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Neo4j kernel is a lightweight, embedded Java database designed to
store data structured as graphs rather than tables. For more
information, see http://neo4j.org.
/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [http://neo4j.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
package org.neo4j.kernel.impl.newapi;
import org.neo4j.internal.kernel.api.PartitionedScan;
import org.neo4j.internal.kernel.api.TokenPredicate;
import org.neo4j.internal.kernel.api.security.AccessMode;
import org.neo4j.io.pagecache.context.CursorContext;
import org.neo4j.kernel.api.index.IndexProgressor;
import org.neo4j.kernel.impl.index.schema.PartitionedTokenScan;
public class PartitionedTokenIndexCursorScan implements PartitionedScan
{
private final Read read;
private final TokenPredicate query;
private final PartitionedTokenScan tokenScan;
PartitionedTokenIndexCursorScan( Read read, TokenPredicate query, PartitionedTokenScan tokenScan )
{
if ( read.hasTxStateWithChanges() )
{
throw new IllegalStateException( "Transaction contains changes; PartitionScan is only valid in Read-Only transactions." );
}
this.read = read;
this.query = query;
this.tokenScan = tokenScan;
}
@Override
public int getNumberOfPartitions()
{
return tokenScan.getNumberOfPartitions();
}
@Override
public boolean reservePartition( Cursor cursor, CursorContext cursorContext, AccessMode accessMode )
{
var indexCursor = (DefaultEntityTokenIndexCursor extends DefaultEntityTokenIndexCursor>>) cursor;
indexCursor.setRead( read );
var indexProgressor = tokenScan.reservePartition( indexCursor, cursorContext );
if ( indexProgressor == IndexProgressor.EMPTY )
{
return false;
}
indexCursor.initialize( indexProgressor, query.tokenId(), null, null, accessMode );
return true;
}
}