fix: removing in memory context creation for every event (#110)

Author: AlexZangerle

src/main/kotlin/at/ac/uibk/dps/cirrina/execution/object/Extent.kt

@@ -1,6 +1,10 @@
 package at.ac.uibk.dps.cirrina.execution.`object`
 
-class Extent private constructor(private val contexts: Array<Context>) {
+class Extent
+private constructor(
+  private val contexts: Array<Context>,
+  private val overlay: Map<String, Any?> = emptyMap(),
+) {
   val high: Context? = contexts.lastOrNull()
 
   fun setOrCreate(name: String, value: Any?): Int =
@@ -12,13 +16,16 @@ class Extent private constructor(private val contexts: Array<Context>) {
       ?: error("variable '$name' not found in any context")
 
   fun resolve(name: String): Any =
-    contexts.lastOrNull { it.has(name) }?.get(name)
+    overlay[name]
+      ?: contexts.lastOrNull { it.has(name) }?.get(name)
       ?: error("variable '$name' not found in any context")
 
-  fun has(name: String): Boolean = contexts.any { it.has(name) }
+  fun has(name: String): Boolean = name in overlay || contexts.any { it.has(name) }
 
   fun extend(high: Context): Extent = Extent(contexts + high)
 
+  fun with(overlay: Map<String, Any?>): Extent = Extent(contexts, overlay)
+
   companion object {
     fun empty() = Extent(emptyArray())
 

src/main/kotlin/at/ac/uibk/dps/cirrina/execution/object/StateMachine.kt

@@ -4,7 +4,6 @@ import TimeoutActionManager
 import at.ac.uibk.dps.cirrina.Runtime
 import at.ac.uibk.dps.cirrina.csm.Csml.EventChannel
 import at.ac.uibk.dps.cirrina.execution.`object`.StateMachine.Factory
-import at.ac.uibk.dps.cirrina.execution.provider.ContextInMemory
 import at.ac.uibk.dps.cirrina.spec.Instance
 import at.ac.uibk.dps.cirrina.spec.StateMachine as StateMachineSpec
 import at.ac.uibk.dps.cirrina.spec.Transition as TransitionSpec
@@ -140,11 +139,7 @@ internal constructor(
     if (candidates.isEmpty()) return null
 
     val evalExtent =
-      activeState!!
-        .extent
-        .extend(
-          ContextInMemory().apply { event.data.forEach { create(VAR_PREFIX + it.name, it.value) } }
-        )
+      activeState!!.extent.with(event.data.associate { VAR_PREFIX + it.name to it.value })
 
     return trySelect(candidates, evalExtent)?.also {
       event.data.forEach { d -> extent.setOrCreate(VAR_PREFIX + d.name, d.value) }