/***********************************************************************************************************************
 * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
 *
 * 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 eu.stratosphere.test.iterative.nephele.customdanglingpagerank;

import eu.stratosphere.api.common.io.DelimitedInputFormat;
import eu.stratosphere.test.iterative.nephele.customdanglingpagerank.types.VertexWithAdjacencyList;
import eu.stratosphere.test.iterative.nephele.danglingpagerank.AsciiLongArrayView;

public class CustomImprovedAdjacencyListInputFormat extends DelimitedInputFormat<VertexWithAdjacencyList> {
	private static final long serialVersionUID = 1L;

	private final AsciiLongArrayView arrayView = new AsciiLongArrayView();

	@Override
	public VertexWithAdjacencyList readRecord(VertexWithAdjacencyList target, byte[] bytes, int offset, int numBytes) {

		if (numBytes == 0) {
			return null;
		}

		arrayView.set(bytes, offset, numBytes);
		
		long[] list = target.getTargets();

		try {

			int pos = 0;
			while (arrayView.next()) {

				if (pos == 0) {
					target.setVertexID(arrayView.element());
				} else {
					if (list.length <= pos - 1) {
						list = new long[list.length < 16 ? 16 : list.length * 2];
						target.setTargets(list);
					}
					list[pos - 1] = arrayView.element();
				}
				pos++;
			}
			
			target.setNumTargets(pos - 1);
		} catch (RuntimeException e) {
			throw new RuntimeException("Error parsing: " + arrayView.toString(), e);
		}

		return target;
	}
}