| /* |
| * |
| * 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.InterruptedIOException; |
| import java.util.Collection; |
| import java.util.function.Consumer; |
| import org.apache.hadoop.hbase.HRegionLocation; |
| import org.apache.hadoop.hbase.ServerName; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * An interface for client request scheduling algorithm. |
| */ |
| @InterfaceAudience.Public |
| public interface RequestController { |
| |
| @InterfaceAudience.Public |
| public enum ReturnCode { |
| /** |
| * Accept current row. |
| */ |
| INCLUDE, |
| /** |
| * Skip current row. |
| */ |
| SKIP, |
| /** |
| * No more row can be included. |
| */ |
| END |
| } |
| |
| /** |
| * Picks up the valid data. |
| */ |
| @InterfaceAudience.Public |
| public interface Checker { |
| /** |
| * Checks the data whether it is valid to submit. |
| * @param loc the destination of data |
| * @param row the data to check |
| * @return describe the decision for the row |
| */ |
| ReturnCode canTakeRow(HRegionLocation loc, Row row); |
| |
| /** |
| * Reset the state of the scheduler when completing the iteration of rows. |
| * @throws InterruptedIOException some controller may wait |
| * for some busy region or RS to complete the undealt request. |
| */ |
| void reset() throws InterruptedIOException ; |
| } |
| |
| /** |
| * @return A new checker for evaluating a batch rows. |
| */ |
| Checker newChecker(); |
| |
| /** |
| * Increment the counter if we build a valid task. |
| * @param regions The destination of task |
| * @param sn The target server |
| */ |
| void incTaskCounters(Collection<byte[]> regions, ServerName sn); |
| |
| /** |
| * Decrement the counter if a task is accomplished. |
| * @param regions The destination of task |
| * @param sn The target server |
| */ |
| void decTaskCounters(Collection<byte[]> regions, ServerName sn); |
| |
| /** |
| * @return The number of running task. |
| */ |
| long getNumberOfTasksInProgress(); |
| |
| /** |
| * Waits for the running tasks to complete. |
| * If there are specified threshold and trigger, the implementation should |
| * wake up once in a while for checking the threshold and calling trigger. |
| * @param max This method will return if the number of running tasks is |
| * less than or equal to max. |
| * @param id the caller's id |
| * @param periodToTrigger The period to invoke the trigger. This value is a |
| * hint. The real period depends on the implementation. |
| * @param trigger The object to call periodically. |
| * @throws java.io.InterruptedIOException If the waiting is interrupted |
| */ |
| void waitForMaximumCurrentTasks(long max, long id, |
| int periodToTrigger, Consumer<Long> trigger) throws InterruptedIOException; |
| |
| /** |
| * Wait until there is at least one slot for a new task. |
| * @param id the caller's id |
| * @param periodToTrigger The period to invoke the trigger. This value is a |
| * hint. The real period depends on the implementation. |
| * @param trigger The object to call periodically. |
| * @throws java.io.InterruptedIOException If the waiting is interrupted |
| */ |
| void waitForFreeSlot(long id, int periodToTrigger, |
| Consumer<Long> trigger) throws InterruptedIOException; |
| } |