/*
* 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.usergrid.corepersistence.pipeline.read;
import com.google.common.base.Optional;
/**
* An internal class that holds a mutable state. When resuming, we only ever honor the seek value on the first call. Afterwards, we will seek from the beginning on newly emitted values.
* Calling get will return the first value to seek, or absent if not specified. Subsequent calls will return absent. Callers should treat the results as seek values for each operation
*/
public class CursorSeek<C> {
private Optional<C> seek;
public CursorSeek( final Optional<C> cursorValue ){
seek = cursorValue;
}
/**
* Get the seek value to use when searching
* @return
*/
public Optional<C> getSeekValue(){
final Optional<C> toReturn = seek;
seek = Optional.absent();
return toReturn;
}
}