/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.tdb.base.file;
import static java.lang.String.format ;
import java.nio.ByteBuffer ;
import java.util.concurrent.atomic.AtomicLong ;
import org.apache.jena.atlas.lib.FileOps ;
import org.slf4j.Logger ;
import com.hp.hpl.jena.tdb.base.block.Block ;
import com.hp.hpl.jena.tdb.base.block.BlockException ;
import com.hp.hpl.jena.tdb.sys.SystemTDB ;
/** Support for a disk file backed FileAccess */
public abstract class BlockAccessBase implements BlockAccess
{
protected final int blockSize ;
protected final FileBase file ;
protected final String label ;
protected long numFileBlocks = -1 ; // Don't overload use of this!
protected final AtomicLong seq ; // Id (future)
protected boolean isEmpty = false ;
public BlockAccessBase(String filename, int blockSize)
{
file = FileBase.create(filename) ;
this.blockSize = blockSize ;
this.label = FileOps.basename(filename) ;
long filesize = file.size() ; // This is not related to used file length in mapped mode.
long longBlockSize = blockSize ;
numFileBlocks = filesize/longBlockSize ; // This is not related to used file length in mapped mode.
seq = new AtomicLong(numFileBlocks) ;
if ( numFileBlocks > Integer.MAX_VALUE )
getLog().warn(format("File size (%d) exceeds tested block number limits (%d)", filesize, blockSize)) ;
if ( filesize%longBlockSize != 0 )
throw new BlockException(format("File size (%d) not a multiple of blocksize (%d)", filesize, blockSize)) ;
if ( filesize == 0 )
isEmpty = true ;
}
protected abstract Logger getLog() ;
@Override
final public boolean isEmpty() { return isEmpty ; }
final protected void writeNotification(Block block) { isEmpty = false ; }
final protected void overwriteNotification(Block block)
{
// Write at end => extend
if ( block.getId() >= numFileBlocks )
{
numFileBlocks = block.getId()+1 ;
seq.set(numFileBlocks) ;
}
}
//@Override
final
//public
protected int allocateId()
{
checkIfClosed() ;
int id = (int)seq.getAndIncrement() ;
numFileBlocks ++ ; // TODO Fix this when proper freeblock management is introduced.
return id ;
}
@Override
final synchronized
public boolean valid(long id)
{
// Access to numFileBlocks not synchronized - it's only a check
if ( id >= numFileBlocks )
return false ;
if ( id < 0 )
return false ;
return true ;
}
final
protected void check(long id)
{
if ( id > Integer.MAX_VALUE )
throw new BlockException(format("BlockAccessBase: Id (%d) too large", id )) ;
// Access to numFileBlocks not synchronized - it's only a check
if ( id < 0 || id >= numFileBlocks )
{
// Do it properly!
synchronized(this)
{
if ( id < 0 || id >= numFileBlocks )
throw new BlockException(format("BlockAccessBase: Bounds exception: %s: (%d,%d)", file.filename, id, numFileBlocks)) ;
}
}
}
final protected void check(Block block)
{
check(block.getId()) ;
ByteBuffer bb = block.getByteBuffer() ;
if ( bb.capacity() != blockSize )
throw new BlockException(format("BlockMgrFile: Wrong size block. Expected=%d : actual=%d", blockSize, bb.capacity())) ;
if ( bb.order() != SystemTDB.NetworkOrder )
throw new BlockException("BlockMgrFile: Wrong byte order") ;
}
protected void force()
{
file.sync() ;
}
//@Override
final public boolean isClosed() { return file.channel() == null ; }
protected final void checkIfClosed()
{
if ( isClosed() )
getLog().error("File has been closed") ;
}
protected abstract void _close() ;
@Override
final public void close()
{
_close() ;
file.close() ;
}
@Override
public String getLabel()
{
return label ;
}
}