[svn-r17306] Description:

	Stabilize file format changes for layout object header message and add
new "storage" object header message.  This version of the layout message
(& future ones) will contain the constant information for a dataset's layout
and the new storage message will contain information that can change over the
course of a dataset's lifetime.

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers w/default API=1.6.x,
                                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in debug mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.5.7 (amazon) in debug mode
        Mac OS X/32 10.5.7 (amazon) w/C++ & FORTRAN, w/threadsafe,
                                in production mode

12 files changed, 1074 insertions, 184 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 5a6634b..59c2e5d 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -4019,12 +4019,12 @@ H5D_chunk_addrmap(const H5D_io_info_t *io_info, haddr_t chunk_addr[])
 
     HDassert(dset);
     HDassert(dset->shared);
-    HDassert((H5D_CHUNK_IDX_EARRAY == dset->shared->layout.u.chunk.idx_type && 
-                H5D_COPS_EARRAY == dset->shared->layout.u.chunk.ops) ||
-            (H5D_CHUNK_IDX_FARRAY == dset->shared->layout.u.chunk.idx_type && 
-                H5D_COPS_FARRAY == dset->shared->layout.u.chunk.ops) ||
-            (H5D_CHUNK_IDX_BTREE == dset->shared->layout.u.chunk.idx_type && 
-                H5D_COPS_BTREE == dset->shared->layout.u.chunk.ops));
+    HDassert((H5D_CHUNK_IDX_EARRAY == dset->shared->layout.storage.u.chunk.idx_type && 
+                H5D_COPS_EARRAY == dset->shared->layout.storage.u.chunk.ops) ||
+            (H5D_CHUNK_IDX_FARRAY == dset->shared->layout.storage.u.chunk.idx_type && 
+                H5D_COPS_FARRAY == dset->shared->layout.storage.u.chunk.ops) ||
+            (H5D_CHUNK_IDX_BTREE == dset->shared->layout.storage.u.chunk.idx_type && 
+                H5D_COPS_BTREE == dset->shared->layout.storage.u.chunk.ops));
     HDassert(chunk_addr);
 
     /* Set up user data for B-tree callback */
diff --git a/src/H5Dcompact.c b/src/H5Dcompact.c
index 831ab13..a33a62e 100644
--- a/src/H5Dcompact.c
+++ b/src/H5Dcompact.c
@@ -192,7 +192,10 @@ H5D_compact_construct(H5F_t *f, H5D_t *dset)
     /* Verify data size is smaller than maximum header message size
      * (64KB) minus other layout message fields.
      */
-    max_comp_data_size = H5O_MESG_MAX_SIZE - H5D_layout_meta_size(f, &(dset->shared->layout), FALSE);
+    if(dset->shared->layout.version < H5O_LAYOUT_VERSION_4)
+        max_comp_data_size = H5O_MESG_MAX_SIZE - H5D_layout_meta_size(f, &(dset->shared->layout), FALSE);
+    else
+        max_comp_data_size = H5O_MESG_MAX_SIZE - H5O_storage_meta_size(f, &(dset->shared->layout.storage), FALSE);
     if(dset->shared->layout.storage.u.compact.size > max_comp_data_size)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "compact dataset size is bigger than header message maximum size")
 
@@ -358,8 +361,15 @@ H5D_compact_flush(H5D_t *dset, hid_t dxpl_id, unsigned UNUSED flags)
 
     /* Check if the buffered compact information is dirty */
     if(dset->shared->layout.storage.u.compact.dirty) {
-        if(H5O_msg_write(&(dset->oloc), H5O_LAYOUT_ID, 0, H5O_UPDATE_TIME, &(dset->shared->layout), dxpl_id) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to update layout message")
+        /* Check whether compact data is storage in layout or storage message */
+        if(dset->shared->layout.version < H5O_LAYOUT_VERSION_4) {
+            if(H5O_msg_write(&(dset->oloc), H5O_LAYOUT_ID, 0, H5O_UPDATE_TIME, &(dset->shared->layout), dxpl_id) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to update layout message")
+        } /* end if */
+        else {
+            if(H5O_msg_write(&(dset->oloc), H5O_STORAGE_ID, 0, H5O_UPDATE_TIME, &(dset->shared->layout.storage), dxpl_id) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to update layout message")
+        } /* end else */
         dset->shared->layout.storage.u.compact.dirty = FALSE;
     } /* end if */
 
diff --git a/src/H5Dlayout.c b/src/H5Dlayout.c
index 7f2fe1f..4453735 100644
--- a/src/H5Dlayout.c
+++ b/src/H5Dlayout.c
@@ -159,15 +159,21 @@ H5D_layout_meta_size(const H5F_t *f, const H5O_layout_t *layout, hbool_t include
 
     switch(layout->type) {
         case H5D_COMPACT:
-            /* Size of raw data */
-            ret_value += 2;
-            if(include_compact_data)
-                ret_value += layout->storage.u.compact.size;/* data for compact dataset             */
+            /* This information only present in older versions of message */
+            if(layout->version < H5O_LAYOUT_VERSION_4) {
+                /* Size of raw data */
+                ret_value += 2;
+                if(include_compact_data)
+                    ret_value += layout->storage.u.compact.size;/* data for compact dataset             */
+            } /* end if */
             break;
 
         case H5D_CONTIGUOUS:
-            ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
-            ret_value += H5F_SIZEOF_SIZE(f);    /* Length of data */
+            /* This information only present in older versions of message */
+            if(layout->version < H5O_LAYOUT_VERSION_4) {
+                ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
+                ret_value += H5F_SIZEOF_SIZE(f);    /* Length of data */
+            } /* end if */
             break;
 
         case H5D_CHUNKED:
@@ -202,24 +208,17 @@ H5D_layout_meta_size(const H5F_t *f, const H5O_layout_t *layout, hbool_t include
 
                 switch(layout->u.chunk.idx_type) {
                     case H5D_CHUNK_IDX_BTREE:   /* Remove this when v2 B-tree indices added */
-                        /* B-tree address */
-                        ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
+                        /* Nothing to do */
                         break;
 
                     case H5D_CHUNK_IDX_FARRAY:
                         /* Fixed array creation parameters */
                         ret_value += 1;
-
-                        /* Fixed array header address */
-                        ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
                         break;
 
                     case H5D_CHUNK_IDX_EARRAY:
                         /* Extensible array creation parameters */
                         ret_value += 5;
-
-                        /* Extensible array header address */
-                        ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
                         break;
 
                     default:
@@ -444,11 +443,24 @@ H5D_layout_oh_create(H5F_t *file, hid_t dxpl_id, H5O_t *oh, H5D_t *dset,
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update external file list message")
     } /* end if */
 
-    /* Create layout message */
-    /* (Don't make layout message constant unless allocation time is early, 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)
-         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout")
+    /* Check what version of the layout message to write */
+    if(layout->version < H5O_LAYOUT_VERSION_4) {
+        /* Create layout message */
+        /* (Don't make layout message constant unless allocation time is early, 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)
+             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout")
+    } /* end if */
+    else {
+        /* Create layout message */
+        /* (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, H5O_MSG_FLAG_CONSTANT, 0, layout) < 0)
+             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout")
+
+        /* Create storage message */
+        if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_STORAGE_ID, 0, 0, &layout->storage) < 0)
+             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update storage")
+    } /* end else */
 
 done:
     /* Error cleanup */
@@ -510,6 +522,15 @@ H5D_layout_oh_read(H5D_t *dataset, hid_t dxpl_id, hid_t dapl_id, H5P_genplist_t
     if(NULL == H5O_msg_read(&(dataset->oloc), H5O_LAYOUT_ID, &(dataset->shared->layout), dxpl_id))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data layout message")
 
+    /* Check for newer version of the layout message, which indicates that some
+     * information is stored in the 'storage' message.
+     */
+    if(dataset->shared->layout.version >= H5O_LAYOUT_VERSION_4) {
+        /* Retrieve the storage information */
+        if(NULL == H5O_msg_read(&(dataset->oloc), H5O_STORAGE_ID, &(dataset->shared->layout.storage), dxpl_id))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data storage message")
+    } /* end if */
+
     /* Check for external file list message (which might not exist) */
     if((msg_exists = H5O_msg_exists(&(dataset->oloc), H5O_EFL_ID, dxpl_id)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't check if message exists")
@@ -596,7 +617,7 @@ done:
 /*-------------------------------------------------------------------------
  * Function:	H5D_layout_oh_write
  *
- * Purpose:	Read layout/pline/efl information for dataset
+ * Purpose:	Write layout/pline/efl information for dataset
  *
  * Return:	Success:    SUCCEED
  *		Failure:    FAIL
@@ -617,9 +638,18 @@ H5D_layout_oh_write(H5D_t *dataset, hid_t dxpl_id, H5O_t *oh, unsigned update_fl
     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")
+    /* Determine which message to write, based on the version of the layout info */
+    if(dataset->shared->layout.version < H5O_LAYOUT_VERSION_4) {
+        /* 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")
+    } /* end if */
+    else {
+        /* Write the storage message to the dataset's header */
+        if(H5O_msg_write_oh(dataset->oloc.file, dxpl_id, oh, H5O_STORAGE_ID, 0, update_flags, &dataset->shared->layout.storage) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update storage message")
+    } /* end else */
+
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Doh.c b/src/H5Doh.c
index d2649f7..e1d9827 100644
--- a/src/H5Doh.c
+++ b/src/H5Doh.c
@@ -155,6 +155,10 @@ H5O_dset_free_copy_file_udata(void *_udata)
     if(udata->src_pline)
         H5O_msg_free(H5O_PLINE_ID, udata->src_pline);
 
+    /* Release copy of dataset's layout, if it was set */
+    if(udata->src_layout)
+        H5O_msg_free(H5O_LAYOUT_ID, udata->src_layout);
+
     /* Release space for 'copy file' user data */
     (void)H5FL_FREE(H5D_copy_file_ud_t, udata);
 
@@ -375,6 +379,15 @@ H5O_dset_bh_info(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5_ih_info_t *bh_info)
     if(NULL == H5O_msg_read_oh(f, dxpl_id, oh, H5O_LAYOUT_ID, &layout))
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't find layout message")
 
+    /* Check for newer version of the layout message, which indicates that some
+     * information is stored in the 'storage' message.
+     */
+    if(layout.version >= H5O_LAYOUT_VERSION_4) {
+        /* Retrieve the storage information */
+        if(NULL == H5O_msg_read_oh(f, dxpl_id, oh, H5O_STORAGE_ID, &(layout.storage)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "unable to read data storage message")
+    } /* end if */
+
     /* Check for chunked dataset storage */
     if(layout.type == H5D_CHUNKED && H5D_chunk_is_space_alloc(&layout.storage)) {
         H5O_pline_t pline;              /* I/O pipeline message */
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index 4c6ed79..d5a1d16 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -143,7 +143,8 @@ typedef struct H5D_dcpl_cache_t {
 typedef struct H5D_copy_file_ud_t {
     struct H5S_extent_t *src_space_extent;     /* Copy of dataspace extent for dataset */
     H5T_t *src_dtype;                   /* Copy of datatype for dataset */
-    H5O_pline_t *src_pline;             /* Copy of filter pipeline for dataet */
+    H5O_pline_t *src_pline;             /* Copy of filter pipeline for dataset */
+    H5O_layout_t *src_layout;           /* Copy of layout for dataset */
 } H5D_copy_file_ud_t;
 
 
diff --git a/src/H5O.c b/src/H5O.c
index 2017e1c..749f9ec 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -125,6 +125,7 @@ const H5O_msg_class_t *const H5O_msg_class_g[] = {
     H5O_MSG_AINFO,		/*0x0015 Attribute information		*/
     H5O_MSG_REFCOUNT,		/*0x0016 Object's ref. count		*/
     H5O_MSG_UNKNOWN,		/*0x0017 Placeholder for unknown message */
+    H5O_MSG_STORAGE,		/*0x0018 Placeholder for unknown message */
 };
 
 /* Header object ID to class mapping */
diff --git a/src/H5Olayout.c b/src/H5Olayout.c
index 0156b2c..ce0e539 100644
--- a/src/H5Olayout.c
+++ b/src/H5Olayout.c
@@ -64,6 +64,8 @@ static herr_t H5O_layout_reset(void *_mesg);
 static herr_t H5O_layout_free(void *_mesg);
 static herr_t H5O_layout_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
     void *_mesg);
+static herr_t H5O_layout_pre_copy_file(H5F_t *file_src,
+    const void *mesg_src, hbool_t *deleted, const H5O_copy_t *cpy_info, void *_udata);
 static void *H5O_layout_copy_file(H5F_t *file_src, void *mesg_src,
     H5F_t *file_dst, hbool_t *recompute_size, H5O_copy_t *cpy_info,
     void *udata, hid_t dxpl_id);
@@ -80,15 +82,15 @@ const H5O_msg_class_t H5O_MSG_LAYOUT[1] = {{
     H5O_layout_encode,      	/*encode message                */
     H5O_layout_copy,        	/*copy the native value         */
     H5O_layout_size,        	/*size of message on disk       */
-    H5O_layout_reset,           /*reset method                  */
+    H5O_layout_reset,		/*reset method                  */
     H5O_layout_free,        	/*free the struct		*/
     H5O_layout_delete,	        /* file delete method		*/
     NULL,			/* link method			*/
     NULL,			/*set share method		*/
     NULL,		    	/*can share method		*/
-    NULL,			/* pre copy native value to file */
-    H5O_layout_copy_file,       /* copy native value to file    */
-    NULL,		        /* post copy native value to file    */
+    H5O_layout_pre_copy_file,	/* pre copy native value to file */
+    H5O_layout_copy_file,	/* copy native value to file    */
+    NULL,		        /* post copy native value to file */
     NULL,			/* get creation index		*/
     NULL,			/* set creation index		*/
     H5O_layout_debug       	/*debug the message             */
@@ -131,6 +133,7 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
     /* decode */
     if(NULL == (mesg = H5FL_CALLOC(H5O_layout_t)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+    mesg->storage.type = H5D_LAYOUT_ERROR;
 
     mesg->version = *p++;
     if(mesg->version < H5O_LAYOUT_VERSION_1 || mesg->version > H5O_LAYOUT_VERSION_4)
@@ -148,6 +151,9 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
         mesg->type = (H5D_layout_t)*p++;
         assert(H5D_CONTIGUOUS == mesg->type || H5D_CHUNKED == mesg->type || H5D_COMPACT == mesg->type);
 
+        /* Set the storage type */
+        mesg->storage.type = mesg->type;
+
         /* Reserved bytes */
         p += 5;
 
@@ -166,7 +172,7 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
 
             /* Set the chunk operations */
             /* (Only "btree" indexing type currently supported in this version) */
-            mesg->storage.u.chunk.idx_type = H5D_CHUNK_BTREE;
+            mesg->storage.u.chunk.idx_type = H5D_CHUNK_IDX_BTREE;
             mesg->storage.u.chunk.ops = H5D_COPS_BTREE;
         } /* end if */
         else {
@@ -214,12 +220,21 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
         /* Interpret the rest of the message according to the layout class */
         switch(mesg->type) {
             case H5D_COMPACT:
-                UINT16DECODE(p, mesg->storage.u.compact.size);
-                if(mesg->storage.u.compact.size > 0) {
-                    if(NULL == (mesg->storage.u.compact.buf = H5MM_malloc(mesg->storage.u.compact.size)))
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for compact data buffer")
-                    HDmemcpy(mesg->storage.u.compact.buf, p, mesg->storage.u.compact.size);
-                    p += mesg->storage.u.compact.size;
+                /* Check which version to decode */
+                /* (layout versions >= 4 have the compact data in the 'storage' message) */
+                if(mesg->version < H5O_LAYOUT_VERSION_4) {
+                    /* Set the storage type */
+                    mesg->storage.type = mesg->type;
+
+                    /* Compact data size */
+                    UINT16DECODE(p, mesg->storage.u.compact.size);
+
+                    if(mesg->storage.u.compact.size > 0) {
+                        if(NULL == (mesg->storage.u.compact.buf = H5MM_malloc(mesg->storage.u.compact.size)))
+                            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for compact data buffer")
+                        HDmemcpy(mesg->storage.u.compact.buf, p, mesg->storage.u.compact.size);
+                        p += mesg->storage.u.compact.size;
+                    } /* end if */
                 } /* end if */
 
                 /* Set the layout operations */
@@ -227,8 +242,18 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
                 break;
 
             case H5D_CONTIGUOUS:
-                H5F_addr_decode(f, &p, &(mesg->storage.u.contig.addr));
-                H5F_DECODE_LENGTH(f, p, mesg->storage.u.contig.size);
+                /* Check which version to decode */
+                /* (layout versions >= 4 have the contiguous storage address in the 'storage' message) */
+                if(mesg->version < H5O_LAYOUT_VERSION_4) {
+                    /* Set the storage type */
+                    mesg->storage.type = mesg->type;
+
+                    /* Contiguous storage address */
+                    H5F_addr_decode(f, &p, &(mesg->storage.u.contig.addr));
+
+                    /* Contiguous storage size */
+                    H5F_DECODE_LENGTH(f, p, mesg->storage.u.contig.size);
+                } /* end if */
 
                 /* Set the layout operations */
                 mesg->ops = H5D_LOPS_CONTIG;
@@ -236,6 +261,9 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
 
             case H5D_CHUNKED:
                 if(mesg->version < H5O_LAYOUT_VERSION_4) {
+                    /* Set the storage type */
+                    mesg->storage.type = mesg->type;
+
                     /* Dimensionality */
                     mesg->u.chunk.ndims = *p++;
                     if(mesg->u.chunk.ndims > H5O_LAYOUT_NDIMS)
@@ -294,13 +322,9 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
                         HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "unknown chunk index type")
                     mesg->storage.u.chunk.idx_type = mesg->u.chunk.idx_type;
 
-                    /* Chunk index address */
-                    H5F_addr_decode(f, &p, &(mesg->storage.u.chunk.idx_addr));
-
                     switch(mesg->u.chunk.idx_type) {
                         case H5D_CHUNK_IDX_BTREE:       /* Remove this when v2 B-tree indices added */
-                            /* Set the chunk operations */
-                            mesg->storage.u.chunk.ops = H5D_COPS_BTREE;
+                            /* Nothing to do */
                             break;
 
                         case H5D_CHUNK_IDX_FARRAY:
@@ -308,9 +332,6 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
                             mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits = *p++;
                             if(0 == mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits)
                                 HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid fixed array creation parameter")
-
-                            /* Set the chunk operations */
-                            mesg->storage.u.chunk.ops = H5D_COPS_FARRAY;
                             break;
 
                         case H5D_CHUNK_IDX_EARRAY:
@@ -330,9 +351,6 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
                             mesg->u.chunk.u.earray.cparam.max_dblk_page_nelmts_bits = *p++;
                             if(0 == mesg->u.chunk.u.earray.cparam.max_dblk_page_nelmts_bits)
                                 HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid extensible array creation parameter")
-
-                            /* Set the chunk operations */
-                            mesg->storage.u.chunk.ops = H5D_COPS_EARRAY;
                             break;
 
                         default:
@@ -419,22 +437,31 @@ H5O_layout_encode(H5F_t *f, hbool_t UNUSED disable_shared, uint8_t *p, const voi
     /* Write out layout class specific information */
     switch(mesg->type) {
         case H5D_COMPACT:
-            /* Size of raw data */
-            UINT16ENCODE(p, mesg->storage.u.compact.size);
+            /* This information is stored in 'storage' message when version >= 4 */
+            if(mesg->version < H5O_LAYOUT_VERSION_4) {
+                /* Size of raw data */
+                UINT16ENCODE(p, mesg->storage.u.compact.size);
 
-            /* Raw data */
-            if(mesg->storage.u.compact.size > 0) {
-                if(mesg->storage.u.compact.buf)
-                    HDmemcpy(p, mesg->storage.u.compact.buf, mesg->storage.u.compact.size);
-                else
-                    HDmemset(p, 0, mesg->storage.u.compact.size);
-                p += mesg->storage.u.compact.size;
+                /* Raw data */
+                if(mesg->storage.u.compact.size > 0) {
+                    if(mesg->storage.u.compact.buf)
+                        HDmemcpy(p, mesg->storage.u.compact.buf, mesg->storage.u.compact.size);
+                    else
+                        HDmemset(p, 0, mesg->storage.u.compact.size);
+                    p += mesg->storage.u.compact.size;
+                } /* end if */
             } /* end if */
             break;
 
         case H5D_CONTIGUOUS:
-            H5F_addr_encode(f, &p, mesg->storage.u.contig.addr);
-            H5F_ENCODE_LENGTH(f, p, mesg->storage.u.contig.size);
+            /* This information is stored in 'storage' message when version >= 4 */
+            if(mesg->version < H5O_LAYOUT_VERSION_4) {
+                /* Contiguous storage address */
+                H5F_addr_encode(f, &p, mesg->storage.u.contig.addr);
+
+                /* Contiguous storage size */
+                H5F_ENCODE_LENGTH(f, p, mesg->storage.u.contig.size);
+            } /* end if */
             break;
 
         case H5D_CHUNKED:
@@ -469,9 +496,6 @@ H5O_layout_encode(H5F_t *f, hbool_t UNUSED disable_shared, uint8_t *p, const voi
                 /* Chunk index type */
                 *p++ = (uint8_t)mesg->u.chunk.idx_type;
 
-                /* Chunk index address */
-                H5F_addr_encode(f, &p, mesg->storage.u.chunk.idx_addr);
-
                 switch(mesg->u.chunk.idx_type) {
                     case H5D_CHUNK_IDX_BTREE:       /* Remove this when v2 B-tree indices added */
                         /* Nothing to do */
@@ -617,19 +641,23 @@ static herr_t
 H5O_layout_reset(void *_mesg)
 {
     H5O_layout_t     *mesg = (H5O_layout_t *)_mesg;
+    herr_t ret_value = SUCCEED;
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_layout_reset)
+    FUNC_ENTER_NOAPI_NOINIT(H5O_layout_reset)
 
     if(mesg) {
-        /* Free the compact storage buffer */
-        if(H5D_COMPACT == mesg->type)
-            mesg->storage.u.compact.buf = H5MM_xfree(mesg->storage.u.compact.buf);
+        /* Reset associated storage information, if it's been initialized */
+        if(H5D_LAYOUT_ERROR != mesg->storage.type) {
+            if(H5O_storage_reset(&mesg->storage) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free message resources")
+        } /* end if */
 
         /* Reset the message */
         mesg->type = H5D_CONTIGUOUS;
     } /* end if */
 
-    FUNC_LEAVE_NOAPI(SUCCEED)
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_layout_reset() */
 
 
@@ -691,27 +719,30 @@ H5O_layout_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, void *_mesg)
     HDassert(open_oh);
     HDassert(mesg);
 
-    /* Perform different actions, depending on the type of storage */
-    switch(mesg->type) {
-        case H5D_COMPACT:       /* Compact data storage */
-            /* Nothing required */
-            break;
+    /* Check version #, older versions are in charge of storage also */
+    if(mesg->version < H5O_LAYOUT_VERSION_4) {
+        /* Perform different actions, depending on the type of storage */
+        switch(mesg->type) {
+            case H5D_COMPACT:       /* Compact data storage */
+                /* Nothing required */
+                break;
 
-        case H5D_CONTIGUOUS:    /* Contiguous block on disk */
-            /* Free the file space for the raw data */
-            if(H5D_contig_delete(f, dxpl_id, &mesg->storage) < 0)
-                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
-            break;
+            case H5D_CONTIGUOUS:    /* Contiguous block on disk */
+                /* Free the file space for the raw data */
+                if(H5D_contig_delete(f, dxpl_id, &mesg->storage) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
+                break;
 
-        case H5D_CHUNKED:       /* Chunked blocks on disk */
-            /* Free the file space for the index & chunk raw data */
-            if(H5D_chunk_delete(f, dxpl_id, open_oh, &mesg->storage) < 0)
-                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
-            break;
+            case H5D_CHUNKED:       /* Chunked blocks on disk */
+                /* Free the file space for the index & chunk raw data */
+                if(H5D_chunk_delete(f, dxpl_id, open_oh, &mesg->storage) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
+                break;
 
-        default:
-            HGOTO_ERROR(H5E_OHDR, H5E_BADTYPE, FAIL, "not valid storage type")
-    } /* end switch */
+            default:
+                HGOTO_ERROR(H5E_OHDR, H5E_BADTYPE, FAIL, "not valid storage type")
+        } /* end switch */
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -719,6 +750,47 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5O_layout_pre_copy_file
+ *
+ * Purpose:     Perform any necessary actions before copying message between
+ *              files
+ *
+ * Return:      Success:        Non-negative
+ *              Failure:        Negative
+ *
+ * Programmer:  Quincey Koziol
+ *              July 30, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_layout_pre_copy_file(H5F_t UNUSED *file_src, const void *mesg_src,
+    hbool_t UNUSED *deleted, const H5O_copy_t UNUSED *cpy_info, void *_udata)
+{
+    const H5O_layout_t *layout_src = (const H5O_layout_t *)mesg_src;    /* Source layout */
+    H5D_copy_file_ud_t *udata = (H5D_copy_file_ud_t *)_udata;   /* Dataset copying user data */
+    herr_t             ret_value = SUCCEED;                     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_layout_pre_copy_file)
+
+    /* check args */
+    HDassert(layout_src);
+
+    /* If the user data is non-NULL, assume we are copying a dataset
+     * and make a copy of the layout for later in the object copying process,
+     * if the layout version is late enough that we know it will be needed
+     * by the 'storage' message.
+     */
+    if(udata && layout_src->version >= H5O_LAYOUT_VERSION_4)
+        if(NULL == (udata->src_layout = (H5O_layout_t *)H5O_layout_copy(layout_src, NULL)))
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, FAIL, "unable to copy layout")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_layout_pre_copy_file() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5O_layout_copy_file
  *
  * Purpose:     Copies a message from _MESG to _DEST in file
@@ -730,10 +802,6 @@ done:
  * Programmer:  Peter Cao
  *              July 23, 2005
  *
- * Modifications:
- *      Vailin Choi; April 2009
- *      Reset address and pointer of the array struct for the chunked storage index
- *
  *-------------------------------------------------------------------------
  */
 static void *
@@ -749,56 +817,62 @@ H5O_layout_copy_file(H5F_t *file_src, void *mesg_src, H5F_t *file_dst,
     FUNC_ENTER_NOAPI_NOINIT(H5O_layout_copy_file)
 
     /* check args */
+    HDassert(file_src);
     HDassert(layout_src);
     HDassert(file_dst);
 
-    /* Allocate space for the destination layout */
-    if(NULL == (layout_dst = H5FL_MALLOC(H5O_layout_t)))
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTALLOC, NULL, "memory allocation failed")
+    /* Copy the layout information */
+    if(NULL == (layout_dst = (H5O_layout_t *)H5O_layout_copy(layout_src, NULL)))
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy layout")
 
-    /* Copy the "top level" information */
-    *layout_dst = *layout_src;
-
-    /* Copy the layout type specific information */
-    switch(layout_src->type) {
-        case H5D_COMPACT:
-	    if(layout_src->storage.u.compact.buf) {
-                /* copy compact raw data */
-                if(H5D_compact_copy(file_src, &layout_src->storage.u.compact, file_dst, &layout_dst->storage.u.compact, udata->src_dtype, cpy_info, dxpl_id) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
-	    } /* end if */
-            break;
+    /* Check if using version of layout message that encodes storage info */
+    if(layout_src->version < H5O_LAYOUT_VERSION_4) {
+        /* Copy the layout type specific information */
+        switch(layout_src->type) {
+            case H5D_COMPACT:
+                if(layout_src->storage.u.compact.buf) {
+                    /* copy compact raw data */
+                    if(H5D_compact_copy(file_src, &layout_src->storage.u.compact, file_dst, &layout_dst->storage.u.compact, udata->src_dtype, cpy_info, dxpl_id) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
+                } /* end if */
+                break;
 
-        case H5D_CONTIGUOUS:
-            /* Compute the size of the contiguous storage for versions of the
-             * layout message less than version 3 because versions 1 & 2 would
-             * truncate the dimension sizes to 32-bits of information. - QAK 5/26/04
-             */
-            if(layout_src->version < 3)
-                layout_dst->storage.u.contig.size = H5S_extent_nelem(udata->src_space_extent) *
-                                        H5T_get_size(udata->src_dtype);
-
-            if(H5D_contig_is_space_alloc(&layout_src->storage)) {
-                /* copy contiguous raw data */
-                if(H5D_contig_copy(file_src, &layout_src->storage.u.contig, file_dst, &layout_dst->storage.u.contig, udata->src_dtype, cpy_info, dxpl_id) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy contiguous storage")
-            } /* end if */
-            break;
+            case H5D_CONTIGUOUS:
+                /* Compute the size of the contiguous storage for versions of the
+                 * layout message less than version 3 because versions 1 & 2 would
+                 * truncate the dimension sizes to 32-bits of information. - QAK 5/26/04
+                 */
+                if(layout_src->version < 3)
+                    layout_dst->storage.u.contig.size = H5S_extent_nelem(udata->src_space_extent) *
+                                            H5T_get_size(udata->src_dtype);
+
+                if(H5D_contig_is_space_alloc(&layout_src->storage)) {
+                    /* copy contiguous raw data */
+                    if(H5D_contig_copy(file_src, &layout_src->storage.u.contig, file_dst, &layout_dst->storage.u.contig, udata->src_dtype, cpy_info, dxpl_id) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy contiguous storage")
+                } /* end if */
+                break;
 
-        case H5D_CHUNKED:
-            if(H5D_chunk_is_space_alloc(&layout_src->storage)) {
-                /* Create chunked layout */
-                if(H5D_chunk_copy(file_src, &layout_src->storage.u.chunk, &layout_src->u.chunk, file_dst, &layout_dst->storage.u.chunk, udata->src_space_extent, udata->src_dtype, udata->src_pline, cpy_info, dxpl_id) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
-            } /* end if */
-            break;
+            case H5D_CHUNKED:
+                if(H5D_chunk_is_space_alloc(&layout_src->storage)) {
+                    /* Create chunked layout */
+                    if(H5D_chunk_copy(file_src, &layout_src->storage.u.chunk, &layout_src->u.chunk, file_dst, &layout_dst->storage.u.chunk, udata->src_space_extent, udata->src_dtype, udata->src_pline, cpy_info, dxpl_id) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
+                } /* end if */
+                break;
 
-        default:
-            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid layout class")
-    } /* end switch */
+            default:
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid layout class")
+        } /* end switch */
 
-    /* Freed by copy routine */
-    udata->src_dtype = NULL;
+        /* Freed by copy routine */
+        udata->src_dtype = NULL;
+    } /* end if */
+    else {
+        /* Dataset's raw data will be copied using the 'storage' message, reset storage her */
+        if(H5O_storage_reset(&layout_dst->storage) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, NULL, "unable to free message resources")
+    } /* end else */
 
     /* Set return value */
     ret_value = layout_dst;
@@ -859,7 +933,7 @@ H5O_layout_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *_mesg,
             HDfprintf(stream, "}\n");
 
             /* Index information */
-            switch(mesg->storage.u.chunk.idx_type) {
+            switch(mesg->u.chunk.idx_type) {
                 case H5D_CHUNK_IDX_BTREE:
                     HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                               "Index Type:", "v1 B-tree");
@@ -877,27 +951,31 @@ H5O_layout_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *_mesg,
 
                 default:
                     HDfprintf(stream, "%*s%-*s %s (%u)\n", indent, "", fwidth,
-                              "Index Type:", "Unknown", (unsigned)mesg->storage.u.chunk.idx_type);
+                              "Index Type:", "Unknown", (unsigned)mesg->u.chunk.idx_type);
                     break;
             } /* end switch */
-            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
-                      "Index address:", mesg->storage.u.chunk.idx_addr);
+            if(mesg->version < H5O_LAYOUT_VERSION_4)
+                HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+                          "Index address:", mesg->storage.u.chunk.idx_addr);
             break;
 
         case H5D_CONTIGUOUS:
             HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                       "Type:", "Contiguous");
-            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
-                      "Data address:", mesg->storage.u.contig.addr);
-            HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
-                      "Data Size:", mesg->storage.u.contig.size);
+            if(mesg->version < H5O_LAYOUT_VERSION_4) {
+                HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+                          "Data address:", mesg->storage.u.contig.addr);
+                HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+                          "Data Size:", mesg->storage.u.contig.size);
+            } /* end if */
             break;
 
         case H5D_COMPACT:
             HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                       "Type:", "Compact");
-            HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
-                      "Data Size:", mesg->storage.u.compact.size);
+            if(mesg->version < H5O_LAYOUT_VERSION_4)
+                HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
+                          "Data Size:", mesg->storage.u.compact.size);
             break;
 
         default:
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index c2e58dd..90f3997 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -30,7 +30,7 @@
 #define H5O_NMESGS	8 		/*initial number of messages	     */
 #define H5O_NCHUNKS	2		/*initial number of chunks	     */
 #define H5O_MIN_SIZE	22		/* Min. obj header data size (must be big enough for a message prefix and a continuation message) */
-#define H5O_MSG_TYPES   24              /* # of types of messages            */
+#define H5O_MSG_TYPES   25              /* # of types of messages            */
 #define H5O_MAX_CRT_ORDER_IDX 65535     /* Max. creation order index value   */
 
 /* Versions of object header structure */
@@ -454,6 +454,9 @@ H5_DLLVAR const H5O_msg_class_t H5O_MSG_REFCOUNT[1];
 /* Placeholder for unknown message. (0x0017) */
 H5_DLLVAR const H5O_msg_class_t H5O_MSG_UNKNOWN[1];
 
+/* Data Storage Message. (0x0018) */
+H5_DLLVAR const H5O_msg_class_t H5O_MSG_STORAGE[1];
+
 
 /*
  * Object header "object" types
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 251e770..21362b0 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -150,7 +150,7 @@ typedef struct H5O_copy_t {
 #define H5O_FILL_NEW_ID 0x0005          /* Fill Value Message. (New)  */
 #define H5O_LINK_ID     0x0006          /* Link Message. */
 #define H5O_EFL_ID	0x0007          /* External File List Message  */
-#define H5O_LAYOUT_ID	0x0008          /* Data Storage Layout Message.  */
+#define H5O_LAYOUT_ID	0x0008          /* Data Layout Message.  */
 #define H5O_BOGUS_ID	0x0009          /* "Bogus" Message.  */
 #define H5O_GINFO_ID	0x000a          /* Group info Message.  */
 #define H5O_PLINE_ID	0x000b          /* Filter pipeline message.  */
@@ -167,6 +167,7 @@ typedef struct H5O_copy_t {
 #define H5O_REFCOUNT_ID 0x0016          /* Reference count message.  */
 #define H5O_UNKNOWN_ID  0x0017          /* Placeholder message ID for unknown message.  */
                                         /* (this should never exist in a file) */
+#define H5O_STORAGE_ID	0x0018          /* Data Storage message.  */
 
 
 /* Shared object message types.
@@ -728,6 +729,12 @@ H5_DLL herr_t H5O_loc_copy(H5O_loc_t *dst, const H5O_loc_t *src, H5_copy_depth_t
 H5_DLL herr_t H5O_loc_hold_file(H5O_loc_t *loc);
 H5_DLL herr_t H5O_loc_free(H5O_loc_t *loc);
 
+/* Storage operators */
+H5_DLL void *H5O_storage_copy(const void *mesg, void *dest);
+H5_DLL herr_t H5O_storage_reset(void *mesg);
+H5_DLL size_t H5O_storage_meta_size(const H5F_t *f, const H5O_storage_t *storage,
+    hbool_t include_compact_data);
+
 /* EFL operators */
 H5_DLL hsize_t H5O_efl_total_size(H5O_efl_t *efl);
 
diff --git a/src/H5Ostorage.c b/src/H5Ostorage.c
new file mode 100644
index 0000000..0229677
--- /dev/null
+++ b/src/H5Ostorage.c
@@ -0,0 +1,738 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * 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:  Quincey Koziol <koziol@hdfgroup.org>
+ *              Wednesday, July 29, 2009
+ *
+ * Purpose:     Message related to data storage.
+ */
+
+#define H5D_PACKAGE		/*suppress error about including H5Dpkg	  */
+#define H5O_PACKAGE		/*suppress error about including H5Opkg	  */
+
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Dpkg.h"		/* Dataset functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5FLprivate.h"	/* Free Lists                           */
+#include "H5MMprivate.h"	/* Memory management			*/
+#include "H5Opkg.h"             /* Object headers			*/
+
+
+/* Local macros */
+
+/* Current version of storage information */
+#define H5O_STORAGE_VERSION 	0
+
+/* Flags for chunked storage feature encoding */
+#ifdef NOT_YET
+#define H5O_STORAGE_CHUNK_HAVE_ELEM_INDEX       0x02
+#define H5O_STORAGE_ALL_CHUNK_FLAGS (                                         \
+    H5O_STORAGE_CHUNK_HAVE_ELEM_INDEX                                         \
+    | H5O_STORAGE_CHUNK_HAVE_CHUNK_INDEX                                      \
+    )
+#else /* NOT_YET */
+#define H5O_STORAGE_CHUNK_HAVE_CHUNK_INDEX      0x01
+#define H5O_STORAGE_ALL_CHUNK_FLAGS             H5O_STORAGE_CHUNK_HAVE_CHUNK_INDEX
+#endif /* NOT_YET */
+
+
+/* PRIVATE PROTOTYPES */
+static void *H5O_storage_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
+    unsigned mesg_flags, unsigned *ioflags, const uint8_t *p);
+static herr_t H5O_storage_encode(H5F_t *f, hbool_t disable_shared, uint8_t *p, const void *_mesg);
+static size_t H5O_storage_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
+static herr_t H5O_storage_free(void *_mesg);
+static herr_t H5O_storage_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
+    void *_mesg);
+static void *H5O_storage_copy_file(H5F_t *file_src, void *mesg_src,
+    H5F_t *file_dst, hbool_t *recompute_size, H5O_copy_t *cpy_info,
+    void *udata, hid_t dxpl_id);
+static herr_t H5O_storage_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg, FILE * stream,
+			       int indent, int fwidth);
+
+/* This message derives from H5O message class */
+const H5O_msg_class_t H5O_MSG_STORAGE[1] = {{
+    H5O_STORAGE_ID,          	/*message id number             */
+    "storage",               	/*message name for debugging    */
+    sizeof(H5O_storage_t),   	/*native message size           */
+    0,				/* messages are sharable?       */
+    H5O_storage_decode,      	/*decode message                */
+    H5O_storage_encode,      	/*encode message                */
+    H5O_storage_copy,        	/*copy the native value         */
+    H5O_storage_size,        	/*size of message on disk       */
+    H5O_storage_reset,		/*reset method                  */
+    H5O_storage_free,        	/*free the struct		*/
+    H5O_storage_delete,	        /* file delete method		*/
+    NULL,			/* link method			*/
+    NULL,			/*set share method		*/
+    NULL,		    	/*can share method		*/
+    NULL,			/* pre copy native value to file */
+    H5O_storage_copy_file,	/* copy native value to file    */
+    NULL,		        /* post copy native value to file    */
+    NULL,			/* get creation index		*/
+    NULL,			/* set creation index		*/
+    H5O_storage_debug       	/*debug the message             */
+}};
+
+
+/* Declare a free list to manage the H5O_storage_t struct */
+H5FL_DEFINE_STATIC(H5O_storage_t);
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_decode
+ *
+ * Purpose:     Decode a data storage message and return a pointer to a
+ *              new one created with malloc().
+ *
+ * Return:      Success:        Ptr to new message in native order.
+ *              Failure:        NULL
+ *
+ * Programmer:  Quincey Koziol
+ *              Wednesday, July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5O_storage_decode(H5F_t *f, hid_t UNUSED dxpl_id, H5O_t UNUSED *open_oh,
+    unsigned UNUSED mesg_flags, unsigned UNUSED *ioflags, const uint8_t *p)
+{
+    H5O_storage_t *mesg = NULL; /* Message decoded */
+    uint8_t version;            /* Version of message decoded */
+    void *ret_value;            /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_decode)
+
+    /* check args */
+    HDassert(f);
+    HDassert(p);
+
+    /* Allocate new message */
+    if(NULL == (mesg = H5FL_CALLOC(H5O_storage_t)))
+        HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "memory allocation failed")
+
+    /* decode */
+    version = *p++;
+    if(H5O_STORAGE_VERSION != version)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad version number for message")
+
+    /* Layout class */
+    mesg->type = (H5D_layout_t)*p++;
+
+    /* Interpret the rest of the message according to the layout class */
+    switch(mesg->type) {
+        case H5D_COMPACT:
+            /* Compact data size */
+            UINT16DECODE(p, mesg->u.compact.size);
+
+            /* Check for any data stored */
+            if(mesg->u.compact.size > 0) {
+                /* Allocate space for compact data */
+                if(NULL == (mesg->u.compact.buf = H5MM_malloc(mesg->u.compact.size)))
+                    HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "memory allocation failed for compact data buffer")
+
+                /* Compact data */
+                HDmemcpy(mesg->u.compact.buf, p, mesg->u.compact.size);
+                p += mesg->u.compact.size;
+            } /* end if */
+            break;
+
+        case H5D_CONTIGUOUS:
+            /* Contiguous storage address */
+            H5F_addr_decode(f, &p, &(mesg->u.contig.addr));
+
+            /* Contiguous storage size */
+            H5F_DECODE_LENGTH(f, p, mesg->u.contig.size);
+            break;
+
+        case H5D_CHUNKED:
+            {
+                uint8_t flags;          /* Flags for decoding chunk feature info */
+
+                /* Get the chunked layout flags */
+                flags = *p++;
+
+                /* Check for valid flags */
+                if(flags & ~H5O_STORAGE_ALL_CHUNK_FLAGS)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad flag value for message")
+
+                /* Check for chunk index */
+                if(flags & H5O_STORAGE_CHUNK_HAVE_CHUNK_INDEX) {
+                    /* Chunk index type */
+                    mesg->u.chunk.idx_type = (H5D_chunk_index_t)*p++;
+                    switch(mesg->u.chunk.idx_type) {
+                        case H5D_CHUNK_IDX_BTREE:       /* Remove this when v2 B-tree indices added */
+                            /* Set the chunk operations */
+                            mesg->u.chunk.ops = H5D_COPS_BTREE;
+                            break;
+
+                        case H5D_CHUNK_IDX_FARRAY:
+                            /* Set the chunk operations */
+                            mesg->u.chunk.ops = H5D_COPS_FARRAY;
+                            break;
+
+                        case H5D_CHUNK_IDX_EARRAY:
+                            /* Set the chunk operations */
+                            mesg->u.chunk.ops = H5D_COPS_EARRAY;
+                            break;
+
+                        default:
+                            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid chunk index type")
+                    } /* end switch */
+
+                    /* Chunk index address */
+                    H5F_addr_decode(f, &p, &(mesg->u.chunk.idx_addr));
+                } /* end if */
+            } /* end block */
+            break;
+
+        default:
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid layout class")
+    } /* end switch */
+
+    /* Set return value */
+    ret_value = mesg;
+
+done:
+    if(ret_value == NULL)
+        if(mesg)
+            (void)H5FL_FREE(H5O_storage_t, mesg);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_decode() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_encode
+ *
+ * Purpose:     Encodes a message.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              Wednesday, July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_storage_encode(H5F_t *f, hbool_t UNUSED disable_shared, uint8_t *p,
+    const void *_mesg)
+{
+    const H5O_storage_t   *mesg = (const H5O_storage_t *) _mesg;
+    herr_t ret_value = SUCCEED;   /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_encode)
+
+    /* check args */
+    HDassert(f);
+    HDassert(mesg);
+    HDassert(p);
+
+    /* Message version */
+    *p++ = (uint8_t)H5O_STORAGE_VERSION;
+
+    /* Layout class */
+    *p++ = mesg->type;
+
+    /* Write out layout class specific information */
+    switch(mesg->type) {
+        case H5D_COMPACT:
+            /* Size of raw data */
+            UINT16ENCODE(p, mesg->u.compact.size);
+
+            /* Raw data */
+            if(mesg->u.compact.size > 0) {
+                if(mesg->u.compact.buf)
+                    HDmemcpy(p, mesg->u.compact.buf, mesg->u.compact.size);
+                else
+                    HDmemset(p, 0, mesg->u.compact.size);
+                p += mesg->u.compact.size;
+            } /* end if */
+            break;
+
+        case H5D_CONTIGUOUS:
+            /* Contiguous storage address */
+            H5F_addr_encode(f, &p, mesg->u.contig.addr);
+
+            /* Contiguous storage size */
+            H5F_ENCODE_LENGTH(f, p, mesg->u.contig.size);
+            break;
+
+        case H5D_CHUNKED:
+            {
+                /* Chunk feature flags */
+                *p++ = (uint8_t)H5O_STORAGE_CHUNK_HAVE_CHUNK_INDEX;
+
+                /* Chunk index type */
+                *p++ = (uint8_t)mesg->u.chunk.idx_type;
+
+                /* Chunk index address */
+                H5F_addr_encode(f, &p, mesg->u.chunk.idx_addr);
+            } /* end block */
+            break;
+
+        default:
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, FAIL, "Invalid layout class")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_encode() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_copy
+ *
+ * Purpose:     Copies a message from _MESG to _DEST, allocating _DEST if
+ *              necessary.
+ *
+ * Return:      Success:        Ptr to _DEST
+ *              Failure:        NULL
+ *
+ * Programmer:  Quincey Koziol
+ *              Wednesday, July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5O_storage_copy(const void *_mesg, void *_dest)
+{
+    const H5O_storage_t    *mesg = (const H5O_storage_t *) _mesg;
+    H5O_storage_t          *dest = (H5O_storage_t *) _dest;
+    void                   *ret_value;          /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_copy)
+
+    /* check args */
+    HDassert(mesg);
+    if(!dest && NULL == (dest = H5FL_MALLOC(H5O_storage_t)))
+        HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "memory allocation failed")
+
+    /* copy */
+    *dest = *mesg;
+
+    /* Deep copy the buffer for compact datasets also */
+    if(mesg->type == H5D_COMPACT) {
+        if(mesg->u.compact.size > 0) {
+            /* Allocate memory for the raw data */
+            if(NULL == (dest->u.compact.buf = H5MM_malloc(dest->u.compact.size)))
+                HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "unable to allocate memory for compact dataset")
+
+            /* Copy over the raw data */
+            HDmemcpy(dest->u.compact.buf, mesg->u.compact.buf, dest->u.compact.size);
+        } /* end if */
+        else
+            HDassert(dest->u.compact.buf == NULL);
+    } /* end if */
+
+    /* Reset the pointer of the chunked storage index but not the address */
+    if(dest->type == H5D_CHUNKED && dest->u.chunk.ops)
+	H5D_chunk_idx_reset(&dest->u.chunk, FALSE);
+
+    /* Set return value */
+    ret_value = dest;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_size
+ *
+ * Purpose:     Returns the size of the raw message in bytes.  If it's
+ *              compact dataset, the data part is also included.
+ *              This function doesn't take into account message alignment.
+ *
+ * Return:      Success:        Message data size in bytes
+ *              Failure:        0
+ *
+ * Programmer:  Quincey Koziol
+ *              Wednesday, July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static size_t
+H5O_storage_size(const H5F_t *f, hbool_t UNUSED disable_shared, const void *_mesg)
+{
+    const H5O_storage_t     *mesg = (const H5O_storage_t *) _mesg;
+    size_t                  ret_value;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_storage_size)
+
+    /* check args */
+    HDassert(f);
+    HDassert(mesg);
+
+    /* Compute the storage message's encoded size in the file */
+    /* (including possible compact data) */
+    ret_value = H5O_storage_meta_size(f, mesg, TRUE);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_size() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_storage_reset
+ *
+ * Purpose:	Frees resources within a message, but doesn't free
+ *		the message itself.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              Wednesday, July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_storage_reset(void *_mesg)
+{
+    H5O_storage_t     *mesg = (H5O_storage_t *)_mesg;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_storage_reset)
+
+    if(mesg) {
+        /* Free the compact storage buffer */
+        if(H5D_COMPACT == mesg->type)
+            mesg->u.compact.buf = H5MM_xfree(mesg->u.compact.buf);
+
+        /* Reset the message */
+        mesg->type = H5D_CONTIGUOUS;
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5O_storage_reset() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_storage_free
+ *
+ * Purpose:	Free's the message
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              Wednesday, July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_storage_free(void *_mesg)
+{
+    H5O_storage_t     *mesg = (H5O_storage_t *) _mesg;
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_free)
+
+    HDassert(mesg);
+
+    /* Free resources within the message */
+    if(H5O_storage_reset(mesg) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free message resources")
+
+    (void)H5FL_FREE(H5O_storage_t, mesg);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_free() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_delete
+ *
+ * Purpose:     Free file space referenced by message
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              Thursday, July 30, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_storage_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, void *_mesg)
+{
+    H5O_storage_t *mesg = (H5O_storage_t *) _mesg;
+    herr_t ret_value = SUCCEED;   /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_delete)
+
+    /* check args */
+    HDassert(f);
+    HDassert(open_oh);
+    HDassert(mesg);
+
+    /* Perform different actions, depending on the type of storage */
+    switch(mesg->type) {
+        case H5D_COMPACT:       /* Compact data storage */
+            /* Nothing required */
+            break;
+
+        case H5D_CONTIGUOUS:    /* Contiguous block on disk */
+            /* Free the file space for the raw data */
+            if(H5D_contig_delete(f, dxpl_id, mesg) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
+            break;
+
+        case H5D_CHUNKED:       /* Chunked blocks on disk */
+            /* Free the file space for the index & chunk raw data */
+            if(H5D_chunk_delete(f, dxpl_id, open_oh, mesg) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
+            break;
+
+        default:
+            HGOTO_ERROR(H5E_OHDR, H5E_BADTYPE, FAIL, "not valid storage type")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_delete() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_copy_file
+ *
+ * Purpose:     Copies a message from _MESG to _DEST in file
+ *
+ * Return:      Success:        Ptr to _DEST
+ *              Failure:        NULL
+ *
+ * Programmer:  Quincey Koziol
+ *              Thursday, July 30, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5O_storage_copy_file(H5F_t *file_src, void *mesg_src, H5F_t *file_dst,
+    hbool_t UNUSED *recompute_size, H5O_copy_t *cpy_info, void *_udata,
+    hid_t dxpl_id)
+{
+    H5D_copy_file_ud_t *udata = (H5D_copy_file_ud_t *)_udata;   /* Dataset copying user data */
+    H5O_storage_t      *storage_src = (H5O_storage_t *)mesg_src;
+    H5O_storage_t      *storage_dst = NULL;
+    void               *ret_value;                              /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_copy_file)
+
+    /* check args */
+    HDassert(file_src);
+    HDassert(storage_src);
+    HDassert(file_dst);
+    HDassert(cpy_info);
+    HDassert(udata);
+    HDassert(udata->src_layout);
+    HDassert(udata->src_layout->version >= H5O_LAYOUT_VERSION_4 );
+
+    /* Allocate space for the destination storage */
+    if(NULL == (storage_dst = H5FL_MALLOC(H5O_storage_t)))
+        HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "memory allocation failed")
+
+    /* Copy the "top level" information */
+    *storage_dst = *storage_src;
+
+    /* Copy the storage type specific information */
+    switch(storage_src->type) {
+        case H5D_COMPACT:
+	    if(storage_src->u.compact.buf) {
+            	if(NULL == (storage_dst->u.compact.buf = H5MM_malloc(storage_src->u.compact.size)))
+                    HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "unable to allocate memory for compact dataset")
+
+                /* Copy compact raw data */
+                if(H5D_compact_copy(file_src, &storage_src->u.compact, file_dst, &storage_dst->u.compact, udata->src_dtype, cpy_info, dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
+
+            	storage_dst->u.compact.dirty = TRUE;
+	    } /* end if */
+            break;
+
+        case H5D_CONTIGUOUS:
+            if(H5D_contig_is_space_alloc(storage_src)) {
+                /* Copy contiguous raw data */
+                if(H5D_contig_copy(file_src, &storage_src->u.contig, file_dst, &storage_dst->u.contig, udata->src_dtype, cpy_info, dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy contiguous storage")
+            } /* end if */
+            break;
+
+        case H5D_CHUNKED:
+            if(H5D_chunk_is_space_alloc(storage_src)) {
+                /* Create chunked layout */
+                if(H5D_chunk_copy(file_src, &storage_src->u.chunk, &udata->src_layout->u.chunk, file_dst, &storage_dst->u.chunk, udata->src_space_extent, udata->src_dtype, udata->src_pline, cpy_info, dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
+            } /* end if */
+            break;
+
+        default:
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid layout class")
+    } /* end switch */
+
+    /* Freed by copy routine */
+    udata->src_dtype = NULL;
+
+    /* Set return value */
+    ret_value = storage_dst;
+
+done:
+    if(!ret_value)
+	if(storage_dst)
+	    (void)H5FL_FREE(H5O_storage_t, storage_dst);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_copy_file() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_debug
+ *
+ * Purpose:     Prints debugging info for a message.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              Thursday, July 30, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_storage_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *_mesg,
+    FILE * stream, int indent, int fwidth)
+{
+    const H5O_storage_t     *mesg = (const H5O_storage_t *) _mesg;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_storage_debug)
+
+    /* check args */
+    HDassert(f);
+    HDassert(mesg);
+    HDassert(stream);
+    HDassert(indent >= 0);
+    HDassert(fwidth >= 0);
+
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+              "Version:", (unsigned)H5O_STORAGE_VERSION);
+    switch(mesg->type) {
+        case H5D_CHUNKED:
+            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                      "Type:", "Chunked");
+
+            /* Index information */
+            switch(mesg->u.chunk.idx_type) {
+                case H5D_CHUNK_IDX_BTREE:
+                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                              "Index Type:", "v1 B-tree");
+                    break;
+
+                case H5D_CHUNK_IDX_FARRAY:
+                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                              "Index Type:", "Fixed Array");
+                    break;
+
+                case H5D_CHUNK_IDX_EARRAY:
+                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                              "Index Type:", "Extensible Array");
+                    break;
+
+                default:
+                    HDfprintf(stream, "%*s%-*s %s (%u)\n", indent, "", fwidth,
+                              "Index Type:", "Unknown", (unsigned)mesg->u.chunk.idx_type);
+                    break;
+            } /* end switch */
+            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+                      "Index address:", mesg->u.chunk.idx_addr);
+            break;
+
+        case H5D_CONTIGUOUS:
+            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                      "Type:", "Contiguous");
+            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+                      "Data address:", mesg->u.contig.addr);
+            HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+                      "Data Size:", mesg->u.contig.size);
+            break;
+
+        case H5D_COMPACT:
+            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+                      "Type:", "Compact");
+            HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
+                      "Data Size:", mesg->u.compact.size);
+            break;
+
+        default:
+            HDfprintf(stream, "%*s%-*s %s (%u)\n", indent, "", fwidth,
+                      "Type:", "Unknown", (unsigned)mesg->type);
+            break;
+    } /* end switch */
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5O_storage_debug() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_storage_meta_size
+ *
+ * Purpose:     Returns the size of the raw message in bytes except raw data
+ *              part for compact dataset.  This function doesn't take into
+ *              account message alignment.
+ *
+ * Return:      Success:        Message data size in bytes
+ *              Failure:        0
+ *
+ * Programmer:  Quincey Koziol
+ *              July 29, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+size_t
+H5O_storage_meta_size(const H5F_t *f, const H5O_storage_t *storage,
+    hbool_t include_compact_data)
+{
+    size_t                  ret_value;
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_storage_meta_size)
+
+    /* check args */
+    HDassert(f);
+    HDassert(storage);
+
+    ret_value = 1 +             /* Version number                       */
+                1;              /* Layout class type                    */
+
+    switch(storage->type) {
+        case H5D_COMPACT:
+            /* Size of raw data */
+            ret_value += 2;
+            if(include_compact_data)
+                ret_value += storage->u.compact.size;/* data for compact dataset             */
+            break;
+
+        case H5D_CONTIGUOUS:
+            ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
+            ret_value += H5F_SIZEOF_SIZE(f);    /* Length of data */
+            break;
+
+        case H5D_CHUNKED:
+            ret_value += 1 +                    /* Chunk feature flags */
+                         1;                     /* Chunk index type */
+            ret_value += H5F_SIZEOF_ADDR(f);    /* Chunk index address */
+            break;
+
+        default:
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, 0, "Invalid layout class")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_storage_meta_size() */
+
diff --git a/src/Makefile.am b/src/Makefile.am
index ce15dd9..8610c16 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -81,8 +81,11 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5Olayout.c \
         H5Olinfo.c H5Olink.c H5Omessage.c H5Omtime.c \
         H5Oname.c H5Onull.c H5Opline.c H5Orefcount.c \
-        H5Osdspace.c H5Oshared.c H5Ostab.c \
-        H5Oshmesg.c H5Otest.c H5Ounknown.c \
+        H5Osdspace.c H5Oshared.c \
+        H5Oshmesg.c \
+        H5Ostab.c \
+        H5Ostorage.c \
+        H5Otest.c H5Ounknown.c \
         H5P.c H5Pacpl.c H5Pdapl.c H5Pdcpl.c \
         H5Pdeprec.c H5Pdxpl.c H5Pfapl.c H5Pfcpl.c H5Pfmpl.c \
         H5Pgcpl.c H5Pint.c \
diff --git a/src/Makefile.in b/src/Makefile.in
index 50a9e33..b6c0ac0 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -85,19 +85,20 @@ am_libhdf5_la_OBJECTS = H5.lo H5checksum.lo H5dbg.lo H5system.lo \
 	H5B2stat.lo H5B2test.lo H5C.lo H5CS.lo H5D.lo H5Dbtree.lo \
 	H5Dchunk.lo H5Dcompact.lo H5Dcontig.lo H5Ddbg.lo H5Ddeprec.lo \
 	H5Dearray.lo H5Defl.lo H5Dfarray.lo H5Dfill.lo H5Dint.lo \
-	H5Dio.lo H5Dlayout.lo H5Dmpio.lo H5Doh.lo H5Dproxy.lo H5Dscatgath.lo \
-	H5Dselect.lo H5Dtest.lo H5E.lo H5Edeprec.lo H5Eint.lo H5EA.lo \
-	H5EAcache.lo H5EAdbg.lo H5EAdblkpage.lo H5EAdblock.lo \
-	H5EAhdr.lo H5EAiblock.lo H5EAint.lo H5EAsblock.lo H5EAstat.lo \
-	H5EAtest.lo H5F.lo H5Faccum.lo H5Fdbg.lo H5Ffake.lo H5Fio.lo \
-	H5Fmount.lo H5Fmpi.lo H5Fquery.lo H5Fsfile.lo H5Fsuper.lo \
-	H5Ftest.lo H5FA.lo H5FAcache.lo H5FAdbg.lo H5FAdblock.lo \
-	H5FAdblkpage.lo H5FAhdr.lo H5FAstat.lo H5FAtest.lo H5FD.lo \
-	H5FDcore.lo H5FDdirect.lo H5FDfamily.lo H5FDint.lo H5FDlog.lo \
-	H5FDmpi.lo H5FDmpio.lo H5FDmpiposix.lo H5FDmulti.lo \
-	H5FDsec2.lo H5FDspace.lo H5FDstdio.lo H5FL.lo H5FO.lo H5FS.lo \
-	H5FScache.lo H5FSdbg.lo H5FSsection.lo H5FSstat.lo H5FStest.lo \
-	H5G.lo H5Gbtree2.lo H5Gcache.lo H5Gcompact.lo H5Gdense.lo \
+	H5Dio.lo H5Dlayout.lo H5Dmpio.lo H5Doh.lo H5Dproxy.lo \
+	H5Dscatgath.lo H5Dselect.lo H5Dtest.lo H5E.lo H5Edeprec.lo \
+	H5Eint.lo H5EA.lo H5EAcache.lo H5EAdbg.lo H5EAdblkpage.lo \
+	H5EAdblock.lo H5EAhdr.lo H5EAiblock.lo H5EAint.lo \
+	H5EAsblock.lo H5EAstat.lo H5EAtest.lo H5F.lo H5Faccum.lo \
+	H5Fdbg.lo H5Ffake.lo H5Fio.lo H5Fmount.lo H5Fmpi.lo \
+	H5Fquery.lo H5Fsfile.lo H5Fsuper.lo H5Ftest.lo H5FA.lo \
+	H5FAcache.lo H5FAdbg.lo H5FAdblock.lo H5FAdblkpage.lo \
+	H5FAhdr.lo H5FAstat.lo H5FAtest.lo H5FD.lo H5FDcore.lo \
+	H5FDdirect.lo H5FDfamily.lo H5FDint.lo H5FDlog.lo H5FDmpi.lo \
+	H5FDmpio.lo H5FDmpiposix.lo H5FDmulti.lo H5FDsec2.lo \
+	H5FDspace.lo H5FDstdio.lo H5FL.lo H5FO.lo H5FS.lo H5FScache.lo \
+	H5FSdbg.lo H5FSsection.lo H5FSstat.lo H5FStest.lo H5G.lo \
+	H5Gbtree2.lo H5Gcache.lo H5Gcompact.lo H5Gdense.lo \
 	H5Gdeprec.lo H5Gent.lo H5Gint.lo H5Glink.lo H5Gloc.lo \
 	H5Gname.lo H5Gnode.lo H5Gobj.lo H5Goh.lo H5Groot.lo H5Gstab.lo \
 	H5Gtest.lo H5Gtraverse.lo H5HF.lo H5HFbtree2.lo H5HFcache.lo \
@@ -112,21 +113,22 @@ am_libhdf5_la_OBJECTS = H5.lo H5checksum.lo H5dbg.lo H5system.lo \
 	H5Odrvinfo.lo H5Odtype.lo H5Oefl.lo H5Ofill.lo H5Oginfo.lo \
 	H5Olayout.lo H5Olinfo.lo H5Olink.lo H5Omessage.lo H5Omtime.lo \
 	H5Oname.lo H5Onull.lo H5Opline.lo H5Orefcount.lo H5Osdspace.lo \
-	H5Oshared.lo H5Ostab.lo H5Oshmesg.lo H5Otest.lo H5Ounknown.lo \
-	H5P.lo H5Pacpl.lo H5Pdapl.lo H5Pdcpl.lo H5Pdeprec.lo \
-	H5Pdxpl.lo H5Pfapl.lo H5Pfcpl.lo H5Pfmpl.lo H5Pgcpl.lo \
-	H5Pint.lo H5Plapl.lo H5Plcpl.lo H5Pocpl.lo H5Pocpypl.lo \
-	H5Pstrcpl.lo H5Ptest.lo H5R.lo H5Rdeprec.lo H5RC.lo H5RS.lo \
-	H5S.lo H5Sall.lo H5Sdbg.lo H5Shyper.lo H5Smpio.lo H5Snone.lo \
-	H5Spoint.lo H5Sselect.lo H5Stest.lo H5SL.lo H5SM.lo \
-	H5SMbtree2.lo H5SMcache.lo H5SMtest.lo H5ST.lo H5T.lo \
-	H5Tarray.lo H5Tbit.lo H5Tcommit.lo H5Tcompound.lo H5Tconv.lo \
-	H5Tcset.lo H5Tdbg.lo H5Tdeprec.lo H5Tenum.lo H5Tfields.lo \
-	H5Tfixed.lo H5Tfloat.lo H5Tinit.lo H5Tnative.lo H5Toffset.lo \
-	H5Toh.lo H5Topaque.lo H5Torder.lo H5Tpad.lo H5Tprecis.lo \
-	H5Tstrpad.lo H5Tvisit.lo H5Tvlen.lo H5TS.lo H5V.lo H5WB.lo \
-	H5Z.lo H5Zdeflate.lo H5Zfletcher32.lo H5Znbit.lo H5Zshuffle.lo \
-	H5Zszip.lo H5Zscaleoffset.lo H5Ztrans.lo
+	H5Oshared.lo H5Oshmesg.lo H5Ostab.lo H5Ostorage.lo H5Otest.lo \
+	H5Ounknown.lo H5P.lo H5Pacpl.lo H5Pdapl.lo H5Pdcpl.lo \
+	H5Pdeprec.lo H5Pdxpl.lo H5Pfapl.lo H5Pfcpl.lo H5Pfmpl.lo \
+	H5Pgcpl.lo H5Pint.lo H5Plapl.lo H5Plcpl.lo H5Pocpl.lo \
+	H5Pocpypl.lo H5Pstrcpl.lo H5Ptest.lo H5R.lo H5Rdeprec.lo \
+	H5RC.lo H5RS.lo H5S.lo H5Sall.lo H5Sdbg.lo H5Shyper.lo \
+	H5Smpio.lo H5Snone.lo H5Spoint.lo H5Sselect.lo H5Stest.lo \
+	H5SL.lo H5SM.lo H5SMbtree2.lo H5SMcache.lo H5SMtest.lo H5ST.lo \
+	H5T.lo H5Tarray.lo H5Tbit.lo H5Tcommit.lo H5Tcompound.lo \
+	H5Tconv.lo H5Tcset.lo H5Tdbg.lo H5Tdeprec.lo H5Tenum.lo \
+	H5Tfields.lo H5Tfixed.lo H5Tfloat.lo H5Tinit.lo H5Tnative.lo \
+	H5Toffset.lo H5Toh.lo H5Topaque.lo H5Torder.lo H5Tpad.lo \
+	H5Tprecis.lo H5Tstrpad.lo H5Tvisit.lo H5Tvlen.lo H5TS.lo \
+	H5V.lo H5WB.lo H5Z.lo H5Zdeflate.lo H5Zfletcher32.lo \
+	H5Znbit.lo H5Zshuffle.lo H5Zszip.lo H5Zscaleoffset.lo \
+	H5Ztrans.lo
 libhdf5_la_OBJECTS = $(am_libhdf5_la_OBJECTS)
 libhdf5_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \
 	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
@@ -467,8 +469,11 @@ libhdf5_la_SOURCES = H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5Olayout.c \
         H5Olinfo.c H5Olink.c H5Omessage.c H5Omtime.c \
         H5Oname.c H5Onull.c H5Opline.c H5Orefcount.c \
-        H5Osdspace.c H5Oshared.c H5Ostab.c \
-        H5Oshmesg.c H5Otest.c H5Ounknown.c \
+        H5Osdspace.c H5Oshared.c \
+        H5Oshmesg.c \
+        H5Ostab.c \
+        H5Ostorage.c \
+        H5Otest.c H5Ounknown.c \
         H5P.c H5Pacpl.c H5Pdapl.c H5Pdcpl.c \
         H5Pdeprec.c H5Pdxpl.c H5Pfapl.c H5Pfcpl.c H5Pfmpl.c \
         H5Pgcpl.c H5Pint.c \
@@ -793,6 +798,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Oshared.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Oshmesg.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Ostab.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Ostorage.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Otest.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Ounknown.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5P.Plo@am__quote@