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Commit 78288792 authored by Jeff DeCew's avatar Jeff DeCew
Browse files

Add NamedListenerSet that can be used to improve Trace performance by caching listener names 

Bug: 289487170
Bug: 289486596
Test: atest SystemUITests
Change-Id: Iee8f852f7a5ff68d8978cb21bdba5f49dfc067bb
parent 8aef12b5

packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/NotifLiveDataStoreImpl.kt

+0 −1
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@@ -21,7 +21,6 @@ import com.android.systemui.dagger.SysUISingleton 
import com.android.systemui.dagger.qualifiers.Main

import com.android.systemui.util.Assert

import com.android.systemui.util.ListenerSet

import com.android.systemui.util.isNotEmpty

import com.android.systemui.util.traceSection

import java.util.Collections.unmodifiableList

import java.util.concurrent.Executor

packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/provider/DebugModeFilterProvider.kt

+0 −1
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@@ -26,7 +26,6 @@ import com.android.systemui.statusbar.commandline.CommandRegistry 
import com.android.systemui.statusbar.notification.collection.NotificationEntry

import com.android.systemui.util.Assert

import com.android.systemui.util.ListenerSet

import com.android.systemui.util.isNotEmpty

import java.io.PrintWriter

import javax.inject.Inject

packages/SystemUI/src/com/android/systemui/util/IListenerSet.kt

0 → 100644
+36 −0
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/*

 * 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.systemui.util



/**

 * A collection of listeners, observers, callbacks, etc.

 *

 * This container is optimized for infrequent mutation and frequent iteration, with thread safety

 * and reentrant-safety guarantees as well. Specifically, to ensure that

 * [ConcurrentModificationException] is never thrown, this iterator will not reflect changes made to

 * the set after the iterator is constructed.

 */

interface IListenerSet<E : Any> : Set<E> {

    /**

     * A thread-safe, reentrant-safe method to add a listener. Does nothing if the listener is

     * already in the set.

     */

    fun addIfAbsent(element: E): Boolean



    /** A thread-safe, reentrant-safe method to remove a listener. */

    fun remove(element: E): Boolean

}

packages/SystemUI/src/com/android/systemui/util/ListenerSet.kt

+3 −11
Original line number Diff line number Diff line
@@ -29,20 +29,12 @@ import java.util.concurrent.CopyOnWriteArrayList 
class ListenerSet<E : Any>

/** Private constructor takes the internal list so that we can use auto-delegation */

private constructor(private val listeners: CopyOnWriteArrayList<E>) :

    Collection<E> by listeners, Set<E> {

    Collection<E> by listeners, IListenerSet<E> {



    /** Create a new instance */

    constructor() : this(CopyOnWriteArrayList())



    /**

     * A thread-safe, reentrant-safe method to add a listener. Does nothing if the listener is

     * already in the set.

     */

    fun addIfAbsent(element: E): Boolean = listeners.addIfAbsent(element)

    override fun addIfAbsent(element: E): Boolean = listeners.addIfAbsent(element)



    /** A thread-safe, reentrant-safe method to remove a listener. */

    fun remove(element: E): Boolean = listeners.remove(element)

    override fun remove(element: E): Boolean = listeners.remove(element)

}
 


/** Extension to match Collection which is implemented to only be (easily) accessible in kotlin */

fun <T : Any> ListenerSet<T>.isNotEmpty(): Boolean = !isEmpty()

packages/SystemUI/src/com/android/systemui/util/NamedListenerSet.kt

0 → 100644
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Original line number Diff line number Diff line 
/*

 * 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.systemui.util



import java.util.concurrent.CopyOnWriteArrayList

import java.util.function.Consumer



/**

 * A collection of listeners, observers, callbacks, etc.

 *

 * This container is optimized for infrequent mutation and frequent iteration, with thread safety

 * and reentrant-safety guarantees as well. Specifically, to ensure that

 * [ConcurrentModificationException] is never thrown, this iterator will not reflect changes made to

 * the set after the iterator is constructed.

 *

 * This class provides all the abilities of [ListenerSet], except that each listener has a name

 * calculated at runtime which can be used for time-efficient tracing of listener invocations.

 */

class NamedListenerSet<E : Any>(

    private val getName: (E) -> String = { it.javaClass.name },

) : IListenerSet<E> {

    private val listeners = CopyOnWriteArrayList<NamedListener>()



    override val size: Int

        get() = listeners.size



    override fun isEmpty() = listeners.isEmpty()



    override fun iterator(): Iterator<E> = iterator {

        listeners.iterator().forEach { yield(it.listener) }

    }



    override fun containsAll(elements: Collection<E>) =

        listeners.count { it.listener in elements } == elements.size



    override fun contains(element: E) = listeners.firstOrNull { it.listener == element } != null



    override fun addIfAbsent(element: E): Boolean = listeners.addIfAbsent(NamedListener(element))



    override fun remove(element: E): Boolean = listeners.removeIf { it.listener == element }



    /** A wrapper for the listener with an associated name. */

    inner class NamedListener(val listener: E) {

        val name: String = getName(listener)



        override fun hashCode(): Int {

            return listener.hashCode()

        }



        override fun equals(other: Any?): Boolean =

            when {

                other === null -> false

                other === this -> true

                other !is NamedListenerSet<*>.NamedListener -> false

                listener == other.listener -> true

                else -> false

            }

    }



    /** Iterate the listeners in the set, providing the name for each one as well. */

    inline fun forEachNamed(block: (String, E) -> Unit) =

        namedIterator().forEach { element -> block(element.name, element.listener) }



    /**

     * Iterate the listeners in the set, wrapping each call to the block with [traceSection] using

     * the listener name.

     */

    inline fun forEachTraced(block: (E) -> Unit) = forEachNamed { name, listener ->

        traceSection(name) { block(listener) }

    }



    /**

     * Iterate the listeners in the set, wrapping each call to the block with [traceSection] using

     * the listener name.

     */

    fun forEachTraced(consumer: Consumer<E>) = forEachNamed { name, listener ->

        traceSection(name) { consumer.accept(listener) }

    }



    /** Iterate over the [NamedListener]s currently in the set. */

    fun namedIterator(): Iterator<NamedListener> = listeners.iterator()

}