001 /*
002 * Sonar, open source software quality management tool.
003 * Copyright (C) 2008-2012 SonarSource
004 * mailto:contact AT sonarsource DOT com
005 *
006 * Sonar is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU Lesser General Public
008 * License as published by the Free Software Foundation; either
009 * version 3 of the License, or (at your option) any later version.
010 *
011 * Sonar is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 * Lesser General Public License for more details.
015 *
016 * You should have received a copy of the GNU Lesser General Public
017 * License along with Sonar; if not, write to the Free Software
018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02
019 */
020
021 package org.sonar.api.measures;
022
023 import org.sonar.api.resources.ResourceUtils;
024
025 import java.util.Arrays;
026 import java.util.List;
027
028 /**
029 * Formula used to compute an average for a given metric A, which is the result of the sum of measures of this metric (A) divided by another metric (B).
030 * <p/>
031 * For example: to compute the metric "complexity by file", the main metric (A) is "complexity" and the other metric (B) is "file".
032 *
033 * @since 3.0
034 */
035 public class AverageFormula implements Formula {
036
037 private Metric mainMetric;
038 private Metric byMetric;
039
040 /**
041 * This method should be private but it kep package-protected because of AverageComplexityFormula.
042 */
043 AverageFormula(Metric mainMetric, Metric byMetric) {
044 this.mainMetric = mainMetric;
045 this.byMetric = byMetric;
046 }
047
048 /**
049 * Creates a new {@link AverageFormula} class.
050 *
051 * @param main The metric on which average should be calculated (ex.: "complexity")
052 * @param by The metric used to divide the main metric to compute average (ex.: "file" for "complexity by file")
053 */
054 public static AverageFormula create(Metric main, Metric by) {
055 return new AverageFormula(main, by);
056 }
057
058 /**
059 * {@inheritDoc}
060 */
061 public List<Metric> dependsUponMetrics() {
062 return Arrays.asList(mainMetric, byMetric);
063 }
064
065 /**
066 * {@inheritDoc}
067 */
068 public Measure calculate(FormulaData data, FormulaContext context) {
069 if (!shouldDecorateResource(data, context)) {
070 return null;
071 }
072
073 Measure result;
074 if (ResourceUtils.isFile(context.getResource())) {
075 result = calculateForFile(data, context);
076 } else {
077 result = calculateOnChildren(data, context);
078 }
079 return result;
080 }
081
082 private Measure calculateOnChildren(FormulaData data, FormulaContext context) {
083 Measure result = null;
084
085 double totalByMeasure = 0;
086 double totalMainMeasure = 0;
087 boolean hasApplicableChildren = false;
088
089 for (FormulaData childrenData : data.getChildren()) {
090 Double childrenByMeasure = MeasureUtils.getValue(childrenData.getMeasure(byMetric), null);
091 Double childrenMainMeasure = MeasureUtils.getValue(childrenData.getMeasure(mainMetric), null);
092 if (childrenMainMeasure != null && childrenByMeasure != null && childrenByMeasure > 0.0) {
093 totalByMeasure += childrenByMeasure;
094 totalMainMeasure += childrenMainMeasure;
095 hasApplicableChildren = true;
096 }
097 }
098 if (hasApplicableChildren) {
099 result = new Measure(context.getTargetMetric(), (totalMainMeasure / totalByMeasure));
100 }
101 return result;
102 }
103
104 private Measure calculateForFile(FormulaData data, FormulaContext context) {
105 Measure result = null;
106
107 Double byMeasure = MeasureUtils.getValue(data.getMeasure(byMetric), null);
108 Double mainMeasure = MeasureUtils.getValue(data.getMeasure(mainMetric), null);
109 if (mainMeasure != null && byMeasure != null && byMeasure > 0.0) {
110 result = new Measure(context.getTargetMetric(), (mainMeasure / byMeasure));
111 }
112
113 return result;
114 }
115
116 private boolean shouldDecorateResource(FormulaData data, FormulaContext context) {
117 return !MeasureUtils.hasValue(data.getMeasure(context.getTargetMetric()));
118 }
119 }