Use more efficient collections where possible (#483)

These avoid boxing, virtual calls, or both. Not all usages have been updated, just the easy targets.

gradle/libs.versions.toml

@@ -1,4 +1,5 @@
 [versions]
+compose = "1.6.11"
 kotlin = "2.0.20"
 kotlinx-coroutines = "1.9.0"
 mordant = "3.0.0"
@@ -11,7 +12,8 @@ kotlin-test = { module = "org.jetbrains.kotlin:kotlin-test", version.ref = "kotl
 kotlinx-coroutines-core = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "kotlinx-coroutines" }
 kotlinx-coroutines-test = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", version.ref = "kotlinx-coroutines" }
 
-compose-runtime = "org.jetbrains.compose.runtime:runtime:1.6.11"
+compose-collection = { module = "org.jetbrains.compose.collection-internal:collection", version.ref = "compose" }
+compose-runtime = { module = "org.jetbrains.compose.runtime:runtime", version.ref = "compose" }
 
 maven-publish-gradlePlugin = "com.vanniktech:gradle-maven-publish-plugin:0.29.0"
 dokka-gradlePlugin = "org.jetbrains.dokka:dokka-gradle-plugin:1.9.20"

mosaic-runtime/build.gradle

@@ -23,6 +23,7 @@ kotlin {
 			dependencies {
 				api libs.compose.runtime
 				api libs.kotlinx.coroutines.core
+				implementation libs.compose.collection
 				implementation libs.finalizationHook
 				implementation libs.mordant.core
 				implementation libs.codepoints

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/canvas.kt

@@ -1,5 +1,7 @@
 package com.jakewharton.mosaic
 
+import androidx.collection.MutableIntList
+import androidx.collection.mutableIntListOf
 import com.jakewharton.mosaic.ui.AnsiLevel
 import com.jakewharton.mosaic.ui.Color
 import com.jakewharton.mosaic.ui.TextStyle
@@ -39,7 +41,7 @@ internal class TextSurface(
 
 	fun appendRowTo(appendable: Appendable, row: Int) {
 		// Reused heap allocation for building ANSI attributes inside the loop.
-		val attributes = mutableListOf<Int>()
+		val attributes = mutableIntListOf()
 
 		val rowPixels = rows[row]
 		var lastPixel = blankPixel
@@ -84,12 +86,14 @@ internal class TextSurface(
 					maybeToggleStyle(Strikethrough, 9, 29)
 				}
 				if (attributes.isNotEmpty()) {
-					attributes.joinTo(
-						appendable,
-						separator = ansiSeparator,
-						prefix = CSI,
-						postfix = ansiClosingCharacter,
-					)
+					appendable.append(CSI)
+					attributes.forEachIndexed { index, element ->
+						if (index > 0) {
+							appendable.append(ansiSeparator)
+						}
+						appendable.append(element.toString())
+					}
+					appendable.append(ansiClosingCharacter)
 					attributes.clear() // This list is reused!
 				}
 			}
@@ -107,7 +111,7 @@ internal class TextSurface(
 		}
 	}
 
-	private fun MutableList<Int>.addColor(
+	private fun MutableIntList.addColor(
 		color: Color,
 		ansiLevel: AnsiLevel,
 		select: Int,

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/layout/Node.kt

@@ -1,5 +1,6 @@
 package com.jakewharton.mosaic.layout
 
+import androidx.collection.MutableObjectList
 import com.jakewharton.mosaic.TextCanvas
 import com.jakewharton.mosaic.TextSurface
 import com.jakewharton.mosaic.layout.Placeable.PlacementScope
@@ -95,7 +96,7 @@ internal class MosaicNode(
 	val onStaticDraw: (() -> Unit)?,
 ) : Measurable {
 	val isStatic get() = onStaticDraw != null
-	val children = mutableListOf<MosaicNode>()
+	val children = ArrayList<MosaicNode>()
 
 	private val bottomLayer: MosaicNodeLayer = BottomLayer(this)
 	var topLayer: MosaicNodeLayer = bottomLayer
@@ -150,8 +151,9 @@ internal class MosaicNode(
 	 * Append any static [TextSurfaces][TextSurface] to [statics].
 	 * A call to [measureAndPlace] must precede calls to this function.
 	 */
-	fun paintStatics(statics: MutableList<TextSurface>, ansiLevel: AnsiLevel) {
-		for (child in children) {
+	fun paintStatics(statics: MutableObjectList<TextSurface>, ansiLevel: AnsiLevel) {
+		for (index in children.indices) {
+			val child = children[index]
 			if (isStatic) {
 				statics += child.paint(ansiLevel)
 			}

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/mosaic.kt

@@ -1,5 +1,6 @@
 package com.jakewharton.mosaic
 
+import androidx.collection.mutableScatterSetOf
 import androidx.compose.runtime.AbstractApplier
 import androidx.compose.runtime.BroadcastFrameClock
 import androidx.compose.runtime.Composable
@@ -176,8 +177,8 @@ internal class MosaicComposition(
 
 	private val applyObserverHandle: ObserverHandle
 
-	private val readingStatesOnLayout = mutableSetOf<Any>()
-	private val readingStatesOnDraw = mutableSetOf<Any>()
+	private val readingStatesOnLayout = mutableScatterSetOf<Any>()
+	private val readingStatesOnDraw = mutableScatterSetOf<Any>()
 
 	private val layoutBlockStateReadObserver: (Any) -> Unit = { readingStatesOnLayout.add(it) }
 	private val drawBlockStateReadObserver: (Any) -> Unit = { readingStatesOnDraw.add(it) }

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/rendering.kt

@@ -1,5 +1,6 @@
 package com.jakewharton.mosaic
 
+import androidx.collection.mutableObjectListOf
 import com.jakewharton.mosaic.layout.MosaicNode
 import com.jakewharton.mosaic.ui.AnsiLevel
 import kotlin.time.ExperimentalTime
@@ -37,20 +38,18 @@ internal class DebugRendering(
 			appendLine(node)
 			appendLine()
 
+			val statics = mutableObjectListOf<TextSurface>()
 			try {
-				val statics = ArrayList<TextSurface>()
-					.also { node.paintStatics(it, ansiLevel) }
-					.map { it.render() }
+				node.paintStatics(statics, ansiLevel)
 				if (statics.isNotEmpty()) {
 					appendLine("STATIC:")
-					for (static in statics) {
-						appendLine(static)
+					statics.forEach { static ->
+						appendLine(static.render())
 					}
 					appendLine()
 				}
 			} catch (t: Throwable) {
 				failed = true
-				appendLine("STATIC:")
 				appendLine(t.stackTraceToString())
 			}
 
@@ -73,7 +72,7 @@ internal class AnsiRendering(
 	private val ansiLevel: AnsiLevel = AnsiLevel.TRUECOLOR,
 ) : Rendering {
 	private val stringBuilder = StringBuilder(100)
-	private val staticSurfaces = ArrayList<TextSurface>()
+	private val staticSurfaces = mutableObjectListOf<TextSurface>()
 	private var lastHeight = 0
 
 	override fun render(node: MosaicNode): CharSequence {
@@ -98,11 +97,15 @@ internal class AnsiRendering(
 				}
 			}
 
-			node.paintStatics(staticSurfaces, ansiLevel)
-			for (staticSurface in staticSurfaces) {
-				appendSurface(staticSurface)
+			staticSurfaces.let { staticSurfaces ->
+				node.paintStatics(staticSurfaces, ansiLevel)
+				if (staticSurfaces.isNotEmpty()) {
+					staticSurfaces.forEach { staticSurface ->
+						appendSurface(staticSurface)
+					}
+					staticSurfaces.clear()
+				}
 			}
-			staticSurfaces.clear()
 
 			val surface = node.paint(ansiLevel)
 			appendSurface(surface)

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/text/AnnotatedString.kt

@@ -116,9 +116,9 @@ public class AnnotatedString internal constructor(
 			}
 		}
 
-		private val text: StringBuilder = StringBuilder(capacity)
-		private val spanStyles: MutableList<MutableRange<SpanStyle>> = mutableListOf()
-		private val styleStack: MutableList<MutableRange<out Any>> = mutableListOf()
+		private val text = StringBuilder(capacity)
+		private val spanStyles = ArrayList<MutableRange<SpanStyle>>()
+		private val styleStack = ArrayList<MutableRange<out Any>>()
 
 		/**
 		 * Create an [Builder] instance using the given [String].