Add argument bucket

Author: k163377

src/main/kotlin/com/fasterxml/jackson/module/kotlin/ArgumentBucket.kt

@@ -0,0 +1,47 @@
+package com.fasterxml.jackson.module.kotlin
+
+import java.util.AbstractMap.SimpleEntry as Entry
+import kotlin.reflect.KParameter
+
+internal class ArgumentBucket(private val parameters: List<KParameter>) : Map<KParameter, Any?> {
+    // This array is sorted by KParameter::index.
+    val valueArray: Array<Any?> = arrayOfNulls(parameters.size)
+    private val initializationStatuses: BooleanArray = BooleanArray(parameters.size)
+    private var count = 0
+
+    operator fun set(key: KParameter, value: Any?): Any? {
+        return valueArray[key.index].apply {
+            valueArray[key.index] = value
+
+            if (!initializationStatuses[key.index]) {
+                initializationStatuses[key.index] = true
+                count++
+            }
+        }
+    }
+
+    fun isFullInitialized(): Boolean = parameters.size == count
+
+    override val entries: Set<Map.Entry<KParameter, Any?>>
+        get() = valueArray.withIndex()
+                .filter { (i, _) -> initializationStatuses[i] }
+                .map { (i, arg) -> Entry(parameters[i], arg) }
+                .toSet()
+    override val keys: Set<KParameter>
+        get() = parameters
+                .filterIndexed { i, _ -> initializationStatuses[i] }
+                .toSet()
+    override val size: Int
+        get() = count
+    override val values: Collection<Any?>
+        get() = valueArray.filterIndexed { i, _ -> initializationStatuses[i] }
+
+    override fun containsKey(key: KParameter): Boolean = initializationStatuses[key.index]
+
+    override fun containsValue(value: Any?): Boolean = valueArray.withIndex()
+            .any { (i, arg) -> initializationStatuses[i] && value == arg }
+
+    override fun get(key: KParameter): Any? = valueArray[key.index]
+
+    override fun isEmpty(): Boolean = count == 0
+}