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The official Couchbase JVM Core IO Library
/*
* Copyright 2023 Couchbase, 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
*
* https://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.couchbase.client.core.util;
import com.couchbase.client.core.annotation.Stability;
import java.security.SecureRandom;
import java.util.concurrent.atomic.AtomicInteger;
@Stability.Internal
public class CoreIdGenerator {
private static final long GLOBAL_ID = new SecureRandom().nextLong() << 32;
private static final AtomicInteger counter = new AtomicInteger();
private CoreIdGenerator() {
throw new AssertionError("not instantiable");
}
/**
* Returns an ID to assigned to a new core.
*
* The high 32 bits are the same for every ID generated by this process.
* The low 32 bits are a counter, incremented for each ID.
*/
public static long nextId() {
return GLOBAL_ID | (counter.incrementAndGet() & 0xffffffffL);
}
}