| /* |
| * 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.colgroup; |
| |
| import java.util.List; |
| |
| import org.apache.sysds.runtime.compress.CompressionSettings; |
| import org.apache.sysds.runtime.data.SparseRow; |
| import org.apache.sysds.runtime.data.SparseRowVector; |
| |
| public class SparseRowIterator extends RowIterator<SparseRow> { |
| private final SparseRowVector _ret; |
| private final double[] _tmp; |
| |
| public SparseRowIterator(int rl, int ru, List<ColGroup> colGroups, int clen) { |
| super(rl, ru, colGroups); |
| _ret = new SparseRowVector(clen); |
| _tmp = new double[clen]; |
| } |
| |
| @Override |
| public SparseRow next() { |
| // prepare meta data common across column groups |
| final int blksz = CompressionSettings.BITMAP_BLOCK_SZ; |
| final int ix = _rpos % blksz; |
| final boolean last = (_rpos + 1 == _ru); |
| // copy group rows into consolidated dense vector |
| // to avoid binary search+shifting or final sort |
| for(int j = 0; j < _iters.length; j++) |
| _iters[j].next(_tmp, _rpos, ix, last); |
| // append non-zero values to consolidated sparse row |
| _ret.setSize(0); |
| for(int i = 0; i < _tmp.length; i++) |
| _ret.append(i, _tmp[i]); |
| // advance to next row and return buffer |
| _rpos++; |
| return _ret; |
| } |
| } |