Merge pull request #473 in HDFFV/hdf5 from ~VCHOI/my_hdf5_fork:develop to develop

* commit 'bacb45b38ae8513024baf2dfe08c8918625489e2':
  Modifications based on pull request review. Made couple changes based on the review comments.
  Incorporate patch from GE Healthcare (HDFFV-9934) This is the same patch that had already been integrated to 1.8 branch (pull request #387). Tested on moohan, ostrich, platypus, emu, osx1010test, quail, kituo, mayll.

9 files changed, 899 insertions, 159 deletions

diff --git a/hl/src/H5DO.c b/hl/src/H5DO.c
index 8db6768..99cf2f7 100644
--- a/hl/src/H5DO.c
+++ b/hl/src/H5DO.c
@@ -32,7 +32,7 @@
  * Return:	Non-negative on success/Negative on failure
  *
  * Programmer:	Raymond Lu
- *		30 July 2012
+ *		        30 July 2012
  *
  *-------------------------------------------------------------------------
  */
@@ -60,7 +60,7 @@ H5DOwrite_chunk(hid_t dset_id, hid_t dxpl_id, uint32_t filters, const hsize_t *o
 
     /* If the user passed in a default DXPL, create one to pass to H5Dwrite() */
     if(H5P_DEFAULT == dxpl_id) {
-	if((dxpl_id = H5Pcreate(H5P_DATASET_XFER)) < 0)
+        if((dxpl_id = H5Pcreate(H5P_DATASET_XFER)) < 0)
             goto done;
         created_dxpl = TRUE;
     } /* end if */
@@ -87,16 +87,87 @@ done:
         if(H5Pclose(dxpl_id) < 0)
             ret_value = FAIL;
     } /* end if */
-    else
+    else {
         /* Reset the direct write flag on user DXPL */
+        do_direct_write = FALSE;
         if(H5Pset(dxpl_id, H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME, &do_direct_write) < 0)
             ret_value = FAIL;
+    }
 
-    return(ret_value);
+    return ret_value;
 } /* end H5DOwrite_chunk() */
 
 
-/*
+/*-------------------------------------------------------------------------
+ * Function:    H5DOread_chunk
+ *
+ * Purpose:     Reads an entire chunk from the file directly.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Matthew Strong (GE Healthcare)
+ *              14 February 2016
+ *
+ *---------------------------------------------------------------------------
+ */
+herr_t
+H5DOread_chunk(hid_t dset_id, hid_t dxpl_id, const hsize_t *offset, uint32_t *filters,
+         void *buf)
+{
+    hbool_t created_dxpl = FALSE;       /* Whether we created a DXPL */
+    hbool_t do_direct_read = TRUE;     /* Flag for direct writes */
+    herr_t  ret_value = FAIL;           /* Return value */
+
+    /* Check arguments */
+    if(dset_id < 0)
+        goto done;
+    if(!buf)
+        goto done;
+    if(!offset)
+        goto done;
+    if(!filters)
+        goto done;
+
+    /* If the user passed in a default DXPL, create one to pass to H5Dwrite() */
+    if(H5P_DEFAULT == dxpl_id) {
+        if((dxpl_id = H5Pcreate(H5P_DATASET_XFER)) < 0)
+            goto done;
+        created_dxpl = TRUE;
+    } /* end if */
+
+    /* Set direct write parameters */
+    if(H5Pset(dxpl_id, H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME, &do_direct_read) < 0)
+        goto done;
+    if(H5Pset(dxpl_id, H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME, &offset) < 0)
+        goto done;
+
+    /* Read chunk */
+    if(H5Dread(dset_id, 0, H5S_ALL, H5S_ALL, dxpl_id, buf) < 0)
+        goto done;
+    /* Get the filter mask */
+    if(H5Pget(dxpl_id, H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME, filters) < 0)
+        goto done;
+
+    /* Indicate success */
+    ret_value = SUCCEED;
+
+done:
+    if(created_dxpl) {
+        if(H5Pclose(dxpl_id) < 0)
+            ret_value = FAIL;
+    } /* end if */
+    else {
+        /* Reset the direct read flag on user DXPL */
+        do_direct_read = FALSE;
+        if(H5Pset(dxpl_id, H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME, &do_direct_read) < 0)
+            ret_value = FAIL;
+    }
+
+    return ret_value;
+} /* end H5DOread_chunk() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5DOappend()
  *
  * Purpose:     To append elements to a dataset.
@@ -122,6 +193,8 @@ done:
  *		  ret_value = FAIL;
  *		  goto done;
  *   		}
+ *
+ *-------------------------------------------------------------------------
  */
 herr_t
 H5DOappend(hid_t dset_id, hid_t dxpl_id, unsigned axis, size_t extension, 
diff --git a/hl/src/H5DOpublic.h b/hl/src/H5DOpublic.h
index ce0d32e..d5c8de4 100644
--- a/hl/src/H5DOpublic.h
+++ b/hl/src/H5DOpublic.h
@@ -28,6 +28,12 @@ extern "C" {
 H5_HLDLL herr_t H5DOwrite_chunk(hid_t dset_id, hid_t dxpl_id, uint32_t filters, 
     const hsize_t *offset, size_t data_size, const void *buf);
 
+H5_HLDLL herr_t H5DOread_chunk(hid_t dset_id, /*in*/
+            hid_t dxpl_id,         /*in*/
+            const hsize_t *offset, /*in*/
+            uint32_t *filters,     /*out*/
+            void *buf);            /*out*/
+
 H5_HLDLL herr_t H5DOappend(hid_t dset_id, hid_t dxpl_id, unsigned axis,
     size_t extension, hid_t memtype, const void *buf);
 
diff --git a/hl/test/test_dset_opt.c b/hl/test/test_dset_opt.c
index 03c467a..d3a6b5c 100644
--- a/hl/test/test_dset_opt.c
+++ b/hl/test/test_dset_opt.c
@@ -76,11 +76,10 @@ const H5Z_class2_t H5Z_BOGUS2[1] = {{
 /*-------------------------------------------------------------------------
  * Function:	test_direct_chunk_write
  *
- * Purpose:	Test the basic functionality of H5DOwrite_chunk
+ * Purpose:	Test the basic functionality of H5DOwrite_chunk/H5DOread_chunk
  *
  * Return:	Success:	0
- *
- *		Failure:	1
+ *		    Failure:	1
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -103,24 +102,31 @@ test_direct_chunk_write (hid_t file)
     int         i, j, n;
 
     unsigned    filter_mask = 0;
+    unsigned    read_filter_mask = 0;
     int         direct_buf[CHUNK_NX][CHUNK_NY];
     int         check_chunk[CHUNK_NX][CHUNK_NY];
     hsize_t     offset[2] = {0, 0};
     size_t      buf_size = CHUNK_NX*CHUNK_NY*sizeof(int);
 
     const Bytef *z_src = (const Bytef*)(direct_buf);
-    Bytef	    *z_dst;		/*destination buffer		*/
+    Bytef	    *z_dst;		        /*destination buffer		*/
     uLongf	     z_dst_nbytes = (uLongf)DEFLATE_SIZE_ADJUST(buf_size);
     uLong	     z_src_nbytes = (uLong)buf_size;
-    int          aggression = 9;     /* Compression aggression setting */
-    void	*outbuf = NULL;         /* Pointer to new buffer */
+    int          aggression = 9;    /* Compression aggression setting */
+    void	     *outbuf = NULL;    /* Pointer to new buffer */
+
+    /* For H5DOread_chunk() */
+    void        *readbuf = NULL;                    /* Buffer for reading data */
+    const Bytef *pt_readbuf;                        /* Point to the buffer for data read */
+    hsize_t     read_chunk_nbytes;                  /* Size of chunk on disk */
+    int         read_dst_buf[CHUNK_NX][CHUNK_NY];   /* Buffer to hold un-compressed data */
 
     hsize_t start[2];  /* Start of hyperslab */
     hsize_t stride[2]; /* Stride of hyperslab */
     hsize_t count[2];  /* Block count */
     hsize_t block[2];  /* Block sizes */
 
-    TESTING("basic functionality of H5DOwrite_chunk");
+    TESTING("basic functionality of H5DOwrite_chunk/H5DOread_chunk");
 
     /*
      * Create the data space with unlimited dimensions.
@@ -151,26 +157,76 @@ test_direct_chunk_write (hid_t file)
 			cparms, H5P_DEFAULT)) < 0)
         goto error;
 
-    /* Initialize the dataset */
-    for(i = n = 0; i < NX; i++)
-        for(j = 0; j < NY; j++)
-	    data[i][j] = n++;
-
     if((dxpl = H5Pcreate(H5P_DATASET_XFER)) < 0)
         goto error;
 
+    HDmemset(data, 0, sizeof(data));
+    /* Initialize data for the first chunk */
+    for(i = n = 0; i < CHUNK_NX; i++)
+        for(j = 0; j < CHUNK_NY; j++)
+            data[i][j] = n++;
+
     /*
-     * Write the data for the dataset.  It should stay in the chunk cache.
-     * It will be evicted from the cache by the H5DOwrite_chunk calls. 
-     */
+     * Write the data for the dataset. */
     if((status = H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL,
 		      dxpl, data)) < 0)
         goto error;
 
+    if(H5Fflush(dataset, H5F_SCOPE_LOCAL) < 0)
+        goto error;
+
+    if(H5Dclose(dataset) < 0)
+        goto error;
+
+    if((dataset = H5Dopen2(file, DATASETNAME1, H5P_DEFAULT)) < 0)
+        goto error;
+
+    offset[0] = offset[1] = 0;
+
+    /* Get the size of the compressed chunk */
+    ret = H5Dget_chunk_storage_size(dataset, offset, &read_chunk_nbytes);
+
+    readbuf = HDmalloc(read_chunk_nbytes);
+    pt_readbuf = (const Bytef *)readbuf;
+
+    /* Test to use H5DOread_chunk() to read the chunk back */
+    if((status = H5DOread_chunk(dataset, H5P_DEFAULT, offset, &read_filter_mask, readbuf)) < 0)
+        goto error;
+
+    /* uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen) */
+    ret = uncompress((Bytef *)read_dst_buf, (uLongf *)&buf_size, pt_readbuf, (uLong)read_chunk_nbytes);
+
+    /* Check for various zlib errors */
+    if(Z_BUF_ERROR == ret) {
+        HDfprintf(stderr, "error: not enough room in output buffer");
+        goto error;
+    } else if(Z_MEM_ERROR == ret) {
+        HDfprintf(stderr, "error: not enough memory");
+        goto error;
+    } else if(Z_OK != ret) {
+        HDfprintf(stderr, "error: corrupted input data");
+        goto error;
+    }
+
+    /* Check that the values read are the same as the values written */
+    for(i = 0; i < CHUNK_NX; i++) {
+        for(j = 0; j < CHUNK_NY; j++) {
+            if(data[i][j] != read_dst_buf[i][j]) {
+                printf("    1. Read different values than written.");
+                printf("    At index %d,%d\n", i, j);
+                printf("    data=%d, read_dst_buf=%d\n", data[i][j], read_dst_buf[i][j]);
+                goto error;
+            }
+        }
+    }
+
+    if(readbuf)
+        HDfree(readbuf);
+
     /* Initialize data for one chunk */
     for(i = n = 0; i < CHUNK_NX; i++)
         for(j = 0; j < CHUNK_NY; j++)
-	    direct_buf[i][j] = n++;
+            direct_buf[i][j] = n++;
 
     /* Allocate output (compressed) buffer */
     outbuf = HDmalloc(z_dst_nbytes);
@@ -181,18 +237,18 @@ test_direct_chunk_write (hid_t file)
 
     /* Check for various zlib errors */
     if(Z_BUF_ERROR == ret) {
-        fprintf(stderr, "overflow");
+        HDfprintf(stderr, "overflow");
         goto error;
     } else if(Z_MEM_ERROR == ret) {
-	fprintf(stderr, "deflate memory error");
+        HDfprintf(stderr, "deflate memory error");
         goto error;
     } else if(Z_OK != ret) {
-	fprintf(stderr, "other deflate error");
+        HDfprintf(stderr, "other deflate error");
         goto error;
     }
 
-    /* Write the compressed chunk data repeatedly to cover all the chunks in the 
-     * dataset, using the direct writing function.     */ 
+    /* Write the compressed chunk data repeatedly to cover all the chunks in the
+     * dataset, using the direct writing function.     */
     for(i=0; i<NX/CHUNK_NX; i++) {
         for(j=0; j<NY/CHUNK_NY; j++) {
             status = H5DOwrite_chunk(dataset, dxpl, filter_mask, offset, z_dst_nbytes, outbuf);
@@ -205,7 +261,7 @@ test_direct_chunk_write (hid_t file)
     if(outbuf)
         HDfree(outbuf);
 
-    if(H5Fflush(dataset, H5F_SCOPE_LOCAL) < 0) 
+    if(H5Fflush(dataset, H5F_SCOPE_LOCAL) < 0)
         goto error;
 
     if(H5Dclose(dataset) < 0)
@@ -214,6 +270,59 @@ test_direct_chunk_write (hid_t file)
     if((dataset = H5Dopen2(file, DATASETNAME1, H5P_DEFAULT)) < 0)
         goto error;
 
+    offset[0] = CHUNK_NX;
+    offset[1] = CHUNK_NY;
+
+    /* Get the size of the compressed chunk */
+    ret = H5Dget_chunk_storage_size(dataset, offset, &read_chunk_nbytes);
+
+    if(read_chunk_nbytes != (hsize_t)z_dst_nbytes) {
+        HDfprintf(stderr, "Read/write chunk size not the same.");
+        goto error;
+    }
+
+    readbuf = HDmalloc(read_chunk_nbytes);
+    pt_readbuf = (const Bytef *)readbuf;
+
+    /* Test to use H5DOread_chunk() to read the chunk back */
+    if((status = H5DOread_chunk(dataset, H5P_DEFAULT, offset, &read_filter_mask, readbuf)) < 0)
+        goto error;
+
+    if(read_filter_mask != filter_mask) {
+        HDfprintf(stderr, "    Read/write filter mask not the same.");
+        goto error;
+    }
+
+    /* uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen) */
+    ret = uncompress((Bytef *)read_dst_buf, (uLongf *)&buf_size, pt_readbuf, (uLong)read_chunk_nbytes);
+
+    /* Check for various zlib errors */
+    if(Z_BUF_ERROR == ret) {
+        HDfprintf(stderr, "error: not enough room in output buffer");
+        goto error;
+    } else if(Z_MEM_ERROR == ret) {
+        HDfprintf(stderr, "error: not enough memory");
+        goto error;
+    } else if(Z_OK != ret) {
+        HDfprintf(stderr, "error: corrupted input data");
+        goto error;
+    }
+
+    /* Check that the values read are the same as the values written */
+    for(i = 0; i < CHUNK_NX; i++) {
+        for(j = 0; j < CHUNK_NY; j++) {
+            if(direct_buf[i][j] != read_dst_buf[i][j]) {
+                printf("    1. Read different values than written.");
+                printf("    At index %d,%d\n", i, j);
+                printf("    direct_buf=%d, read_dst_buf=%d\n", direct_buf[i][j], read_dst_buf[i][j]);
+                goto error;
+            }
+        }
+    }
+
+    if(readbuf)
+        HDfree(readbuf);
+
     /*
      * Select hyperslab for one chunk in the file
      */
@@ -224,7 +333,7 @@ test_direct_chunk_write (hid_t file)
     if((status = H5Sselect_hyperslab(dataspace, H5S_SELECT_SET, start, stride, count, block)) < 0)
         goto error;
 
-    /* Read the chunk back */
+    /* Test to use H5Dread() to read the chunk back */
     if((status = H5Dread(dataset, H5T_NATIVE_INT, mem_space, dataspace, H5P_DEFAULT, check_chunk)) < 0)
         goto error;
 
@@ -234,38 +343,40 @@ test_direct_chunk_write (hid_t file)
             if(direct_buf[i][j] != check_chunk[i][j]) {
                 printf("    1. Read different values than written.");
                 printf("    At index %d,%d\n", i, j);
-                printf("    direct_buf=%d, check_chunk=%d\n", direct_buf[i][j], check_chunk[i][j]); 
+                printf("    direct_buf=%d, check_chunk=%d\n", direct_buf[i][j], check_chunk[i][j]);
                 goto error;
             }
         }
     }
 
+
     /* Reinitialize different data for one chunk */
     for(i = 0; i < CHUNK_NX; i++)
         for(j = 0; j < CHUNK_NY; j++)
-	    direct_buf[i][j] = i + j;
+            direct_buf[i][j] = i + j;
 
     /* Allocate output (compressed) buffer */
     outbuf = HDmalloc(z_dst_nbytes);
     z_dst = (Bytef *)outbuf;
 
+    
     /* Perform compression from the source to the destination buffer */
     ret = compress2(z_dst, &z_dst_nbytes, z_src, z_src_nbytes, aggression);
 
     /* Check for various zlib errors */
     if(Z_BUF_ERROR == ret) {
-        fprintf(stderr, "overflow");
+        HDfprintf(stderr, "overflow");
         goto error;
     } else if(Z_MEM_ERROR == ret) {
-	fprintf(stderr, "deflate memory error");
+        HDfprintf(stderr, "deflate memory error");
         goto error;
     } else if(Z_OK != ret) {
-	fprintf(stderr, "other deflate error");
+        HDfprintf(stderr, "other deflate error");
         goto error;
     }
 
-    /* Rewrite the compressed chunk data repeatedly to cover all the chunks in the 
-     * dataset, using the direct writing function.     */ 
+    /* Rewrite the compressed chunk data repeatedly to cover all the chunks in the
+     * dataset, using the direct writing function.     */
     offset[0] = offset[1] = 0;
     for(i=0; i<NX/CHUNK_NX; i++) {
         for(j=0; j<NY/CHUNK_NY; j++) {
@@ -279,7 +390,7 @@ test_direct_chunk_write (hid_t file)
     if(outbuf)
         HDfree(outbuf);
 
-    if(H5Fflush(dataset, H5F_SCOPE_LOCAL) < 0) 
+    if(H5Fflush(dataset, H5F_SCOPE_LOCAL) < 0)
         goto error;
 
     if(H5Dclose(dataset) < 0)
@@ -288,7 +399,60 @@ test_direct_chunk_write (hid_t file)
     if((dataset = H5Dopen2(file, DATASETNAME1, H5P_DEFAULT)) < 0)
         goto error;
 
-    /* Read the chunk back */
+    offset[0] = CHUNK_NX;
+    offset[1] = CHUNK_NY;
+
+    /* Get the size of the compressed chunk */
+    ret = H5Dget_chunk_storage_size(dataset, offset, &read_chunk_nbytes);
+
+    if(read_chunk_nbytes != (hsize_t)z_dst_nbytes) {
+        HDfprintf(stderr, "Read/write chunk size not the same.");
+        goto error;
+    }
+
+    readbuf = HDmalloc(read_chunk_nbytes);
+    pt_readbuf = (const Bytef *)readbuf;
+
+    /* Test to use H5DOread_chunk() to read the chunk back */
+    if((status = H5DOread_chunk(dataset, H5P_DEFAULT, offset, &read_filter_mask, readbuf)) < 0)
+        goto error;
+
+    if(read_filter_mask != filter_mask) {
+        HDfprintf(stderr, "    Read/write filter mask not the same.");
+        goto error;
+    }
+
+    /* uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen) */
+    ret = uncompress((Bytef *)read_dst_buf, (uLongf *)&buf_size, pt_readbuf, (uLong)read_chunk_nbytes);
+
+    /* Check for various zlib errors */
+    if(Z_BUF_ERROR == ret) {
+        HDfprintf(stderr, "error: not enough room in output buffer");
+        goto error;
+    } else if(Z_MEM_ERROR == ret) {
+        HDfprintf(stderr, "error: not enough memory");
+        goto error;
+    } else if(Z_OK != ret) {
+        HDfprintf(stderr, "error: corrupted input data");
+        goto error;
+    }
+
+    /* Check that the values read are the same as the values written */
+    for(i = 0; i < CHUNK_NX; i++) {
+        for(j = 0; j < CHUNK_NY; j++) {
+            if(direct_buf[i][j] != read_dst_buf[i][j]) {
+                printf("    1. Read different values than written.");
+                printf("    At index %d,%d\n", i, j);
+                printf("    direct_buf=%d, my_buf=%d\n", direct_buf[i][j], read_dst_buf[i][j]);
+                goto error;
+            }
+        }
+    }
+
+    if(readbuf)
+        HDfree(readbuf);
+
+    /* Test to use H5Dread() to read the chunk back */
     if((status = H5Dread(dataset, H5T_NATIVE_INT, mem_space, dataspace, H5P_DEFAULT, check_chunk)) < 0)
         goto error;
 
@@ -298,7 +462,7 @@ test_direct_chunk_write (hid_t file)
             if(direct_buf[i][j] != check_chunk[i][j]) {
                 printf("    2. Read different values than written.");
                 printf("    At index %d,%d\n", i, j);
-                printf("    direct_buf=%d, check_chunk=%d\n", direct_buf[i][j], check_chunk[i][j]); 
+                printf("    direct_buf=%d, check_chunk=%d\n", direct_buf[i][j], check_chunk[i][j]);
                 goto error;
             }
         }
@@ -312,7 +476,7 @@ test_direct_chunk_write (hid_t file)
     H5Sclose(dataspace);
     H5Pclose(cparms);
     H5Pclose(dxpl);
-    
+
     PASSED();
     return 0;
 
@@ -327,6 +491,8 @@ error:
 
     if(outbuf)
         HDfree(outbuf);
+    if(readbuf)
+        HDfree(readbuf);
 
     return 1;
 }
@@ -335,12 +501,11 @@ error:
 /*-------------------------------------------------------------------------
  * Function:	test_skip_compress_write1
  *
- * Purpose:	Test skipping compression filter when it is the only filter
+ * Purpose:	    Test skipping compression filter when it is the only filter
  *              for the dataset
  *
  * Return:	Success:	0
- *
- *		Failure:	1
+ *		    Failure:	1
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -360,6 +525,7 @@ test_skip_compress_write1(hid_t file)
     int         i, j, n;
 
     unsigned    filter_mask = 0;
+    unsigned    read_filter_mask = 0;
     int         direct_buf[CHUNK_NX][CHUNK_NY];
     int         check_chunk[CHUNK_NX][CHUNK_NY];
     hsize_t     offset[2] = {0, 0};
@@ -371,7 +537,7 @@ test_skip_compress_write1(hid_t file)
     hsize_t count[2];  /* Block count */
     hsize_t block[2];  /* Block sizes */
 
-    TESTING("skipping compression filter for H5DOwrite_chunk");
+    TESTING("skipping compression filter for H5DOwrite_chunk/H5DOread_chunk");
 
     /*
      * Create the data space with unlimited dimensions.
@@ -408,7 +574,7 @@ test_skip_compress_write1(hid_t file)
     /* Initialize data for one chunk */
     for(i = n = 0; i < CHUNK_NX; i++)
         for(j = 0; j < CHUNK_NY; j++) {
-	    direct_buf[i][j] = n++;
+            direct_buf[i][j] = n++;
     }
 
     /* write the uncompressed chunk data repeatedly to dataset, using the direct writing function. 
@@ -430,6 +596,30 @@ test_skip_compress_write1(hid_t file)
     if((dataset = H5Dopen2(file, DATASETNAME2, H5P_DEFAULT)) < 0)
         goto error;
 
+    /* Use H5DOread_chunk() to read the uncompressed data */
+    if((status = H5DOread_chunk(dataset, dxpl, offset, &read_filter_mask, check_chunk)) < 0)
+        goto error;
+
+    if(read_filter_mask != filter_mask) {
+        HDfprintf(stderr, "    Read/write filter mask not the same.");
+        goto error;
+    }
+
+    /* Check that the values read are the same as the values written */
+    for(i = 0; i < CHUNK_NX; i++) {
+        for(j = 0; j < CHUNK_NY; j++) {
+            if(direct_buf[i][j] != check_chunk[i][j]) {
+                printf("    1. Read different values than written.");
+                printf("    At index %d,%d\n", i, j);
+                printf("    direct_buf=%d, check_chunk=%d\n", direct_buf[i][j], check_chunk[i][j]);
+                goto error;
+            }
+        }
+    }
+
+    /* Clear the buffer */
+    HDmemset(check_chunk, 0, buf_size);
+
     /*
      * Select hyperslab for the chunk just written in the file
      */
@@ -440,7 +630,7 @@ test_skip_compress_write1(hid_t file)
     if((status = H5Sselect_hyperslab(dataspace, H5S_SELECT_SET, start, stride, count, block)) < 0)
         goto error;
 
-    /* Read the chunk back */
+    /* Use H5Dread() to read the chunk back */
     if((status = H5Dread(dataset, H5T_NATIVE_INT, mem_space, dataspace, H5P_DEFAULT, check_chunk)) < 0)
         goto error;
 
@@ -483,9 +673,9 @@ error:
 /*-------------------------------------------------------------------------
  * Function:	filter_bogus1
  *
- * Purpose:	A bogus filte that adds ADD_ON to the original value
+ * Purpose:	    A bogus filter that adds ADD_ON to the original value
  *
- * Return:	Success:	Data chunk size
+ * Return:	    Success:	Data chunk size
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -558,12 +748,11 @@ filter_bogus2(unsigned int flags, size_t H5_ATTR_UNUSED cd_nelmts,
 /*-------------------------------------------------------------------------
  * Function:	test_skip_compress_write2
  *
- * Purpose:	Test skipping compression filter when there are three filters
+ * Purpose:	    Test skipping compression filter when there are three filters
  *              for the dataset
  *
- * Return:	Success:	0
- *
- *		Failure:	1
+ * Return:	    Success:	0
+ *		        Failure:	1
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -583,6 +772,7 @@ test_skip_compress_write2(hid_t file)
     int         i, j, n;
 
     unsigned    filter_mask = 0;
+    unsigned    read_filter_mask = 0;
     int         origin_direct_buf[CHUNK_NX][CHUNK_NY];
     int         direct_buf[CHUNK_NX][CHUNK_NY];
     int         check_chunk[CHUNK_NX][CHUNK_NY];
@@ -618,10 +808,10 @@ test_skip_compress_write2(hid_t file)
 
     /* Register and enable first bogus filter */
     if(H5Zregister (H5Z_BOGUS1) < 0) 
-	goto error;
+        goto error;
 
     if(H5Pset_filter(cparms, H5Z_FILTER_BOGUS1, 0, (size_t)0, NULL) < 0) 
-	goto error;
+        goto error;
 
     /* Enable compression filter */
     if((status = H5Pset_deflate( cparms, (unsigned) aggression)) < 0)
@@ -629,10 +819,10 @@ test_skip_compress_write2(hid_t file)
 
     /* Register and enable second bogus filter */
     if(H5Zregister (H5Z_BOGUS2) < 0) 
-	goto error;
+        goto error;
 
     if(H5Pset_filter(cparms, H5Z_FILTER_BOGUS2, 0, (size_t)0, NULL) < 0) 
-	goto error;
+        goto error;
 
     /*
      * Create a new dataset within the file using cparms
@@ -648,9 +838,9 @@ test_skip_compress_write2(hid_t file)
     /* Initialize data for one chunk. Apply operations of two bogus filters to the chunk */
     for(i = n = 0; i < CHUNK_NX; i++)
         for(j = 0; j < CHUNK_NY; j++) {
-	    origin_direct_buf[i][j] = n++;
-	    direct_buf[i][j] = (origin_direct_buf[i][j] + ADD_ON) * FACTOR;
-    }
+            origin_direct_buf[i][j] = n++;
+            direct_buf[i][j] = (origin_direct_buf[i][j] + ADD_ON) * FACTOR;
+        }
 
     /* write the uncompressed chunk data repeatedly to dataset, using the direct writing function. 
      * Indicate skipping the compression filter but keep the other two bogus filters */ 
@@ -672,6 +862,35 @@ test_skip_compress_write2(hid_t file)
     if((dataset = H5Dopen2(file, DATASETNAME3, H5P_DEFAULT)) < 0)
         goto error;
 
+    /* Use H5DOread_chunk() to read the uncompressed data */
+    if((status = H5DOread_chunk(dataset, dxpl, offset, &read_filter_mask, check_chunk)) < 0)
+        goto error;
+
+    if(read_filter_mask != filter_mask) {
+        HDfprintf(stderr, "    Read/write filter mask not the same.");
+        goto error;
+    }
+
+    /* De-compress the operations of the two bogus filters to the chunk */
+    for(i = n = 0; i < CHUNK_NX; i++)
+        for(j = 0; j < CHUNK_NY; j++)
+            check_chunk[i][j] = (check_chunk[i][j]/FACTOR) - ADD_ON;
+
+    /* Check that the values read are the same as the values written */
+    for(i = 0; i < CHUNK_NX; i++) {
+        for(j = 0; j < CHUNK_NY; j++) {
+            if(origin_direct_buf[i][j] != check_chunk[i][j]) {
+                printf("    1. Read different values than written.");
+                printf("    At index %d,%d\n", i, j);
+                printf("    origin_direct_buf=%d, check_chunk=%d\n", origin_direct_buf[i][j], check_chunk[i][j]);
+                goto error;
+            }
+        }
+    }
+
+    /* Clear the buffer */
+    HDmemset(check_chunk, 0, buf_size);
+
     /*
      * Select hyperslab for one chunk in the file
      */
@@ -682,7 +901,7 @@ test_skip_compress_write2(hid_t file)
     if((status = H5Sselect_hyperslab(dataspace, H5S_SELECT_SET, start, stride, count, block)) < 0)
         goto error;
 
-    /* Read the chunk back */
+    /* Use H5Dread() to read the chunk back */
     if((status = H5Dread(dataset, H5T_NATIVE_INT, mem_space, dataspace, H5P_DEFAULT, check_chunk)) < 0)
         goto error;
 
@@ -725,11 +944,10 @@ error:
 /*-------------------------------------------------------------------------
  * Function:	test_data_conv
  *
- * Purpose:	Test data conversion
- *
- * Return:	Success:	0
+ * Purpose:	    Test data conversion
  *
- *		Failure:	1
+ * Return:	    Success:	0
+ *		        Failure:	1
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -740,10 +958,10 @@ static int
 test_data_conv(hid_t file)
 {
     typedef struct {
-	int a, b, c[4], d, e;
+        int a, b, c[4], d, e;
     } src_type_t;
     typedef struct {
-	int a,    c[4],    e;
+        int a,    c[4],    e;
     } dst_type_t;
 
     hid_t       dataspace = -1, dataset = -1;
@@ -761,6 +979,8 @@ test_data_conv(hid_t file)
     unsigned    filter_mask = 0;
     src_type_t  direct_buf[CHUNK_NX][CHUNK_NY];
     dst_type_t  check_chunk[CHUNK_NX][CHUNK_NY];
+    src_type_t  read_chunk[CHUNK_NX][CHUNK_NY];       /* For H5DOread_chunk */
+
     hsize_t     offset[2] = {0, 0};
     size_t      buf_size = CHUNK_NX*CHUNK_NY*sizeof(src_type_t);
 
@@ -769,7 +989,7 @@ test_data_conv(hid_t file)
     hsize_t count[2];  /* Block count */
     hsize_t block[2];  /* Block sizes */
 
-    TESTING("data conversion for H5DOwrite_chunk");
+    TESTING("data conversion for H5DOwrite_chunk/H5DOread_chunk");
 
     /*
      * Create the data space with unlimited dimensions.
@@ -854,6 +1074,36 @@ test_data_conv(hid_t file)
     if((dataset = H5Dopen2(file, DATASETNAME4, H5P_DEFAULT)) < 0)
         goto error;
 
+    /* Use H5DOread_chunk() to read the uncompressed data */
+    if((status = H5DOread_chunk(dataset, dxpl, offset, &filter_mask, read_chunk)) < 0)
+        goto error;
+
+    /* Check that the values read are the same as the values written */
+    for(i = 0; i < CHUNK_NX; i++) {
+        for(j = 0; j < CHUNK_NY; j++) {
+            if ((direct_buf[i][j]).a    != (read_chunk[i][j]).a    ||
+                (direct_buf[i][j]).b    != (read_chunk[i][j]).b    ||
+                (direct_buf[i][j]).c[0] != (read_chunk[i][j]).c[0] ||
+                (direct_buf[i][j]).c[1] != (read_chunk[i][j]).c[1] ||
+                (direct_buf[i][j]).c[2] != (read_chunk[i][j]).c[2] ||
+                (direct_buf[i][j]).c[3] != (read_chunk[i][j]).c[3] ||
+                (direct_buf[i][j]).d    != (read_chunk[i][j]).d    ||
+                (direct_buf[i][j]).e    != (read_chunk[i][j]).e) {
+                    printf("    1. Read different values than written.");
+                    printf("    At index %d,%d\n", i, j);
+                    printf("    src={a=%d, b=%d, c=[%d,%d,%d,%d], d=%d, e=%d\n",
+                        (direct_buf[i][j]).a, (direct_buf[i][j]).b, (direct_buf[i][j]).c[0], (direct_buf[i][j]).c[1],
+                        (direct_buf[i][j]).c[2], (direct_buf[i][j]).c[3], (direct_buf[i][j]).d, (direct_buf[i][j]).e);
+                    printf("    dst={a=%d, b=%d, c=[%d,%d,%d,%d], d=%d, e=%d\n",
+                        (read_chunk[i][j]).a, (read_chunk[i][j]).b, (read_chunk[i][j]).c[0], (read_chunk[i][j]).c[1],
+                        (read_chunk[i][j]).c[2], (read_chunk[i][j]).c[3], (read_chunk[i][j]).d, (read_chunk[i][j]).e);
+
+                    goto error;
+            }
+        }
+    }
+
+
     /*
      * Select hyperslab for the chunk just written in the file
      */
@@ -879,14 +1129,14 @@ test_data_conv(hid_t file)
 	        (direct_buf[i][j]).e    != (check_chunk[i][j]).e) {
                 printf("    1. Read different values than written.");
                 printf("    At index %d,%d\n", i, j);
-	        printf("    src={a=%d, b=%d, c=[%d,%d,%d,%d], d=%d, e=%d\n",
+                printf("    src={a=%d, b=%d, c=[%d,%d,%d,%d], d=%d, e=%d\n",
                    (direct_buf[i][j]).a, (direct_buf[i][j]).b, (direct_buf[i][j]).c[0], (direct_buf[i][j]).c[1], 
                    (direct_buf[i][j]).c[2], (direct_buf[i][j]).c[3], (direct_buf[i][j]).d, (direct_buf[i][j]).e);
-	        printf("    dst={a=%d, c=[%d,%d,%d,%d], e=%d\n",
+                printf("    dst={a=%d, c=[%d,%d,%d,%d], e=%d\n",
                    (check_chunk[i][j]).a, (check_chunk[i][j]).c[0], (check_chunk[i][j]).c[1], (check_chunk[i][j]).c[2], 
                    (check_chunk[i][j]).c[3], (check_chunk[i][j]).e);
 
-	    goto error;
+                goto error;
             }
         }
     }
@@ -923,11 +1173,10 @@ error:
 /*-------------------------------------------------------------------------
  * Function:	test_invalid_parameters
  *
- * Purpose:	Test invalid parameters for H5DOwrite_chunk
- *
- * Return:	Success:	0
+ * Purpose:	    Test invalid parameters for H5DOwrite_chunk and H5DOread_chunk
  *
- *		Failure:	1
+ * Return:	    Success:	0
+ *		        Failure:	1
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -951,7 +1200,9 @@ test_invalid_parameters(hid_t file)
     size_t      buf_size = CHUNK_NX*CHUNK_NY*sizeof(int);
     int         aggression = 9;     /* Compression aggression setting */
 
-    TESTING("invalid parameters for H5DOwrite_chunk");
+    hsize_t     chunk_nbytes;       /* Chunk size */
+
+    TESTING("invalid parameters for H5DOwrite_chunk/H5DOread_chunk");
 
     /*
      * Create the data space with unlimited dimensions.
@@ -969,7 +1220,7 @@ test_invalid_parameters(hid_t file)
         goto error;
 
     /*
-     * Create a new contiguous dataset to verify H5DOwrite_chunk doesn't work
+     * Create a new contiguous dataset to verify H5DOwrite_chunk/H5DOread_chunk doesn't work
      */
     if((dataset = H5Dcreate2(file, DATASETNAME5, H5T_NATIVE_INT, dataspace, H5P_DEFAULT,
 			cparms, H5P_DEFAULT)) < 0)
@@ -981,8 +1232,8 @@ test_invalid_parameters(hid_t file)
     /* Initialize data for one chunk */
     for(i = n = 0; i < CHUNK_NX; i++)
         for(j = 0; j < CHUNK_NY; j++) {
-	    direct_buf[i][j] = n++;
-    }
+            direct_buf[i][j] = n++;
+        }
 
     /* Try to write the chunk data to contiguous dataset.  It should fail */
     offset[0] = CHUNK_NX;
@@ -993,6 +1244,18 @@ test_invalid_parameters(hid_t file)
             goto error;
     } H5E_END_TRY;
 
+     /* Try to get chunk size for a contiguous dataset.  It should fail */
+    H5E_BEGIN_TRY {
+        if((status = H5Dget_chunk_storage_size(dataset, offset, &chunk_nbytes)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
+    /* Try to H5DOread_chunk from the contiguous dataset.  It should fail */
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk(dataset, dxpl, offset, &filter_mask, direct_buf)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
     if(H5Dclose(dataset) < 0)
         goto error;
 
@@ -1011,25 +1274,40 @@ test_invalid_parameters(hid_t file)
 			cparms, H5P_DEFAULT)) < 0)
         goto error;
 
-    /* Check invalid dataset ID */ 
+    /* Check invalid dataset ID for H5DOwrite_chunk and H5DOread_chunk */
     H5E_BEGIN_TRY {
         if((status = H5DOwrite_chunk((hid_t)-1, dxpl, filter_mask, offset, buf_size, direct_buf)) != FAIL)
             goto error;
     } H5E_END_TRY;
 
-    /* Check invalid DXPL ID */
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk((hid_t)-1, dxpl, offset, &filter_mask, direct_buf)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
+    /* Check invalid DXPL ID for H5DOwrite_chunk and H5DOread_chunk */
     H5E_BEGIN_TRY {
         if((status = H5DOwrite_chunk(dataset, (hid_t)-1, filter_mask, offset, buf_size, direct_buf)) != FAIL)
             goto error;
     } H5E_END_TRY;
 
-    /* Check invalid OFFSET */
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk(dataset, (hid_t)-1, offset, &filter_mask, direct_buf)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
+    /* Check invalid OFFSET for H5DOwrite_chunk and H5DOread_chunk */
     H5E_BEGIN_TRY {
         if((status = H5DOwrite_chunk(dataset, dxpl, filter_mask, NULL, buf_size, direct_buf)) != FAIL)
             goto error;
     } H5E_END_TRY;
 
-    /* Check when OFFSET is out of dataset range */
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk(dataset, dxpl, NULL, &filter_mask, direct_buf)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
+    /* Check when OFFSET is out of dataset range for H5DOwrite_chunk and H5DOread_chunk */
     offset[0] = NX + 1;
     offset[1] = NY;
     H5E_BEGIN_TRY {
@@ -1037,7 +1315,12 @@ test_invalid_parameters(hid_t file)
             goto error;
     } H5E_END_TRY;
 
-    /* Check when OFFSET is not on chunk boundary */
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk(dataset, dxpl, offset, &filter_mask, direct_buf)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
+    /* Check when OFFSET is not on chunk boundary for H5DOwrite_chunk and H5DOread_chunk */
     offset[0] = CHUNK_NX;
     offset[1] = CHUNK_NY + 1;
     H5E_BEGIN_TRY {
@@ -1045,7 +1328,12 @@ test_invalid_parameters(hid_t file)
             goto error;
     } H5E_END_TRY;
 
-    /* Check invalid buffer size */
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk(dataset, dxpl, offset, &filter_mask, direct_buf)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
+    /* Check invalid buffer size for H5DOwrite_chunk only */
     offset[0] = CHUNK_NX;
     offset[1] = CHUNK_NY;
     buf_size = 0; 
@@ -1054,13 +1342,18 @@ test_invalid_parameters(hid_t file)
             goto error;
     } H5E_END_TRY;
 
-    /* Check invalid data buffer */
+    /* Check invalid data buffer for H5DOwrite_chunk and H5DOread_chunk */
     buf_size = CHUNK_NX*CHUNK_NY*sizeof(int);
     H5E_BEGIN_TRY {
         if((status = H5DOwrite_chunk(dataset, dxpl, filter_mask, offset, buf_size, NULL)) != FAIL)
             goto error;
     } H5E_END_TRY;
 
+    H5E_BEGIN_TRY {
+        if((status = H5DOread_chunk(dataset, dxpl, offset, &filter_mask, NULL)) != FAIL)
+            goto error;
+    } H5E_END_TRY;
+
     if(H5Dclose(dataset) < 0)
         goto error;
 
@@ -1090,11 +1383,11 @@ error:
 /*-------------------------------------------------------------------------
  * Function:	Main function
  *
- * Purpose:	Test direct chunk write function H5DOwrite_chunk
- *
- * Return:	Success:	0
+ * Purpose:	    Test direct chunk write function H5DOwrite_chunk and
+ *              chunk direct read function H5DOread_chunk
  *
- *		Failure:	1
+ * Return:	    Success:	0
+ *		        Failure:	1
  *
  * Programmer:  Raymond Lu	
  *              30 November 2012
@@ -1112,7 +1405,7 @@ int main( void )
     if((file_id = H5Fcreate(FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
         goto error;
 
-    /* Test direct chunk write */
+    /* Test direct chunk write and direct chunk read */
 #ifdef H5_HAVE_FILTER_DEFLATE
     nerrors += test_direct_chunk_write(file_id);
 #endif /* H5_HAVE_FILTER_DEFLATE */
diff --git a/src/H5D.c b/src/H5D.c
index 6f69ee4..fc2024a 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -1087,3 +1087,43 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* H5Dget_chunk_index_type() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Dget_chunk_storage_size
+ *
+ * Purpose:     Returns the size of an allocated 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)
+    H5TRACE3("e", "i*h*h", dset_id, offset, chunk_nbytes);
+
+    /* 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, H5P_DATASET_XFER_DEFAULT, offset, chunk_nbytes) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get storage size of chunk")
+
+done:
+    FUNC_LEAVE_API(ret_value);
+} /* H5Dget_chunk_storage_size() */
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index ce684a0..4905a70 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -303,6 +303,9 @@ 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 */
 /*********************/
@@ -369,8 +372,7 @@ H5FL_EXTERN(H5S_sel_iter_t);
 /*-------------------------------------------------------------------------
  * 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
  *
@@ -408,7 +410,7 @@ H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters,
 
     /* Allocate dataspace and initialize it if it hasn't been. */
     if(!(*layout->ops->is_space_alloc)(&layout->storage)) {
- 	/* Allocate storage */
+        /* Allocate storage */
         if(H5D__alloc_storage(&io_info, H5D_ALLOC_WRITE, FALSE, NULL) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize storage")
     }
@@ -465,7 +467,7 @@ H5D__chunk_direct_write(const H5D_t *dset, hid_t dxpl_id, uint32_t filters,
             HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't fill dxpl cache")
 
         if(H5D__chunk_cache_evict(dset, io_info.md_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")
     } /* end if */
 
     /* Write the data to the file */
@@ -491,6 +493,244 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * 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 */
+    hsize_t scaled[H5S_MAX_RANK];       /* Scaled coordinates for this chunk */
+    H5D_io_info_t io_info;              /* to hold the dset and two dxpls (meta and raw data) */
+    H5D_dxpl_cache_t   _dxpl_cache;     /* Data transfer property cache buffer */
+    H5D_dxpl_cache_t   *dxpl_cache = &_dxpl_cache; /* Data transfer property cache */
+    hbool_t md_dxpl_generated = FALSE;  /* bool to indicate whether we should free the md_dxpl_id at exit */
+    herr_t             ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_STATIC_TAG(dxpl_id, dset->oloc.addr, FAIL)
+
+    /* Check args */
+    HDassert(dset && H5D_CHUNKED == layout->type);
+    HDassert(offset);
+    HDassert(filters);
+    HDassert(buf);
+
+    io_info.dset = dset;
+    io_info.raw_dxpl_id = dxpl_id;
+    io_info.md_dxpl_id = dxpl_id;
+
+    /* set the dxpl IO type for sanity checking at the FD layer */
+#ifdef H5_DEBUG_BUILD
+    if(H5D_set_io_info_dxpls(&io_info, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't set metadata and raw data dxpls")
+    md_dxpl_generated = TRUE;
+#endif /* H5_DEBUG_BUILD */
+
+    /* Allocate dataspace and initialize it if it hasn't been. */
+    if(!(*layout->ops->is_space_alloc)(&layout->storage))
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "storage is not initialized")
+
+    /* Calculate the index of this chunk */
+    H5VM_chunk_scaled(dset->shared->ndims, offset, layout->u.chunk.dim, scaled);
+    scaled[dset->shared->ndims] = 0;
+
+    /* Reset fields about the chunk we are looking for */
+    udata.filter_mask = 0;
+    udata.chunk_block.offset = HADDR_UNDEF;
+    udata.chunk_block.length = 0;
+    udata.idx_hint = UINT_MAX;
+
+    /* Find out the file address of the chunk */
+    if(H5D__chunk_lookup(dset, io_info.md_dxpl_id, scaled, &udata) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+
+    /* Sanity check */
+    HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
+            (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
+
+    /* 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(io_info.raw_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, io_info.md_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.filter_mask = 0;
+            udata.chunk_block.offset = HADDR_UNDEF;
+            udata.chunk_block.length = 0;
+            udata.idx_hint = UINT_MAX;
+
+            /* Get the new file address / chunk size after flushing */
+            if(H5D__chunk_lookup(dset, io_info.md_dxpl_id, scaled, &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.chunk_block.offset))
+        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.chunk_block.offset, udata.chunk_block.length, io_info.raw_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:
+#ifdef H5_DEBUG_BUILD
+    if(md_dxpl_generated && H5I_dec_ref(io_info.md_dxpl_id) < 0)
+        HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, FAIL, "can't close metadata dxpl")
+#endif /* H5_DEBUG_BUILD */
+    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 */
+    hsize_t scaled[H5S_MAX_RANK];       /* Scaled coordinates for this chunk */
+    H5D_io_info_t io_info;              /* to hold the dset and two dxpls (meta and raw data) */
+    H5D_chunk_ud_t     udata;           /* User data for querying chunk info */
+    H5D_dxpl_cache_t   _dxpl_cache;     /* Data transfer property cache buffer */
+    H5D_dxpl_cache_t   *dxpl_cache = &_dxpl_cache; /* Data transfer property cache */
+    hbool_t md_dxpl_generated = FALSE;  /* bool to indicate whether we should free the md_dxpl_id at exit */
+    herr_t             ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_STATIC_TAG(dxpl_id, dset->oloc.addr, FAIL)
+
+    /* Check args */
+    HDassert(dset && H5D_CHUNKED == layout->type);
+    HDassert(offset);
+    HDassert(storage_size);
+
+    io_info.dset = dset;
+    io_info.raw_dxpl_id = dxpl_id;
+    io_info.md_dxpl_id = dxpl_id;
+
+    /* set the dxpl IO type for sanity checking at the FD layer */
+#ifdef H5_DEBUG_BUILD
+    if(H5D_set_io_info_dxpls(&io_info, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't set metadata and raw data dxpls")
+    md_dxpl_generated = TRUE;
+#endif /* H5_DEBUG_BUILD */
+
+    /* Allocate dataspace and initialize it if it hasn't been. */
+    if(!(*layout->ops->is_space_alloc)(&layout->storage)) {
+        *storage_size = 0;
+        HGOTO_DONE(SUCCEED)
+    }
+
+    /* Calculate the index of this chunk */
+    H5VM_chunk_scaled(dset->shared->ndims, offset, layout->u.chunk.dim, scaled);
+    scaled[dset->shared->ndims] = 0;
+
+    /* Reset fields about the chunk we are looking for */
+    udata.chunk_block.offset = HADDR_UNDEF;
+    udata.chunk_block.length = 0;
+    udata.idx_hint = UINT_MAX;
+
+    /* Find out the file address of the chunk */
+    if(H5D__chunk_lookup(dset, io_info.md_dxpl_id, scaled, &udata) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+
+    /* Sanity check */
+    HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
+            (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
+
+    /* The requested chunk is not in cache or on disk */
+    if(!H5F_addr_defined(udata.chunk_block.offset) && 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, io_info.md_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.chunk_block.offset = HADDR_UNDEF;
+                udata.chunk_block.length = 0;
+                udata.idx_hint = UINT_MAX;
+
+                /* Get the new file address / chunk size after flushing */
+                if(H5D__chunk_lookup(dset, io_info.md_dxpl_id, scaled, &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.chunk_block.offset))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
+
+        /* Return the chunk size on disk */
+        *storage_size = udata.chunk_block.length;
+    }
+    /* There are no filters registered, return the chunk size from the storage layout */
+    else
+        *storage_size = dset->shared->layout.u.chunk.size;
+
+done:
+#ifdef H5_DEBUG_BUILD
+    if(md_dxpl_generated && H5I_dec_ref(io_info.md_dxpl_id) < 0)
+        HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, FAIL, "can't close metadata dxpl")
+#endif /* H5_DEBUG_BUILD */
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5D__get_chunk_storage_size */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D__chunk_set_info_real
  *
  * Purpose:	Internal routine to set the information about chunks for a dataset
@@ -519,22 +759,22 @@ H5D__chunk_set_info_real(H5O_layout_chunk_t *layout, unsigned ndims,
     /* Compute the # of chunks in dataset dimensions */
     for(u = 0, layout->nchunks = 1, layout->max_nchunks = 1; u < ndims; u++) {
         /* Round up to the next integer # of chunks, to accomodate partial chunks */
-	layout->chunks[u] = ((curr_dims[u] + layout->dim[u]) - 1) / layout->dim[u];
+        layout->chunks[u] = ((curr_dims[u] + layout->dim[u]) - 1) / layout->dim[u];
         if(H5S_UNLIMITED == max_dims[u])
             layout->max_chunks[u] = H5S_UNLIMITED;
         else
             layout->max_chunks[u] = ((max_dims[u] + layout->dim[u]) - 1) / layout->dim[u];
 
         /* Accumulate the # of chunks */
-	layout->nchunks *= layout->chunks[u];
-	layout->max_nchunks *= layout->max_chunks[u];
+        layout->nchunks *= layout->chunks[u];
+        layout->max_nchunks *= layout->max_chunks[u];
     } /* end for */
 
     /* Get the "down" sizes for each dimension */
     if(H5VM_array_down(ndims, layout->chunks, layout->down_chunks) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't compute 'down' chunk size value")
     if(H5VM_array_down(ndims, layout->max_chunks, layout->max_down_chunks) < 0)
-	HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't compute 'down' chunk size value")
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't compute 'down' chunk size value")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -2383,14 +2623,14 @@ H5D__chunk_dest(H5D_t *dset, hid_t dxpl_id)
 
     /* Flush all the cached chunks */
     for(ent = rdcc->head; ent; ent = next) {
-	next = ent->next;
-	if(H5D__chunk_cache_evict(dset, dxpl_id, dxpl_cache, ent, TRUE) < 0)
-	    nerrors++;
+        next = ent->next;
+        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")
+        HDONE_ERROR(H5E_IO, H5E_CANTFLUSH, FAIL, "unable to flush one or more raw data chunks")
 
     /* Release cache structures */
     if(rdcc->slot)
@@ -2997,27 +3237,27 @@ 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_mem_xfree(ent->chunk,
+        if(ent->chunk != NULL)
+            ent->chunk = (uint8_t *)H5D__chunk_mem_xfree(ent->chunk,
                     ((ent->edge_chunk_state & H5D_RDCC_DISABLE_FILTERS) ? NULL
                     : &(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;
 
     /* Unlink from temporary list */
diff --git a/src/H5Dio.c b/src/H5Dio.c
index dfd3f17..572e6cf 100644
--- a/src/H5Dio.c
+++ b/src/H5Dio.c
@@ -125,9 +125,13 @@ 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;
-    const H5S_t		   *mem_space = NULL;
-    const H5S_t		   *file_space = NULL;
-    herr_t                  ret_value = SUCCEED;  /* Return value */
+    const H5S_t	    *mem_space = NULL;
+    const H5S_t	    *file_space = NULL;
+    H5P_genplist_t     *plist;              /* Property list pointer */
+    hsize_t         *direct_offset = NULL;
+    hbool_t         direct_read = FALSE;
+    uint32_t        direct_filters = 0;
+    herr_t          ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "iiiiix", dset_id, mem_type_id, mem_space_id, file_space_id,
@@ -135,28 +139,29 @@ 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 */
@@ -166,9 +171,55 @@ 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;
+        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 */
+        for(u = 0; u < dset->shared->ndims; u++) {
+            /* Make sure the offset doesn't exceed the dataset's dimensions */
+            if(direct_offset[u] > dset->shared->curr_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[dset->shared->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)
@@ -245,28 +296,28 @@ H5Dwrite(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
     /* Check dataspace selections if this is not a direct write */
     if(!direct_write) {
         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 */
+            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(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")
+        HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't prepare for writing data")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -300,15 +351,15 @@ 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;
-	hsize_t  internal_offset[H5O_LAYOUT_NDIMS];
-	unsigned u;                 /* Local index variable */
+        hsize_t  internal_offset[H5O_LAYOUT_NDIMS];
+        unsigned u;                 /* Local index variable */
 
         /* 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)
@@ -318,19 +369,19 @@ 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 
+        /* The library's chunking code requires the offset terminates with a zero. So transfer the 
          * offset array to an internal offset array */ 
-	for(u = 0; u < dset->shared->ndims; u++) {
-	    /* Make sure the offset doesn't exceed the dataset's dimensions */
+        for(u = 0; u < dset->shared->ndims; u++) {
+            /* Make sure the offset doesn't exceed the dataset's dimensions */
             if(direct_offset[u] > dset->shared->curr_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")
+            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 */
+            internal_offset[u] = direct_offset[u]; 
+        } /* end for */
 	   
 	/* Terminate the offset with a zero */ 
 	internal_offset[dset->shared->ndims] = 0;
@@ -342,7 +393,7 @@ H5D__pre_write(H5D_t *dset, hbool_t direct_write, hid_t mem_type_id,
     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:
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index 8a4711f..b123b81 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -578,6 +578,7 @@ 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_io_info_t *io_info, 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,
@@ -685,6 +686,8 @@ 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 fe408b2..baa844a 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -40,6 +40,11 @@
 #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 */
@@ -146,6 +151,7 @@ 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*/);
diff --git a/src/H5Pdxpl.c b/src/H5Pdxpl.c
index fdb402f..3c53c15 100644
--- a/src/H5Pdxpl.c
+++ b/src/H5Pdxpl.c
@@ -169,6 +169,13 @@
 #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
 /* Ring type - private property */
 #define H5AC_XFER_RING_SIZE      sizeof(unsigned)
 #define H5AC_XFER_RING_DEF       H5AC_RING_USER
@@ -293,6 +300,9 @@ static const hbool_t H5D_def_direct_chunk_flag_g = H5D_XFER_DIRECT_CHUNK_WRITE_F
 static const uint32_t H5D_def_direct_chunk_filters_g = H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_DEF;	/* Default value for the filters of direct chunk write */
 static const hsize_t *H5D_def_direct_chunk_offset_g = H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_DEF; 	/* Default value for the offset of direct chunk write */
 static const uint32_t H5D_def_direct_chunk_datasize_g = H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_DEF; /* Default value for the datasize of direct chunk write */
+static const hbool_t direct_chunk_read_flag = H5D_XFER_DIRECT_CHUNK_READ_FLAG_DEF;         /* Default value for the flag of direct chunk read */
+static const hsize_t *direct_chunk_read_offset = H5D_XFER_DIRECT_CHUNK_READ_OFFSET_DEF;    /* Default value for the offset of direct chunk read */
+static const uint32_t direct_chunk_read_filters = H5D_XFER_DIRECT_CHUNK_READ_FILTERS_DEF;    /* Default value for the filters of direct chunk read */
 static const H5AC_ring_t H5D_ring_g = H5AC_XFER_RING_DEF; /* Default value for the cache entry ring type */
 #ifdef H5_DEBUG_BUILD
 static const H5FD_dxpl_type_t H5D_dxpl_type_g = H5FD_NOIO_DXPL; /* Default value for the dxpl type */
@@ -497,6 +507,24 @@ H5P__dxfr_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, 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, 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, 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, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
     /* Register the ring property (private) */
     if(H5P_register_real(pclass, H5AC_RING_NAME, H5AC_XFER_RING_SIZE, &H5D_ring_g,
             NULL, NULL, NULL, H5AC_XFER_RING_ENC, H5AC_XFER_RING_DEC,