<html><head><base target=k-main></head><body bgcolor=white><nobr>
<font face=Helvetica size=3>
<dl><dt>
<b>class c4_Strategy</b>
<br><br>
<dd><font face=Times size=3>
A strategy encapsulates code dealing with the I/O system interface.<br><br>
</font></dl>
<table cellborder=0>
<tr>
<td colspan=2>
<font face=Helvetica size=-1><b>Public members</b></font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
</td>
<td>
<nobr>
<b>c4_Strategy</b> ();
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual
</td>
<td>
<nobr>
<b>~c4_Strategy</b> ();
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual bool
</td>
<td>
<nobr>
<b>IsValid</b> () <i>const</i>;
<font face=Helvetica size=-1><br>
True if we can do I/O with this object</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual void
</td>
<td>
<nobr>
<b>DataSeek</b> (t4_i32 position_);
<font face=Helvetica size=-1><br>
Set file position</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual int
</td>
<td>
<nobr>
<b>DataRead</b> (void* buffer_, int length_);
<font face=Helvetica size=-1><br>
Read a number of bytes</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
void
</td>
<td>
<nobr>
<b>DataLoad</b> (void* buffer_, int length_);
<font face=Helvetica size=-1><br>
Read an exact number of bytes</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual bool
</td>
<td>
<nobr>
<b>DataWrite</b> (const void* buffer_, int length_);
<font face=Helvetica size=-1><br>
Write a number of bytes, return true if successful</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual void
</td>
<td>
<nobr>
<b>DataCommit</b> (t4_i32 newSize_);
<font face=Helvetica size=-1><br>
Flush and truncate file</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
virtual void
</td>
<td>
<nobr>
<b>ResetFileMapping</b> ();
<font face=Helvetica size=-1><br>
Override to support memory-mapped files</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
bool
</td>
<td>
<nobr>
<b>_keepAfterCommit</b>;
<font face=Helvetica size=-1><br>
Keep data in memory after each commit (default is false)</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
bool
</td>
<td>
<nobr>
<b>_bytesFlipped</b>;
<font face=Helvetica size=-1><br>
True if the storage format is not native (default is false)</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
int
</td>
<td>
<nobr>
<b>_failure</b>;
<font face=Helvetica size=-1><br>
Error code of last failed I/O operation, zero if I/O was ok</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
const t4_byte*
</td>
<td>
<nobr>
<b>_mapStart</b>;
<font face=Helvetica size=-1><br>
First byte in file mapping, zero if not active</font>
</td>
</tr>
<tr>
<td valign=top align=right width=150>
const t4_byte*
</td>
<td>
<nobr>
<b>_mapLimit</b>;
<font face=Helvetica size=-1><br>
Past last byte in file mapping, zero if not active</font>
</td>
</tr>
</table>
<br><hr size=1 width=50 align=left>
<table cellborder=0>
<tr>
<td width=150>
<font face=Helvetica size=-1><b>Header file</b></font>
</td>
<td>
"mk4.h" -- Dec 9, 1999
</td>
</tr>
</table>
</font></font>
</nobr></body></html>
