// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.chrome.browser.uid;
import java.util.HashMap;
import java.util.Map;
/**
* Factory for setting and retrieving instances of {@link UniqueIdentificationGenerator}s.
* <p/>
* A generator must always be set for a generator type before it is asked for. A generator type
* is any string you want to use for your generator. It is typically defined as a public static
* field in the generator itself.
*/
public final class UniqueIdentificationGeneratorFactory {
private static final Object LOCK = new Object();
private static final Map<String, UniqueIdentificationGenerator> GENERATOR_MAP =
new HashMap<String, UniqueIdentificationGenerator>();
private UniqueIdentificationGeneratorFactory() {}
/**
* Returns a UniqueIdentificationGenerator if it exists, else throws IllegalArgumentException.
*
* @param generatorType the generator type you want
* @return a unique ID generator
*/
public static UniqueIdentificationGenerator getInstance(String generatorType) {
synchronized (LOCK) {
if (!GENERATOR_MAP.containsKey(generatorType)) {
throw new IllegalArgumentException("Unknown generator type " + generatorType);
}
return GENERATOR_MAP.get(generatorType);
}
}
/**
* During startup of the application, and before any calls to
* {@link #getInstance(String)} you must add all supported generators
* to this factory.
*
* @param generatorType the type of generator this is. Must be a unique string.
* @param gen the generator.
* @param force if set to true, will override any existing generator for this type. Else
* discards calls where a generator exists.
*/
public static void registerGenerator(
String generatorType, UniqueIdentificationGenerator gen, boolean force) {
synchronized (LOCK) {
if (GENERATOR_MAP.containsKey(generatorType) && !force) {
return;
}
GENERATOR_MAP.put(generatorType, gen);
}
}
public static void clearGeneratorMapForTest() {
synchronized (LOCK) {
GENERATOR_MAP.clear();
}
}
}