| /* |
| * 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.data; |
| |
| import java.io.Serializable; |
| |
| /** |
| * Base class for sparse row implementations such as sparse |
| * row vectors and sparse scalars (single value per row). |
| * |
| */ |
| public abstract class SparseRow implements Serializable |
| { |
| private static final long serialVersionUID = 5806895317005796456L; |
| |
| /** |
| * Get the number of non-zero values of the sparse row. |
| * |
| * @return number of non-zeros |
| */ |
| public abstract int size(); |
| |
| /** |
| * Indicates if the sparse row is empty, i.e., if is has |
| * size zero. |
| * |
| * @return true if empty |
| */ |
| public abstract boolean isEmpty(); |
| |
| /** |
| * Get the value array of non-zero entries, co-aligned |
| * with the array of indexes. |
| * |
| * @return array of values |
| */ |
| public abstract double[] values(); |
| |
| /** |
| * Get the index array of non-zero entries, co-aligned |
| * with the array of values. |
| * |
| * @return array of indexes |
| */ |
| public abstract int[] indexes(); |
| |
| /** |
| * Resets the sparse row to empty, after this call size and |
| * isEmpty are guaranteed to return 0 and true, respectively. |
| * |
| * @param estnns estimated number of non-zeros |
| * @param maxnns maximum number of non-zeros, e.g., number of columns |
| */ |
| public abstract void reset(int estnns, int maxnns); |
| |
| /** |
| * Sets the value of a specified column with awareness of |
| * potential overwrites or deletes (set to value zero). |
| * |
| * @param col column index, zero-based |
| * @param v value |
| * @return true if the size of the sparse row changed |
| */ |
| public abstract boolean set(int col, double v); |
| |
| /** |
| * Add a value to a specified column with awareness of |
| * potential insertions. |
| * |
| * @param col column index, zero-based |
| * @param v value |
| * @return true if the size of the sparse row changed |
| */ |
| public abstract boolean add(int col, double v); |
| |
| /** |
| * Appends a value to the end of the sparse row. |
| * |
| * @param col column index, zero-based |
| * @param v value |
| */ |
| public abstract void append(int col, double v); |
| |
| /** |
| * Gets the value of a specified column. If the column |
| * index does not exist in the sparse row, this call |
| * returns zero. |
| * |
| * @param col column index, zero-based |
| * @return value |
| */ |
| public abstract double get(int col); |
| |
| /** |
| * In-place sort of column-index value pairs in order to allow binary search |
| * after constant-time append was used for reading unordered sparse rows. We |
| * first check if already sorted and subsequently sort if necessary in order |
| * to get O(n) best case. |
| * |
| * Note: In-place sort is necessary in order to guarantee the memory estimate |
| * for operations that implicitly read that data set. |
| */ |
| public abstract void sort(); |
| |
| /** |
| * In-place compaction of non-zero-entries; removes zero entries |
| * and shifts non-zero entries to the left if necessary. |
| */ |
| public abstract void compact(); |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder(); |
| for(int i=0; i<size(); i++) { |
| sb.append(indexes()[i]); |
| sb.append(": "); |
| sb.append(values()[i]); |
| sb.append("\t"); |
| } |
| return sb.toString(); |
| } |
| } |