Merging in latest from upstream (HDFFV/hdf5:refs/heads/hdf5_1_8)

* commit '043aabe8cbd1abcc41ea2fb887b3a8ddd706500c':
  Made corrections according to code review. 1) Change fprintf to HDfprintf in hl/test/test_dset_opt.c 2) Remove extra line in src/H5Dpkg.h 3) Add one more test to hl/test/test_dset_opt.c Tested on mayll and osx1010test.
  Incorporate patch from GE Heathcare (HDFFV-9934) 1) Integrate the patch 2) Fix bugs when debugging the patch 3) Add test to hl/test/test_dset_opt.c Tested on moohan, ostrich, platypus, emu, osx1010test, quail, kituo, mayll.

6 files changed, 473 insertions, 128 deletions

diff --git a/src/H5D.c b/src/H5D.c
index cd3d989..7f2a96d 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -416,7 +416,7 @@ H5Dclose(hid_t dset_id)
 
     /*
      * Decrement the counter on the dataset.  It will be freed if the count
-     * reaches zero.  
+     * reaches zero.
      *
      * Pass in TRUE for the 3rd parameter to tell the function to remove
      * dataset's ID even though the freeing function might fail.  Please
@@ -1002,3 +1002,44 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dset_extent() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Dget_chunk_storage_size
+ *
+ * Purpose:     Returns the size of an allocated of chunk.
+ *
+ * Return:	Non-negative on success, negative on failure
+ *
+ * Programmer:  Matthew Strong (GE Healthcare)
+ *              20 October 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Dget_chunk_storage_size(hid_t dset_id, const hsize_t *offset, hsize_t *chunk_nbytes)
+{
+    H5D_t       *dset = NULL;
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("h", "i", dset_id);
+
+    /* Check arguments */
+    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+    if( NULL == offset )
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid argument (null)")
+    if( NULL == chunk_nbytes )
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid argument (null)")
+
+    if(H5D_CHUNKED != dset->shared->layout.type)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+
+    /* Call private function */
+    if(H5D__get_chunk_storage_size(dset, H5AC_ind_dxpl_id, offset, chunk_nbytes) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get storage size of chunk")
+
+done:
+    FUNC_LEAVE_API(ret_value);
+}
+
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 3bac996..a55a156 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -242,6 +242,9 @@ static herr_t H5D__chunk_collective_fill(const H5D_t *dset, hid_t dxpl_id,
     H5D_chunk_coll_info_t *chunk_info, size_t chunk_size, const void *fill_buf);
 #endif /* H5_HAVE_PARALLEL */
 
+static int
+H5D__chunk_dump_index_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata);
+
 /*********************/
 /* Package Variables */
 /*********************/
@@ -303,8 +306,7 @@ H5FL_BLK_DEFINE_STATIC(chunk);
 /*-------------------------------------------------------------------------
  * Function:	H5D__chunk_direct_write
  *
- * Purpose:	Internal routine to write a chunk 
- *              directly into the file.
+ * Purpose:	Internal routine to write a chunk directly into the file.
  *
  * Return:	Non-negative on success/Negative on failure
  *
@@ -314,16 +316,16 @@ H5FL_BLK_DEFINE_STATIC(chunk);
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters, hsize_t *offset, 
+H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters, hsize_t *offset,
      uint32_t data_size, const void *buf)
 {
     const H5O_layout_t *layout = &(dset->shared->layout);       /* Dataset layout */
     H5D_chunk_ud_t udata;               /* User data for querying chunk info */
-    hsize_t chunk_idx;
+    hsize_t chunk_idx;                  /* Index of chunk cache entry */
     H5D_dxpl_cache_t _dxpl_cache;       /* Data transfer property cache buffer */
     H5D_dxpl_cache_t *dxpl_cache = &_dxpl_cache;   /* Data transfer property cache */
     const H5D_rdcc_t       *rdcc = &(dset->shared->cache.chunk);	/*raw data chunk cache */
-    int         space_ndims;    /* Dataset's space rank */
+    unsigned    space_ndims;            /* Dataset's space rank */
     hsize_t     space_dim[H5O_LAYOUT_NDIMS];    /* Dataset's dataspace dimensions */
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -331,17 +333,16 @@ H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters, hsiz
 
     /* Allocate data space and initialize it if it hasn't been. */
     if(!(*dset->shared->layout.ops->is_space_alloc)(&dset->shared->layout.storage))
- 	/* Allocate storage */
+        /* Allocate storage */
         if(H5D__alloc_storage(dset, dxpl_id, H5D_ALLOC_WRITE, FALSE, NULL) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize storage")
 
     /* Retrieve the dataset dimensions */
-    if((space_ndims = H5S_get_simple_extent_dims(dset->shared->space, space_dim, NULL)) < 0)
-         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to get simple dataspace info")
+    space_ndims = dset->shared->layout.u.chunk.ndims - 1;
 
     /* Calculate the index of this chunk */
-    if(H5VM_chunk_index((unsigned)space_ndims, offset,
-	layout->u.chunk.dim, layout->u.chunk.down_chunks, &chunk_idx) < 0)
+    if(H5VM_chunk_index(space_ndims, offset,
+                        layout->u.chunk.dim, layout->u.chunk.down_chunks, &chunk_idx) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't get chunk index")
 
     /* Find out the file address of the chunk */
@@ -354,28 +355,28 @@ H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters, hsiz
      *      the 'insert' operation could resize it)
      */
     {
-	H5D_chk_idx_info_t idx_info;        /* Chunked index info */
+        H5D_chk_idx_info_t idx_info;        /* Chunked index info */
 
-	/* Compose chunked index info struct */
-	idx_info.f = dset->oloc.file;
-	idx_info.dxpl_id = dxpl_id;
-	idx_info.pline = &(dset->shared->dcpl_cache.pline);
-	idx_info.layout = &(dset->shared->layout.u.chunk);
-	idx_info.storage = &(dset->shared->layout.storage.u.chunk);
+        /* Compose chunked index info struct */
+        idx_info.f = dset->oloc.file;
+        idx_info.dxpl_id = dxpl_id;
+        idx_info.pline = &(dset->shared->dcpl_cache.pline);
+        idx_info.layout = &(dset->shared->layout.u.chunk);
+        idx_info.storage = &(dset->shared->layout.storage.u.chunk);
 
-	/* Set up the size of chunk for user data */
-	udata.nbytes = data_size;
+        /* Set up the size of chunk for user data */
+        udata.nbytes = data_size;
 
         /* Create the chunk it if it doesn't exist, or reallocate the chunk
          *  if its size changed.
          */
-	if((dset->shared->layout.storage.u.chunk.ops->insert)(&idx_info, &udata) < 0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert/resize chunk")
+        if((dset->shared->layout.storage.u.chunk.ops->insert)(&idx_info, &udata) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert/resize chunk")
 
-	/* Make sure the address of the chunk is returned. */
-	if(!H5F_addr_defined(udata.addr))
-	    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
-    } /* end if */
+        /* Make sure the address of the chunk is returned. */
+        if(!H5F_addr_defined(udata.addr))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
+     }
 
     /* Fill the DXPL cache values for later use */
     if(H5D__get_dxpl_cache(dxpl_id, &dxpl_cache) < 0)
@@ -385,7 +386,7 @@ H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters, hsiz
      * it to disk */
     if(UINT_MAX != udata.idx_hint)
         if(H5D__chunk_cache_evict(dset, dxpl_id, dxpl_cache, rdcc->slot[udata.idx_hint], FALSE) < 0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_CANTREMOVE, FAIL, "unable to evict chunk")
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTREMOVE, FAIL, "unable to evict chunk")
 
     /* Write the data to the file */
     if(H5F_block_write(dset->oloc.file, H5FD_MEM_DRAW, udata.addr, data_size, dxpl_id, buf) < 0)
@@ -395,6 +396,222 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D__chunk_direct_write() */
 
+/*-------------------------------------------------------------------------
+ * Function:    H5D__chunk_direct_read
+ *
+ * Purpose: Internal routine to read a chunk directly from the file.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ * Programmer:  Matthew Strong (GE Healthcare)
+ *              14 February 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5D__chunk_direct_read(const H5D_t *dset, hid_t dxpl_id, hsize_t *offset,
+    uint32_t* filters, void *buf)
+{
+    const H5O_layout_t *layout = &(dset->shared->layout);    /* Dataset layout */
+    const H5D_rdcc_t   *rdcc = &(dset->shared->cache.chunk); /* raw data chunk cache */
+    H5D_chunk_ud_t     udata;          /* User data for querying chunk info */
+    unsigned            space_ndims;    /* Dataset's space rank */
+    hsize_t            space_dim[H5O_LAYOUT_NDIMS]; /* Dataset's dataspace dimensions */
+    hsize_t            chunk_offset[H5O_LAYOUT_NDIMS]; /* Dataset's chunk offset */
+    hsize_t            chunk_idx;      /* Index of chunk cache entry */
+    H5D_dxpl_cache_t   _dxpl_cache;    /* Data transfer property cache buffer */
+    H5D_dxpl_cache_t   *dxpl_cache = &_dxpl_cache; /* Data transfer property cache */
+    herr_t             ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* Check args */
+    HDassert(dset && H5D_CHUNKED == layout->type);
+    HDassert(offset);
+    HDassert(filters);
+    HDassert(buf);
+
+    /* Retrieve the dataset dimensions */
+    space_ndims = dset->shared->layout.u.chunk.ndims - 1;
+
+    /* Check if chunk storage is allocated for dataset */
+    if(H5D__chunk_is_space_alloc(&(layout->storage)) == FALSE)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "storage is not initialized")
+
+    /* Initialize the chunk offset */
+    HDmemcpy(chunk_offset, offset, (space_ndims * sizeof(chunk_offset[0])));
+    chunk_offset[space_ndims] = (hsize_t)0;
+
+    /* Calculate the index of this chunk */
+    if(H5VM_chunk_index(space_ndims, chunk_offset,
+                        layout->u.chunk.dim, layout->u.chunk.down_chunks, &chunk_idx) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't get chunk index")
+
+    /* Reset fields about the chunk we are looking for */
+    udata.nbytes = 0;
+    udata.filter_mask = 0;
+    udata.addr = HADDR_UNDEF;
+    udata.idx_hint = UINT_MAX;
+
+    /* Find out the file address of the chunk */
+    if(H5D__chunk_lookup(dset, dxpl_id, chunk_offset, chunk_idx, &udata) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+
+    /* Check if the requested chunk exists in the chunk cache */
+    if(UINT_MAX != udata.idx_hint) {
+        H5D_rdcc_ent_t *ent = rdcc->slot[udata.idx_hint];
+
+        /* Sanity checks  */
+        HDassert(udata->idx_hint < rdcc->nslots);
+        HDassert(rdcc->slot[udata->idx_hint]);
+
+        /* If the cached chunk is dirty, it must be flushed to get accurate size */
+        if( ent->dirty == TRUE ) {
+            /* Fill the DXPL cache values for later use */
+            if(H5D__get_dxpl_cache(dxpl_id, &dxpl_cache) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't fill dxpl cache")
+
+            /* Flush the chunk to disk and clear the cache entry */
+            if(H5D__chunk_cache_evict(dset, dxpl_id, dxpl_cache, rdcc->slot[udata.idx_hint], TRUE) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTREMOVE, FAIL, "unable to evict chunk")
+
+            /* Reset fields about the chunk we are looking for */
+            udata.nbytes = 0;
+            udata.filter_mask = 0;
+            udata.addr = HADDR_UNDEF;
+            udata.idx_hint = UINT_MAX;
+
+            /* Get the new file address / chunk size after flushing */
+            if(H5D__chunk_lookup(dset, dxpl_id, chunk_offset, chunk_idx, &udata) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+        }
+    }
+
+    /* Make sure the address of the chunk is returned. */
+    if(!H5F_addr_defined(udata.addr))
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
+
+    /* Read the chunk data into the supplied buffer */
+    if(H5F_block_read(dset->oloc.file, H5FD_MEM_DRAW, udata.addr, udata.nbytes, dxpl_id, buf) < 0)
+        HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to read raw data chunk")
+    
+    /* Return the filter mask */
+    *filters = udata.filter_mask;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D__chunk_direct_read() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5D__get_chunk_storage_size
+ *
+ * Purpose: Internal routine to read the storage size of a chunk on disk.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ * Programmer:  Matthew Strong (GE Healthcare)
+ *              20 October 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5D__get_chunk_storage_size(H5D_t *dset, hid_t dxpl_id, const hsize_t *offset, hsize_t *storage_size)
+{
+    const H5O_layout_t *layout = &(dset->shared->layout);    /* Dataset layout */
+    const H5D_rdcc_t   *rdcc = &(dset->shared->cache.chunk); /* raw data chunk cache */
+    H5D_chunk_ud_t     udata;          /* User data for querying chunk info */
+    unsigned           space_ndims;    /* Dataset's space rank */
+    hsize_t            space_dim[H5O_LAYOUT_NDIMS]; /* Dataset's dataspace dimensions */
+    hsize_t            chunk_offset[H5O_LAYOUT_NDIMS]; /* Dataset's chunk offset */
+    hsize_t            chunk_idx;      /* Index of chunk cache entry */
+    H5D_dxpl_cache_t   _dxpl_cache;    /* Data transfer property cache buffer */
+    H5D_dxpl_cache_t   *dxpl_cache = &_dxpl_cache; /* Data transfer property cache */
+    herr_t             ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* Check args */
+    HDassert(dset && H5D_CHUNKED == layout->type);
+    HDassert(offset);
+    HDassert(filters);
+    HDassert(buf);
+
+    /* Retrieve the dataset dimensions */
+    space_ndims = dset->shared->layout.u.chunk.ndims - 1;
+    
+    if(H5D__chunk_is_space_alloc(&(layout->storage)) == FALSE) {
+        *storage_size = 0;
+        HGOTO_DONE(SUCCEED)
+    }
+
+    /* Initialize the chunk offset */
+    HDmemcpy(chunk_offset, offset, (space_ndims * sizeof(chunk_offset[0])));
+    chunk_offset[space_ndims] = (hsize_t)0;
+
+    /* Calculate the index of this chunk */
+    if(H5VM_chunk_index(space_ndims, chunk_offset,
+                        layout->u.chunk.dim, layout->u.chunk.down_chunks, &chunk_idx) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't get chunk index")
+
+    /* Reset fields about the chunk we are looking for */
+    udata.nbytes = 0;
+    udata.addr = HADDR_UNDEF;
+    udata.idx_hint = UINT_MAX;
+
+    /* Find out the file address of the chunk */
+    if(H5D__chunk_lookup(dset, dxpl_id, chunk_offset, chunk_idx, &udata) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+
+    /* The requested chunk is not in cache or on disk */
+    if(!H5F_addr_defined(udata.addr) && UINT_MAX == udata.idx_hint)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk storage is not allocated")
+
+    /* Check if there are filters registered to the dataset */
+    if( dset->shared->dcpl_cache.pline.nused > 0 ) {
+        /* Check if the requested chunk exists in the chunk cache */
+        if(UINT_MAX != udata.idx_hint) {
+            /* Sanity checks  */
+            HDassert(udata->idx_hint < rdcc->nslots);
+            HDassert(rdcc->slot[udata->idx_hint]);
+            H5D_rdcc_ent_t *ent = rdcc->slot[udata.idx_hint];
+
+            /* If the cached chunk is dirty, it must be flushed to get accurate size */
+            if( ent->dirty == TRUE ) {
+                /* Fill the DXPL cache values for later use */
+                if(H5D__get_dxpl_cache(dxpl_id, &dxpl_cache) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't fill dxpl cache")
+
+                /* Flush the chunk to disk and clear the cache entry */
+                if(H5D__chunk_cache_evict(dset, dxpl_id, dxpl_cache, rdcc->slot[udata.idx_hint], TRUE) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTREMOVE, FAIL, "unable to evict chunk")
+
+                /* Reset fields about the chunk we are looking for */
+                udata.nbytes = 0;
+                udata.addr = HADDR_UNDEF;
+                udata.idx_hint = UINT_MAX;
+
+                /* Get the new file address / chunk size after flushing */
+                if(H5D__chunk_lookup(dset, dxpl_id, chunk_offset, chunk_idx, &udata) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")            
+            }
+        }
+
+        /* Make sure the address of the chunk is returned. */
+        if(!H5F_addr_defined(udata.addr))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
+
+        /* Return the chunk size on disk */
+        *storage_size = udata.nbytes;
+    }
+    /* There are no filters registered, return the chunk size from the storage layout */
+    else
+        *storage_size = dset->shared->layout.u.chunk.size;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5D__get_chunk_storage_size */
+
+
 
 /*-------------------------------------------------------------------------
  * Function:	H5D__chunk_set_info_real
@@ -2636,25 +2853,25 @@ H5D__chunk_cache_evict(const H5D_t *dset, hid_t dxpl_id, const H5D_dxpl_cache_t
     HDassert(ent->idx < rdcc->nslots);
 
     if(flush) {
-	/* Flush */
-	if(H5D__chunk_flush_entry(dset, dxpl_id, dxpl_cache, ent, TRUE) < 0)
-	    HDONE_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "cannot flush indexed storage buffer")
+        /* Flush */
+        if(H5D__chunk_flush_entry(dset, dxpl_id, dxpl_cache, ent, TRUE) < 0)
+            HDONE_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "cannot flush indexed storage buffer")
     } /* end if */
     else {
         /* Don't flush, just free chunk */
-	if(ent->chunk != NULL)
-	    ent->chunk = (uint8_t *)H5D__chunk_xfree(ent->chunk, &(dset->shared->dcpl_cache.pline));
+        if(ent->chunk != NULL)
+            ent->chunk = (uint8_t *)H5D__chunk_xfree(ent->chunk, &(dset->shared->dcpl_cache.pline));
     } /* end else */
 
     /* Unlink from list */
     if(ent->prev)
-	ent->prev->next = ent->next;
+        ent->prev->next = ent->next;
     else
-	rdcc->head = ent->next;
+        rdcc->head = ent->next;
     if(ent->next)
-	ent->next->prev = ent->prev;
+        ent->next->prev = ent->prev;
     else
-	rdcc->tail = ent->prev;
+        rdcc->tail = ent->prev;
     ent->prev = ent->next = NULL;
 
     /* Remove from cache */
@@ -3534,7 +3751,7 @@ H5D__chunk_allocate(const H5D_t *dset, hid_t dxpl_id, hbool_t full_overwrite,
                 } /* end if */
                 else {
 #endif /* H5_HAVE_PARALLEL */
-                    if(H5F_block_write(dset->oloc.file, H5FD_MEM_DRAW, udata.addr, chunk_size, 
+                    if(H5F_block_write(dset->oloc.file, H5FD_MEM_DRAW, udata.addr, chunk_size,
                                        dxpl_id, fb_info.fill_buf) < 0)
                         HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write raw data to file")
 #ifdef H5_HAVE_PARALLEL
@@ -3600,7 +3817,7 @@ done:
  * Function:	H5D__chunk_collective_fill
  *
  * Purpose:     Use MPIO collective write to fill the chunks (if number of
- *              chunks to fill is greater than the number of MPI procs; 
+ *              chunks to fill is greater than the number of MPI procs;
  *              otherwise use independent I/O).
  *
  * Return:	Non-negative on success/Negative on failure
@@ -3683,13 +3900,13 @@ H5D__chunk_collective_fill(const H5D_t *dset, hid_t dxpl_id,
        distributing. If there are, then round robin the distribution
        to processes 0 -> leftover. */
     if(leftover && leftover > mpi_rank) {
-        chunk_disp_array[blocks] = (MPI_Aint)chunk_info->addr[blocks*mpi_size + mpi_rank];        
+        chunk_disp_array[blocks] = (MPI_Aint)chunk_info->addr[blocks*mpi_size + mpi_rank];
         block_lens[blocks] = block_len;
         blocks++;
     }
 
     /* MSC
-     * should not have a special case for blocks == 0, but ompi (as of 1.8.1) has a bug 
+     * should not have a special case for blocks == 0, but ompi (as of 1.8.1) has a bug
      * in file_set_view when a zero size datatype is create with hindexed or hvector.
      */
     if(0 == blocks) {
@@ -3701,11 +3918,11 @@ H5D__chunk_collective_fill(const H5D_t *dset, hid_t dxpl_id,
             HMPI_GOTO_ERROR(FAIL, "MPI_Type_contiguous failed", mpi_code)
     }
     else {
-        /* MSC 
-         * should use this if MPI_type_create_hindexed block is working 
+        /* MSC
+         * should use this if MPI_type_create_hindexed block is working
          * mpi_code = MPI_Type_create_hindexed_block(blocks, block_len, chunk_disp_array, MPI_BYTE, &file_type);
          */
-        mpi_code = MPI_Type_create_hindexed(blocks, block_lens, chunk_disp_array, 
+        mpi_code = MPI_Type_create_hindexed(blocks, block_lens, chunk_disp_array,
                                             MPI_BYTE, &file_type);
         if(mpi_code != MPI_SUCCESS)
             HMPI_GOTO_ERROR(FAIL, "MPI_Type_create_hindexed failed", mpi_code)
@@ -3740,7 +3957,7 @@ H5D__chunk_collective_fill(const H5D_t *dset, hid_t dxpl_id,
     }
 
     /* low level write */
-    if(H5F_block_write(dset->oloc.file, H5FD_MEM_DRAW, (haddr_t)0, (blocks) ? (size_t)1 : (size_t)0, 
+    if(H5F_block_write(dset->oloc.file, H5FD_MEM_DRAW, (haddr_t)0, (blocks) ? (size_t)1 : (size_t)0,
                        data_dxpl_id, fill_buf) < 0)
         HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write raw data to file")
 
@@ -5158,7 +5375,7 @@ H5D__chunk_dest(H5F_t *f, hid_t dxpl_id, H5D_t *dset)
 	if(H5D__chunk_cache_evict(dset, dxpl_id, dxpl_cache, ent, TRUE) < 0)
 	    nerrors++;
     } /* end for */
-    
+
     /* Continue even if there are failures. */
     if(nerrors)
 	HDONE_ERROR(H5E_IO, H5E_CANTFLUSH, FAIL, "unable to flush one or more raw data chunks")
@@ -5351,4 +5568,3 @@ H5D__nonexistent_readvv(const H5D_io_info_t *io_info,
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5D__nonexistent_readvv() */
-
diff --git a/src/H5Dio.c b/src/H5Dio.c
index 58031e8..58fc855 100644
--- a/src/H5Dio.c
+++ b/src/H5Dio.c
@@ -55,7 +55,7 @@
 static herr_t H5D__write(H5D_t *dataset, hid_t mem_type_id,
     const H5S_t *mem_space, const H5S_t *file_space, hid_t dset_xfer_plist,
     const void *buf);
-static herr_t H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id, 
+static herr_t H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id,
     const H5S_t *mem_space, const H5S_t *file_space, hid_t dxpl_id, const void *buf);
 
 /* Setup/teardown routines */
@@ -127,9 +127,13 @@ H5Dread(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
 	hid_t file_space_id, hid_t plist_id, void *buf/*out*/)
 {
     H5D_t		   *dset = NULL;
+    H5P_genplist_t 	   *plist;      /* Property list pointer */
     const H5S_t		   *mem_space = NULL;
     const H5S_t		   *file_space = NULL;
     herr_t                  ret_value = SUCCEED;  /* Return value */
+    hsize_t         *direct_offset = NULL;
+    hbool_t         direct_read = FALSE;
+    uint32_t        direct_filters = 0;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "iiiiix", dset_id, mem_type_id, mem_space_id, file_space_id,
@@ -137,28 +141,28 @@ H5Dread(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
 
     /* check arguments */
     if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
     if(NULL == dset->oloc.file)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
 
     if(mem_space_id < 0 || file_space_id < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
 
     if(H5S_ALL != mem_space_id) {
-	if(NULL == (mem_space = (const H5S_t *)H5I_object_verify(mem_space_id, H5I_DATASPACE)))
-	    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
+        if(NULL == (mem_space = (const H5S_t *)H5I_object_verify(mem_space_id, H5I_DATASPACE)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
 
-	/* Check for valid selection */
-	if(H5S_SELECT_VALID(mem_space) != TRUE)
-	    HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "selection+offset not within extent")
+        /* Check for valid selection */
+        if(H5S_SELECT_VALID(mem_space) != TRUE)
+            HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "selection+offset not within extent")
     } /* end if */
     if(H5S_ALL != file_space_id) {
-	if(NULL == (file_space = (const H5S_t *)H5I_object_verify(file_space_id, H5I_DATASPACE)))
-	    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
+        if(NULL == (file_space = (const H5S_t *)H5I_object_verify(file_space_id, H5I_DATASPACE)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
 
-	/* Check for valid selection */
-	if(H5S_SELECT_VALID(file_space) != TRUE)
-	    HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "selection+offset not within extent")
+        /* Check for valid selection */
+        if(H5S_SELECT_VALID(file_space) != TRUE)
+            HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "selection+offset not within extent")
     } /* end if */
 
     /* Get the default dataset transfer property list if the user didn't provide one */
@@ -168,9 +172,58 @@ H5Dread(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
         if(TRUE != H5P_isa_class(plist_id, H5P_DATASET_XFER))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not xfer parms")
 
-    /* read raw data */
-    if(H5D__read(dset, mem_type_id, mem_space, file_space, plist_id, buf/*out*/) < 0)
-	HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read data")
+    /* Get the dataset transfer property list */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(plist_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset transfer property list")
+
+    /* Retrieve the 'direct read' flag */
+    if(H5P_get(plist, H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME, &direct_read) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "error getting flag for direct chunk read")
+
+    if(direct_read) {
+        unsigned u;
+        int      ndims = 0;
+        hsize_t  dims[H5O_LAYOUT_NDIMS];
+        hsize_t  internal_offset[H5O_LAYOUT_NDIMS];
+
+        if(H5D_CHUNKED != dset->shared->layout.type)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+        /* Get the direct chunk offset property */
+        if(H5P_get(plist, H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME, &direct_offset) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "error getting direct offset from xfer properties")
+
+        /* The library's chunking code requires the offset terminates with a zero. So transfer the
+         * offset array to an internal offset array */
+        if((ndims = H5S_get_simple_extent_dims(dset->shared->space, dims, NULL)) < 0)
+            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't retrieve dataspace extent dims")
+
+        for(u = 0; u < ndims; u++) {
+            /* Make sure the offset doesn't exceed the dataset's dimensions */
+            if(direct_offset[u] > dims[u])
+                HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "offset exceeds dimensions of dataset")
+
+            /* Make sure the offset fall right on a chunk's boundary */
+            if(direct_offset[u] % dset->shared->layout.u.chunk.dim[u])
+                HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "offset doesn't fall on chunks's boundary")
+
+            internal_offset[u] = direct_offset[u];
+        } /* end for */
+
+        /* Terminate the offset with a zero */
+        internal_offset[ndims] = 0;
+
+        /* Read the raw chunk */
+        if(H5D__chunk_direct_read(dset, plist_id, internal_offset, &direct_filters, buf) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read chunk directly")
+        /* Set the chunk filter mask property */
+        if(H5P_set(plist, H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME, &direct_filters) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "error setting filter mask xfer property")
+    }
+    else {
+      /* read raw data */
+      if(H5D__read(dset, mem_type_id, mem_space, file_space, plist_id, buf/*out*/) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read data")
+    }
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -225,9 +278,9 @@ H5Dwrite(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
 
     /* check arguments */
     if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
     if(NULL == dset->oloc.file)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
 
     /* Get the default dataset transfer property list if the user didn't provide one */
     if(H5P_DEFAULT == dxpl_id)
@@ -249,26 +302,26 @@ H5Dwrite(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
         if(mem_space_id < 0 || file_space_id < 0)
 	    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
 
-	if(H5S_ALL != mem_space_id) {
-	    if(NULL == (mem_space = (const H5S_t *)H5I_object_verify(mem_space_id, H5I_DATASPACE)))
-	        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
-
-	    /* Check for valid selection */
-	    if(H5S_SELECT_VALID(mem_space) != TRUE)
-		HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "memory selection+offset not within extent")
-	} /* end if */
-	if(H5S_ALL != file_space_id) {
-	    if(NULL == (file_space = (const H5S_t *)H5I_object_verify(file_space_id, H5I_DATASPACE)))
-		HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
-
-	    /* Check for valid selection */
-	    if(H5S_SELECT_VALID(file_space) != TRUE)
-		HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "file selection+offset not within extent")
-	} /* end if */
+        if(H5S_ALL != mem_space_id) {
+            if(NULL == (mem_space = (const H5S_t *)H5I_object_verify(mem_space_id, H5I_DATASPACE)))
+                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+
+            /* Check for valid selection */
+            if(H5S_SELECT_VALID(mem_space) != TRUE)
+                HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "memory selection+offset not within extent")
+        } /* end if */
+        if(H5S_ALL != file_space_id) {
+            if(NULL == (file_space = (const H5S_t *)H5I_object_verify(file_space_id, H5I_DATASPACE)))
+                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+
+            /* Check for valid selection */
+            if(H5S_SELECT_VALID(file_space) != TRUE)
+                HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, FAIL, "file selection+offset not within extent")
+        } /* end if */
     }
 
-    if(H5D__pre_write(dset, direct_write, mem_type_id, mem_space, file_space, dxpl_id, buf) < 0) 
-	HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't prepare for writing data")
+    if(H5D__pre_write(dset, direct_write, mem_type_id, mem_space, file_space, dxpl_id, buf) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't prepare for writing data")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -278,7 +331,7 @@ done:
 /*-------------------------------------------------------------------------
  * Function:	H5D__pre_write
  *
- * Purpose:	Preparation for writing data.  
+ * Purpose:	Preparation for writing data.
  *
  * Return:	Non-negative on success/Negative on failure
  *
@@ -288,8 +341,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id, 
-         const H5S_t *mem_space, const H5S_t *file_space, 
+H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id,
+         const H5S_t *mem_space, const H5S_t *file_space,
          hid_t dxpl_id, const void *buf)
 {
     herr_t                  ret_value = SUCCEED;  /* Return value */
@@ -302,17 +355,17 @@ H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id,
         uint32_t direct_filters;
         hsize_t *direct_offset;
         uint32_t direct_datasize;
-	int      ndims = 0;
-	hsize_t  dims[H5O_LAYOUT_NDIMS];
-	hsize_t  internal_offset[H5O_LAYOUT_NDIMS];
-	unsigned u;
+        int      ndims = 0;
+        hsize_t  dims[H5O_LAYOUT_NDIMS];
+        hsize_t  internal_offset[H5O_LAYOUT_NDIMS];
+        unsigned u;
 
         /* Get the dataset transfer property list */
         if(NULL == (plist = (H5P_genplist_t *)H5I_object(dxpl_id)))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset transfer property list")
 
         if(H5D_CHUNKED != dset->shared->layout.type)
-	    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
 
         /* Retrieve parameters for direct chunk write */
         if(H5P_get(plist, H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME, &direct_filters) < 0)
@@ -322,34 +375,34 @@ H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id,
         if(H5P_get(plist, H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME, &direct_datasize) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "error getting data size for direct chunk write")
 
-	/* The library's chunking code requires the offset terminates with a zero. So transfer the 
-         * offset array to an internal offset array */ 
-	if((ndims = H5S_get_simple_extent_dims(dset->shared->space, dims, NULL)) < 0)
-	    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't retrieve dataspace extent dims")
+        /* The library's chunking code requires the offset terminates with a zero. So transfer the
+         * offset array to an internal offset array */
+        if((ndims = H5S_get_simple_extent_dims(dset->shared->space, dims, NULL)) < 0)
+            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't retrieve dataspace extent dims")
 
-	for(u = 0; u < ndims; u++) {
-	    /* Make sure the offset doesn't exceed the dataset's dimensions */
+        for(u = 0; u < ndims; u++) {
+            /* Make sure the offset doesn't exceed the dataset's dimensions */
             if(direct_offset[u] > dims[u])
-		HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "offset exceeds dimensions of dataset")
+                HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "offset exceeds dimensions of dataset")
 
             /* Make sure the offset fall right on a chunk's boundary */
-	    if(direct_offset[u] % dset->shared->layout.u.chunk.dim[u])
-		HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "offset doesn't fall on chunks's boundary")
-
-	    internal_offset[u] = direct_offset[u]; 
-	} /* end for */
-	   
-	/* Terminate the offset with a zero */ 
-	internal_offset[ndims] = 0;
-
-	/* write raw data */
-	if(H5D__chunk_direct_write(dset, dxpl_id, direct_filters, internal_offset, direct_datasize, buf) < 0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write chunk directly")
+            if(direct_offset[u] % dset->shared->layout.u.chunk.dim[u])
+                HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "offset doesn't fall on chunks's boundary")
+
+            internal_offset[u] = direct_offset[u];
+        } /* end for */
+
+        /* Terminate the offset with a zero */
+        internal_offset[ndims] = 0;
+
+        /* write raw data */
+        if(H5D__chunk_direct_write(dset, dxpl_id, direct_filters, internal_offset, direct_datasize, buf) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write chunk directly")
     } /* end if */
     else {     /* Normal write */
         /* write raw data */
         if(H5D__write(dset, mem_type_id, mem_space, file_space, dxpl_id, buf) < 0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write data")
+            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write data")
     } /* end else */
 
 done:
@@ -430,7 +483,7 @@ H5D__read(H5D_t *dataset, hid_t mem_type_id, const H5S_t *mem_space,
 
 #ifdef H5_HAVE_PARALLEL
     /* Collective access is not permissible without a MPI based VFD */
-    if(dxpl_cache->xfer_mode == H5FD_MPIO_COLLECTIVE && 
+    if(dxpl_cache->xfer_mode == H5FD_MPIO_COLLECTIVE &&
        !(H5F_HAS_FEATURE(dataset->oloc.file, H5FD_FEAT_HAS_MPI)))
         HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL, "collective access for MPI-based drivers only")
 #endif /*H5_HAVE_PARALLEL*/
@@ -459,16 +512,16 @@ H5D__read(H5D_t *dataset, hid_t mem_type_id, const H5S_t *mem_space,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "memory dataspace does not have extent set")
 
     /* H5S_select_shape_same() has been modified to accept topologically identical
-     * selections with different rank as having the same shape (if the most 
-     * rapidly changing coordinates match up), but the I/O code still has 
+     * selections with different rank as having the same shape (if the most
+     * rapidly changing coordinates match up), but the I/O code still has
      * difficulties with the notion.
      *
-     * To solve this, we check to see if H5S_select_shape_same() returns true, 
-     * and if the ranks of the mem and file spaces are different.  If the are, 
-     * construct a new mem space that is equivalent to the old mem space, and 
+     * To solve this, we check to see if H5S_select_shape_same() returns true,
+     * and if the ranks of the mem and file spaces are different.  If the are,
+     * construct a new mem space that is equivalent to the old mem space, and
      * use that instead.
      *
-     * Note that in general, this requires us to touch up the memory buffer as 
+     * Note that in general, this requires us to touch up the memory buffer as
      * well.
      */
     if(TRUE == H5S_select_shape_same(mem_space, file_space) &&
@@ -715,17 +768,17 @@ H5D__write(H5D_t *dataset, hid_t mem_type_id, const H5S_t *mem_space,
     if(!(H5S_has_extent(mem_space)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "memory dataspace does not have extent set")
 
-    /* H5S_select_shape_same() has been modified to accept topologically 
-     * identical selections with different rank as having the same shape 
-     * (if the most rapidly changing coordinates match up), but the I/O 
+    /* H5S_select_shape_same() has been modified to accept topologically
+     * identical selections with different rank as having the same shape
+     * (if the most rapidly changing coordinates match up), but the I/O
      * code still has difficulties with the notion.
      *
-     * To solve this, we check to see if H5S_select_shape_same() returns 
-     * true, and if the ranks of the mem and file spaces are different.  
-     * If the are, construct a new mem space that is equivalent to the 
+     * To solve this, we check to see if H5S_select_shape_same() returns
+     * true, and if the ranks of the mem and file spaces are different.
+     * If the are, construct a new mem space that is equivalent to the
      * old mem space, and use that instead.
      *
-     * Note that in general, this requires us to touch up the memory buffer 
+     * Note that in general, this requires us to touch up the memory buffer
      * as well.
      */
     if(TRUE == H5S_select_shape_same(mem_space, file_space) &&
@@ -1237,4 +1290,3 @@ H5D__typeinfo_term(const H5D_type_info_t *type_info)
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5D__typeinfo_term() */
-
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index ff01041..91cf5f3 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -538,6 +538,7 @@ H5_DLL herr_t H5D__get_space_status(H5D_t *dset, H5D_space_status_t *allocation,
 H5_DLL herr_t H5D__alloc_storage(const H5D_t *dset, hid_t dxpl_id, H5D_time_alloc_t time_alloc,
     hbool_t full_overwrite, hsize_t old_dim[]);
 H5_DLL herr_t H5D__get_storage_size(H5D_t *dset, hid_t dxpl_id, hsize_t *storage_size);
+H5_DLL herr_t H5D__get_chunk_storage_size(H5D_t *dset, hid_t dxpl_id, const hsize_t *offset, hsize_t *storage_size);
 H5_DLL haddr_t H5D__get_offset(const H5D_t *dset);
 H5_DLL void *H5D__vlen_get_buf_size_alloc(size_t size, void *info);
 H5_DLL herr_t H5D__vlen_get_buf_size(void *elem, hid_t type_id, unsigned ndim,
@@ -638,6 +639,8 @@ H5_DLL herr_t H5D__chunk_delete(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
     H5O_storage_t *store);
 H5_DLL herr_t H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters, 
          hsize_t *offset, uint32_t data_size, const void *buf);
+H5_DLL herr_t H5D__chunk_direct_read(const H5D_t *dset, hid_t dxpl_id, hsize_t *offset,
+         uint32_t *filters, void *buf);
 #ifdef H5D_CHUNK_DEBUG
 H5_DLL herr_t H5D__chunk_stats(const H5D_t *dset, hbool_t headers);
 #endif /* H5D_CHUNK_DEBUG */
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index e7ae3ae..2eb5ff8 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -34,12 +34,17 @@
 #define H5D_CHUNK_CACHE_NBYTES_DEFAULT      ((size_t) -1)
 #define H5D_CHUNK_CACHE_W0_DEFAULT          (-1.0f)
 
-/* Property names for H5LTDdirect_chunk_write */   
+/* Property names for H5LTDdirect_chunk_write */
 #define H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME	        "direct_chunk_flag"
 #define H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME	"direct_chunk_filters"
 #define H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_NAME		"direct_chunk_offset"
 #define H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME	"direct_chunk_datasize"
- 
+
+/* Property names for H5LTDdirect_chunk_read */
+#define H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME        "direct_chunk_read_flag"
+#define H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME      "direct_chunk_read_offset"
+#define H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME      "direct_chunk_read_filters"
+
 /*******************/
 /* Public Typedefs */
 /*******************/
@@ -128,6 +133,7 @@ H5_DLL hid_t H5Dget_type(hid_t dset_id);
 H5_DLL hid_t H5Dget_create_plist(hid_t dset_id);
 H5_DLL hid_t H5Dget_access_plist(hid_t dset_id);
 H5_DLL hsize_t H5Dget_storage_size(hid_t dset_id);
+H5_DLL herr_t H5Dget_chunk_storage_size(hid_t dset_id, const hsize_t *offset, hsize_t *chunk_bytes);
 H5_DLL haddr_t H5Dget_offset(hid_t dset_id);
 H5_DLL herr_t H5Dread(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
 			hid_t file_space_id, hid_t plist_id, void *buf/*out*/);
@@ -170,4 +176,3 @@ H5_DLL herr_t H5Dextend(hid_t dset_id, const hsize_t size[]);
 }
 #endif
 #endif /* _H5Dpublic_H */
-
diff --git a/src/H5Pdxpl.c b/src/H5Pdxpl.c
index ce16036..d9e7ec7 100644
--- a/src/H5Pdxpl.c
+++ b/src/H5Pdxpl.c
@@ -137,6 +137,13 @@
 #define H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_DEF		NULL
 #define H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_SIZE	sizeof(uint32_t)
 #define H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_DEF	0
+/* Definitions for properties of direct chunk read */
+#define H5D_XFER_DIRECT_CHUNK_READ_FLAG_SIZE        sizeof(hbool_t)
+#define H5D_XFER_DIRECT_CHUNK_READ_FLAG_DEF         FALSE
+#define H5D_XFER_DIRECT_CHUNK_READ_FILTERS_SIZE     sizeof(uint32_t)
+#define H5D_XFER_DIRECT_CHUNK_READ_FILTERS_DEF      0
+#define H5D_XFER_DIRECT_CHUNK_READ_OFFSET_SIZE		sizeof(hsize_t *)
+#define H5D_XFER_DIRECT_CHUNK_READ_OFFSET_DEF		NULL
 
 /******************/
 /* Local Typedefs */
@@ -241,6 +248,9 @@ H5P__dxfr_reg_prop(H5P_genclass_t *pclass)
     uint32_t direct_chunk_filters = H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_DEF;	/* Default value for the filters of direct chunk write */
     hsize_t *direct_chunk_offset = H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_DEF; 	/* Default value for the offset of direct chunk write */
     uint32_t direct_chunk_datasize = H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_DEF;    /* Default value for the datasize of direct chunk write */
+    hbool_t direct_chunk_read_flag = H5D_XFER_DIRECT_CHUNK_READ_FLAG_DEF;         /* Default value for the flag of direct chunk read */
+    hsize_t *direct_chunk_read_offset = H5D_XFER_DIRECT_CHUNK_READ_OFFSET_DEF; 	  /* Default value for the offset of direct chunk read */
+    uint32_t direct_chunk_read_filters = H5D_XFER_DIRECT_CHUNK_READ_FILTERS_DEF;    /* Default value for the filters of direct chunk read */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
@@ -365,6 +375,24 @@ H5P__dxfr_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the property of flag for direct chunk read */
+    /* (Note: this property should not have an encode/decode callback) */
+    if(H5P_register_real(pclass, H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME, H5D_XFER_DIRECT_CHUNK_READ_FLAG_SIZE, &direct_chunk_read_flag,
+            NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
+    /* Register the property of filter for direct chunk read */
+    /* (Note: this property should not have an encode/decode callback) */
+    if(H5P_register_real(pclass, H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME, H5D_XFER_DIRECT_CHUNK_READ_FILTERS_SIZE, &direct_chunk_read_filters,
+            NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
+    /* Register the property of offset for direct chunk read */
+    /* (Note: this property should not have an encode/decode callback) */
+    if(H5P_register_real(pclass, H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME, H5D_XFER_DIRECT_CHUNK_READ_OFFSET_SIZE, &direct_chunk_read_offset,
+            NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5P__dxfr_reg_prop() */