Improved memory allocations in meter cache (#42)

* Improved memory allocations in meter cache by avoiding frequent linkToTargetMethod allocations by lambda executions.

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.12.0] - 2023-10-03
+
+### Changed
+
+* Improved memory allocations in meter cache by avoiding frequent linkToTargetMethod allocations by lambda executions.
+
 ## [1.11.1] - 2023-08-17
 
 ### Fixed

gradle.properties

@@ -1 +1 @@
-version=1.11.1
+version=1.12.0

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.3-bin.zip
 networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -83,10 +83,8 @@ done
 # This is normally unused
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -133,10 +131,13 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
@@ -197,6 +198,10 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
 # Collect all arguments for the java command;
 #   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
 #     shell script including quotes and variable substitutions, so put them in

tw-base-utils/src/main/java/com/transferwise/common/baseutils/meters/cache/IMeterCache.java

@@ -23,20 +23,60 @@ public interface IMeterCache {
    * Allows to also cache Objects, which contain multiple meters.
    *
    * <p>Even when those can be cached by other means, it is convenient, that meterCache.clear() will also clear those.
+   *
+   * @deprecated in a favor of {@link #metersContainer(String, TagsSet, MeterContainerCreator)}.
    */
+  @Deprecated(forRemoval = true)
   <T> T metersContainer(String name, TagsSet tags, Supplier<T> collectionCreator);
 
+  <T> T metersContainer(String name, TagsSet tags, MeterContainerCreator<T> meterContainerCreator);
+
   DistributionSummary summary(String name, TagsSet tags);
 
+  /**
+   * Returns a DistributionSummary.
+   *
+   * @deprecated in a favor of {@link #summary(String, TagsSet, MeterCreator)} .
+   */
+  @Deprecated(forRemoval = true)
   DistributionSummary summary(String name, TagsSet tags, Supplier<DistributionSummary> supplier);
 
+  DistributionSummary summary(String name, TagsSet tags, MeterCreator<DistributionSummary> meterCreator);
+
   Timer timer(String name, TagsSet tags);
 
+  /**
+   * Returns a counter.
+   *
+   * @deprecated in a favor of {@link #timer(String, TagsSet, MeterCreator)} .
+   */
+  @Deprecated(forRemoval = true)
   Timer timer(String name, TagsSet tags, Supplier<Timer> supplier);
 
+  Timer timer(String name, TagsSet tags, MeterCreator<Timer> meterCreator);
+
+
   Counter counter(String name, TagsSet tags);
 
+  /**
+   * Returns a counter.
+   *
+   * @deprecated in a favor of {@link #counter(String, TagsSet, MeterCreator)} .
+   */
+  @Deprecated(forRemoval = true)
   Counter counter(String name, TagsSet tags, Supplier<Counter> supplier);
 
+  Counter counter(String name, TagsSet tags, MeterCreator<Counter> meterCreator);
+
   MeterRegistry getMeterRegistry();
+
+  interface MeterCreator<M extends Meter> {
+
+    M create(String name, TagsSet tags);
+  }
+
+  interface MeterContainerCreator<T> {
+
+    T create(String name, TagsSet tags);
+  }
 }

tw-base-utils/src/main/java/com/transferwise/common/baseutils/meters/cache/MeterCache.java

@@ -7,19 +7,28 @@
 import io.micrometer.core.instrument.Timer;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Function;
 import java.util.function.Supplier;
 import org.apache.commons.lang3.tuple.Pair;
 
 public class MeterCache implements IMeterCache {
 
-  private Map<Pair<String, TagsSet>, Meter> metersMap = new ConcurrentHashMap<>();
+  private final Map<Pair<String, TagsSet>, Meter> metersMap = new ConcurrentHashMap<>();
 
-  private Map<Pair<String, TagsSet>, Object> metersContainersMap = new ConcurrentHashMap<>();
+  private final Map<Pair<String, TagsSet>, Object> metersContainersMap = new ConcurrentHashMap<>();
 
-  private MeterRegistry meterRegistry;
+  /*
+     Following 2 are meant to avoid creating linkToTargetMethod instances on every lambda invocation.
+   */
+  private Function<Pair<String, TagsSet>, Counter> counterCreaterFunction;
+  private Function<Pair<String, TagsSet>, Timer> timerCreaterFunction;
+
+  private final MeterRegistry meterRegistry;
 
   public MeterCache(MeterRegistry meterRegistry) {
     this.meterRegistry = meterRegistry;
+    this.counterCreaterFunction = k -> meterRegistry.counter(k.getKey(), k.getValue().getMicrometerTags());
+    this.timerCreaterFunction = k -> meterRegistry.timer(k.getKey(), k.getValue().getMicrometerTags());
   }
 
   @Override
@@ -49,41 +58,67 @@ public Object removeMetersContainer(String name, TagsSet tags) {
   }
 
   @Override
+  @Deprecated(forRemoval = true)
   @SuppressWarnings("unchecked")
   public <T> T metersContainer(String name, TagsSet tags, Supplier<T> containerCreator) {
     return (T) metersContainersMap.computeIfAbsent(Pair.of(name, tags), k -> containerCreator.get());
   }
 
+  @Override
+  @SuppressWarnings("unchecked")
+  public <T> T metersContainer(String name, TagsSet tags, MeterContainerCreator<T> meterContainerCreator) {
+    return (T) metersContainersMap.computeIfAbsent(Pair.of(name, tags), k -> meterContainerCreator.create(k.getKey(), k.getValue()));
+  }
+
   @Override
   public DistributionSummary summary(String name, TagsSet tags) {
-    return (DistributionSummary) metersMap.computeIfAbsent(Pair.of(name, tags), k -> meterRegistry.summary(name, tags.getMicrometerTags()));
+    return (DistributionSummary) metersMap.computeIfAbsent(Pair.of(name, tags),
+        k -> meterRegistry.summary(k.getKey(), k.getValue().getMicrometerTags()));
   }
 
   @Override
+  @Deprecated(forRemoval = true)
   public DistributionSummary summary(String name, TagsSet tags, Supplier<DistributionSummary> metricCreator) {
     return (DistributionSummary) metersMap.computeIfAbsent(Pair.of(name, tags), k -> metricCreator.get());
   }
 
+  @Override
+  public DistributionSummary summary(String name, TagsSet tags, MeterCreator<DistributionSummary> meterCreator) {
+    return (DistributionSummary) metersMap.computeIfAbsent(Pair.of(name, tags), k -> meterCreator.create(k.getKey(), k.getValue()));
+  }
+
   @Override
   public Timer timer(String name, TagsSet tags) {
-    return (Timer) metersMap.computeIfAbsent(Pair.of(name, tags), k -> meterRegistry.timer(name, tags.getMicrometerTags()));
+    return (Timer) metersMap.computeIfAbsent(Pair.of(name, tags), timerCreaterFunction);
   }
 
   @Override
+  @Deprecated(forRemoval = true)
   public Timer timer(String name, TagsSet tags, Supplier<Timer> metricCreator) {
     return (Timer) metersMap.computeIfAbsent(Pair.of(name, tags), k -> metricCreator.get());
   }
 
+  @Override
+  public Timer timer(String name, TagsSet tags, MeterCreator<Timer> meterCreator) {
+    return (Timer) metersMap.computeIfAbsent(Pair.of(name, tags), k -> meterCreator.create(k.getKey(), k.getValue()));
+  }
+
   @Override
   public Counter counter(String name, TagsSet tagsSet) {
-    return (Counter) metersMap.computeIfAbsent(Pair.of(name, tagsSet), k -> meterRegistry.counter(name, tagsSet.getMicrometerTags()));
+    return (Counter) metersMap.computeIfAbsent(Pair.of(name, tagsSet), counterCreaterFunction);
   }
 
   @Override
+  @Deprecated(forRemoval = true)
   public Counter counter(String name, TagsSet tags, Supplier<Counter> metricCreator) {
     return (Counter) metersMap.computeIfAbsent(Pair.of(name, tags), k -> metricCreator.get());
   }
 
+  @Override
+  public Counter counter(String name, TagsSet tags, MeterCreator<Counter> meterCreator) {
+    return (Counter) metersMap.computeIfAbsent(Pair.of(name, tags), k -> meterCreator.create(k.getKey(), k.getValue()));
+  }
+
   @Override
   public MeterRegistry getMeterRegistry() {
     return meterRegistry;