Invalidate search sources list only on filters change

app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/globalsearch/SearchScreenModel.kt

@@ -9,6 +9,7 @@ import eu.kanade.domain.source.service.SourcePreferences
 import eu.kanade.presentation.util.ioCoroutineScope
 import eu.kanade.tachiyomi.extension.ExtensionManager
 import eu.kanade.tachiyomi.source.CatalogueSource
+import eu.kanade.tachiyomi.util.lang.resetableLazy
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.asCoroutineDispatcher
 import kotlinx.coroutines.async
@@ -42,6 +43,9 @@ abstract class SearchScreenModel(
     private var lastQuery: String? = null
     private var lastSourceFilter: SourceFilter? = null
 
+    private val sourcesHolder = resetableLazy { getSelectedSources() }
+    private val sources by sourcesHolder
+
     protected var extensionFilter: String? = null
     protected val pinnedSources = sourcePreferences.pinnedSources().get()
 
@@ -100,6 +104,7 @@ abstract class SearchScreenModel(
 
     fun setSourceFilter(filter: SourceFilter) {
         mutableState.update { it.copy(sourceFilter = filter) }
+        sourcesHolder.reset()
         search()
     }
 
@@ -119,8 +124,6 @@ abstract class SearchScreenModel(
 
         searchJob?.cancel()
 
-        val sources = getSelectedSources()
-
         val initialItems = sources.associateWith { SearchItemResult.Loading }
         updateItems(initialItems)
 

app/src/main/java/eu/kanade/tachiyomi/util/lang/Lazy.kt

@@ -0,0 +1,39 @@
+package eu.kanade.tachiyomi.util.lang
+
+@Suppress("ClassName")
+internal object UNINITIALIZED_VALUE
+
+interface ResetableLazy<out T> : Lazy<T> {
+    fun reset()
+}
+
+fun <T> resetableLazy(initializer: () -> T): ResetableLazy<T> = ResetableLazyImpl(initializer)
+
+class ResetableLazyImpl<out T>(private val initializer: () -> T, lock: Any? = null) : ResetableLazy<T> {
+    private val lock = lock ?: this
+
+    @Volatile
+    private var _value: Any? = UNINITIALIZED_VALUE
+
+    override val value: T
+        get() {
+            if (_value !== UNINITIALIZED_VALUE) {
+                @Suppress("UNCHECKED_CAST")
+                return _value as T
+            }
+
+            return synchronized(lock) {
+                val value = initializer()
+                _value = value
+                value
+            }
+        }
+
+    override fun isInitialized(): Boolean = _value !== UNINITIALIZED_VALUE
+
+    override fun reset() {
+        _value = UNINITIALIZED_VALUE
+    }
+
+    override fun toString(): String = if (isInitialized()) value.toString() else "Lazy value not initialized yet."
+}