Benchmark LCS diff implementation

Author: satabin

.gitignore

@@ -20,11 +20,9 @@ syntax: glob
 .idea
 *.iml
 
-#bsp
-.bsp
-
 # building
 target
+out
 build
 null
 tmp*
@@ -51,3 +49,15 @@ build.log
 #ensime
 .ensime*
 ensime.sbt
+
+# website
+site/content/api
+site/content/documentation/
+site/output
+
+.metals/
+.bloop/
+.bsp/
+metals.sbt
+
+.vscode/settings.json

benchmarks/src/main/scala/diffson/PatienceBenchmarks.scala

@@ -0,0 +1,58 @@
+package diffson
+
+import org.openjdk.jmh.annotations.State
+import org.openjdk.jmh.annotations.Scope
+import org.openjdk.jmh.annotations.BenchmarkMode
+import org.openjdk.jmh.annotations.Mode
+import org.openjdk.jmh.annotations.Fork
+import org.openjdk.jmh.annotations.Warmup
+import org.openjdk.jmh.annotations.Measurement
+
+import diffson.circe._
+import diffson.jsonpatch.lcsdiff._
+import diffson.lcs._
+
+import io.circe.syntax._
+import io.circe.Json
+import org.openjdk.jmh.annotations.Benchmark
+
+@BenchmarkMode(Array(Mode.Throughput))
+@State(Scope.Benchmark)
+@Fork(value = 1)
+@Warmup(iterations = 3, time = 2)
+@Measurement(iterations = 5, time = 2)
+class PatienceBenchmarks {
+
+  implicit val lcs = new Patience[Json]
+
+  private def createJson(depth: Int, arrayStep: Int) =
+    List
+      .range(depth, 0, -1)
+      .foldLeft(Json.obj("array" := List.range(0, 1000, arrayStep).map(n => Json.obj("n" := n, "other" := "common")))) {
+        (acc, idx) =>
+          Json.obj(s"key$idx" := acc, "other" := arrayStep)
+      }
+
+  def array(size: Int, step: Int) =
+    Json.obj("array" := List.range(0, size, step))
+
+  val deep1 =
+    createJson(100, 1)
+
+  val deep2 =
+    createJson(100, 2)
+
+  val array1 =
+    array(1000, 2)
+
+  val array2 =
+    array(1000, 1)
+
+  @Benchmark
+  def diffArray() =
+    diff(array1, array2)
+
+  @Benchmark
+  def diffDeep() =
+    diff(deep1, deep2)
+}

build.sbt

@@ -90,3 +90,16 @@ lazy val circe = crossProject(JSPlatform, JVMPlatform, NativePlatform)
     )
   )
   .dependsOn(core, testkit % Test)
+
+lazy val benchmarks = crossProject(JVMPlatform)
+  .crossType(CrossType.Pure)
+  .in(file("benchmarks"))
+  .enablePlugins(NoPublishPlugin, JmhPlugin)
+  .settings(commonSettings: _*)
+  .settings(
+    name := "diffson-benchmarks",
+    libraryDependencies ++= Seq(
+      "io.circe" %% "circe-literal" % circeVersion
+    )
+  )
+  .dependsOn(circe)

project/plugins.sbt

@@ -2,3 +2,4 @@ addSbtPlugin("org.typelevel" % "sbt-typelevel" % "0.4.18")
 addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.13.0")
 addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.4.10")
 addSbtPlugin("org.portable-scala" % "sbt-scala-native-crossproject" % "1.2.0")
+addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.4")