/*
 * Copyright 2008 Fedora Commons, Inc.
 *
 * Licensed 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 org.mulgara.resolver.distributed.remote;

import java.io.Serializable;
import java.util.AbstractSet;
import java.util.ArrayList;
import java.util.Iterator;

import org.jrdf.graph.ObjectNode;
import org.jrdf.graph.PredicateNode;
import org.jrdf.graph.SubjectNode;
import org.jrdf.graph.Triple;
import org.mulgara.query.TuplesException;
import org.mulgara.query.rdf.TripleImpl;
import org.mulgara.resolver.spi.GlobalizeException;
import org.mulgara.resolver.spi.ResolverSession;
import org.mulgara.resolver.spi.Statements;

/**
 * Creates a small Set of statements that be be shipped across a network.
 *
 * @created 2007-04-23
 * @author <a href="mailto:gearon@users.sourceforge.net">Paula Gearon</a>
 * @copyright © 2007 <a href="http://www.fedora-commons.org/">Fedora Commons</a>
 */
public class ShortGlobalStatementSet extends AbstractSet<Triple> implements Serializable {

  /**
   * Allow newer compiled version of the stub to operate when changes
   * have not occurred with the class.
   * NOTE : update this serialVersionUID when a method or a public member is
   * deleted.
   */
  private static final long serialVersionUID = 896369800817370415L;


  /** Internally, use a list as this has a shorter serialization. */
  private ArrayList<Triple> data;


  /**
   * Builds the set of Triple data, containing globalized triples.
   * @param statements Contains the data for the set.  This must not contain duplicates.
   * @throws TuplesException There was an error accessing the statements.
   * @throws GlobalizeException Some of the statements could not be globalized.
   */
  ShortGlobalStatementSet(Statements statements, ResolverSession session) throws TuplesException, GlobalizeException {
    // build the array
    long rowCount = statements.getRowCount();
    assert rowCount < StatementSetFactory.WATER_MARK;
    data = new ArrayList<Triple>((int)rowCount);
    // populate the array
    statements.beforeFirst();
    while (statements.next()) {
      Triple t = new TripleImpl(
          (SubjectNode)session.globalize(statements.getSubject()),
          (PredicateNode)session.globalize(statements.getPredicate()),
          (ObjectNode)session.globalize(statements.getObject())
      );
      data.add(t);
    }
  }

  @Override
  public Iterator<Triple> iterator() {
    return data.iterator();
  }

  @Override
  public int size() {
    return data.size();
  }

}