content: /*
   * Copyright (C) 2015 The Android Open Source Project
   *
   * 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.
   */
  
  package com.android.ahat;
  
  import com.android.tools.perflib.heap.ClassObj;
  import com.android.tools.perflib.heap.Field;
  import com.android.tools.perflib.heap.Instance;
  import java.io.File;
  import java.io.IOException;
  import java.util.Map;
  
  /**
   * The TestDump class is used to get an AhatSnapshot for the test-dump
   * program.
   */
  public class TestDump {
    // It can take on the order of a second to parse and process the test-dump
    // hprof. To avoid repeating this overhead for each test case, we cache the
    // loaded instance of TestDump and reuse it when possible. In theory the
    // test cases should not be able to modify the cached snapshot in a way that
    // is visible to other test cases.
    private static TestDump mCachedTestDump = null;
  
    private AhatSnapshot mSnapshot = null;
  
    /**
     * Load the test-dump.hprof file.
     * The location of the file is read from the system property
     * "ahat.test.dump.hprof", which is expected to be set on the command line.
     * For example:
     *   java -Dahat.test.dump.hprof=test-dump.hprof -jar ahat-tests.jar
     *
     * An IOException is thrown if there is a failure reading the hprof file.
     */
    private TestDump() throws IOException {
        String hprof = System.getProperty("ahat.test.dump.hprof");
        mSnapshot = AhatSnapshot.fromHprof(new File(hprof));
    }
  
    /**
     * Get the AhatSnapshot for the test dump program.
     */
    public AhatSnapshot getAhatSnapshot() {
      return mSnapshot;
    }
  
    /**
     * Return the value of a field in the DumpedStuff instance in the
     * snapshot for the test-dump program.
     */
    public Object getDumpedThing(String name) {
      ClassObj main = mSnapshot.findClass("Main");
      Instance stuff = null;
      for (Map.Entry<Field, Object> fields : main.getStaticFieldValues().entrySet()) {
        if ("stuff".equals(fields.getKey().getName())) {
          stuff = (Instance) fields.getValue();
        }
      }
      return InstanceUtils.getField(stuff, name);
    }
  
    /**
     * Get the test dump.
     * An IOException is thrown if there is an error reading the test dump hprof
     * file.
     * To improve performance, this returns a cached instance of the TestDump
     * when possible.
     */
    public static synchronized TestDump getTestDump() throws IOException {
      if (mCachedTestDump == null) {
        mCachedTestDump = new TestDump();
      }
      return mCachedTestDump;
    }
  }
  