/*
* Copyright (C) 2008 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.
*/
import java.util.Comparator;
/**
* Ranks classes for preloading based on how long their operations took
* and how early the operations happened. Higher ranked classes come first.
*/
class ClassRank implements Comparator<Operation> {
/**
* Increase this number to add more weight to classes which were loaded
* earlier.
*/
static final int SEQUENCE_WEIGHT = 500; // 5 ms
static final int BUCKET_SIZE = 5;
public int compare(Operation a, Operation b) {
// Higher ranked operations should come first.
int result = rankOf(b) - rankOf(a);
if (result != 0) {
return result;
}
// Make sure we don't drop one of two classes w/ the same rank.
// If a load and an initialization have the same rank, it's OK
// to treat the operations equally.
return a.loadedClass.name.compareTo(b.loadedClass.name);
}
/** Ranks the given operation. */
private static int rankOf(Operation o) {
return o.medianExclusiveTimeMicros()
+ SEQUENCE_WEIGHT / (o.index / BUCKET_SIZE + 1);
}
}