001/*
002 * SonarQube
003 * Copyright (C) 2009-2016 SonarSource SA
004 * mailto:contact AT sonarsource DOT com
005 *
006 * This program 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 * This program 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 License
017 * along with this program; if not, write to the Free Software Foundation,
018 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019 */
020package org.sonar.api.ce.measure;
021
022import java.util.List;
023import java.util.Set;
024import javax.annotation.CheckForNull;
025import org.sonar.api.ExtensionPoint;
026import org.sonar.api.ce.measure.MeasureComputer.MeasureComputerDefinition.Builder;
027import org.sonar.api.server.ServerSide;
028
029/**
030 * Define how to compute new measures on some metrics declared by {@link org.sonar.api.measures.Metrics}.
031 * <p/>
032 * This interface replaces the deprecated class org.sonar.api.batch.Decorator.
033 * <p/>
034 * <h3>How to use</h3>
035 * <pre>
036 * public class MyMeasureComputer implements MeasureComputer {
037 *
038 *   {@literal @}Override
039 *   public MeasureComputerDefinition define(MeasureComputerDefinitionContext defContext) {
040 *     return defContext.newDefinitionBuilder()
041 *
042 *     // Input metrics can be empty, for instance if only issues will be read
043 *     .setInputMetrics("ncloc")
044 *
045 *     // Output metrics must contains at least one metric
046 *     .setOutputMetrics("my_new_metric")
047 *
048 *     .build();
049 *   }
050 *
051 *   {@literal @}Override
052 *   public void compute(MeasureComputerContext context) {
053 *     int ncloc = context.getMeasure("ncloc");
054 *     List&lt;Issue&gt; issues = context.getIssues();
055 *     if (ncloc != null && !issues.isEmpty()) {
056 *       double value = issues.size() / ncloc;
057 *       context.addMeasure("my_new_metric", value);
058 *     }
059 *   }
060 * }
061 * </pre>
062 * <p/>
063 * <h3>How to test</h3>
064 * <pre>
065 * public class MyMeasureComputerTest {
066 *
067 *   MyMeasureComputer underTest = new MyMeasureComputer();
068 *
069 *   {@literal @}Test
070 *   public void test_definition() {
071 *     TestMeasureComputerDefinitionContext defContext = new TestMeasureComputerDefinitionContext();
072 *     MeasureComputerDefinition def = underTest.define(defContext);
073 *     assertThat(def).isNotNull();
074 *     assertThat(def.getInputMetrics()).containsOnly("ncloc");
075 *     assertThat(def.getOutputMetrics()).containsOnly("my_new_metric");
076 *   }
077 *
078 *   {@literal @}Test
079 *   public void sum_ncloc_and_issues() {
080 *     TestMeasureComputerContext context = new TestMeasureComputerContext(underTest);
081 *     context.addMeasure("ncloc", 2);
082 *     context.setIssues(Arrays.asList(new TestIssue.Builder().setKey("ABCD").build()));
083 *     underTest.compute(context);
084 *
085 *     assertThat(context.getMeasureValue("my_new_metric")).isEqualTo(0.5);
086 *   }
087 * </pre>
088 *
089 * @since 5.2
090 */
091@ServerSide
092@ExtensionPoint
093public interface MeasureComputer {
094
095  /**
096   * Use to define which metrics are required to compute some measures on some given metrics
097   */
098  MeasureComputerDefinition define(MeasureComputerDefinitionContext defContext);
099
100  /**
101   * Context specific to the definition of the measure computer
102   */
103  interface MeasureComputerDefinitionContext {
104    Builder newDefinitionBuilder();
105  }
106
107  interface MeasureComputerDefinition {
108    /**
109     * Return the metric keys that can be read using {@link MeasureComputerContext}.
110     * Can be empty for instance when the computer only need to access to issues.
111     */
112    Set<String> getInputMetrics();
113
114    /**
115     * Return the metric keys that can be create using {@link MeasureComputerContext}.
116     * Can never ne empty.
117     */
118    Set<String> getOutputMetrics();
119
120    interface Builder {
121
122      /**
123       * List of metric keys of the measures that will be loaded by this computer. It can be empty (for instance when only issues are needed).
124       * A metric must be either a {@link org.sonar.api.measures.CoreMetrics} or a metric provided by {@link org.sonar.api.measures.Metrics}
125       *
126       * @throws NullPointerException if inputMetrics is null
127       * @throws NullPointerException if the metrics contains a {@code null}
128       * */
129      Builder setInputMetrics(String... inputMetrics);
130
131      /**
132       * List of metric keys of the measures that can be added by this computer. At least one metric key must be defined.
133       *
134       * At runtime, the following conditions will be validated :
135       * <ul>
136       *   <li>A metric must be defined by {@link org.sonar.api.measures.Metrics}</li>
137       *   <li>A metric cannot be a {@link org.sonar.api.measures.CoreMetrics}</li>
138       *   <li>A metric must be generated by only one {@link MeasureComputer}</li>
139       * </ul>
140       *
141       * @throws NullPointerException if outputMetrics is null
142       * @throws IllegalArgumentException if there's not at least one output metrics
143       * @throws NullPointerException if the metrics contains a {@code null}
144       */
145      Builder setOutputMetrics(String... outputMetrics);
146
147      /**
148       * @throws NullPointerException if inputMetrics is null
149       * @throws NullPointerException if inputs metrics contains a {@code null}
150       * @throws NullPointerException if outputMetrics is null
151       * @throws IllegalArgumentException if there's not at least one output metrics
152       * @throws NullPointerException if outputs metrics contains a {@code null}
153       */
154      MeasureComputerDefinition build();
155    }
156  }
157
158  /**
159   * This method will be called on each component of the projects.
160   */
161  void compute(MeasureComputerContext context);
162
163  /**
164   * Context specific to the computation of the measure(s) of a given component
165   */
166  interface MeasureComputerContext {
167    /**
168     * Returns the current component.
169     */
170    Component getComponent();
171
172    /**
173     * Returns settings of the current component.
174     */
175    Settings getSettings();
176
177    /**
178     * Returns the measure from a given metric on the current component.
179     *
180     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getInputMetrics()}
181     */
182    @CheckForNull
183    Measure getMeasure(String metric);
184
185    /**
186     * Returns measures from a given metric on children of the current component.
187     * It no measure is found for a child, this measure is ignored
188     *
189     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getInputMetrics()} 
190     * or in {@link MeasureComputerDefinition#getOutputMetrics()}
191     */
192    Iterable<Measure> getChildrenMeasures(String metric);
193
194    /**
195     * Add a new measure of a given metric which measure type will be int
196     *
197     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getOutputMetrics()}
198     * @throws UnsupportedOperationException if a measure for the specified metric already exists for the current component
199     */
200    void addMeasure(String metric, int value);
201
202    /**
203     * Add a new measure of a given metric which measure type will be double
204     *
205     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getOutputMetrics()}
206     * @throws UnsupportedOperationException if a measure for the specified metric already exists for the current component
207     */
208    void addMeasure(String metric, double value);
209
210    /**
211     * Add a new measure of a given metric which measure type will be long
212     *
213     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getOutputMetrics()}
214     * @throws UnsupportedOperationException if a measure for the specified metric already exists for the current component
215     */
216    void addMeasure(String metric, long value);
217
218    /**
219     * Add a new measure of a given metric which measure type will be string
220     *
221     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getOutputMetrics()}
222     * @throws UnsupportedOperationException if a measure for the specified metric already exists for the current component
223     */
224    void addMeasure(String metric, String value);
225
226    /**
227     * Add a new measure of a given metric which measure type will be boolean
228     *
229     * @throws IllegalArgumentException if the metric is not listed in {@link MeasureComputerDefinition#getOutputMetrics()}
230     * @throws UnsupportedOperationException if a measure for the specified metric already exists for the current component
231     */
232    void addMeasure(String metric, boolean value);
233
234    /**
235     * Return list of all issues (open, closed, etc.) of current component.
236     */
237    List<? extends Issue> getIssues();
238  }
239}