| /* |
| * 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.ignite.igfs; |
| |
| import java.util.concurrent.Callable; |
| import org.apache.ignite.internal.util.typedef.F; |
| import org.apache.ignite.lang.IgniteOutClosure; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * Provides ability to execute IGFS code in a context of a specific user. |
| */ |
| public abstract class IgfsUserContext { |
| /** Thread local to hold the current user context. */ |
| private static final ThreadLocal<String> userStackThreadLocal = new ThreadLocal<>(); |
| |
| /** |
| * Executes given callable in the given user context. |
| * The main contract of this method is that {@link #currentUser()} method invoked |
| * inside closure always returns 'user' this callable executed with. |
| * @param user the user name to invoke closure on behalf of. |
| * @param c the closure to execute |
| * @param <T> The type of closure result. |
| * @return the result of closure execution. |
| * @throws IllegalArgumentException if user name is null or empty String or if the closure is null. |
| */ |
| public static <T> T doAs(String user, final IgniteOutClosure<T> c) { |
| if (F.isEmpty(user)) |
| throw new IllegalArgumentException("Failed to use null or empty user name."); |
| |
| final String ctxUser = userStackThreadLocal.get(); |
| |
| if (F.eq(ctxUser, user)) |
| return c.apply(); // correct context is already there |
| |
| userStackThreadLocal.set(user); |
| |
| try { |
| return c.apply(); |
| } |
| finally { |
| userStackThreadLocal.set(ctxUser); |
| } |
| } |
| |
| /** |
| * Same contract that {@link #doAs(String, IgniteOutClosure)} has, but accepts |
| * callable that throws checked Exception. |
| * The Exception is not ever wrapped anyhow. |
| * If your Callable throws Some specific checked Exceptions, the recommended usage pattern is: |
| * <pre name="code" class="java"> |
| * public Foo myOperation() throws MyCheckedException1, MyCheckedException2 { |
| * try { |
| * return IgfsUserContext.doAs(user, new Callable<Foo>() { |
| * @Override public Foo call() throws MyCheckedException1, MyCheckedException2 { |
| * return makeSomeFoo(); // do the job |
| * } |
| * }); |
| * } |
| * catch (MyCheckedException1 | MyCheckedException2 | RuntimeException | Error e) { |
| * throw e; |
| * } |
| * catch (Exception e) { |
| * throw new AssertionError("Must never go there."); |
| * } |
| * } |
| * </pre> |
| * @param user the user name to invoke closure on behalf of. |
| * @param c the Callable to execute |
| * @param <T> The type of callable result. |
| * @return the result of closure execution. |
| * @throws IllegalArgumentException if user name is null or empty String or if the closure is null. |
| */ |
| public static <T> T doAs(String user, final Callable<T> c) throws Exception { |
| if (F.isEmpty(user)) |
| throw new IllegalArgumentException("Failed to use null or empty user name."); |
| |
| final String ctxUser = userStackThreadLocal.get(); |
| |
| if (F.eq(ctxUser, user)) |
| return c.call(); // correct context is already there |
| |
| userStackThreadLocal.set(user); |
| |
| try { |
| return c.call(); |
| } |
| finally { |
| userStackThreadLocal.set(ctxUser); |
| } |
| } |
| |
| /** |
| * Gets the current context user. |
| * If this method is invoked outside of any {@link #doAs(String, IgniteOutClosure)} on the call stack, it will |
| * return null. Otherwise it will return the user name set in the most lower |
| * {@link #doAs(String, IgniteOutClosure)} call on the call stack. |
| * @return The current user, may be null. |
| */ |
| @Nullable public static String currentUser() { |
| return userStackThreadLocal.get(); |
| } |
| } |