1 /* 2 * 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 package org.apache.hadoop.hbase; 17 18 import org.apache.hadoop.classification.InterfaceAudience; 19 import org.apache.hadoop.classification.InterfaceStability; 20 21 import java.io.IOException; 22 23 /** 24 * Coprocess interface. 25 */ 26 @InterfaceAudience.Public 27 @InterfaceStability.Evolving 28 public interface Coprocessor { 29 int VERSION = 1; 30 31 /** Highest installation priority */ 32 int PRIORITY_HIGHEST = 0; 33 /** High (system) installation priority */ 34 int PRIORITY_SYSTEM = Integer.MAX_VALUE / 4; 35 /** Default installation priority for user coprocessors */ 36 int PRIORITY_USER = Integer.MAX_VALUE / 2; 37 /** Lowest installation priority */ 38 int PRIORITY_LOWEST = Integer.MAX_VALUE; 39 40 /** 41 * Lifecycle state of a given coprocessor instance. 42 */ 43 enum State { 44 UNINSTALLED, 45 INSTALLED, 46 STARTING, 47 ACTIVE, 48 STOPPING, 49 STOPPED 50 } 51 52 // Interface 53 void start(CoprocessorEnvironment env) throws IOException; 54 55 void stop(CoprocessorEnvironment env) throws IOException; 56 }