/**
* 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.hadoop.hbase.client;
import java.io.IOException;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
/**
* Used to separate the row constructing logic.
* <p>
* After we add heartbeat support for scan, RS may return partial result even if allowPartial is
* false and batch is 0. With this interface, the implementation now looks like:
* <ol>
* <li>Get results from ScanResponse proto.</li>
* <li>Pass them to ScanResultCache and get something back.</li>
* <li>If we actually get something back, then pass it to ScanConsumer.</li>
* </ol>
*/
@InterfaceAudience.Private
interface ScanResultCache {
static final Result[] EMPTY_RESULT_ARRAY = new Result[0];
/**
* Add the given results to cache and get valid results back.
* @param results the results of a scan next. Must not be null.
* @param isHeartbeatMessage indicate whether the results is gotten from a heartbeat response.
* @return valid results, never null.
*/
Result[] addAndGet(Result[] results, boolean isHeartbeatMessage) throws IOException;
/**
* Clear the cached result if any. Called when scan error and we will start from a start of a row
* again.
*/
void clear();
/**
* Return the number of complete rows. Used to implement limited scan.
*/
int numberOfCompleteRows();
}