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.Instance;
  import com.android.tools.perflib.heap.Heap;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Iterator;
  
  /**
   * Provides Comparators and helper functions for sorting Instances, Sites, and
   * other things.
   *
   * Note: The Comparators defined here impose orderings that are inconsistent
   * with equals. They should not be used for element lookup or search. They
   * should only be used for showing elements to the user in different orders.
   */
  class Sort {
    /**
     * Compare instances by their instance id.
     * This sorts instances from smaller id to larger id.
     */
    public static class InstanceById implements Comparator<Instance> {
      @Override
      public int compare(Instance a, Instance b) {
        return Long.compare(a.getId(), b.getId());
      }
    }
  
    /**
     * Compare instances by their total retained size.
     * Different instances with the same total retained size are considered
     * equal for the purposes of comparison.
     * This sorts instances from larger retained size to smaller retained size.
     */
    public static class InstanceByTotalRetainedSize implements Comparator<Instance> {
      @Override
      public int compare(Instance a, Instance b) {
        return Long.compare(b.getTotalRetainedSize(), a.getTotalRetainedSize());
      }
    }
  
    /**
     * Compare instances by their retained size for a given heap index.
     * Different instances with the same total retained size are considered
     * equal for the purposes of comparison.
     * This sorts instances from larger retained size to smaller retained size.
     */
    public static class InstanceByHeapRetainedSize implements Comparator<Instance> {
      private int mIndex;
  
      public InstanceByHeapRetainedSize(AhatSnapshot snapshot, Heap heap) {
        mIndex = snapshot.getHeapIndex(heap);
      }
  
      public InstanceByHeapRetainedSize(int heapIndex) {
        mIndex = heapIndex;
      }
  
      @Override
      public int compare(Instance a, Instance b) {
        return Long.compare(b.getRetainedSize(mIndex), a.getRetainedSize(mIndex));
      }
    }
  
    /**
     * Compare objects based on a list of comparators, giving priority to the
     * earlier comparators in the list.
     */
    public static class WithPriority<T> implements Comparator<T> {
      private List<Comparator<T>> mComparators;
  
      public WithPriority(Comparator<T>... comparators) {
        mComparators = Arrays.asList(comparators);
      }
  
      public WithPriority(List<Comparator<T>> comparators) {
        mComparators = comparators;
      }
  
      @Override
      public int compare(T a, T b) {
        int res = 0;
        Iterator<Comparator<T>> iter = mComparators.iterator();
        while (res == 0 && iter.hasNext()) {
          res = iter.next().compare(a, b);
        }
        return res;
      }
    }
  
    public static Comparator<Instance> defaultInstanceCompare(AhatSnapshot snapshot) {
      List<Comparator<Instance>> comparators = new ArrayList<Comparator<Instance>>();
  
      // Priority goes to the app heap, if we can find one.
      Heap appHeap = snapshot.getHeap("app");
      if (appHeap != null) {
        comparators.add(new InstanceByHeapRetainedSize(snapshot, appHeap));
      }
  
      // Next is by total retained size.
      comparators.add(new InstanceByTotalRetainedSize());
      return new WithPriority<Instance>(comparators);
    }
  
    /**
     * Compare Sites by the size of objects allocated on a given heap.
     * Different object infos with the same size on the given heap are
     * considered equal for the purposes of comparison.
     * This sorts sites from larger size to smaller size.
     */
    public static class SiteBySize implements Comparator<Site> {
      String mHeap;
  
      public SiteBySize(String heap) {
        mHeap = heap;
      }
  
      @Override
      public int compare(Site a, Site b) {
        return Long.compare(b.getSize(mHeap), a.getSize(mHeap));
      }
    }
  
    /**
     * Compare Site.ObjectsInfo by their size.
     * Different object infos with the same total retained size are considered
     * equal for the purposes of comparison.
     * This sorts object infos from larger retained size to smaller size.
     */
    public static class ObjectsInfoBySize implements Comparator<Site.ObjectsInfo> {
      @Override
      public int compare(Site.ObjectsInfo a, Site.ObjectsInfo b) {
        return Long.compare(b.numBytes, a.numBytes);
      }
    }
  
    /**
     * Compare Site.ObjectsInfo by heap name.
     * Different object infos with the same heap name are considered equal for
     * the purposes of comparison.
     */
    public static class ObjectsInfoByHeapName implements Comparator<Site.ObjectsInfo> {
      @Override
      public int compare(Site.ObjectsInfo a, Site.ObjectsInfo b) {
        return a.heap.getName().compareTo(b.heap.getName());
      }
    }
  
    /**
     * Compare Site.ObjectsInfo by class name.
     * Different object infos with the same class name are considered equal for
     * the purposes of comparison.
     */
    public static class ObjectsInfoByClassName implements Comparator<Site.ObjectsInfo> {
      @Override
      public int compare(Site.ObjectsInfo a, Site.ObjectsInfo b) {
        String aName = AhatSnapshot.getClassName(a.classObj);
        String bName = AhatSnapshot.getClassName(b.classObj);
        return aName.compareTo(bName);
      }
    }
  
    /**
     * Compare AhatSnapshot.NativeAllocation by heap name.
     * Different allocations with the same heap name are considered equal for
     * the purposes of comparison.
     */
    public static class NativeAllocationByHeapName
        implements Comparator<InstanceUtils.NativeAllocation> {
      @Override
      public int compare(InstanceUtils.NativeAllocation a, InstanceUtils.NativeAllocation b) {
        return a.heap.getName().compareTo(b.heap.getName());
      }
    }
  
    /**
     * Compare InstanceUtils.NativeAllocation by their size.
     * Different allocations with the same size are considered equal for the
     * purposes of comparison.
     * This sorts allocations from larger size to smaller size.
     */
    public static class NativeAllocationBySize implements Comparator<InstanceUtils.NativeAllocation> {
      @Override
      public int compare(InstanceUtils.NativeAllocation a, InstanceUtils.NativeAllocation b) {
        return Long.compare(b.size, a.size);
      }
    }
  }
  
  