1 files changed, 62 insertions, 1 deletions
diff --git a/src/H5FDdirect.h b/src/H5FDdirect.h
index eec10de..f06de7f 100644
--- a/src/H5FDdirect.h
+++ b/src/H5FDdirect.h
@@ -37,8 +37,69 @@ extern "C" {
 #define FBSIZE_DEF    4096
 #define CBSIZE_DEF    16 * 1024 * 1024
 
-H5_DLL hid_t  H5FD_direct_init(void);
+H5_DLL hid_t H5FD_direct_init(void);
+
+/**
+ * \ingroup FAPL
+ *
+ * \brief Sets up use of the direct I/O driver
+ *
+ * \fapl_id
+ * \param[in] alignment Required memory alignment boundary
+ * \param[in] block_size File system block size
+ * \param[in] cbuf_size Copy buffer size
+ * \returns \herr_t
+ *
+ * \details H5Pset_fapl_direct() sets the file access property list, \p fapl_id,
+ *          to use the direct I/O driver, #H5FD_DIRECT. With this driver, data
+ *          is written to or read from the file synchronously without being
+ *          cached by the system.
+ *
+ *          File systems usually require the data address in memory, the file
+ *          address, and the size of the data to be aligned. The HDF5 library’s
+ *          direct I/O driver is able to handle unaligned data, though that will
+ *          consume some additional memory resources and may slow
+ *          performance. To get better performance, use the system function \p
+ *          posix_memalign to align the data buffer in memory and the HDF5
+ *          function H5Pset_alignment() to align the data in the file. Be aware,
+ *          however, that aligned data I/O may cause the HDF5 file to be bigger
+ *          than the actual data size would otherwise require because the
+ *          alignment may leave some holes in the file.
+ *
+ *          \p alignment specifies the required alignment boundary in memory.
+ *
+ *          \p block_size specifies the file system block size. A value of 0
+ *          (zero) means to use HDF5 library’s default value of 4KB.
+ *
+ *          \p cbuf_size specifies the copy buffer size.
+ *
+ * \since 1.8.0
+ *
+ */
 H5_DLL herr_t H5Pset_fapl_direct(hid_t fapl_id, size_t alignment, size_t block_size, size_t cbuf_size);
+
+/**
+ * \ingroup FAPL
+ *
+ * \brief Retrieves direct I/O driver settings
+ *
+ * \fapl_id
+ * \param[out] boundary Required memory alignment boundary
+ * \param[out] block_size File system block size
+ * \param[out] cbuf_size Copy buffer size
+ * \returns \herr_t
+ *
+ * \details H5Pget_fapl_direct() retrieves the required memory alignment (\p
+ *          alignment), file system block size (\p block_size), and copy buffer
+ *          size (\p cbuf_size) settings for the direct I/O driver, #H5FD_DIRECT,
+ *          from the file access property list \p fapl_id.
+ *
+ *          See H5Pset_fapl_direct() for discussion of these values,
+ *          requirements, and important considerations.
+ *
+ * \since 1.8.0
+ *
+ */
 H5_DLL herr_t H5Pget_fapl_direct(hid_t fapl_id, size_t *boundary /*out*/, size_t *block_size /*out*/,
                                  size_t *cbuf_size /*out*/);