LCOM2-3 Impl

src/main/java/org/jpeek/metrics/cohesion/LCOM2.java

@@ -0,0 +1,142 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.jpeek.metrics.cohesion;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import javassist.CannotCompileException;
+import javassist.CtClass;
+import org.jpeek.Base;
+import org.jpeek.Metric;
+import org.jpeek.metrics.Colors;
+import org.jpeek.metrics.JavassistClasses;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.xembly.Directive;
+
+/**
+ * Lack of Cohesion in Methods 2 (LCOM2).
+ *
+ * <p>Consider a class C with methods M1, M2,….., Mn. Let {Ii} = set of
+ * instance variables used by method Mi. There are n such sets, i.e., {1i},
+ * {I2},….., {In}. Let  P = { (Ii, Ij ) | Ii  Ij  = } and Q = {(Ii, Ij ) |
+ * Ii  Ij   }. If all n sets {1i}, {I2},….., {In} are  then let P = .</p>
+ *
+ * <p>There is no thread-safety guarantee.</p>
+ *
+ * @author Mehmet Yildirim (memoyil@gmail.com)
+ * @version $Id$
+ * @see <a href="http://www.pitt.edu/~ckemerer/CK%20research%20papers/MetricForOOD_ChidamberKemerer94.pdf">A metrics suite for object oriented design</a>
+ * @since 0.2
+ * @checkstyle AbbreviationAsWordInNameCheck (5 lines)
+ * @checkstyle ClassDataAbstractionCouplingCheck (500 lines)
+ */
+public final class LCOM2 implements Metric {
+
+    /**
+     * The base.
+     */
+    private final Base base;
+
+    /**
+     * Ctor.
+     *
+     * @param bse The base
+     */
+    public LCOM2(final Base bse) {
+        this.base = bse;
+    }
+
+    @Override
+    public Iterable<Directive> xembly() throws IOException {
+        return new JavassistClasses(
+            this.base, LCOM2::cohesion,
+            // @checkstyle MagicNumberCheck (1 line)
+            new Colors(1.0d, 0.0d)
+        ).xembly();
+    }
+
+    /**
+     * Calculate LCOM2 metric for a single Java class.
+     *
+     * @param ctc The .class file
+     * @return Metrics
+     * @checkstyle ParameterNumberCheck (100 lines)
+     * @checkstyle AnonInnerLengthCheck (25 lines)
+     */
+    @SuppressWarnings({"PMD.UseObjectForClearerAPI", "PMD.UseVarargs"})
+    private static double cohesion(final CtClass ctc) {
+        final ClassReader reader;
+        try {
+            reader = new ClassReader(ctc.toBytecode());
+        } catch (final IOException | CannotCompileException ex) {
+            throw new IllegalStateException(ex);
+        }
+        final List<Collection<String>> methods = new LinkedList<>();
+        final Set<String> attrs = new HashSet<>();
+        reader.accept(
+            new ClassVisitor(Opcodes.ASM6) {
+                @Override
+                public MethodVisitor visitMethod(final int access, final
+                    String mtd, final String desc, final String signature, final
+                    String[] exceptions) {
+                    super.visitMethod(access, mtd, desc, signature, exceptions);
+                    final Collection<String> methodattrs = new HashSet<>(0);
+                    methods.add(methodattrs);
+                    return new MethodVisitor(Opcodes.ASM6) {
+                        @Override
+                        public void visitFieldInsn(final int opcode,
+                            final String owner, final String attr,
+                            final String details) {
+                            super.visitFieldInsn(opcode, owner, attr, details);
+                            attrs.add(attr);
+                            methodattrs.add(attr);
+                        }
+                    };
+                }
+            },
+            0
+        );
+        int sum = 0;
+        int result = 0;
+        for (final String attr : attrs) {
+            for (final Collection<String> methodattrs : methods) {
+                if (methodattrs.contains(attr)) {
+                    ++sum;
+                }
+            }
+        }
+        if (!attrs.isEmpty() && !methods.isEmpty()) {
+            result = 1 - sum / (attrs.size() * methods.size());
+        }
+        return result;
+    }
+
+}

src/main/java/org/jpeek/metrics/cohesion/LCOM3.java

@@ -0,0 +1,140 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.jpeek.metrics.cohesion;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import javassist.CannotCompileException;
+import javassist.CtClass;
+import org.jpeek.Base;
+import org.jpeek.Metric;
+import org.jpeek.metrics.Colors;
+import org.jpeek.metrics.JavassistClasses;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.xembly.Directive;
+
+/**
+ * Lack of Cohesion in Methods 2 (LCOM2).
+ *
+ * <p>Consider an undirected graph G where the vertices are the methods of a
+ * class, and there is an edge between two vertices if the corresponding
+ * methods share at least one instance variable.</p>
+ *
+ * <p>There is no thread-safety guarantee.</p>
+ *
+ * @author Mehmet Yildirim (memoyil@gmail.com)
+ * @version $Id$
+ * @see <a href="http://www.pitt.edu/~ckemerer/CK%20research%20papers/MetricForOOD_ChidamberKemerer94.pdf">A metrics suite for object oriented design</a>
+ * @since 0.2
+ * @checkstyle AbbreviationAsWordInNameCheck (5 lines)
+ * @checkstyle ClassDataAbstractionCouplingCheck (500 lines)
+ */
+public final class LCOM3 implements Metric {
+
+    /**
+     * The base.
+     */
+    private final Base base;
+
+    /**
+     * Ctor.
+     * @param bse The base
+     */
+    public LCOM3(final Base bse) {
+        this.base = bse;
+    }
+
+    @Override
+    public Iterable<Directive> xembly() throws IOException {
+        return new JavassistClasses(
+            this.base, LCOM3::cohesion,
+            // @checkstyle MagicNumberCheck (1 line)
+            new Colors(0.35d, 0.0d)
+        ).xembly();
+    }
+
+    /**
+     * Calculate LCOM2 metric for a single Java class.
+     * @param ctc The .class file
+     * @return Metrics
+     * @checkstyle ParameterNumberCheck (100 lines)
+     * @checkstyle AnonInnerLengthCheck (25 lines)
+     */
+    @SuppressWarnings({"PMD.UseObjectForClearerAPI", "PMD.UseVarargs"})
+    private static double cohesion(final CtClass ctc) {
+        final ClassReader reader;
+        try {
+            reader = new ClassReader(ctc.toBytecode());
+        } catch (final IOException | CannotCompileException ex) {
+            throw new IllegalStateException(ex);
+        }
+        final List<Collection<String>> methods = new LinkedList<>();
+        final Set<String> attrs = new HashSet<>();
+        reader.accept(
+            new ClassVisitor(Opcodes.ASM6) {
+                @Override
+                public MethodVisitor visitMethod(final int access, final
+                    String mtd, final String desc, final String signature,
+                    final String[] exceptions) {
+                    super.visitMethod(access, mtd, desc, signature, exceptions);
+                    final Collection<String> methodattrs = new HashSet<>(0);
+                    methods.add(methodattrs);
+                    return new MethodVisitor(Opcodes.ASM6) {
+                        @Override
+                        public void visitFieldInsn(final int opcode,
+                            final String owner, final String attr,
+                            final String details) {
+                            super.visitFieldInsn(opcode, owner, attr, details);
+                            attrs.add(attr);
+                            methodattrs.add(attr);
+                        }
+                    };
+                }
+            },
+            0
+        );
+        int sum = 0;
+        int result = 0;
+        for (final String attr : attrs) {
+            for (final Collection<String> methodattrs : methods) {
+                if (methodattrs.contains(attr)) {
+                    ++sum;
+                }
+            }
+        }
+        if (!attrs.isEmpty() && methods.size() != 1) {
+            final int methodsize = methods.size();
+            result = (methodsize - (sum / attrs.size())) / (methodsize - 1);
+        }
+        return result;
+    }
+
+}

src/test/java/org/jpeek/metrics/cohesion/LCOM2Test.java

@@ -0,0 +1,79 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.jpeek.metrics.cohesion;
+
+import com.jcabi.matchers.XhtmlMatchers;
+import java.io.IOException;
+import java.nio.file.Paths;
+import org.hamcrest.MatcherAssert;
+import org.jpeek.DefaultBase;
+import org.jpeek.metrics.FakeBase;
+import org.junit.Test;
+import org.xembly.Xembler;
+
+/**
+ * Test case for {@link LCOM2}.
+ * @author Mehmet Yildirim (memoyil@gmail.com)
+ * @version $Id$
+ * @since 0.2
+ * @checkstyle AbbreviationAsWordInNameCheck (5 lines)
+ * @checkstyle JavadocMethodCheck (500 lines)
+ */
+public final class LCOM2Test {
+
+    @Test
+    public void createsBigXmlReport() throws IOException {
+        MatcherAssert.assertThat(
+            XhtmlMatchers.xhtml(
+                new Xembler(
+                    new LCOM2(
+                        new DefaultBase(Paths.get("."))
+                    ).xembly()
+                ).xmlQuietly()
+            ),
+            XhtmlMatchers.hasXPaths(
+                "/metric/app/package/class[@id='LCOM2Test']",
+                "//class[@id='DefaultBase' and @value='0.0000']"
+            )
+        );
+    }
+
+    @Test
+    public void createsXmlReportForFixtureClassA() throws IOException {
+        MatcherAssert.assertThat(
+            XhtmlMatchers.xhtml(
+                new Xembler(
+                    new LCOM2(
+                        new FakeBase("Foo")
+                    ).xembly()
+                ).xmlQuietly()
+            ),
+            XhtmlMatchers.hasXPaths(
+                "/metric/app/package/class[@id='Foo']",
+                "//class[@id='Foo' and @value='1.0000']",
+                "//class[@id='Foo' and @color='yellow']"
+            )
+        );
+    }
+}