [address of the chunk]
+ *		filtered chunk record: 	[address of the chunk, chunk size, filter mask]
+ *
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#include "H5Dmodule.h"          /* This source code file is part of the H5D module */
+
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Dpkg.h"		/* Datasets				*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5FLprivate.h"	/* Free Lists                           */
+#include "H5MFprivate.h"	/* File space management		*/
+#include "H5VMprivate.h"         /* Vector functions			*/
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+/* Single Chunk Index chunking I/O ops */
+static herr_t H5D__single_idx_init(const H5D_chk_idx_info_t *idx_info,
+    const H5S_t *space, haddr_t dset_ohdr_addr);
+static herr_t H5D__single_idx_create(const H5D_chk_idx_info_t *idx_info);
+static hbool_t H5D__single_idx_is_space_alloc(const H5O_storage_chunk_t *storage);
+static herr_t H5D__single_idx_insert(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_ud_t *udata, const H5D_t *dset);
+static herr_t H5D__single_idx_get_addr(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_ud_t *udata);
+static int H5D__single_idx_iterate(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_cb_func_t chunk_cb, void *chunk_udata);
+static herr_t H5D__single_idx_remove(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_common_ud_t *udata);
+static herr_t H5D__single_idx_delete(const H5D_chk_idx_info_t *idx_info);
+static herr_t H5D__single_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
+    const H5D_chk_idx_info_t *idx_info_dst);
+static herr_t H5D__single_idx_size(const H5D_chk_idx_info_t *idx_info,
+    hsize_t *size);
+static herr_t H5D__single_idx_reset(H5O_storage_chunk_t *storage, hbool_t reset_addr);
+static herr_t H5D__single_idx_dump(const H5O_storage_chunk_t *storage, FILE *stream);
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+/* Non Index chunk I/O ops */
+const H5D_chunk_ops_t H5D_COPS_SINGLE[1] = {{
+    H5D__single_idx_init,		/* init */
+    H5D__single_idx_create,		/* create */
+    H5D__single_idx_is_space_alloc, 	/* is_space_alloc */
+    H5D__single_idx_insert,	        /* insert */
+    H5D__single_idx_get_addr,		/* get_addr */
+    NULL,				/* resize */
+    H5D__single_idx_iterate,		/* iterate */
+    H5D__single_idx_remove,		/* remove */
+    H5D__single_idx_delete,		/* delete */
+    H5D__single_idx_copy_setup,		/* copy_setup */
+    NULL,				/* copy_shutdown */
+    H5D__single_idx_size,		/* size */
+    H5D__single_idx_reset,		/* reset */
+    H5D__single_idx_dump,		/* dump */
+    NULL				/* destroy */
+}};
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5D__single_idx_init
+ *
+ * Purpose:     Initialize the indexing information for a dataset.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Vailin Choi
+ *              July, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_init(const H5D_chk_idx_info_t *idx_info,
+    const H5S_t H5_ATTR_UNUSED *space, haddr_t H5_ATTR_UNUSED dset_ohdr_addr)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check args */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+
+    if(idx_info->pline->nused)
+	idx_info->layout->flags |= H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER;
+    else
+	idx_info->layout->flags = 0;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D__single_idx_init() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_create
+ *
+ * Purpose:	Set up Single Chunk Index: filtered or non-filtered
+ *		
+ * Return:	Non-negative on success 
+ *		Negative on failure.
+ *
+ * Programmer:	Vailin Choi; July 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_create(const H5D_chk_idx_info_t *idx_info)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check args */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(idx_info->layout->max_nchunks == idx_info->layout->nchunks);
+    HDassert(idx_info->layout->nchunks == 1);
+    HDassert(!H5F_addr_defined(idx_info->storage->idx_addr));
+
+    if(idx_info->pline->nused)
+	HDassert(idx_info->layout->flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER);
+    else
+	HDassert(!(idx_info->layout->flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER));
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D__single_idx_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_is_space_alloc
+ *
+ * Purpose:	Query if space is allocated for the single chunk
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; July 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static hbool_t
+H5D__single_idx_is_space_alloc(const H5O_storage_chunk_t *storage)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check args */
+    HDassert(storage);
+
+    FUNC_LEAVE_NOAPI((hbool_t)H5F_addr_defined(storage->idx_addr))
+} /* end H5D__single_idx_is_space_alloc() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_insert
+ *
+ * Purpose:	Allocate space for the single chunk
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; July 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata,
+    const H5D_t *dset)
+{
+    herr_t	ret_value = SUCCEED;	/* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(idx_info->layout->nchunks == 1);
+    HDassert(idx_info->layout->max_nchunks == 1);
+    HDassert(udata);
+
+    /* Set the address for the chunk */
+    HDassert(H5F_addr_defined(udata->chunk_block.offset));
+    idx_info->storage->idx_addr = udata->chunk_block.offset;
+
+    if(idx_info->pline->nused > 0) {
+        H5_CHECKED_ASSIGN(idx_info->storage->u.single.nbytes, uint32_t, udata->chunk_block.length, hsize_t);
+	idx_info->storage->u.single.filter_mask = udata->filter_mask;
+    } /* end if */
+
+    if(dset) {
+	if(dset->shared->dcpl_cache.fill.alloc_time != H5D_ALLOC_TIME_EARLY || idx_info->pline->nused > 0) {
+	    /* Mark the layout dirty so that the address of the single chunk will be flushed later */
+	    if(H5D__mark(dset, idx_info->dxpl_id, H5D_MARK_LAYOUT) < 0)
+		HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "unable to mark layout as dirty")
+	} /* end if */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5D__single_idx_insert() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_get_addr
+ *
+ * Purpose:	Get the file address of a chunk.
+ *		Save the retrieved information in the udata supplied.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; July 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_get_addr(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Sanity checks */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(idx_info->layout->nchunks == 1);
+    HDassert(idx_info->layout->max_nchunks == 1);
+    HDassert(udata);
+
+    udata->chunk_block.offset = idx_info->storage->idx_addr;
+    if(idx_info->layout->flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
+	udata->chunk_block.length = idx_info->storage->u.single.nbytes;
+	udata->filter_mask = idx_info->storage->u.single.filter_mask;
+    } /* end if */
+    else {
+	udata->chunk_block.length = idx_info->layout->size;
+	udata->filter_mask = 0;
+    } /* end else */
+    if(!H5F_addr_defined(udata->chunk_block.offset))
+        udata->chunk_block.length = 0;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5D__single_idx_get_addr() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_iterate
+ *
+ * Purpose:	Make callback for the single chunk
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; July 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5D__single_idx_iterate(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_cb_func_t chunk_cb, void *chunk_udata)
+{
+    H5D_chunk_rec_t chunk_rec;		/* generic chunk record  */
+    int ret_value = -1;    		/* Return value */
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Sanity checks */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(chunk_cb);
+    HDassert(chunk_udata);
+    HDassert(H5F_addr_defined(idx_info->storage->idx_addr));
+
+    /* Initialize generic chunk record */
+    HDmemset(&chunk_rec, 0, sizeof(chunk_rec));
+    chunk_rec.chunk_addr = idx_info->storage->idx_addr;
+
+    if(idx_info->layout->flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
+	chunk_rec.nbytes = idx_info->storage->u.single.nbytes;
+	chunk_rec.filter_mask = idx_info->storage->u.single.filter_mask;
+    } /* end if */
+    else {
+	chunk_rec.nbytes = idx_info->layout->size;
+	chunk_rec.filter_mask = 0;
+    } /* end else */
+
+    /* Make "generic chunk" callback */
+    if((ret_value = (*chunk_cb)(&chunk_rec, chunk_udata)) < 0)
+	HERROR(H5E_DATASET, H5E_CALLBACK, "failure in generic chunk iterator callback");
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D__single_idx_iterate() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_remove
+ *
+ * Purpose:	Remove the single chunk
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; July 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_remove(const H5D_chk_idx_info_t *idx_info, H5D_chunk_common_ud_t H5_ATTR_UNUSED *udata)
+{
+    hsize_t nbytes;                 /* Size of all chunks */
+    herr_t ret_value = SUCCEED;     /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(H5F_addr_defined(idx_info->storage->idx_addr));
+
+    if(idx_info->layout->flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER)
+	nbytes = idx_info->storage->u.single.nbytes;
+    else
+	nbytes = idx_info->layout->size;
+
+    if(H5MF_xfree(idx_info->f, H5FD_MEM_DRAW, idx_info->dxpl_id, idx_info->storage->idx_addr, nbytes) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTFREE, H5_ITER_ERROR, "unable to free dataset chunks")
+
+    idx_info->storage->idx_addr = HADDR_UNDEF;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5D__single_idx_remove() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_delete
+ *
+ * Purpose:	Delete raw data storage for entire dataset (i.e. the only chunk)
+ *
+ * Return:	Success:	Non-negative
+ *		Failure:	negative
+ *
+ * Programmer:	Vailin Choi; Sept 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_delete(const H5D_chk_idx_info_t *idx_info)
+{
+    herr_t ret_value = SUCCEED;     /* Return value */
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Sanity checks */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+
+    if(H5F_addr_defined(idx_info->storage->idx_addr))
+	ret_value = H5D__single_idx_remove(idx_info, NULL);
+    else
+	HDassert(!H5F_addr_defined(idx_info->storage->idx_addr));
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D__single_idx_delete() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_copy_setup
+ *
+ * Purpose:	Set up any necessary information for copying the single chunk
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Sept 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
+    const H5D_chk_idx_info_t *idx_info_dst)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Check args */
+    HDassert(idx_info_src);
+    HDassert(idx_info_src->f);
+    HDassert(idx_info_src->pline);
+    HDassert(idx_info_src->layout);
+    HDassert(idx_info_src->storage);
+    HDassert(H5F_addr_defined(idx_info_src->storage->idx_addr));
+
+    HDassert(idx_info_dst);
+    HDassert(idx_info_dst->f);
+    HDassert(idx_info_dst->pline);
+    HDassert(idx_info_dst->layout);
+    HDassert(idx_info_dst->storage);
+
+    /* Set copied metadata tag */
+    H5_BEGIN_TAG(idx_info_dst->dxpl_id, H5AC__COPIED_TAG, FAIL);
+
+    /* Set up information at the destination file */
+    if(H5D__single_idx_create(idx_info_dst) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize chunked storage")
+
+    /* Reset metadata tag */
+    H5_END_TAG(FAIL);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D__single_idx_copy_setup() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5D__single_idx_size
+ *
+ * Purpose:     Retrieve the amount of index storage for the chunked dataset
+ *
+ * Return:      Success:        Non-negative
+ *              Failure:        negative
+ *
+ * Programmer:	Vailin Choi; Sept 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_size(const H5D_chk_idx_info_t H5_ATTR_UNUSED *idx_info, hsize_t *index_size)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check args */
+    HDassert(index_size);
+
+    *index_size = 0;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D__single_idx_size() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_reset
+ *
+ * Purpose:	Reset indexing information.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Sept 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_reset(H5O_storage_chunk_t *storage, hbool_t reset_addr)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check args */
+    HDassert(storage);
+
+    /* Reset index info */
+    if(reset_addr)
+	storage->idx_addr = HADDR_UNDEF;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D__single_idx_reset() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D__single_idx_dump
+ *
+ * Purpose:	Dump the address of the single chunk
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; September 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__single_idx_dump(const H5O_storage_chunk_t *storage, FILE *stream)
+{
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check args */
+    HDassert(storage);
+    HDassert(stream);
+
+    HDfprintf(stream, "    Address: %a\n", storage->idx_addr);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D__single_idx_dump() */
+
diff --git a/src/H5Olayout.c b/src/H5Olayout.c
index bc1ebc6..299a43e 100644
--- a/src/H5Olayout.c
+++ b/src/H5Olayout.c
@@ -298,6 +298,16 @@ H5O__layout_decode(H5F_t *f, hid_t H5_ATTR_UNUSED dxpl_id, H5O_t H5_ATTR_UNUSED
                             HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "v1 B-tree index type should never be in a v4 layout message")
                             break;
 
+                        case H5D_CHUNK_IDX_SINGLE:     /* Single Chunk Index */
+                            if(mesg->u.chunk.flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
+                                H5F_DECODE_LENGTH(f, p, mesg->storage.u.chunk.u.single.nbytes);
+                                UINT32DECODE(p, mesg->storage.u.chunk.u.single.filter_mask);
+                            } /* end if */
+
+                            /* Set the chunk operations */
+                            mesg->storage.u.chunk.ops = H5D_COPS_SINGLE;
+                            break;
+
                         case H5D_CHUNK_IDX_FARRAY:
                             /* Fixed array creation parameters */
                             mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits = *p++;
@@ -618,6 +628,14 @@ H5O__layout_encode(H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, uint8_t *p,
                         HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "v1 B-tree index type should never be in a v4 layout message")
                         break;
 
+                    case H5D_CHUNK_IDX_SINGLE:     /* Single Chunk */
+                        /* Filter information */
+                        if(mesg->u.chunk.flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
+                            H5F_ENCODE_LENGTH(f, p, mesg->storage.u.chunk.u.single.nbytes);
+                            UINT32ENCODE(p, mesg->storage.u.chunk.u.single.filter_mask);
+                        } /* end if */
+                        break;
+
                     case H5D_CHUNK_IDX_FARRAY:
                         /* Fixed array creation parameters */
                         *p++ = mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits;
@@ -1174,6 +1192,11 @@ H5O__layout_debug(H5F_t H5_ATTR_UNUSED *f, hid_t H5_ATTR_UNUSED dxpl_id, const v
                               "Index Type:", "v1 B-tree");
                     break;
 
+                case H5D_CHUNK_IDX_SINGLE:
+                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                              "Index Type:", "Single Chunk");
+                    break;
+
                 case H5D_CHUNK_IDX_FARRAY:
                     HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                               "Index Type:", "Fixed Array");
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 46845a3..17ab665 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -369,8 +369,10 @@ typedef struct H5O_efl_t {
 
 /* Flags for chunked layout feature encoding */
 #define H5O_LAYOUT_CHUNK_DONT_FILTER_PARTIAL_BOUND_CHUNKS         0x01
+#define H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER		  0x02
 #define H5O_LAYOUT_ALL_CHUNK_FLAGS                    (                     \
     H5O_LAYOUT_CHUNK_DONT_FILTER_PARTIAL_BOUND_CHUNKS                       \
+    | H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER                             \
     )
 
 /* Initial version of the layout information.  Used when space is allocated */
@@ -432,6 +434,12 @@ typedef struct H5O_storage_chunk_earray_t {
     struct H5EA_t *ea;                  /* Pointer to extensible index array struct */
 } H5O_storage_chunk_earray_t;
 
+/* Filtered info for single chunk index */
+typedef struct H5O_storage_chunk_single_filt_t {
+    uint32_t nbytes;            /* Size of chunk (in file) */
+    uint32_t filter_mask;       /* Excluded filters for chunk */
+} H5O_storage_chunk_single_filt_t;
+
 /* Forward declaration of structs used below */
 struct H5B2_t;                          /* Defined in H5B2pkg.h          */
 
@@ -449,6 +457,7 @@ typedef struct H5O_storage_chunk_t {
         H5O_storage_chunk_bt2_t btree2;    /* Information for v2 B-tree index */	
         H5O_storage_chunk_earray_t earray; /* Information for extensible array index   */
         H5O_storage_chunk_farray_t farray; /* Information for fixed array index   */
+        H5O_storage_chunk_single_filt_t single; /* Information for single chunk w/ filters index */
     } u;
 } H5O_storage_chunk_t;
 
diff --git a/src/H5trace.c b/src/H5trace.c
index a2ca7e2..92d3d20 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -522,6 +522,10 @@ H5_trace(const double *returning, const char *func, const char *type, ...)
                                     fprintf(out, "H5D_CHUNK_IDX_BT2");
                                     break;
 
+                                case H5D_CHUNK_IDX_SINGLE:
+                                    fprintf(out, "H5D_CHUNK_IDX_SINGLE");
+                                    break;
+
                                 case H5D_CHUNK_IDX_NTYPES:
                                     fprintf(out, "ERROR: H5D_CHUNK_IDX_NTYPES (invalid value)");
                                     break;
diff --git a/src/Makefile.am b/src/Makefile.am
index ec8c007..f376969 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -50,7 +50,8 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5D.c H5Dbtree.c H5Dbtree2.c H5Dchunk.c H5Dcompact.c H5Dcontig.c H5Ddbg.c \
         H5Ddeprec.c H5Dearray.c H5Defl.c H5Dfarray.c H5Dfill.c H5Dint.c \
         H5Dio.c H5Dlayout.c \
-        H5Doh.c H5Dscatgath.c H5Dselect.c H5Dtest.c H5Dvirtual.c \
+        H5Doh.c H5Dscatgath.c H5Dselect.c \
+        H5Dsingle.c H5Dtest.c H5Dvirtual.c \
         H5E.c H5Edeprec.c H5Eint.c \
         H5EA.c H5EAcache.c H5EAdbg.c H5EAdblkpage.c H5EAdblock.c H5EAhdr.c \
         H5EAiblock.c H5EAint.c H5EAsblock.c H5EAstat.c H5EAtest.c \