Improve the performance of Version.Component.parse (#2010)

Author: fthomas

.github/workflows/ci.yml

@@ -59,7 +59,7 @@ jobs:
         uses: codecov/codecov-action@v1
 
       - name: Compress target directories
-        run: tar cf targets.tar target modules/core/.jvm/target modules/sbt-plugin/.jvm/target modules/mill-plugin/.jvm/target project/target
+        run: tar cf targets.tar target modules/mill-plugin/.jvm/target modules/sbt-plugin/.jvm/target modules/core/.jvm/target modules/benchmark/.jvm/target project/target
 
       - name: Upload target directories
         uses: actions/upload-artifact@v2

build.sbt

@@ -9,6 +9,7 @@ val rootPkg = groupId.replace("-", "")
 val gitHubOwner = "scala-steward-org"
 
 val moduleCrossPlatformMatrix: Map[String, List[Platform]] = Map(
+  "benchmark" -> List(JVMPlatform),
   "core" -> List(JVMPlatform),
   "sbt-plugin" -> List(JVMPlatform),
   "mill-plugin" -> List(JVMPlatform)
@@ -55,10 +56,19 @@ ThisBuild / githubWorkflowBuild :=
 
 lazy val root = project
   .in(file("."))
-  .aggregate(core.jvm, `sbt-plugin`.jvm, `mill-plugin`.jvm)
+  .aggregate(benchmark.jvm, core.jvm, `sbt-plugin`.jvm, `mill-plugin`.jvm)
   .settings(commonSettings)
   .settings(noPublishSettings)
 
+lazy val benchmark = myCrossProject("benchmark")
+  .dependsOn(core)
+  .enablePlugins(JmhPlugin)
+  .settings(noPublishSettings)
+  .settings(
+    coverageEnabled := false,
+    unusedCompileDependencies := Set.empty
+  )
+
 lazy val core = myCrossProject("core")
   .enablePlugins(BuildInfoPlugin, JavaAppPackaging, DockerPlugin)
   .settings(dockerSettings)

modules/benchmark/src/main/scala/org/scalasteward/benchmark/VersionBenchmark.scala

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2018-2021 Scala Steward contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.scalasteward.benchmark
+
+import org.openjdk.jmh.annotations.{Benchmark, BenchmarkMode, Mode, OutputTimeUnit}
+import org.scalasteward.core.data.Version
+
+import java.util.concurrent.TimeUnit
+
+@BenchmarkMode(Array(Mode.AverageTime))
+class VersionBenchmark {
+  @Benchmark
+  @OutputTimeUnit(TimeUnit.MICROSECONDS)
+  def constructor: Any = {
+    Version("1.1.2-1")
+    Version("8.0.192-R14")
+    Version("1.2.0+9-4a769501")
+  }
+}

modules/core/src/main/scala/org/scalasteward/core/data/Version.scala

@@ -156,12 +156,13 @@ object Version {
 
     def parse(str: String): List[Component] =
       str match {
-        case hash(sep, value, rest) if !startsWithDate(value) =>
-          Separator(sep.head) +: Hash(value) +: parse(rest)
+        case "" => List.empty
         case numeric(value, rest) =>
           Numeric(value) +: parse(rest)
         case alpha(value, rest) =>
           Alpha(value) +: parse(rest)
+        case hash(sep, value, rest) if !startsWithDate(value) =>
+          Separator(sep.head) +: Hash(value) +: parse(rest)
         case separator(value, rest) =>
           Separator(value.head) +: parse(rest)
         case _ => List.empty

project/plugins.sbt

@@ -8,6 +8,7 @@ addSbtPlugin("com.github.tkawachi" % "sbt-doctest" % "0.9.9")
 addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.8.1")
 addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.6.0")
 addSbtPlugin("io.github.davidgregory084" % "sbt-tpolecat" % "0.1.17")
+addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.0")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.0.0")
 addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.6.1")
 addSbtPlugin("org.wartremover" % "sbt-wartremover" % "2.4.13")