Façade and Computer

docs/pages/pmd/devdocs/adding_metrics_framework_for_language.md

@@ -36,9 +36,10 @@ a singleton.
 your `MetricsComputer`. It backs the real end user façade, and handles user provided parameters before delegating to 
 your `MetricsComputer`.
 * Create the static façade of your framework. This one has an instance of your `MetricsFaçade` object and delegates 
-static methods to that instance. It should be able to give back
+static methods to that instance.
 * If you want to implement signature matching, create an `AbstractMetric` class, which gives access to a 
-`SignatureMatcher` to your metrics. 
+`SignatureMatcher` to your metrics. Typically, your implementation of `ProjectMirror` implements a 
+custom `SignatureMatcher` interface, and your façade can give back its instance of the project mirror.
 * Create classes `AbstractOperationMetric` and `AbstractClassMetric`. These must implement `Metric<T>` and 
 `Metric<O>`, respectively. They typically provide defaults for the `supports` method of each metric. 
 * Create enums `ClassMetricKey` and `OperationMetricKey`. These must implement `MetricKey<T>` and `MetricKey<O>`. The

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/metrics/ApexMetrics.java

@@ -0,0 +1,132 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.apex.metrics;
+
+import net.sourceforge.pmd.lang.apex.ast.ASTMethod;
+import net.sourceforge.pmd.lang.apex.ast.ASTUserClass;
+import net.sourceforge.pmd.lang.metrics.Metric.Version;
+import net.sourceforge.pmd.lang.metrics.MetricKey;
+import net.sourceforge.pmd.lang.metrics.MetricVersion;
+import net.sourceforge.pmd.lang.metrics.ResultOption;
+
+/**
+ * @author Clément Fournier
+ */
+public final class ApexMetrics {
+
+    private static final ApexMetricsFacade FACADE = new ApexMetricsFacade();
+
+
+    private ApexMetrics() { // Cannot be instantiated
+
+    }
+
+
+    /**
+     * Returns the project mirror of the analysed project.
+     *
+     * @return The project mirror
+     */
+    static ApexProjectMirror getTopLevelPackageStats() {
+        return FACADE.getLanguageSpecificProjectMirror();
+    }
+
+
+    /** Resets the entire data structure. Used for tests. */
+    static void reset() {
+        FACADE.reset();
+    }
+
+
+    /**
+     * Computes the standard value of the metric identified by its code on a class AST node.
+     *
+     * @param key  The key identifying the metric to be computed
+     * @param node The node on which to compute the metric
+     *
+     * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed
+     */
+    public static double get(MetricKey<ASTUserClass> key, ASTUserClass node) {
+        return FACADE.computeForType(key, node, Version.STANDARD);
+    }
+
+
+    /**
+     * Computes a metric identified by its code on a class AST node, possibly selecting a variant with the {@code
+     * MetricVersion} parameter.
+     *
+     * @param key     The key identifying the metric to be computed
+     * @param node    The node on which to compute the metric
+     * @param version The version of the metric
+     *
+     * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed
+     */
+    public static double get(MetricKey<ASTUserClass> key, ASTUserClass node, MetricVersion version) {
+        return FACADE.computeForType(key, node, version);
+    }
+
+
+    /**
+     * Computes the standard version of the metric identified by the key on a operation AST node.
+     *
+     * @param key  The key identifying the metric to be computed
+     * @param node The node on which to compute the metric
+     *
+     * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed
+     */
+    public static double get(MetricKey<ASTMethod> key, ASTMethod node) {
+        return FACADE.computeForOperation(key, node, Version.STANDARD);
+    }
+
+
+    /**
+     * Computes a metric identified by its key on a operation AST node.
+     *
+     * @param key     The key identifying the metric to be computed
+     * @param node    The node on which to compute the metric
+     * @param version The version of the metric
+     *
+     * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed
+     */
+    public static double get(MetricKey<ASTMethod> key, ASTMethod node, MetricVersion version) {
+        return FACADE.computeForOperation(key, node, version);
+    }
+
+
+    /**
+     * Compute the sum, average, or highest value of the standard operation metric on all operations of the class node.
+     * The type of operation is specified by the {@link ResultOption} parameter.
+     *
+     * @param key    The key identifying the metric to be computed
+     * @param node   The node on which to compute the metric
+     * @param option The result option to use
+     *
+     * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed or {@code option} is
+     * {@code null}
+     */
+    public static double get(MetricKey<ASTMethod> key, ASTUserClass node, ResultOption option) {
+        return FACADE.computeWithResultOption(key, node, Version.STANDARD, option);
+    }
+
+
+    /**
+     * Compute the sum, average, or highest value of the operation metric on all operations of the class node. The type
+     * of operation is specified by the {@link ResultOption} parameter.
+     *
+     * @param key     The key identifying the metric to be computed
+     * @param node    The node on which to compute the metric
+     * @param version The version of the metric
+     * @param option  The result option to use
+     *
+     * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed or {@code option} is
+     * {@code null}
+     */
+    public static double get(MetricKey<ASTMethod> key, ASTUserClass node, MetricVersion version,
+                             ResultOption option) {
+        return FACADE.computeWithResultOption(key, node, version, option);
+    }
+
+
+}

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/metrics/ApexMetricsComputer.java

@@ -0,0 +1,24 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.apex.metrics;
+
+import java.util.List;
+
+import net.sourceforge.pmd.lang.apex.ast.ASTMethod;
+import net.sourceforge.pmd.lang.apex.ast.ASTUserClass;
+import net.sourceforge.pmd.lang.metrics.AbstractMetricsComputer;
+
+/**
+ * @author Clément Fournier
+ */
+public class ApexMetricsComputer extends AbstractMetricsComputer<ASTUserClass, ASTMethod> {
+
+    public static final ApexMetricsComputer INSTANCE = new ApexMetricsComputer();
+
+    @Override
+    protected List<ASTMethod> findOperations(ASTUserClass node) {
+        return node.findChildrenOfType(ASTMethod.class);
+    }
+}

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/metrics/ApexMetricsFacade.java

@@ -0,0 +1,36 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.apex.metrics;
+
+import net.sourceforge.pmd.lang.apex.ast.ASTMethod;
+import net.sourceforge.pmd.lang.apex.ast.ASTUserClass;
+import net.sourceforge.pmd.lang.metrics.AbstractMetricsFacade;
+import net.sourceforge.pmd.lang.metrics.MetricsComputer;
+
+/**
+ * @author Clément Fournier
+ */
+public class ApexMetricsFacade extends AbstractMetricsFacade<ASTUserClass, ASTMethod> {
+
+    private final ApexProjectMirror projectMirror = new ApexProjectMirror();
+
+
+    /** Resets the entire project mirror. Used for tests. */
+    void reset() {
+        projectMirror.reset();
+    }
+
+
+    @Override
+    protected MetricsComputer<ASTUserClass, ASTMethod> getLanguageSpecificComputer() {
+        return ApexMetricsComputer.INSTANCE;
+    }
+
+
+    @Override
+    protected ApexProjectMirror getLanguageSpecificProjectMirror() {
+        return projectMirror;
+    }
+}

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/metrics/ApexProjectMirror.java

@@ -25,6 +25,12 @@ public class ApexProjectMirror implements ProjectMirror<ASTUserClass, ASTMethod>
     private final Map<ApexQualifiedName, ApexClassStats> classes = new HashMap<>();
 
 
+    void reset() {
+        operations.clear();
+        classes.clear();
+    }
+
+
     ApexOperationStats addOperation(ApexQualifiedName qname, ApexOperationSignature sig) {
         if (!operations.containsKey(sig)) {
             operations.put(sig, new HashMap<>());