an internal action that collects java expression statistics to be used in completion

java/java-impl/src/com/intellij/internal/ExpressionStatisticsAction.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright 2000-2015 JetBrains s.r.o.
+ *
+ * Licensed 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.
+ */
+
+/*
+ * @author max
+ */
+package com.intellij.internal;
+
+import com.intellij.openapi.actionSystem.AnAction;
+import com.intellij.openapi.actionSystem.AnActionEvent;
+import com.intellij.openapi.actionSystem.CommonDataKeys;
+import com.intellij.openapi.application.ex.ApplicationManagerEx;
+import com.intellij.openapi.progress.ProgressIndicator;
+import com.intellij.openapi.progress.ProgressManager;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.roots.ContentIterator;
+import com.intellij.openapi.roots.ProjectFileIndex;
+import com.intellij.openapi.ui.Messages;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.*;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class ExpressionStatisticsAction extends AnAction {
+  @Override
+  public void actionPerformed(AnActionEvent e) {
+    final Project project = CommonDataKeys.PROJECT.getData(e.getDataContext());
+    assert project != null;
+
+    final Data topLevelData = new Data();
+    final Data subData = new Data();
+
+    final VirtualFile dir = CommonDataKeys.VIRTUAL_FILE.getData(e.getDataContext());
+    assert dir != null;
+
+    final List<VirtualFile> javaFiles = collectJavaFiles(dir, project);
+
+    if (!ApplicationManagerEx.getApplicationEx().runProcessWithProgressSynchronouslyInReadAction(project, "Traversing PSI", true, "Cancel", null, new Runnable() {
+      @Override
+      public void run() {
+        final PsiManager psiManager = PsiManager.getInstance(project);
+        ProgressIndicator indicator = ProgressManager.getInstance().getProgressIndicator();
+        indicator.setIndeterminate(false);
+        for (int i = 0; i < javaFiles.size(); i++) {
+          VirtualFile file = javaFiles.get(i);
+          indicator.setText2(file.getPath());
+          indicator.setFraction((double)i / javaFiles.size());
+          PsiFile psiFile = psiManager.findFile(file);
+          if (psiFile instanceof PsiJavaFile) {
+            psiFile.accept(new PsiRecursiveElementWalkingVisitor() {
+              @Override
+              public void visitElement(PsiElement element) {
+                if (element instanceof PsiIdentifier) {
+                  int offset = element.getTextRange().getStartOffset();
+                  PsiExpression minExpression = PsiTreeUtil.getParentOfType(element, PsiExpression.class);
+                  if (minExpression != null && minExpression.getTextRange().getStartOffset() == offset) {
+                    PsiExpression maxExpression = minExpression;
+                    while (true) {
+                      PsiExpression nextExpression = PsiTreeUtil.getParentOfType(maxExpression, PsiExpression.class, true);
+                      if (nextExpression == null || nextExpression.getTextRange().getStartOffset() != offset) break;
+                      maxExpression = nextExpression;
+                    }
+                    collectExpressionData(minExpression, maxExpression, topLevelData, subData);
+                  }
+                }
+
+                super.visitElement(element);
+              }
+            });
+          }
+        }
+      }
+    })) {
+      return;
+    }
+
+    Messages.showMessageDialog("Top-level: " + topLevelData.toString() + "\n\n" + "Sub-expressions: " + subData.toString(), "Expression Statistics", null);
+  }
+
+  @NotNull
+  private static List<VirtualFile> collectJavaFiles(VirtualFile dir, Project project) {
+    final List<VirtualFile> javaFiles = ContainerUtil.newArrayList();
+    ProjectFileIndex.SERVICE.getInstance(project).iterateContentUnderDirectory(dir, new ContentIterator() {
+      @Override
+      public boolean processFile(VirtualFile file) {
+        if (file.getName().endsWith(".java")) {
+          javaFiles.add(file);
+        }
+        return true;
+      }
+    });
+    return javaFiles;
+  }
+
+  private static void collectExpressionData(PsiExpression minExpression, PsiExpression maxExpression, Data topLevelData, Data subExpressionData) {
+    Data data;
+    if (minExpression == maxExpression || maxExpression instanceof PsiMethodCallExpression && minExpression == ((PsiMethodCallExpression)maxExpression).getMethodExpression()) {
+      data = topLevelData;
+    } else {
+      data = subExpressionData;
+    }
+
+    if (minExpression instanceof PsiClassObjectAccessExpression || minExpression instanceof PsiThisExpression || minExpression instanceof PsiSuperExpression) {
+      data.classes++;
+      return;
+    }
+
+    if (!(minExpression instanceof PsiJavaCodeReferenceElement)) {
+      data.other++;
+      return;
+    }
+
+    classifyTarget(data, ((PsiJavaCodeReferenceElement)minExpression).resolve());
+  }
+
+  private static void classifyTarget(Data data, PsiElement target) {
+    if (target instanceof PsiLocalVariable) {
+      data.localVars++;
+    }
+    else if (target instanceof PsiParameter) {
+      data.parameters++;
+    }
+    else if (target instanceof PsiMethod) {
+      data.methods++;
+    }
+    else if (target instanceof PsiClass) {
+      data.classes++;
+    }
+    else if (target instanceof PsiPackage) {
+      data.packages++;
+    }
+    else if (target instanceof PsiField) {
+      data.fields++;
+    }
+    else {
+      data.other++;
+    }
+  }
+
+  private static class Data {
+    int localVars;
+    int parameters;
+    int methods;
+    int classes;
+    int fields;
+    int packages;
+    int other;
+
+    @Override
+    public String toString() {
+      return "localVars=" + localVars +
+             "\nparameters=" + parameters +
+             "\nmethods=" + methods +
+             "\nfields=" + fields +
+             "\nclasses=" + classes +
+             "\npackages=" + packages +
+             "\nother=" + other +
+             "\ntotal=" + (localVars + parameters + methods + fields + classes + packages + other);
+    }
+  }
+
+
+}
+

resources/src/idea/JavaActions.xml

@@ -150,6 +150,10 @@
             text="List Used Icons">
       <add-to-group group-id="Internal"/>
     </action>
+    <action id="ExpressionStatistics" internal="true" class="com.intellij.internal.ExpressionStatisticsAction"
+            text="Collect Java Expression Statistics">
+      <add-to-group group-id="Internal"/>
+    </action>
 
     <action id="StaticIconFields" internal="true" class="com.intellij.internal.StaticIconFieldsAction"
             text="List Static Field Initializers">