Use separate cache dispatchers with limited parallelism (#3929)

components/resources/library/src/blockingMain/kotlin/org/jetbrains/compose/resources/Resource.blocking.kt

@@ -1,9 +0,0 @@
-package org.jetbrains.compose.resources
-
-import kotlinx.coroutines.CoroutineDispatcher
-import kotlinx.coroutines.DelicateCoroutinesApi
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.newSingleThreadContext
-
-@OptIn(ExperimentalCoroutinesApi::class, DelicateCoroutinesApi::class)
-internal actual val cacheDispatcher: CoroutineDispatcher = newSingleThreadContext("resources_cache_ctx")

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/ImageResources.kt

@@ -9,6 +9,8 @@ import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.graphics.vector.rememberVectorPainter
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.withContext
 import org.jetbrains.compose.resources.vector.toImageVector
 import org.jetbrains.compose.resources.vector.xmldom.Element
@@ -88,6 +90,8 @@ private sealed interface ImageCache {
     class Vector(val vector: ImageVector) : ImageCache
 }
 
+@OptIn(ExperimentalCoroutinesApi::class)
+private val imageCacheDispatcher = Dispatchers.Default.limitedParallelism(1)
 private val imageCache = mutableMapOf<String, ImageCache>()
 
 //@TestOnly
@@ -99,6 +103,6 @@ private suspend fun loadImage(
     path: String,
     resourceReader: ResourceReader,
     decode: (ByteArray) -> ImageCache
-): ImageCache = withContext(cacheDispatcher) {
+): ImageCache = withContext(imageCacheDispatcher) {
     imageCache.getOrPut(path) { decode(resourceReader.read(path)) }
 }

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/Resource.kt

@@ -1,10 +1,6 @@
 package org.jetbrains.compose.resources
 
-import kotlinx.coroutines.CoroutineDispatcher
-
 internal typealias ResourceId = String
 
 @RequiresOptIn("This API is experimental and is likely to change in the future.")
-annotation class ExperimentalResourceApi
-
-internal expect val cacheDispatcher: CoroutineDispatcher
+annotation class ExperimentalResourceApi

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/StringResources.kt

@@ -2,6 +2,8 @@ package org.jetbrains.compose.resources
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.withContext
 import org.jetbrains.compose.resources.vector.xmldom.Element
 import org.jetbrains.compose.resources.vector.xmldom.NodeList
@@ -14,6 +16,8 @@ private sealed interface StringItem {
     data class Array(val items: List<String>) : StringItem
 }
 
+@OptIn(ExperimentalCoroutinesApi::class)
+private val stringsCacheDispatcher = Dispatchers.Default.limitedParallelism(1)
 private val parsedStringsCache = mutableMapOf<String, Map<String, StringItem>>()
 
 //@TestOnly
@@ -22,7 +26,7 @@ internal fun dropStringsCache() {
 }
 
 private suspend fun getParsedStrings(path: String, resourceReader: ResourceReader): Map<String, StringItem> =
-    withContext(cacheDispatcher) {
+    withContext(stringsCacheDispatcher) {
         parsedStringsCache.getOrPut(path) {
             val nodes = resourceReader.read(path).toXmlElement().childNodes
             val strings = nodes.getElementsWithName("string").associate { element ->

components/resources/library/src/jsMain/kotlin/org/jetbrains/compose/resources/Resource.js.kt

@@ -1,10 +1,5 @@
 package org.jetbrains.compose.resources
 
-import kotlinx.coroutines.CoroutineDispatcher
-import kotlinx.coroutines.Dispatchers
-
-internal actual val cacheDispatcher: CoroutineDispatcher = Dispatchers.Default
-
 /**
  * Represents the configuration object for web resources.
  *