Benchmark for classpah lookup

Author: retronym

test/benchmarks/src/main/scala/scala/tools/nsc/AggregateClassPathBenchmark.scala

@@ -0,0 +1,43 @@
+package scala.tools.nsc
+
+import java.nio.file.{Files, Paths}
+import java.util.concurrent.TimeUnit
+
+import org.openjdk.jmh
+import org.openjdk.jmh.annotations._
+import org.openjdk.jmh.infra.Blackhole
+
+import scala.tools.nsc
+import scala.tools.nsc.util.ClassPath
+import scala.tools.util.PathResolver
+
+@BenchmarkMode(Array(jmh.annotations.Mode.AverageTime))
+@Fork(2)
+@Threads(1)
+@Warmup(iterations = 10)
+@Measurement(iterations = 10)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Benchmark)
+class AggregateClassPathBenchmark {
+  @Param(Array(""))
+  var classpathString: String = _
+  var classpath: ClassPath = _
+  val closeableRegistry = new CloseableRegistry
+  @Setup def setup(): Unit = {
+    val settings = new nsc.Settings()
+    if (classpathString.startsWith("@"))
+      classpathString = new String(Files.readAllBytes(Paths.get(classpathString.drop(1))))
+    settings.classpath.value = classpathString
+    val resolver = new PathResolver(settings, closeableRegistry)
+    classpath = resolver.result
+    classpath.list("")
+  }
+
+  @TearDown def teardown(): Unit = {
+    closeableRegistry.close()
+  }
+
+  @Benchmark def test(bh: Blackhole) = {
+    classpath.list("")._1.foreach(entry => bh.consume(classpath.list(entry.name)))
+  }
+}