| /* |
| * 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.coprocessor; |
| |
| import java.util.Optional; |
| import org.apache.hadoop.hbase.CoprocessorEnvironment; |
| import org.apache.hadoop.hbase.ipc.RpcServer; |
| import org.apache.hadoop.hbase.security.User; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * This is the only implementation of {@link ObserverContext}, which serves as the interface for |
| * third-party Coprocessor developers. |
| */ |
| @InterfaceAudience.Private |
| public class ObserverContextImpl<E extends CoprocessorEnvironment> implements ObserverContext<E> { |
| private E env; |
| private boolean bypass; |
| /** |
| * Is this operation bypassable? |
| */ |
| private final boolean bypassable; |
| private final User caller; |
| |
| public ObserverContextImpl(User caller) { |
| this(caller, false); |
| } |
| |
| public ObserverContextImpl(User caller, boolean bypassable) { |
| this.caller = caller; |
| this.bypassable = bypassable; |
| } |
| |
| @Override |
| public E getEnvironment() { |
| return env; |
| } |
| |
| public void prepare(E env) { |
| this.env = env; |
| } |
| |
| public boolean isBypassable() { |
| return this.bypassable; |
| } |
| |
| @Override |
| public void bypass() { |
| if (!this.bypassable) { |
| throw new UnsupportedOperationException("This method does not support 'bypass'."); |
| } |
| bypass = true; |
| } |
| |
| /** |
| * @return {@code true}, if {@link ObserverContext#bypass()} was called by one of the loaded |
| * coprocessors, {@code false} otherwise. |
| */ |
| public boolean shouldBypass() { |
| if (!isBypassable()) { |
| return false; |
| } |
| if (bypass) { |
| bypass = false; |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public Optional<User> getCaller() { |
| return Optional.ofNullable(caller); |
| } |
| |
| /** |
| * Instantiates a new ObserverContext instance if the passed reference is <code>null</code> and |
| * sets the environment in the new or existing instance. This allows deferring the instantiation |
| * of a ObserverContext until it is actually needed. |
| * @param <E> The environment type for the context |
| * @param env The coprocessor environment to set |
| * @return An instance of <code>ObserverContext</code> with the environment set |
| */ |
| @Deprecated |
| // TODO: Remove this method, ObserverContext should not depend on RpcServer |
| public static <E extends CoprocessorEnvironment> ObserverContext<E> createAndPrepare(E env) { |
| ObserverContextImpl<E> ctx = new ObserverContextImpl<>(RpcServer.getRequestUser().orElse(null)); |
| ctx.prepare(env); |
| return ctx; |
| } |
| } |