com.datastax.driver.core.TimestampGenerator Maven / Gradle / Ivy
Show all versions of cassandra-driver Show documentation
/*
* Copyright DataStax, 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.datastax.driver.core;
/**
* Generates client-side, microsecond-precision query timestamps.
*
* Given that Cassandra uses those timestamps to resolve conflicts, implementations should
* generate monotonically increasing timestamps for successive invocations of {@link #next()}.
*/
public interface TimestampGenerator {
/**
* Returns the next timestamp.
*
*
Implementors should enforce increasing monotonicity of timestamps, that is, a timestamp
* returned should always be strictly greater that any previously returned timestamp.
*
*
Implementors should strive to achieve microsecond precision in the best possible way, which
* is usually largely dependent on the underlying operating system's capabilities.
*
* @return the next timestamp (in microseconds). If it equals {@link Long#MIN_VALUE}, it won't be
* sent by the driver, letting Cassandra generate a server-side timestamp.
*/
long next();
}