| /* |
| * Copyright (C) 2023 The Android Open Source Project |
| * |
| * Licensed 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 com.android.app.tracing |
| |
| /** Utilities to trace automatically computations happening for each element of a list. */ |
| public object ListenersTracing { |
| |
| /** |
| * Like [forEach], but outputs a trace for each element. |
| * |
| * The ideal usage of this is to debug what's taking long in a list of Listeners. For example: |
| * ``` |
| * listeners.forEach { it.dispatch(state) } |
| * ``` |
| * |
| * often it's tricky to udnerstand which listener is causing delays. This can be used instead to |
| * log how much each listener is taking: |
| * ``` |
| * listeners.forEachTraced(TAG) { it.dispatch(state) } |
| * ``` |
| */ |
| public inline fun <T : Any> List<T>.forEachTraced(tag: String = "", f: (T) -> Unit) { |
| forEach { traceSection({ "$tag#${it::javaClass.get().name}" }) { f(it) } } |
| } |
| } |
