com.google.gwt.dev.util.MemoryBackedObject Maven / Gradle / Ivy
/*
* Copyright 2014 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.gwt.dev.util;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.thirdparty.guava.common.base.Preconditions;
import java.io.Serializable;
/**
* A Noop PersistentBackedObject that stores a reference to the data it's provided. Used only
* in per file compiles.
*
* NOTE: Use this class with care as it does not provide a fresh deserialized copy of the data
* provided,
*
* @param the type of object serialized into the file
*/
public class MemoryBackedObject implements PersistenceBackedObject {
private T data;
private final Class clazz;
public MemoryBackedObject(Class clazz) {
this.clazz = clazz;
}
@Override
public boolean exists() {
return data != null;
}
@Override
public String getPath() {
return null;
}
@Override
public T newInstance(TreeLogger logger) throws UnableToCompleteException {
T result = data;
data = null;
return result;
}
@Override
public void set(TreeLogger logger, T object)
throws IllegalStateException, UnableToCompleteException {
assert clazz.isInstance(object);
Preconditions.checkState(data == null);
data = object;
}
@Override
public String toString() {
return "MemoryBackedObject" + "<" + clazz.getName() + ">";
}
}