001/* 002 * 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, software 014 * distributed under the License is distributed on an "AS IS" BASIS, 015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 016 * See the License for the specific language governing permissions and 017 * limitations under the License. 018 */ 019package org.apache.hadoop.hbase.coprocessor; 020 021import org.apache.yetus.audience.InterfaceAudience; 022 023import java.lang.annotation.ElementType; 024import java.lang.annotation.Inherited; 025import java.lang.annotation.Retention; 026import java.lang.annotation.RetentionPolicy; 027import java.lang.annotation.Target; 028 029/** 030 * Marker annotation that denotes Coprocessors that are core to HBase. 031 * A Core Coprocessor is a CP that realizes a core HBase feature. Features are sometimes 032 * implemented first as a Coprocessor to prove viability. The idea is that once proven, they then 033 * migrate to core. Meantime, HBase Core Coprocessors get this annotation. No other Coprocessors 034 * can carry this annotation. 035 */ 036// Core Coprocessors are generally naughty making use of HBase internals doing accesses no 037// Coprocessor should be up to so we mark these special Coprocessors with this annotation and on 038// Coprocessor load, we'll give these Coprocessors a 'richer' Environment with access to internals 039// not allowed other Coprocessors. see the *CoprocessorHost where they do the Coprocessor loadings. 040@Target(ElementType.TYPE) 041@Inherited 042@InterfaceAudience.Private 043@Retention(RetentionPolicy.RUNTIME) 044// This Annotation is not @Documented because I don't want users figuring out its mechanics. 045public @interface CoreCoprocessor {}