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Diffstat (limited to 'doc/html/H5.format.html')
| -rw-r--r-- | doc/html/H5.format.html | 103 |
1 files changed, 95 insertions, 8 deletions
diff --git a/doc/html/H5.format.html b/doc/html/H5.format.html index 59bc28d..afcd444 100644 --- a/doc/html/H5.format.html +++ b/doc/html/H5.format.html @@ -266,7 +266,7 @@ each high-level object. </tr> <tr align=center> - <td colspan=4>Reserved Address</td> + <td colspan=4>Driver Information Block Address</td> </tr> <tr align=center> @@ -480,12 +480,14 @@ each high-level object. used.</td> </tr> - <tr valign=top> - <td>Reserved Address</td> - <td>This address field is present for alignment purposes and - is always set to the undefined address value (all bits - set).</td> - </tr> + <tr valign=top> + <td>Driver Information Block Address</td> + <td>This is the relative file address of the file driver + information block which contains driver-specific + information needed to reopen the file. If there is no + driver information block then this entry should be the + undefined address (all bits set).</td> + </tr> <tr valign=top> <td>Root Group Symbol Table Entry</td> @@ -497,6 +499,91 @@ each high-level object. </table> </center> + <p>The file driver information block is an optional region of the + file which contains information needed by the file driver in + order to reopen a file. The format of the driver information + block is: + + <p> + <center> + <table border align=center cellpadding=4 width="80%"> + <caption align=top> + <B>Driver Information Block</B> + </caption> + + <tr align=center> + <th width="25%">byte</th> + <th width="25%">byte</th> + <th width="25%">byte</th> + <th width="25%">byte</th> + </tr> + + <tr align=center> + <td>Version</td> + <td colspan=3>Reserved (zero)</td> + </tr> + + <tr align=center> + <td colspan=4>Driver Information Size (4 bytes)</td> + </tr> + + <tr align=center> + <td colspan=4><br>Driver Identification (8 bytes)<br><br></td> + </tr> + + <tr align=center> + <td colspan=4><br><br>Driver Information<br><br><br></td> + </tr> + </table> + </center> + + <p> + <center> + <table align=center width="80%"> + <tr> + <th width="30%">Field Name</th> + <th width="70%">Description</th> + </tr> + + <tr valign=top> + <td>Version</td> + <td>The version number of the driver information block. The + file format documented here is version zero.</td> + </tr> + + <tr valign=top> + <td>Driver Information Size</td> + <td>The size in bytes of the Driver Information part of this + structure.</td> + </tr> + + <tr valign=top> + <td>Driver Identification</td> + <td>This is an eight-byte ASCII string without null + termination which identifies the driver and version number + of the Driver Information block. The predefined drivers + supplied with the HDF5 library are identified by the + letters "NCSA" followed by the first four characters of + the driver name. If the Driver Information block is not + the original version then the last letter(s) of the + identification will be replaced by a version number in + ASCII. For example, the various versions of the "family" + driver will be identified by "NCSAfami", "NCSAfam0", + NCSAfam1", etc. Identification for user-defined drivers is + arbitrary but should be unique.</td> + </tr> + + <tr valign=top> + <td>Driver Information</td> + <td>Driver information is stored in a format defined by the + file driver and encoded/decoded by the driver callbacks + invoked from the <code>H5FD_sb_encode</code> and + <code>H5FD_sb_decode</code> functions.</td> + </tr> + </table> + </center> + + <h3><a name="Btrees">Disk Format: Level 1A - B-link Trees</a></h3> <p>B-link trees allow flexible storage for objects which tend to grow @@ -3584,7 +3671,7 @@ data-type. <address><a href="mailto:koziol@ncsa.uiuc.edu">Quincey Koziol</a></address> <address><a href="mailto:matzke@llnl.gov">Robb Matzke</a></address> <!-- hhmts start --> -Last modified: Fri Jun 11 14:11:57 EDT 1999 +Last modified: Tue Aug 17 10:57:50 EDT 1999 <!-- hhmts end --> </body> </html> |