[K/N] Added copy array benchmark

kotlin-native/performance/ring/src/main/kotlin/main.kt

@@ -212,7 +212,8 @@ class RingLauncher : Launcher() {
                     "LinkedListWithAtomicsBenchmark" to BenchmarkEntryWithInit.create(::LinkedListWithAtomicsBenchmark, { ensureNext() }),
                     "Inheritance.baseCalls" to BenchmarkEntryWithInit.create(::InheritanceBenchmark, { baseCalls() }),
                     "ChainableBenchmark.testChainable" to BenchmarkEntryWithInit.create(::ChainableBenchmark, { testChainable() }),
-                    "BunnymarkBenchmark.testBunnymark" to BenchmarkEntryWithInit.create(::BunnymarkBenchmark, { testBunnymark() })
+                    "BunnymarkBenchmark.testBunnymark" to BenchmarkEntryWithInit.create(::BunnymarkBenchmark, { testBunnymark() }),
+                    "ArrayCopyBenchmark.copyInSameArray" to BenchmarkEntryWithInit.create(::ArrayCopyBenchmark, { copyInSameArray() })
             )
     )
 }

kotlin-native/performance/ring/src/main/kotlin/org/jetbrains/ring/ArrayCopyBenchmark.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+package org.jetbrains.ring
+
+import org.jetbrains.benchmarksLauncher.Blackhole
+import kotlin.random.Random
+
+open class ArrayCopyBenchmark {
+    class CustomArray<T>(capacity: Int = 0) {
+        private var hashes: IntArray = IntArray(capacity)
+        private var values: Array<T?> = arrayOfNulls<Any>(capacity) as Array<T?>
+        private var _size: Int = 0
+
+        fun add(index: Int, element: T): Boolean {
+            val oldSize = _size
+
+            // Grow the array if needed.
+            if (oldSize == hashes.size) {
+                val newSize = if (oldSize > 0) oldSize * 2 else 2
+                hashes = hashes.copyOf(newSize)
+                values = values.copyOf(newSize)
+            }
+
+            // Shift the array if needed.
+            if (index < oldSize) {
+                hashes.copyInto(
+                        hashes,
+                        destinationOffset = index + 1,
+                        startIndex = index,
+                        endIndex = oldSize
+                )
+                values.copyInto(
+                        values,
+                        destinationOffset = index + 1,
+                        startIndex = index,
+                        endIndex = oldSize
+                )
+            }
+
+            hashes[index] = element.hashCode()
+            values[index] = element
+
+            _size++
+            return true
+        }
+    }
+
+    //Benchmark
+    fun copyInSameArray(): CustomArray<Int> {
+        val array = CustomArray<Int>()
+        for (i in 0 until 2 * BENCHMARK_SIZE) {
+            array.add(0, i)
+        }
+        return array
+    }
+}