src/java/org/apache/cassandra/db/ExpiringCell.java

/*
 * 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.cassandra.db;

import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.utils.concurrent.OpOrder;
import org.apache.cassandra.utils.memory.AbstractAllocator;
import org.apache.cassandra.utils.memory.MemtableAllocator;

/**
 * Alternative to Cell that have an expiring time.
 * ExpiringCell is immutable (as Cell is).
 *
 * Note that ExpiringCell does not override Cell.getMarkedForDeleteAt,
 * which means that it's in the somewhat unintuitive position of being deleted (after its expiration)
 * without having a time-at-which-it-became-deleted.  (Because ttl is a server-side measurement,
 * we can't mix it with the timestamp field, which is client-supplied and whose resolution we
 * can't assume anything about.)
 */
public interface ExpiringCell extends Cell
{
    public static final int MAX_TTL = 20 * 365 * 24 * 60 * 60; // 20 years in seconds

    public int getTimeToLive();

    ExpiringCell localCopy(CFMetaData metadata, AbstractAllocator allocator);

    ExpiringCell localCopy(CFMetaData metaData, MemtableAllocator allocator, OpOrder.Group opGroup);
}