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Diffstat (limited to 'doc/html/RM_H5P.html')
| -rw-r--r-- | doc/html/RM_H5P.html | 116 |
1 files changed, 107 insertions, 9 deletions
diff --git a/doc/html/RM_H5P.html b/doc/html/RM_H5P.html index 6be0a9b..8c314a7 100644 --- a/doc/html/RM_H5P.html +++ b/doc/html/RM_H5P.html @@ -170,6 +170,9 @@ many different parameters to be easily manipulated. <li><a href="#Property-GetDxplMpio">H5Pget_dxpl_mpio</a> || <li><a href="#Property-SetDxplMulti">H5Pset_dxpl_multi</a> <li><a href="#Property-GetDxplMulti">H5Pget_dxpl_multi</a> + <br> + <li><a href="#Property-SetSmallData">H5Pset_small_data_block_size</a> + <li><a href="#Property-GetSmallData">H5Pget_small_data_block_size</a> </ul> </td></tr> @@ -1620,7 +1623,7 @@ facilitate moving easily between them.</i> used by file drivers that are capable of using data sieving. <p> The data sieve buffer is used when performing I/O on datasets - in the file. Using a buffer which is large anough to hold + in the file. Using a buffer which is large enough to hold several pieces of the dataset being read in for hyperslab selections boosts performance by quite a bit. <p> @@ -2169,6 +2172,101 @@ facilitate moving easily between them.</i> <hr> <dl> + <dt><strong>Name:</strong> <a name="Property-SetSmallData">H5Pset_small_data_block_size</a> + <dt><strong>Signature:</strong> + <dd><em>herr_t</em> <code>H5Pset_small_data_block_size</code>(<em>hid_t</em> <code>fapl_id</code>, + <em>hsize_t</em> <code>size</code> + ) + <dt><strong>Purpose:</strong> + <dd>Sets the size of a contiguous block reserved for small data. + <dt><strong>Description:</strong> + <dd><code>H5Pset_small_data_block_size</code> reserves blocks of + <code>size</code> bytes for the contiguous storage of the raw data + portion of <em>small</em> datasets. + The HDF5 library then writes the raw data from small datasets + to this reserved space, thus reducing unnecessary discontinuities + within blocks of meta data and improving IO performance. + <p> + A small data block is actually allocated the first time a + qualifying small dataset is written to the file. + Space for the raw data portion of this small dataset is suballocated + within the small data block. + The raw data from each subsequent small dataset is also written to + the small data block until it is filled; additional small data blocks + are allocated as required. + <p> + The HDF5 library employs an algorithm that determines whether + IO performance is likely to benefit from the use of this mechanism + with each dataset as storage space is allocated in the file. + A larger <code>size</code> will result in this mechanism being + employed with larger datasets. + <p> + The small data block size is set as an allocation property in the + file access property list identified by <code>fapl_id</code>. + <p> + Setting <code>size</code> to zero (<code>0</code>) disables the + small data block mechanism. + <dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>fapl_id</code> + <dd>IN: File access property list identifier . + <dt><em>hsize_t</em> <code>size</code> + <dd>IN: Maximum size, in bytes, of the small data block. + <br> + The default size is <code>2048</code>. + </dl> + <dt><strong>Returns:</strong> + <dd>Returns a non-negative value if successful; + otherwise a negative value. + <!-- + <dt><strong>Non-C API(s):</strong> + <dd><a href="fortran/h5p_FORTRAN.html#h5pxxx" + target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a> + --> <!-- + <img src="Graphics/Java.gif"> + <img src="Graphics/C++.gif"> + --> +</dl> + + +<hr> +<dl> + <dt><strong>Name:</strong> <a name="Property-GetSmallData">H5Pget_small_data_block_size</a> + <dt><strong>Signature:</strong> + <dd><em>herr_t</em> <code>H5Pget_small_data_block_size</code>(<em>hid_t</em> <code>fapl_id</code>, + <em>hsize_t *</em><code>size</code> + ) + <dt><strong>Purpose:</strong> + <dd>Retrieves the current small data block size setting. + <dt><strong>Description:</strong> + <dd><code>H5Pget_small_data_block_size</code> retrieves the + current setting for the size of the small data block. + <p> + If the returned value is zero (<code>0</code>), the small data + block mechanism has been disabled for the file. + <dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>fapl_id</code> + <dd>IN: File access property list identifier . + <dt><em>hsize_t *</em><code>size</code> + <dd>OUT: Maximum size, in bytes, of the small data block. + </dl> + <dt><strong>Returns:</strong> + <dd>Returns a non-negative value if successful; + otherwise a negative value. + <!-- + <dt><strong>Non-C API(s):</strong> + <dd><a href="fortran/h5p_FORTRAN.html#h5pxxx" + target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a> + --> <!-- + <img src="Graphics/Java.gif"> + <img src="Graphics/C++.gif"> + --> +</dl> + + +<hr> +<dl> <dt><strong>Name:</strong> <a name="Property-SetPreserve">H5Pset_preserve</a> <dt><strong>Signature:</strong> <dd><em>herr_t</em> <code>H5Pset_preserve</code>(<em>hid_t</em> <code>plist</code>, @@ -2939,7 +3037,7 @@ facilitate moving easily between them.</i> <p> The array <code>memb_addr</code> specifies the offsets within the virtual address space, from <code>0</code> (zero) to - <code>HADDR_MAX</code>, at wihch each type of data storage begins. + <code>HADDR_MAX</code>, at which each type of data storage begins. <p> If <code>relax</code> is set to <code>TRUE</code> (or <code>1</code>), then opening an existing file for read-only access will not fail @@ -2989,7 +3087,7 @@ facilitate moving easily between them.</i> <dt><em>const haddr_t *</em><code>memb_addr</code> <dd>IN: The offsets within the virtual address space, from <code>0</code> (zero) to <code>HADDR_MAX</code>, - at wihch each type of data storage begins. + at which each type of data storage begins. <dt><em>hbool_t</em> <code>relax</code> <dd>IN: Allows read-only access to incomplete file sets when <code>TRUE</code>. @@ -3176,7 +3274,7 @@ facilitate moving easily between them.</i> <dt><strong>Purpose:</strong> <dd>Emulates the old split file driver. <dt><strong>Description:</strong> - <dd><code>H5Pset_fapl_split</code> is a compatability function that + <dd><code>H5Pset_fapl_split</code> is a compatibility function that enables the multi-file driver to emulate the split driver from HDF5 Releases 1.0 and 1.2. The split file driver stored metadata and raw data in separate files @@ -3458,7 +3556,7 @@ fid=H5Fcreate("PointA",H5F_ACC_TRUNC,H5P_DEFAULT,fapl); <dd><code>H5Pset_driver</code> sets the file driver, <code>driver_id</code>, for a file access or data transfer property list, <code>plist_id</code>, and supplies an - optional struct containing the driver-specific properites, + optional struct containing the driver-specific properties, <code>driver_info</code>. <p> <font color=red><b><i>Need <code>driver_info</code> struct definition.</i></b></font> @@ -3472,7 +3570,7 @@ fid=H5Fcreate("PointA",H5F_ACC_TRUNC,H5P_DEFAULT,fapl); <dt><em>hid_t</em> <code>plist_id</code> <dd>IN: File access or data transfer property list identifier. <dt><em>hid_t</em> <code>driver_id</code> - <dd>IN: Driver indentifier. + <dd>IN: Driver identifier. <dt><em>const void *</em> <code>driver_info</code> <dd>IN: Optional struct containing driver properties. </dl> @@ -3501,7 +3599,7 @@ fid=H5Fcreate("PointA",H5F_ACC_TRUNC,H5P_DEFAULT,fapl); <dt><strong>Description:</strong> <dd><code>H5Pget_driver</code> returns the identifier of the low-level file driver associated with the file access property list - or data transfer propert list <code>plist_id</code>. + or data transfer property list <code>plist_id</code>. <p> Valid driver identifiers with the standard HDF5 library distribution include the following: @@ -3528,7 +3626,7 @@ fid=H5Fcreate("PointA",H5F_ACC_TRUNC,H5P_DEFAULT,fapl); <dd>IN: File access or data transfer property list identifier. </dl> <dt><strong>Returns:</strong> - <dd>Returns a vaild low-level driver identifier if successful. + <dd>Returns a valid low-level driver identifier if successful. Otherwise returns a negative value. <!-- <dt><strong>Non-C API(s):</strong> @@ -3996,7 +4094,7 @@ H5P <a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a> <br> -Last modified: 25 April 2002 +Last modified: 5 July 2002 <br> Describes HDF5 Release 1.5, Unreleased Development Branch |