SI-10167: Implement mutable.ArrayDeque

benchmarks/time/src/main/scala/strawman/collection/mutable/ArrayDequeBenchmark.scala

@@ -0,0 +1,45 @@
+package strawman.collection.mutable
+
+import scala._
+import scala.collection.mutable
+import scala.Predef._
+
+import java.lang.System.nanoTime
+
+object ArrayDequeBenchmark extends App {
+  val candidates = Seq(
+    strawman.collection.mutable.ArrayDeque.empty[Int],
+    scala.collection.mutable.ArrayBuffer.empty[Int]
+  )
+
+  def benchmark[U](name: String, f: mutable.Buffer[Int] => U) = {
+    def profile(buffer: mutable.Buffer[Int]) = {
+      val t1 = nanoTime()
+      f(buffer)
+      (nanoTime() - t1)/1e6
+    }
+    println(s"===============[$name]=================")
+    candidates foreach (c =>
+      println(f"${c.getClass.getSimpleName}%12s: ${profile(c)}%8.2f ms")
+    )
+    candidates.sliding(2) foreach {case Seq(a, b) =>
+      assert(a == b, s"Operations are not same [$name] for ${a.getClass.getName} and ${b.getClass.getName}")
+    }
+  }
+
+  val range10m = (1 to 1e7.toInt).toArray
+
+  benchmark("Insert lots of items", _ ++= range10m)
+  benchmark("Drop some items from an head index", _.remove(5, 10000))
+  benchmark("Drop some items from a tail index", b => b.remove(b.length - 10000, 10000))
+  benchmark("Append lots of items one by one", b => range10m.foreach(b.+=))
+  benchmark("Prepend few items one by one", b => (1 to 1000).foreach(_ +=: b))
+  benchmark("Prepend lots of items at once", range10m ++=: _)
+  benchmark("Insert items near head", _.insertAll(1000, range10m))
+  benchmark("Reversal", _.reverse)
+  benchmark("Insert items near tail", b => b.insertAll(b.size - 1000, range10m))
+  benchmark("Sliding", _.sliding(size = 1000, step = 1000).size)
+  benchmark("Random indexing", b => range10m.foreach(i => if (b.isDefinedAt(i)) b(i)))
+  benchmark("toArray", _.toArray)
+  benchmark("Clear lots of items", _.clear())
+}

build.sbt

@@ -37,6 +37,7 @@ val commonSettings = Seq(
     <developers>
       <developer><id>ichoran</id><name>Rex Kerr</name></developer>
       <developer><id>odersky</id><name>Martin Odersky</name></developer>
+      <developer><id>pathikrit</id><name>Pathikrit Bhowmick</name></developer>
       <developer><id>julienrf</id><name>Julien Richard-Foy</name></developer>
       <developer><id>szeiger</id><name>Stefan Zeiger</name></developer>
     </developers>,