1 /* 2 * Copyright 2022 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.google.android.libraries.mobiledatadownload.tracing; 17 18 import com.google.common.base.Function; 19 import com.google.common.util.concurrent.AsyncCallable; 20 import com.google.common.util.concurrent.AsyncFunction; 21 import com.google.common.util.concurrent.ClosingFuture.ClosingFunction; 22 import com.google.common.util.concurrent.FutureCallback; 23 import com.google.errorprone.annotations.CheckReturnValue; 24 import java.util.concurrent.Callable; 25 26 /** 27 * Contains decorators for propagating the current trace into a callback. When the wrapped callback 28 * runs, it will run under the same trace the wrapper was created in. 29 */ 30 @CheckReturnValue 31 public final class TracePropagation { 32 33 @CheckReturnValue propagateAsyncCallable(final AsyncCallable<V> asyncCallable)34 public static <V> AsyncCallable<V> propagateAsyncCallable(final AsyncCallable<V> asyncCallable) { 35 return asyncCallable; 36 } 37 38 @CheckReturnValue propagateAsyncFunction( final AsyncFunction<I, O> function)39 public static <I, O> AsyncFunction<I, O> propagateAsyncFunction( 40 final AsyncFunction<I, O> function) { 41 return function; 42 } 43 44 @CheckReturnValue propagateCallable(final Callable<V> callable)45 public static <V> Callable<V> propagateCallable(final Callable<V> callable) { 46 return callable; 47 } 48 49 @CheckReturnValue propagateFunction(final Function<I, O> function)50 public static <I, O> Function<I, O> propagateFunction(final Function<I, O> function) { 51 return function; 52 } 53 54 @CheckReturnValue propagateFutureCallback(final FutureCallback<T> callback)55 public static <T> FutureCallback<T> propagateFutureCallback(final FutureCallback<T> callback) { 56 return callback; 57 } 58 propagateClosingFunction( final ClosingFunction<I, O> closingFunction)59 public static <I, O> ClosingFunction<I, O> propagateClosingFunction( 60 final ClosingFunction<I, O> closingFunction) { 61 return closingFunction; 62 } 63 64 @CheckReturnValue propagateRunnable(Runnable runnable)65 public static Runnable propagateRunnable(Runnable runnable) { 66 return runnable; 67 } 68 TracePropagation()69 private TracePropagation() {} 70 } 71