feat: add proper JMH benchmarks

Signed-off-by: Andreas Reichel <[email protected]>

Author: manticore-projects

build.gradle

@@ -641,3 +641,11 @@ tasks.register('upload') {
 check {
     dependsOn jacocoTestCoverageVerification
 }
+
+jmh {
+    includes = ['.*JSQLParserBenchmark.*']
+    warmupIterations = 3
+    fork = 3
+    iterations = 10
+    timeOnIteration = '1s'
+}

src/site/sphinx/_static/jmh_results.txt

@@ -0,0 +1,20 @@
+-- Optimised LOOKAHEADS (replacing all syntactic lookahead by numeric lookaheads)
+Benchmark                               (version)  Mode  Cnt    Score    Error  Units
+JSQLParserBenchmark.parseSQLStatements     latest  avgt   15  264.132 ±  9.636  ms/op
+JSQLParserBenchmark.parseSQLStatements        5.2  avgt   15  415.744 ± 20.602  ms/op
+JSQLParserBenchmark.parseSQLStatements        5.1  avgt   15   89.387 ±  1.916  ms/op
+JSQLParserBenchmark.parseSQLStatements        5.0  avgt   15   68.810 ±  2.591  ms/op
+JSQLParserBenchmark.parseSQLStatements        4.9  avgt   15   60.515 ±  1.650  ms/op
+JSQLParserBenchmark.parseSQLStatements        4.8  avgt   15   60.002 ±  1.259  ms/op
+JSQLParserBenchmark.parseSQLStatements        4.7  avgt   15   73.291 ±  3.049  ms/op
+
+-- Optimised LOOKAHEADS (replacing huge numeric lookaheads with syntactic lookaheads again)
+Benchmark                               (version)  Mode  Cnt    Score    Error  Units
+JSQLParserBenchmark.parseSQLStatements     latest  avgt   15  249.408 ± 11.340  ms/op
+JSQLParserBenchmark.parseSQLStatements        5.2  avgt   15  388.453 ± 13.149  ms/op
+
+-- Disable `FunctionAllColumns()`
+Benchmark                               (version)  Mode  Cnt    Score   Error  Units
+JSQLParserBenchmark.parseSQLStatements     latest  avgt   30   83.504 ± 1.557  ms/op
+JSQLParserBenchmark.parseSQLStatements        5.2  avgt   30  400.876 ± 8.291  ms/op
+JSQLParserBenchmark.parseSQLStatements        5.1  avgt   30   85.731 ± 1.288  ms/op

src/test/java/net/sf/jsqlparser/benchmark/DynamicParserRunner.java

@@ -0,0 +1,40 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2025 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.benchmark;
+
+import net.sf.jsqlparser.parser.CCJSqlParser;
+import net.sf.jsqlparser.statement.Statements;
+
+import java.lang.reflect.Method;
+import java.net.URLClassLoader;
+import java.util.concurrent.ExecutorService;
+import java.util.function.Consumer;
+
+public class DynamicParserRunner implements SqlParserRunner {
+    private final Method parseStatementsMethod;
+
+    public DynamicParserRunner(URLClassLoader loader) throws Exception {
+        Class<?> utilClass = loader.loadClass("net.sf.jsqlparser.parser.CCJSqlParserUtil");
+        Class<?> ccjClass = loader.loadClass("net.sf.jsqlparser.parser.CCJSqlParser");
+        Class<?> consumerClass = Class.forName("java.util.function.Consumer"); // interface OK
+        parseStatementsMethod = utilClass.getMethod(
+                "parseStatements",
+                String.class,
+                ExecutorService.class,
+                consumerClass);
+    }
+
+    @Override
+    public Statements parseStatements(String sql,
+            ExecutorService executorService,
+            Consumer<CCJSqlParser> consumer) throws Exception {
+        return (Statements) parseStatementsMethod.invoke(null, sql, executorService, null);
+    }
+}

src/test/java/net/sf/jsqlparser/benchmark/JSQLParserBenchmark.java

@@ -0,0 +1,89 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2025 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.benchmark;
+
+import net.sf.jsqlparser.parser.CCJSqlParser;
+import net.sf.jsqlparser.statement.Statements;
+import org.openjdk.jmh.annotations.*;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.*;
+import java.util.concurrent.*;
+import java.util.function.Consumer;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@State(Scope.Benchmark)
+public class JSQLParserBenchmark {
+
+    private String sqlContent;
+    private ExecutorService executorService;
+
+    SqlParserRunner runner;
+
+    // @Param({ "latest", "5.2", "5.1", "5.0", "4.9", "4.8", "4.7", "4.6", "4.5" })
+    @Param({"latest", "5.2", "5.1"})
+    public String version;
+
+    @Setup(Level.Trial)
+    public void setup() throws Exception {
+        if ("latest".equals(version)) {
+            runner = new LatestClasspathRunner(); // direct call, no reflection
+        } else {
+            Path jarPath = downloadJsqlparserJar(version);
+            URLClassLoader loader = new URLClassLoader(new URL[] {jarPath.toUri().toURL()}, null);
+            runner = new DynamicParserRunner(loader);
+        }
+
+        // Adjust path as necessary based on where source root is during test execution
+        Path path = Paths.get("src/test/resources/net/sf/jsqlparser/performance.sql");
+        sqlContent = Files.readString(path, StandardCharsets.UTF_8);
+        executorService = Executors.newSingleThreadExecutor();
+    }
+
+    private Path downloadJsqlparserJar(String version) throws IOException {
+        String jarUrl = String.format(
+                "https://repo1.maven.org/maven2/com/github/jsqlparser/jsqlparser/%s/jsqlparser-%s.jar",
+                version, version);
+
+        Path cacheDir = Paths.get("build/libs/downloaded-jars");
+        Files.createDirectories(cacheDir);
+        Path jarFile = cacheDir.resolve("jsqlparser-" + version + ".jar");
+
+        if (!Files.exists(jarFile)) {
+            System.out.println("Downloading " + version);
+            try (InputStream in = new URL(jarUrl).openStream()) {
+                Files.copy(in, jarFile);
+            }
+        }
+
+        return jarFile;
+    }
+
+    @Benchmark
+    public void parseSQLStatements() throws Exception {
+        final Statements statements = runner.parseStatements(
+                sqlContent,
+                executorService,
+                (Consumer<CCJSqlParser>) parser -> {
+                    // No-op consumer (or you can log/validate each parser if desired)
+                });
+        assert statements.size() == 4;
+    }
+
+    @TearDown(Level.Trial)
+    public void tearDown() {
+        executorService.shutdown();
+    }
+}

src/test/java/net/sf/jsqlparser/benchmark/LatestClasspathRunner.java

@@ -0,0 +1,28 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2025 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.benchmark;
+
+import net.sf.jsqlparser.parser.CCJSqlParser;
+import net.sf.jsqlparser.statement.Statements;
+
+import java.util.concurrent.ExecutorService;
+import java.util.function.Consumer;
+
+public class LatestClasspathRunner implements SqlParserRunner {
+
+    @Override
+    public Statements parseStatements(String sql,
+            ExecutorService executorService,
+            Consumer<CCJSqlParser> consumer) throws Exception {
+        return net.sf.jsqlparser.parser.CCJSqlParserUtil.parseStatements(sql, executorService,
+                consumer);
+    }
+}
+

src/test/java/net/sf/jsqlparser/benchmark/SqlParserRunner.java

@@ -0,0 +1,21 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2025 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.benchmark;
+
+import net.sf.jsqlparser.parser.CCJSqlParser;
+import net.sf.jsqlparser.statement.Statements;
+
+import java.util.concurrent.ExecutorService;
+import java.util.function.Consumer;
+
+public interface SqlParserRunner {
+    Statements parseStatements(String sql, ExecutorService executorService,
+            Consumer<CCJSqlParser> consumer) throws Exception;
+}

src/test/java/net/sf/jsqlparser/statement/select/SpeedTest.java

@@ -15,6 +15,7 @@
 import net.sf.jsqlparser.statement.simpleparsing.CCJSqlParserManagerTest;
 import net.sf.jsqlparser.test.TestException;
 import net.sf.jsqlparser.util.TablesNamesFinder;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
 import java.io.BufferedReader;
@@ -30,6 +31,7 @@ public class SpeedTest {
     private final CCJSqlParserManager parserManager = new CCJSqlParserManager();
 
     @Test
+    @Disabled
     public void testSpeed() throws Exception {
         // all the statements in testfiles/simple_parsing.txt
         BufferedReader in = new BufferedReader(