/*
* 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.index.bplustree;
import java.util.Iterator ;
import java.util.NoSuchElementException ;
import com.hp.hpl.jena.tdb.base.buffer.RecordBuffer ;
import com.hp.hpl.jena.tdb.base.record.Record ;
import com.hp.hpl.jena.tdb.base.recordbuffer.RecordBufferPage ;
import com.hp.hpl.jena.tdb.base.recordbuffer.RecordBufferPageMgr ;
/** Iterate over a stream of records, packing them into RecordBufferPage -- the leaf of a B+Tree
* This class does not write the blocks back to the block manager.
* This cleass does allocate block ids and blocks.
* @see RecordBufferPageLinker
*/
class RecordBufferPagePacker implements Iterator<RecordBufferPage>
{
Iterator<Record> records = null ;
RecordBufferPage recordBufferPage = null ;
RecordBufferPageMgr rbMgr = null ;
RecordBufferPagePacker(Iterator<Record> records, RecordBufferPageMgr rbMgr)
{
this.records = records ;
this.rbMgr = rbMgr ;
}
@Override
public boolean hasNext()
{
if ( recordBufferPage == null )
{
if ( records == null )
return false ;
if ( !records.hasNext() )
{
records = null ;
return false ;
}
// At least one record to be processed.
// No pending RecordBufferPage
// ==> There will be a RecordBufferPage to yield.
// int id = rbMgr.allocateId() ;
// //System.out.println("Allocate : "+id) ;
recordBufferPage = rbMgr.create() ;
RecordBuffer rb = recordBufferPage.getRecordBuffer() ;
while ( !rb.isFull() && records.hasNext() )
{
Record r = records.next();
rb.add(r) ;
}
if ( ! records.hasNext() )
records = null ;
return true ;
}
return true ;
}
@Override
public RecordBufferPage next()
{
if ( ! hasNext() ) throw new NoSuchElementException() ;
RecordBufferPage rbp = recordBufferPage ;
recordBufferPage = null ;
return rbp ;
}
@Override
public void remove()
{ throw new UnsupportedOperationException() ; }
}