| /* |
| * 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.ratis.util; |
| |
| import org.apache.ratis.util.function.CheckedFunction; |
| import org.apache.ratis.util.function.CheckedRunnable; |
| import org.apache.ratis.util.function.CheckedSupplier; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.lang.management.ManagementFactory; |
| import java.lang.management.ThreadInfo; |
| import java.lang.management.ThreadMXBean; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.text.SimpleDateFormat; |
| import java.util.Collection; |
| import java.util.Date; |
| import java.util.Objects; |
| import java.util.Timer; |
| import java.util.TimerTask; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.CompletableFuture; |
| import java.util.concurrent.CompletionException; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.TimeUnit; |
| import java.util.function.BiConsumer; |
| import java.util.function.BooleanSupplier; |
| import java.util.function.Consumer; |
| import java.util.function.Function; |
| import java.util.function.Supplier; |
| |
| /** |
| * General Java utility methods. |
| */ |
| public interface JavaUtils { |
| Logger LOG = LoggerFactory.getLogger(JavaUtils.class); |
| |
| CompletableFuture<?>[] EMPTY_COMPLETABLE_FUTURE_ARRAY = {}; |
| |
| ConcurrentMap<Class<?>, String> CLASS_SIMPLE_NAMES = new ConcurrentHashMap<>(); |
| static String getClassSimpleName(Class<?> clazz) { |
| return CLASS_SIMPLE_NAMES.computeIfAbsent(clazz, Class::getSimpleName); |
| } |
| |
| static String date() { |
| return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss,SSS").format(new Date()); |
| } |
| |
| /** |
| * The same as {@link Class#cast(Object)} except that |
| * this method returns null (but not throw {@link ClassCastException}) |
| * if the given object is not an instance of the given class. |
| */ |
| static <T> T cast(Object obj, Class<T> clazz) { |
| return clazz.isInstance(obj)? clazz.cast(obj): null; |
| } |
| |
| static <T> T cast(Object obj) { |
| @SuppressWarnings("unchecked") |
| final T t = (T)obj; |
| return t; |
| } |
| |
| static StackTraceElement getCallerStackTraceElement() { |
| final StackTraceElement[] trace = Thread.currentThread().getStackTrace(); |
| return trace[3]; |
| } |
| |
| static StackTraceElement getCurrentStackTraceElement() { |
| final StackTraceElement[] trace = Thread.currentThread().getStackTrace(); |
| return trace[2]; |
| } |
| |
| static <T extends Throwable> void runAsUnchecked(CheckedRunnable<T> runnable) { |
| runAsUnchecked(runnable, RuntimeException::new); |
| } |
| |
| static <THROWABLE extends Throwable> void runAsUnchecked( |
| CheckedRunnable<THROWABLE> runnable, Function<THROWABLE, ? extends RuntimeException> converter) { |
| try { |
| runnable.run(); |
| } catch(RuntimeException | Error e) { |
| throw e; |
| } catch(Throwable t) { |
| throw converter.apply(cast(t)); |
| } |
| } |
| |
| /** |
| * Invoke {@link Callable#call()} and, if there any, |
| * wrap the checked exception by {@link RuntimeException}. |
| */ |
| static <T> T callAsUnchecked(Callable<T> callable) { |
| return callAsUnchecked(callable::call, RuntimeException::new); |
| } |
| |
| static <OUTPUT, THROWABLE extends Throwable> OUTPUT callAsUnchecked( |
| CheckedSupplier<OUTPUT, THROWABLE> checkedSupplier, |
| Function<THROWABLE, ? extends RuntimeException> converter) { |
| try { |
| return checkedSupplier.get(); |
| } catch(RuntimeException | Error e) { |
| throw e; |
| } catch(Throwable t) { |
| throw converter.apply(cast(t)); |
| } |
| } |
| |
| static <T> T doPrivileged(Supplier<T> action, Function<SecurityException, T> exceptionHandler) { |
| try { |
| return System.getSecurityManager() == null? action.get() |
| : AccessController.doPrivileged((PrivilegedAction<T>) action::get); |
| } catch (SecurityException e) { |
| return exceptionHandler.apply(e); |
| } |
| } |
| |
| static <T> T doPrivileged(Supplier<T> action, Supplier<String> name) { |
| return doPrivileged(action, e -> { |
| LOG.warn("Failed to " + name.get(), e); |
| return null; |
| }); |
| } |
| |
| /** |
| * Similar to {@link System#getProperty(String)} |
| * except that this method may invoke {@link AccessController#doPrivileged(PrivilegedAction)} |
| * if there is a {@link SecurityManager}. |
| * |
| * @return null if either the property is not set or there is a {@link SecurityException}; |
| * otherwise, return system property value. |
| */ |
| static String getSystemProperty(final String key) { |
| Preconditions.assertNotNull(key, "key"); |
| Preconditions.assertTrue(!key.isEmpty(), "key is empty."); |
| return doPrivileged(() -> System.getProperty(key), () -> "get system property " + key); |
| } |
| |
| static String getEnv(String variable) { |
| final String value = System.getenv().get(variable); |
| LOG.info("ENV: {} = {}", variable, value); |
| return value; |
| } |
| |
| /** |
| * Similar to {@link System#setProperty(String, String)} |
| * except that this method may invoke {@link AccessController#doPrivileged(PrivilegedAction)} |
| * if there is a {@link SecurityManager}. |
| * When there is a {@link SecurityException}, this becomes a NOOP. |
| */ |
| static void setSystemProperty(String key, String value) { |
| Preconditions.assertNotNull(key, "key"); |
| Preconditions.assertTrue(!key.isEmpty(), "key is empty."); |
| Preconditions.assertNotNull(value, "value"); |
| doPrivileged(() -> System.setProperty(key, value), () -> "set system property " + key + " to " + value); |
| } |
| |
| /** |
| * Create a memoized supplier which gets a value by invoking the initializer once |
| * and then keeps returning the same value as its supplied results. |
| * |
| * @param initializer to supply at most one non-null value. |
| * @param <T> The supplier result type. |
| * @return a memoized supplier which is thread-safe. |
| */ |
| static <T> MemoizedSupplier<T> memoize(Supplier<T> initializer) { |
| return MemoizedSupplier.valueOf(initializer); |
| } |
| |
| Supplier<ThreadGroup> ROOT_THREAD_GROUP = memoize(() -> { |
| for (ThreadGroup g = Thread.currentThread().getThreadGroup(), p;; g = p) { |
| if ((p = g.getParent()) == null) { |
| return g; |
| } |
| } |
| }); |
| |
| static ThreadGroup getRootThreadGroup() { |
| return ROOT_THREAD_GROUP.get(); |
| } |
| |
| /** Attempt to get a return value from the given supplier multiple times. */ |
| static <RETURN, THROWABLE extends Throwable> RETURN attemptRepeatedly( |
| CheckedSupplier<RETURN, THROWABLE> supplier, |
| int numAttempts, TimeDuration sleepTime, String name, Logger log) |
| throws THROWABLE, InterruptedException { |
| return attempt(supplier, numAttempts, sleepTime, () -> name, log); |
| } |
| |
| /** Attempt to get a return value from the given supplier multiple times. */ |
| static <RETURN, THROWABLE extends Throwable> RETURN attempt( |
| CheckedSupplier<RETURN, THROWABLE> supplier, |
| int numAttempts, TimeDuration sleepTime, Supplier<?> name, Logger log) |
| throws THROWABLE, InterruptedException { |
| return attempt(i -> supplier.get(), numAttempts, sleepTime, name, log); |
| } |
| |
| static <RETURN, THROWABLE extends Throwable> RETURN attempt( |
| CheckedFunction<Integer, RETURN, THROWABLE> attemptMethod, |
| int numAttempts, TimeDuration sleepTime, Supplier<?> name, Logger log) |
| throws THROWABLE, InterruptedException { |
| Objects.requireNonNull(attemptMethod, "attemptMethod == null"); |
| Preconditions.assertTrue(numAttempts > 0, () -> "numAttempts = " + numAttempts + " <= 0"); |
| Preconditions.assertTrue(!sleepTime.isNegative(), () -> "sleepTime = " + sleepTime + " < 0"); |
| |
| for(int i = 1; i <= numAttempts; i++) { |
| try { |
| return attemptMethod.apply(i); |
| } catch (Throwable t) { |
| if (i == numAttempts) { |
| throw t; |
| } |
| if (log != null && log.isWarnEnabled()) { |
| log.warn("FAILED \"" + name.get() + "\", attempt #" + i + "/" + numAttempts |
| + ", sleep " + sleepTime + " and then retry: " + t); |
| } |
| } |
| |
| sleepTime.sleep(); |
| } |
| throw new IllegalStateException("BUG: this line should be unreachable."); |
| } |
| |
| /** Attempt to run the given op multiple times. */ |
| static <THROWABLE extends Throwable> void attempt( |
| CheckedRunnable<THROWABLE> runnable, int numAttempts, TimeDuration sleepTime, String name, Logger log) |
| throws THROWABLE, InterruptedException { |
| attemptRepeatedly(CheckedRunnable.asCheckedSupplier(runnable), numAttempts, sleepTime, name, log); |
| } |
| |
| /** Attempt to wait the given condition to return true multiple times. */ |
| static void attemptUntilTrue( |
| BooleanSupplier condition, int numAttempts, TimeDuration sleepTime, String name, Logger log) |
| throws InterruptedException { |
| Objects.requireNonNull(condition, "condition == null"); |
| attempt(() -> { |
| if (!condition.getAsBoolean()) { |
| throw new IllegalStateException("Condition " + name + " is false."); |
| } |
| }, numAttempts, sleepTime, name, log); |
| } |
| |
| static Timer runRepeatedly(Runnable runnable, long delay, long period, TimeUnit unit) { |
| final Timer timer = new Timer(true); |
| timer.schedule(new TimerTask() { |
| @Override |
| public void run() { |
| runnable.run(); |
| } |
| }, unit.toMillis(delay), unit.toMillis(period)); |
| |
| return timer; |
| } |
| |
| static void dumpAllThreads(Consumer<String> println) { |
| final ThreadMXBean threadMxBean = ManagementFactory.getThreadMXBean(); |
| for (ThreadInfo ti : threadMxBean.dumpAllThreads(true, true)) { |
| println.accept(ti.toString()); |
| } |
| } |
| |
| static <E> CompletableFuture<E> completeExceptionally(Throwable t) { |
| final CompletableFuture<E> future = new CompletableFuture<>(); |
| future.completeExceptionally(t); |
| return future; |
| } |
| |
| static boolean isCompletedNormally(CompletableFuture<?> future) { |
| return future.isDone() && !future.isCancelled() && !future.isCompletedExceptionally(); |
| } |
| |
| static Throwable unwrapCompletionException(Throwable t) { |
| Objects.requireNonNull(t, "t == null"); |
| return t instanceof CompletionException && t.getCause() != null? t.getCause(): t; |
| } |
| |
| static <T> CompletableFuture<Void> allOf(Collection<CompletableFuture<T>> futures) { |
| if (futures == null || futures.isEmpty()) { |
| return CompletableFuture.completedFuture(null); |
| } |
| return CompletableFuture.allOf(futures.toArray(EMPTY_COMPLETABLE_FUTURE_ARRAY)); |
| } |
| |
| static <V> BiConsumer<V, Throwable> asBiConsumer(CompletableFuture<V> future) { |
| return (v, t) -> { |
| if (t != null) { |
| future.completeExceptionally(t); |
| } else { |
| future.complete(v); |
| } |
| }; |
| } |
| |
| static <OUTPUT, THROWABLE extends Throwable> OUTPUT supplyAndWrapAsCompletionException( |
| CheckedSupplier<OUTPUT, THROWABLE> supplier) { |
| try { |
| return supplier.get(); |
| } catch (RuntimeException e) { |
| throw e; |
| } catch (Throwable t) { |
| throw new CompletionException(t); |
| } |
| } |
| } |