Add basic infrastructure for benchmarking (JMH).

- Execute `./gradlew jmh` to run all benchmarks (i.e., all combinations of fixes and input files).
- Place fixes to benchmark in `metafix/src/jmh/resources/org/metafacture/metafix/fixes/` and add to `MetafixBenchmark.fixDef` parameter.
- Place input files to benchmark in `metafix/src/jmh/resources/org/metafacture/metafix/input/` and add to `MetafixBenchmark.input` parameter.

https://github.com/openjdk/jmh

Author: blackwinter

metafix/build.gradle

@@ -1,5 +1,6 @@
 plugins {
   id 'maven-publish'
+  id 'me.champeau.jmh' version '0.6.6'
 }
 
 def passSystemProperties = {
@@ -45,6 +46,14 @@ dependencies {
   mwe2 "org.eclipse.xtext:org.eclipse.xtext.common.types:${versions.xtext}"
   mwe2 "org.eclipse.xtext:org.eclipse.xtext.xtext.generator:${versions.xtext}"
   mwe2 'org.eclipse.xtext:xtext-antlr-generator'
+
+  jmh "org.metafacture:metafacture-io:${versions.metafacture}"
+  jmh "org.metafacture:metafacture-json:${versions.metafacture}"
+}
+
+jmhJar {
+  // SLF4J: Class path contains multiple SLF4J bindings.
+  exclude '/org/slf4j/impl/StaticLoggerBinder.class'
 }
 
 test {

metafix/src/jmh/java/org/metafacture/metafix/MetafixBenchmark.java

@@ -0,0 +1,133 @@
+/*
+ * Copyright 2022 hbz NRW
+ *
+ * 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.metafacture.metafix;
+
+import org.metafacture.framework.helpers.DefaultStreamReceiver;
+import org.metafacture.io.FileOpener;
+import org.metafacture.io.ObjectStdoutWriter;
+import org.metafacture.io.RecordReader;
+import org.metafacture.json.JsonDecoder;
+import org.metafacture.json.JsonEncoder;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+//import org.openjdk.jmh.profile.GCProfiler;
+//import org.openjdk.jmh.profile.StackProfiler;
+//import org.openjdk.jmh.runner.Runner;
+//import org.openjdk.jmh.runner.RunnerException;
+//import org.openjdk.jmh.runner.options.Options;
+//import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.io.FileNotFoundException;
+import java.util.concurrent.TimeUnit;
+
+@Fork(2)
+@Warmup(iterations = 2)
+@Measurement(iterations = 4) // checkstyle-disable-line MagicNumber
+@BenchmarkMode(Mode.Throughput) // AverageTime
+@OutputTimeUnit(TimeUnit.MILLISECONDS) // SECONDS
+@State(Scope.Thread)
+public class MetafixBenchmark {
+
+    // TODO: Need to inject system properties into JMHTask's JavaExec process.
+    //private static final boolean DEBUG_OUTPUT = Boolean.parseBoolean(System.getProperty("org.metafacture.metafix.debugBenchmarkOutput"));
+    private static final boolean DEBUG_OUTPUT = false;
+
+    private static final String BASE = "src/jmh/resources/org/metafacture/metafix";
+
+    private static final String FIXES = BASE + "/fixes/%s" + Metafix.FIX_EXTENSION;
+    private static final String INPUT = BASE + "/input/%s.json";
+
+    @Param({ // checkstyle-disable-line AnnotationUseStyle
+        "nothing"
+    })
+    private String fixDef;
+
+    @Param({ // checkstyle-disable-line AnnotationUseStyle
+        "empty"
+    })
+    private String input;
+
+    private String fixFile;
+    private String inputFile;
+
+    private FileOpener fileOpener;
+
+    public MetafixBenchmark() {
+    }
+
+    @Setup
+    public void setup() throws FileNotFoundException {
+        fixFile = String.format(FIXES, fixDef);
+        inputFile = String.format(INPUT, input);
+
+        final Metafix metafix = new Metafix(fixFile);
+
+        if (DEBUG_OUTPUT) {
+            metafix
+                .setReceiver(new JsonEncoder())
+                .setReceiver(new ObjectStdoutWriter<String>());
+        }
+        else {
+            metafix
+                .setReceiver(new DefaultStreamReceiver());
+        }
+
+        fileOpener = new FileOpener();
+        fileOpener
+            .setReceiver(new RecordReader())
+            .setReceiver(new JsonDecoder())
+            .setReceiver(metafix);
+    }
+
+    @Benchmark
+    public void baseline() {
+        // this method was intentionally left blank.
+    }
+
+    @Benchmark
+    public void parse() {
+        FixStandaloneSetup.parseFix(fixFile);
+    }
+
+    @Benchmark
+    public void process() {
+        fileOpener.process(inputFile);
+    }
+
+    /*
+    public static void main(final String[] args) throws RunnerException {
+        final Options opt = new OptionsBuilder()
+            .include(MetafixBenchmark.class.getSimpleName())
+            .addProfiler(StackProfiler.class)
+            //.addProfiler(GCProfiler.class)
+            .build();
+
+        new Runner(opt).run();
+    }
+    */
+
+}

metafix/src/jmh/resources/org/metafacture/metafix/fixes/nothing.fix

@@ -0,0 +1 @@
+nothing()

metafix/src/jmh/resources/org/metafacture/metafix/input/empty.json

@@ -0,0 +1 @@
+{}