| /* |
| * 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 org.apache.sysds.runtime.compress; |
| |
| import org.apache.sysds.runtime.compress.utils.DblArray; |
| |
| /** Base class for all column selection readers. */ |
| public abstract class ReaderColumnSelection { |
| protected int[] _colIndexes = null; |
| protected int _numRows = -1; |
| protected int _lastRow = -1; |
| |
| private DblArray nonZeroReturn; |
| |
| protected CompressionSettings _compSettings; |
| |
| protected ReaderColumnSelection(int[] colIndexes, int numRows, CompressionSettings compSettings) { |
| _colIndexes = colIndexes; |
| _numRows = numRows; |
| _lastRow = -1; |
| _compSettings = compSettings; |
| } |
| |
| /** |
| * Gets the next row, null when no more rows. |
| * |
| * @return next row |
| */ |
| public DblArray nextRow() { |
| while((nonZeroReturn = getNextRow()) != null && DblArray.isZero(nonZeroReturn)) { |
| } |
| return nonZeroReturn; |
| } |
| |
| protected abstract DblArray getNextRow(); |
| |
| public int getCurrentRowIndex() { |
| return _lastRow; |
| } |
| |
| /** |
| * Resets the reader to the first row. |
| */ |
| public void reset() { |
| _lastRow = -1; |
| } |
| } |