modernize the simulator to use jdk21 (unrelated to the core library)

As dependencies are moving on from jdk11, it makes sense for the
analysis tools to upgrade as well. This was already executing as 21
to support those dependencies and now simply requires it at the
language level. The user-facing library and jmh benchmarks remain jdk11
compatible.

A profile of the execution showed excessive garbage, which is now
reduced to improve runtimes.
- A direct mapped cache of boxed Long keys are used to reduce the
allocations by caching libraries. The research policies use primitive
based data structures, but user-facing libraries are not as fortunate.
- Using cache listeners to track eviction counts can require the
libraries allocate, e.g. copy the entry. This is safe enough to trust
their stats because its usually the hit rate that is accidentally
miscalculated and we verify that matches. The eviction count is easily
derrived (miss count - size) so just a sanity check.
* This particular sped up Ehcache from an 18.25m run to 17m, because
if any event type is registered against then it emits and does work for
the unregistered event types too. This may seem like low-hanging fruit
for them to fix, but every other cache runs in seconds (7s for
Caffeine) so it is already unusable. Their response was that Ehcache v3
is not intended to be used in scenarios where LRU eviction might occur,
only as a safety net, so any eviction is considered user error.

Some nice simplifications due to language improvements:
- Replaced AutoValue with Records
- More concise instanceof casting
- More concise switch expressions

.github/actions/run-gradle/action.yml

@@ -79,6 +79,8 @@ runs:
       with:
         add-job-summary: never
         cache-read-only: false
+        cache-overwrite-existing: true
+        gradle-home-cache-cleanup: true
         gradle-home-cache-strict-match: true
         gradle-home-cache-includes: |
           caches

.github/workflows/spelling.yml

@@ -42,4 +42,4 @@ jobs:
         with:
           persist-credentials: false
       - name: Typos
-        uses: crate-ci/typos@11ca4583f2f3f74c7e7785c0ecb20fe2c99a4308 # v1.29.5
+        uses: crate-ci/typos@51f257b946f503b768e522781f56e9b7b5570d48 # v1.29.7

caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java

@@ -206,7 +206,7 @@ public void deschedule(Node<K, V> node) {
   @SuppressWarnings("Varifier")
   Node<K, V> findBucket(@Var long time) {
     long duration = Math.max(0L, time - nanos);
-    if (duration <= 0L) {
+    if (duration == 0L) {
       time = nanos;
     }
 

gradle/libs.versions.toml

@@ -1,6 +1,5 @@
 [versions]
 asm = "9.7.1"
-auto-value = "1.11.0"
 awaitility = "4.2.2"
 bcel = "6.10.0"
 bnd = "7.1.0"
@@ -40,7 +39,7 @@ hamcrest = "3.0"
 hazelcast = "5.5.0"
 httpclient = "4.5.14"
 idea = "1.1.10"
-jackrabbit = "1.74.0"
+jackrabbit = "1.76.0"
 jackson = "2.18.2"
 jacoco = "0.8.12"
 jakarta-inject = "2.0.1"
@@ -82,15 +81,15 @@ pmd = "7.10.0"
 protobuf = "4.29.3"
 slf4j = "2.0.16"
 slf4j-test = "3.0.1"
-snakeyaml = "2.3"
+snakeyaml = "2.4"
 sigstore = "1.2.0"
 sonarqube = "6.0.1.5171"
 spotbugs = "4.9.1"
 spotbugs-contrib = "7.6.9"
-spotbugs-plugin = "6.1.4"
+spotbugs-plugin = "6.1.5"
 stream = "2.9.8"
 tcache = "2.0.1"
-testng = "7.10.2"
+testng = "7.11.0"
 truth = "1.4.4"
 univocity-parsers = "2.9.1"
 versions = "0.52.0"
@@ -101,8 +100,6 @@ zstd = "1.5.6-10"
 
 [libraries]
 asm-bom = { module = "org.ow2.asm:asm-bom", version.ref = "asm" }
-auto-value-annotations = { module = "com.google.auto.value:auto-value-annotations", version.ref = "auto-value" }
-auto-value-processor = { module = "com.google.auto.value:auto-value", version.ref = "auto-value" }
 awaitility = { module = "org.awaitility:awaitility", version.ref = "awaitility" }
 bcel = { module = "org.apache.bcel:bcel", version.ref = "bcel" }
 bouncycastle-jdk18on = { module = "org.bouncycastle:bcprov-jdk18on", version.ref = "bouncycastle-jdk18on" }

gradle/plugins/src/main/kotlin/lifecycle/java-library.caffeine.gradle.kts

@@ -18,19 +18,16 @@ dependencies {
   annotationProcessor(platform(libs.kotlin.bom))
 }
 
-val javaVersion = JavaLanguageVersion.of(System.getenv("JAVA_VERSION")?.toIntOrNull() ?: 11)
-val javaVendor = System.getenv("JAVA_VENDOR")?.let { JvmVendorSpec.matching(it) }
-val javaRuntimeVersion = maxOf(javaVersion, JavaLanguageVersion.of(21))
 java.toolchain {
-  languageVersion = javaVersion
-  vendor = javaVendor
+  languageVersion = JavaLanguageVersion.of(System.getenv("JAVA_VERSION")?.toIntOrNull() ?: 11)
+  vendor = System.getenv("JAVA_VENDOR")?.let { JvmVendorSpec.matching(it) }
 }
+val javaRuntimeVersion: Provider<JavaLanguageVersion> =
+  java.toolchain.languageVersion.map { maxOf(it, JavaLanguageVersion.of(21)) }
 
 tasks.withType<JavaCompile>().configureEach {
-  inputs.property("javaVendor", javaVendor.toString())
-  sourceCompatibility = javaVersion.toString()
-  targetCompatibility = javaVersion.toString()
-  options.release = javaVersion.asInt()
+  inputs.property("javaVendor", java.toolchain.vendor.get().toString())
+  options.release = java.toolchain.languageVersion.get().asInt()
 
   javaCompiler = javaToolchains.compilerFor {
     // jdk 17+ is required by compiler plugins, e.g. error-prone
@@ -44,7 +41,7 @@ tasks.withType<JavaCompile>().configureEach {
     if (isCI()) {
       compilerArgs.add("-Werror")
     }
-    if (javaVersion.canCompileOrRun(21)) {
+    if (java.toolchain.languageVersion.get().canCompileOrRun(21)) {
       compilerArgs.add("-proc:full")
     }
     encoding = "UTF-8"
@@ -80,10 +77,10 @@ tasks.jar {
     properties.empty()
     bnd(mapOf(
       "Bundle-License" to "https://www.apache.org/licenses/LICENSE-2.0",
+      "Build-Jdk-Spec" to java.toolchain.languageVersion.get(),
       "Implementation-Title" to project.description,
       "Bundle-Description" to project.description,
       "Implementation-Version" to version,
-      "Build-Jdk-Spec" to javaVersion,
       "-noextraheaders" to true,
       "-reproducible" to true,
       "-snapshot" to "SNAPSHOT"))
@@ -96,14 +93,14 @@ tasks.withType<Javadoc>().configureEach {
     use()
     quiet()
     noTimestamp()
-    addStringOption("-release", javaVersion.toString())
+    addStringOption("-release", java.toolchain.languageVersion.get().toString())
     addStringOption("-link-modularity-mismatch", "info")
     links(
       "https://jspecify.dev/docs/api/",
       "https://errorprone.info/api/latest/",
       "https://lightbend.github.io/config/latest/api/",
-      "https://docs.oracle.com/en/java/javase/$javaVersion/docs/api/",
-      "https://guava.dev/releases/${libs.versions.guava.get()}/api/docs/")
+      "https://guava.dev/releases/${libs.versions.guava.get()}/api/docs/",
+      "https://docs.oracle.com/en/java/javase/${java.toolchain.languageVersion.get()}/docs/api/")
 
     if (project != project(":caffeine")) {
       linksOffline("https://static.javadoc.io/$group/caffeine/$version/",

simulator/build.gradle.kts

@@ -6,7 +6,6 @@ import net.ltgt.gradle.nullaway.nullaway
 
 plugins {
   id("application")
-  id("auto-value.caffeine")
   id("java-library.caffeine")
 }
 
@@ -47,6 +46,10 @@ application {
   mainClass = "com.github.benmanes.caffeine.cache.simulator.Simulator"
 }
 
+java.toolchain {
+  languageVersion = maxOf(languageVersion.get(), JavaLanguageVersion.of(21))
+}
+
 forbiddenApis {
   bundledSignatures.addAll(listOf("commons-io-unsafe-2.15.1", "jdk-deprecated",
     "jdk-internal", "jdk-non-portable", "jdk-reflection", "jdk-unsafe"))

simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/Synthetic.java

@@ -20,7 +20,6 @@
 
 import java.util.stream.LongStream;
 
-import com.github.benmanes.caffeine.cache.simulator.BasicSettings.SyntheticSettings.HotspotSettings;
 import com.github.benmanes.caffeine.cache.simulator.BasicSettings.TraceSettings;
 import com.github.benmanes.caffeine.cache.simulator.parser.TraceReader.KeyOnlyTraceReader;
 
@@ -46,32 +45,33 @@ private Synthetic() {}
   /** Returns a sequence of events based on the setting's distribution. */
   public static KeyOnlyTraceReader generate(TraceSettings settings) {
     int events = settings.synthetic().events();
-    switch (settings.synthetic().distribution().toLowerCase(US)) {
-      case "counter":
-        return counter(settings.synthetic().counter().start(), events);
-      case "repeating":
-        return repeating(settings.synthetic().repeating().items(), events);
-      case "uniform":
-        var uniform = settings.synthetic().uniform();
-        return uniform(uniform.lowerBound(), uniform.upperBound(), events);
-      case "exponential":
-        return exponential(settings.synthetic().exponential().mean(), events);
-      case "hotspot":
-        HotspotSettings hotspot = settings.synthetic().hotspot();
-        return Synthetic.hotspot(hotspot.lowerBound(), hotspot.upperBound(),
+    return switch (settings.synthetic().distribution().toLowerCase(US)) {
+      case "counter" ->
+        counter(settings.synthetic().counter().start(), events);
+      case "repeating" ->
+        repeating(settings.synthetic().repeating().items(), events);
+      case "uniform" ->
+        uniform(settings.synthetic().uniform().lowerBound(),
+            settings.synthetic().uniform().upperBound(), events);
+      case "exponential" ->
+        exponential(settings.synthetic().exponential().mean(), events);
+      case "hotspot" -> {
+        var hotspot = settings.synthetic().hotspot();
+        yield hotspot(hotspot.lowerBound(), hotspot.upperBound(),
             hotspot.hotOpnFraction(), hotspot.hotsetFraction(), events);
-      case "zipfian":
-        return zipfian(settings.synthetic().zipfian().items(),
+      }
+      case "zipfian" ->
+        zipfian(settings.synthetic().zipfian().items(),
             settings.synthetic().zipfian().constant(), events);
-      case "scrambled-zipfian":
-        return scrambledZipfian(settings.synthetic().zipfian().items(),
+      case "scrambled-zipfian" ->
+        scrambledZipfian(settings.synthetic().zipfian().items(),
             settings.synthetic().zipfian().constant(), events);
-      case "skewed-zipfian-latest":
-        return skewedZipfianLatest(settings.synthetic().zipfian().items(), events);
-      default:
+      case "skewed-zipfian-latest" ->
+        skewedZipfianLatest(settings.synthetic().zipfian().items(), events);
+      default ->
         throw new IllegalStateException("Unknown distribution: "
             + settings.synthetic().distribution());
-    }
+    };
   }
 
   /**

simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/admission/TinyLfu.java

@@ -86,22 +86,22 @@ public boolean admit(long candidateKey, long victimKey) {
   /** Returns the frequency histogram. */
   private static Frequency makeSketch(BasicSettings settings) {
     String type = settings.tinyLfu().sketch();
-    switch (type.toLowerCase(US)) {
-      case "count-min-4": {
+    return switch (type.toLowerCase(US)) {
+      case "count-min-4" -> {
         String reset = settings.tinyLfu().countMin4().reset();
-        switch (reset.toLowerCase(US)) {
-          case "climber": return new ClimberResetCountMin4(settings.config());
-          case "periodic": return new PeriodicResetCountMin4(settings.config());
-          case "indicator": return new IndicatorResetCountMin4(settings.config());
-          case "incremental": return new IncrementalResetCountMin4(settings.config());
-          default: throw new IllegalStateException("Unknown reset type: " + reset);
-        }
+        yield switch (reset.toLowerCase(US)) {
+          case "climber" -> new ClimberResetCountMin4(settings.config());
+          case "periodic" -> new PeriodicResetCountMin4(settings.config());
+          case "indicator" -> new IndicatorResetCountMin4(settings.config());
+          case "incremental" -> new IncrementalResetCountMin4(settings.config());
+          default -> throw new IllegalStateException("Unknown reset type: " + reset);
+        };
       }
-      case "tiny-table": return new TinyCacheAdapter(settings.config());
-      case "count-min-64": return new CountMin64TinyLfu(settings.config());
-      case "perfect-table": return new PerfectFrequency(settings.config());
-      case "random-table": return new RandomRemovalFrequencyTable(settings.config());
-      default: throw new IllegalStateException("Unknown sketch type: " + type);
-    }
+      case "tiny-table" -> new TinyCacheAdapter(settings.config());
+      case "count-min-64" -> new CountMin64TinyLfu(settings.config());
+      case "perfect-table" -> new PerfectFrequency(settings.config());
+      case "random-table" -> new RandomRemovalFrequencyTable(settings.config());
+      default -> throw new IllegalStateException("Unknown sketch type: " + type);
+    };
   }
 }

simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/parser/AbstractTraceReader.java

@@ -67,27 +67,27 @@ protected BufferedInputStream readFile() {
 
   @SuppressWarnings("PMD.CloseResource")
   protected BufferedInputStream readInput(InputStream input) {
-    @Var BufferedInputStream buffered = null;
+    @Var BufferedInputStream bufferedStream = null;
     try {
-      buffered = new BufferedInputStream(input, BUFFER_SIZE);
+      bufferedStream = new BufferedInputStream(input, BUFFER_SIZE);
       var extractors = List.<UnaryOperator<InputStream>>of(
           AbstractTraceReader::tryXz, AbstractTraceReader::tryCompressed, this::tryArchived);
       for (var extractor : extractors) {
-        buffered.mark(100);
-        InputStream next = extractor.apply(buffered);
+        bufferedStream.mark(100);
+        InputStream next = extractor.apply(bufferedStream);
         if (next == null) {
-          buffered.reset();
-        } else if (next instanceof BufferedInputStream) {
-          buffered = (BufferedInputStream) next;
+          bufferedStream.reset();
+        } else if (next instanceof BufferedInputStream buffered) {
+          bufferedStream = buffered;
         } else {
-          buffered = new BufferedInputStream(next, BUFFER_SIZE);
+          bufferedStream = new BufferedInputStream(next, BUFFER_SIZE);
         }
       }
-      return buffered;
+      return bufferedStream;
     } catch (Throwable t) {
       try {
-        if (buffered != null) {
-          buffered.close();
+        if (bufferedStream != null) {
+          bufferedStream.close();
         }
       } catch (IOException e) {
         t.addSuppressed(e);

simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/parser/Rewriter.java

@@ -22,12 +22,13 @@
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
 
 import com.google.common.base.CaseFormat;
 import com.google.common.base.Stopwatch;
-import com.google.common.collect.Lists;
 import com.google.errorprone.annotations.Var;
 
 import picocli.CommandLine;
@@ -91,7 +92,7 @@ public void run() {
   }
 
   private static String[] argumentsWithDefaults(String[] args) {
-    var params = Lists.newArrayList(args);
+    var params = new ArrayList<>(Arrays.asList(args));
     if (!params.contains("--inputFormat")) {
       @Var boolean found = false;
       @Var boolean defaultFormat = true;

simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/parser/wikipedia/WikipediaTraceReader.java

@@ -15,6 +15,8 @@
  */
 package com.github.benmanes.caffeine.cache.simulator.parser.wikipedia;
 
+import static java.util.Objects.requireNonNull;
+
 import java.util.Objects;
 import java.util.stream.LongStream;
 
@@ -23,7 +25,6 @@
 
 import com.github.benmanes.caffeine.cache.simulator.parser.TextTraceReader;
 import com.github.benmanes.caffeine.cache.simulator.parser.TraceReader.KeyOnlyTraceReader;
-import com.google.auto.value.AutoValue;
 import com.google.common.collect.ImmutableList;
 import com.google.common.hash.Hashing;
 import com.google.errorprone.annotations.Var;
@@ -42,8 +43,8 @@ public final class WikipediaTraceReader extends TextTraceReader implements KeyOn
       "wiki/Special:Search", "w/query.php", "wiki/Talk:", "wiki/Special:AutoLogin",
       "Special:UserLogin", "w/api.php", "error:");
   private static final ImmutableList<Replacement> REPLACEMENTS = ImmutableList.of(
-      Replacement.of("%2F", "/"), Replacement.of("%20", " "),
-      Replacement.of("&amp;", "&"), Replacement.of("%3A", ":"));
+      new Replacement("%2F", "/"), new Replacement("%20", " "),
+      new Replacement("&amp;", "&"), new Replacement("%3A", ":"));
 
   public WikipediaTraceReader(String filePath) {
     super(filePath);
@@ -133,13 +134,10 @@ public static boolean isAllowed(String path) {
     return true;
   }
 
-  @AutoValue
-  abstract static class Replacement {
-    abstract String search();
-    abstract String replace();
-
-    static Replacement of(String search, String replace) {
-      return new AutoValue_WikipediaTraceReader_Replacement(search, replace);
+  record Replacement(String search, String replace) {
+    Replacement {
+      requireNonNull(search);
+      requireNonNull(replace);
     }
   }
 }