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/* jcifs smb client library in Java
* Copyright (C) 2003 "Michael B. Allen" <jcifs at samba dot org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
import jcifs.smb.*;
import java.io.*;
public class SmbTableFile extends SmbRandomAccessFile {
static final byte BYTE_FULL = (byte)0xFF;
byte[] hdr = new byte[512];
byte[] buf = new byte[1024];
char[] cbuf = new char[512];
int recordSize, row;
public SmbTableFile( SmbFile file, String mode, int recordSize ) throws IOException {
super( file, mode );
this.recordSize = recordSize;
read( hdr, 0, 512 );
}
public SmbTableFile( String url, String mode, int shareAccess, int recordSize ) throws IOException {
super( url, mode, shareAccess );
this.recordSize = recordSize;
read( hdr, 0, 512 );
}
public void insert( SmbTableFileRecord tfr ) throws IOException {
int i, b = 0;
/* Find an unset bit it in the bitmap
*/
for( i = 128; i < 512; i++ ) {
if( hdr[i] != BYTE_FULL ) {
/* bitwise complement inverts each bit
* mask with 0xFF ensures we only use 8 bits of int b
*/
b = ~hdr[i] & 0xFF;
/* clever trick to isolate first bit on
*/
b = b & -b;
break;
}
}
if( i == 512 ) {
throw new IOException( "No more space in " + this );
}
/* convert power of two to position
*/
switch( b ) {
case 1: b = 0; break;
case 2: b = 1; break;
case 4: b = 2; break;
case 8: b = 3; break;
case 16: b = 4; break;
case 32: b = 5; break;
case 64: b = 6; break;
case 128: b = 7; break;
}
tfr.rowid = (i - 128) * 8 + b;
update( tfr );
}
public void update( SmbTableFileRecord tfr ) throws IOException {
int i;
seek( 512L + tfr.rowid * recordSize );
tfr.encode( this );
i = 128 + tfr.rowid / 8;
seek( i );
hdr[i] |= 1 << (tfr.rowid % 8);
write( hdr[i] );
}
public void get( SmbTableFileRecord tfr ) throws IOException {
seek( 512L + tfr.rowid * recordSize );
tfr.decode( this );
}
public void iterate() {
row = 0;
}
public boolean next( SmbTableFileRecord tfr ) throws IOException {
int i, b;
i = 128 + row / 8; /* Search bitmap for next bit that is on */
b = 1 << (row % 8);
for( ; i < 512; i++ ) {
if(( hdr[i] & -b ) != 0 ) {
b = hdr[i] & -b;
b = b & -b;
break;
}
b = 1;
}
if( i == 512 ) { /* Are no more on bits, return */
return false;
}
switch( b ) {
case 1: b = 0; break;
case 2: b = 1; break;
case 4: b = 2; break;
case 8: b = 3; break;
case 16: b = 4; break;
case 32: b = 5; break;
case 64: b = 6; break;
case 128: b = 7; break;
}
tfr.rowid = (i - 128) * 8 + b; /* Set rowid and get */
get( tfr );
row = tfr.rowid + 1; /* Iterate row for next caller */
return true;
}
}
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