com.google.test.metric.example.MutableGlobalState.MutableGlobalExample Maven / Gradle / Ivy
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/*
* Copyright 2007 Google Inc.
*
* 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.google.test.metric.example.MutableGlobalState;
/**
* This class illustrates globally mutable state through a non-final
* {@code public static} instance.
*
* See also the documentation on {@link com.google.test.metric.example.MutableGlobalState.FinalGlobalExample}.
*/
public class MutableGlobalExample {
public static class Gadget {
/** This is final, so even if the Gadget object is global, this field
* won't count as global mutable state. */
private final String id;
/** This is not final, so if Gadget is global, this field will count
* as global mutable state. */
private int count;
public Gadget(String id, int count) {
this.id = id;
this.count = count;
}
public String getId() {
return id;
}
public int getCount() {
return count;
}
public int increment() {
return ++count;
}
}
/** This class has reference to global mutable state */
public static class MutableGlobal {
/** Holds a non-final instance to global state. This does
* count as globally mutable state. */
public static Gadget mutableInstance = new Gadget("Global", 1);
}
/* The rest are instance methods on {@code MutableGlobalExample} */
public Gadget getInstance() {
return MutableGlobal.mutableInstance;
}
/** The field {@code id} in Gadget is final, so accessing it is not
* counted as a cost. (But other fields can be, and the mutableInstance
* itself are global state). */
public String getGlobalId() {
return MutableGlobal.mutableInstance.getId();
}
public int getGlobalCount() {
return MutableGlobal.mutableInstance.getCount();
}
public int globalIncrement() {
return MutableGlobal.mutableInstance.increment();
}
}