1 /*
<lambda>null2  * Copyright 2024 The Android Open Source Project
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 
17 package androidx.testutils
18 
19 import java.util.concurrent.ExecutorService
20 import kotlin.coroutines.CoroutineContext
21 import kotlinx.coroutines.CoroutineDispatcher
22 
23 /**
24  * A coroutine dispatcher that can block some known coroutine runnables. We use it to slow down
25  * database invalidation events.
26  */
27 class FilteringCoroutineContext(delegate: ExecutorService) : CoroutineDispatcher() {
28 
29     val executor = FilteringExecutor(delegate)
30 
31     var filterFunction: (CoroutineContext, Runnable) -> Boolean = { _, _ -> true }
32         set(value) {
33             field = value
34             executor.filterFunction = this::filter
35         }
36 
37     private fun filter(runnable: Runnable): Boolean {
38         if (runnable is RunnableWithCoroutineContext) {
39             return filterFunction.invoke(runnable.context, runnable)
40         }
41         return true
42     }
43 
44     override fun dispatch(context: CoroutineContext, block: Runnable) {
45         executor.execute(RunnableWithCoroutineContext(context, block))
46     }
47 
48     override fun isDispatchNeeded(context: CoroutineContext): Boolean = true
49 
50     class RunnableWithCoroutineContext(val context: CoroutineContext, val actual: Runnable) :
51         Runnable by actual
52 }
53