Add simple benchmark for utf8Decode

src/test/scala/scalaz/stream/examples/ReadingUTF8.scala

@@ -0,0 +1,68 @@
+package scalaz.stream
+
+import java.io._
+import org.scalacheck._
+import Prop._
+import process1._
+import scalaz.concurrent.Task
+
+object ReadingUTF8 extends Properties("examples.ReadingUTF8") {
+
+  def time[A](a: => A): (A, Double) = {
+    val now = System.nanoTime
+    val result = a
+    val millis = (System.nanoTime - now) / 1e6
+    (result, millis)
+  }
+
+  def benchmark[A](descr: String, n: Int, a: => A) = {
+    (0 to n).foreach { _ =>
+      val (result, millis) = time(a)
+      println(s"$descr:\t$millis\t$result")
+    }
+    true
+  }
+
+  val bufferSize = 4096
+  //val bufferSize = 8192
+  val testFile = "testdata/utf8.txt"
+
+  val scalazIo: Task[Option[Long]] =
+    Process.constant(bufferSize)
+      .through(io.fileChunkR(testFile, bufferSize))
+      .map(a => Bytes.unsafe(a))
+      .pipe(utf8Decode)
+      .map(_.map(_.toLong).sum)
+      .reduce(_ + _)
+      .runLast
+
+  def javaIo = {
+    val fileStream = new FileInputStream(testFile)
+    val inputStream = new InputStreamReader(fileStream, "UTF-8")
+    val bufferedReader = new BufferedReader(inputStream, bufferSize)
+
+    val array = Array.ofDim[Char](bufferSize)
+    def readChars(a: Array[Char]) = bufferedReader.read(a, 0, bufferSize)
+
+    var l = 0
+    var sum: Long = 0
+    var count = readChars(array)
+    while (count >= 0) {
+      l += 1
+      val s = new String(array, 0, count)
+      sum += s.map(_.toLong).sum
+      count = readChars(array)
+    }
+
+    bufferedReader.close()
+    inputStream.close()
+    fileStream.close()
+
+    Some(sum)
+  }
+
+  property("benchmark") = secure {
+    benchmark("scalaz", 10, scalazIo.run)
+    benchmark("Java", 10, javaIo)
+  }
+}