| /** |
| * 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.yetus.audience.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(); |
| } |