#2053 reduce latency when a lot of key maps with open app actions

Author: sds100

CHANGELOG.md

@@ -1,11 +1,12 @@
 ## [4.0.5](https://github.com/sds100/KeyMapper/releases/tag/v4.0.5)
 
-#### TO BE RELEASED
+#### 26 February 2026
 
 ## Fixed
 
 - #2047 allow empty text in Text action.
 - #2056 replace old "PRO" in triggers on home screen with "Expert".
+- #2053 reduce latency when a lot of key maps with open app actions.
 
 ## [4.0.4](https://github.com/sds100/KeyMapper/releases/tag/v4.0.4)
 

base/src/main/java/io/github/sds100/keymapper/base/actions/ActionErrorSnapshot.kt

@@ -27,6 +27,7 @@ import io.github.sds100.keymapper.system.permissions.PermissionAdapter
 import io.github.sds100.keymapper.system.permissions.SystemFeatureAdapter
 import io.github.sds100.keymapper.system.ringtones.RingtoneAdapter
 import io.github.sds100.keymapper.system.settings.SettingType
+import java.util.concurrent.ConcurrentHashMap
 
 class LazyActionErrorSnapshot(
     private val packageManager: PackageManagerAdapter,
@@ -65,6 +66,9 @@ class LazyActionErrorSnapshot(
         }
     }
 
+    private val isAppEnabledCache = ConcurrentHashMap<String, Boolean>()
+    private val isAppInstalledCache = ConcurrentHashMap<String, Boolean>()
+
     private val isSystemBridgeConnected: Boolean by lazy {
         systemBridgeConnectionManager.isConnected()
     }
@@ -250,13 +254,30 @@ class LazyActionErrorSnapshot(
     }
 
     private fun getAppError(packageName: String): KMError? {
+        if (isAppEnabledCache.contains(packageName) && isAppInstalledCache.contains(packageName)) {
+            if (isAppEnabledCache[packageName] == false) {
+                return KMError.AppDisabled(packageName)
+            }
+
+            if (isAppInstalledCache[packageName] == false) {
+                return KMError.AppDisabled(packageName)
+            }
+
+            return null
+        }
+
+        val isAppInstalled = packageManager.isAppInstalled(packageName)
+        isAppInstalledCache[packageName] = isAppInstalled
+
         packageManager.isAppEnabled(packageName).onSuccess { isEnabled ->
+            isAppEnabledCache[packageName] = isEnabled
+
             if (!isEnabled) {
                 return KMError.AppDisabled(packageName)
             }
         }
 
-        if (!packageManager.isAppInstalled(packageName)) {
+        if (!isAppInstalled) {
             return KMError.AppNotFound(packageName)
         }
 

base/src/main/java/io/github/sds100/keymapper/base/actions/GetActionErrorUseCase.kt

@@ -14,15 +14,20 @@ import io.github.sds100.keymapper.system.permissions.SystemFeatureAdapter
 import io.github.sds100.keymapper.system.ringtones.RingtoneAdapter
 import javax.inject.Inject
 import javax.inject.Singleton
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.channelFlow
 import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.drop
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.merge
+import kotlinx.coroutines.flow.stateIn
 
 @Singleton
 class GetActionErrorUseCaseImpl @Inject constructor(
+    private val coroutineScope: CoroutineScope,
     private val packageManagerAdapter: PackageManagerAdapter,
     private val inputMethodAdapter: InputMethodAdapter,
     private val switchImeInterface: SwitchImeInterface,
@@ -49,13 +54,13 @@ class GetActionErrorUseCaseImpl @Inject constructor(
         ),
     )
 
-    override val actionErrorSnapshot: Flow<ActionErrorSnapshot> = channelFlow {
+    override val actionErrorSnapshot: StateFlow<ActionErrorSnapshot> = channelFlow {
         send(createSnapshot())
 
         invalidateActionErrors.collectLatest {
             send(createSnapshot())
         }
-    }
+    }.stateIn(coroutineScope, SharingStarted.Eagerly, createSnapshot())
 
     private fun createSnapshot(): ActionErrorSnapshot {
         return LazyActionErrorSnapshot(

base/src/main/java/io/github/sds100/keymapper/base/detection/KeyMapAlgorithm.kt

@@ -802,6 +802,8 @@ class KeyMapAlgorithm(
         val detectedShortPressTriggers = mutableSetOf<Int>()
         val vibrateDurations = mutableListOf<Long>()
 
+        val errorSnapshot = performActionsUseCase.getErrorSnapshot()
+
         /*
         loop through triggers in a different loop first to increment the last matched index.
         Otherwise the order of the key maps affects the logic.
@@ -815,8 +817,6 @@ class KeyMapAlgorithm(
 
             val lastMatchedIndex = lastMatchedEventIndices[triggerIndex]
 
-            val errorSnapshot = performActionsUseCase.getErrorSnapshot()
-
             val actionList = triggerActions[triggerIndex]
                 .map { actionKey -> actionMap[actionKey]?.data }
                 .filterNotNull()

base/src/test/java/io/github/sds100/keymapper/base/actions/GetActionErrorUseCaseTest.kt

@@ -68,6 +68,7 @@ class GetActionErrorUseCaseTest {
         mockSystemBridgeConnectionManager = mock()
 
         useCase = GetActionErrorUseCaseImpl(
+            coroutineScope = testScope,
             packageManagerAdapter = mock(),
             inputMethodAdapter = fakeInputMethodAdapter,
             switchImeInterface = mock(),