/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.jena.riot.lang;
import java.util.UUID;
/**
* A variant of {@link BlankNodeAllocatorHash} where a fixed seed is used so
* repeated runs produce identical allocations
*
*/
public class BlankNodeAllocatorFixedSeedHash extends BlankNodeAllocatorHash {
private UUID seed;
/**
* Creates a new allocator which will use a new random seed but that seed
* will remain fixed
*/
public BlankNodeAllocatorFixedSeedHash() {
this(UUID.randomUUID());
}
/**
* Creates a new allocator which will use a fixed seed
*
* @param seed
* Seed
*/
public BlankNodeAllocatorFixedSeedHash(UUID seed) {
super();
if (seed == null)
throw new NullPointerException("seed cannot be null");
this.seed = seed;
this.reset();
}
@Override
protected UUID freshSeed() {
// NB - The parent constructor calls reset() so we have to provide a
// fake value here temorarily which we then replace with the user
// specified seed by calling reset() again in our own constructor
return this.seed == null ? UUID.randomUUID() : this.seed;
}
}