Avoid auto-boxing for gauge metrics. (#1526)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

ethereum/eth/src/main/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/WorldStateDownloader.java

@@ -24,7 +24,7 @@ import java.time.Clock;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
-import java.util.function.Supplier;
+import java.util.function.IntSupplier;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -78,7 +78,7 @@ public class WorldStateDownloader {
         downloadStateValue(WorldDownloadState::getOutstandingTaskCount));
   }
 
-  private Supplier<Integer> downloadStateValue(final Function<WorldDownloadState, Integer> getter) {
+  private IntSupplier downloadStateValue(final Function<WorldDownloadState, Integer> getter) {
     return () -> {
       final WorldDownloadState state = this.downloadState.get();
       return state != null ? getter.apply(state) : 0;

ethereum/p2p/src/main/java/tech/pegasys/pantheon/ethereum/p2p/discovery/VertxPeerDiscoveryAgent.java

@@ -32,6 +32,7 @@ import java.net.InetSocketAddress;
 import java.net.SocketException;
 import java.util.OptionalInt;
 import java.util.concurrent.CompletableFuture;
+import java.util.function.IntSupplier;
 import java.util.function.Supplier;
 import java.util.stream.StreamSupport;
 
@@ -69,7 +70,7 @@ public class VertxPeerDiscoveryAgent extends PeerDiscoveryAgent {
         pendingTaskCounter(vertx.nettyEventLoopGroup()));
   }
 
-  private Supplier<Integer> pendingTaskCounter(final EventLoopGroup eventLoopGroup) {
+  private IntSupplier pendingTaskCounter(final EventLoopGroup eventLoopGroup) {
     return () ->
         StreamSupport.stream(eventLoopGroup.spliterator(), false)
             .filter(eventExecutor -> eventExecutor instanceof SingleThreadEventExecutor)

ethereum/p2p/src/main/java/tech/pegasys/pantheon/ethereum/p2p/network/DefaultP2PNetwork.java

@@ -69,7 +69,7 @@ import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
-import java.util.function.Supplier;
+import java.util.function.IntSupplier;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
@@ -249,7 +249,7 @@ public class DefaultP2PNetwork implements P2PNetwork {
     return new Builder();
   }
 
-  private Supplier<Integer> pendingTaskCounter(final EventLoopGroup eventLoopGroup) {
+  private IntSupplier pendingTaskCounter(final EventLoopGroup eventLoopGroup) {
     return () ->
         StreamSupport.stream(eventLoopGroup.spliterator(), false)
             .filter(eventExecutor -> eventExecutor instanceof SingleThreadEventExecutor)

ethereum/permissioning/src/test/java/tech/pegasys/pantheon/ethereum/permissioning/node/provider/SyncStatusNodePermissioningProviderTest.java

@@ -29,7 +29,7 @@ import tech.pegasys.pantheon.util.enode.EnodeURL;
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.function.Supplier;
+import java.util.function.IntSupplier;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -44,7 +44,7 @@ public class SyncStatusNodePermissioningProviderTest {
   @Mock private Counter checkCounter;
   @Mock private Counter checkPermittedCounter;
   @Mock private Counter checkUnpermittedCounter;
-  private Supplier<Integer> syncGauge;
+  private IntSupplier syncGauge;
 
   private static final EnodeURL bootnode =
       EnodeURL.fromString(
@@ -70,8 +70,8 @@ public class SyncStatusNodePermissioningProviderTest {
     bootnodes.add(bootnode);
 
     @SuppressWarnings("unchecked")
-    final ArgumentCaptor<Supplier<Integer>> syncGaugeCallbackCaptor =
+    final ArgumentCaptor<IntSupplier> syncGaugeCallbackCaptor =
-        ArgumentCaptor.forClass(Supplier.class);
+        ArgumentCaptor.forClass(IntSupplier.class);
 
     when(metricsSystem.createCounter(
             MetricCategory.PERMISSIONING,
@@ -106,7 +106,7 @@ public class SyncStatusNodePermissioningProviderTest {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 2));
 
     assertThat(provider.hasReachedSync()).isFalse();
-    assertThat(syncGauge.get()).isEqualTo(0);
+    assertThat(syncGauge.getAsInt()).isEqualTo(0);
   }
 
   @Test
@@ -114,29 +114,29 @@ public class SyncStatusNodePermissioningProviderTest {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 1));
 
     assertThat(provider.hasReachedSync()).isTrue();
-    assertThat(syncGauge.get()).isEqualTo(1);
+    assertThat(syncGauge.getAsInt()).isEqualTo(1);
   }
 
   @Test
   public void whenInSyncChangesFromTrueToFalseHasReachedSyncShouldReturnTrue() {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 2));
     assertThat(provider.hasReachedSync()).isFalse();
-    assertThat(syncGauge.get()).isEqualTo(0);
+    assertThat(syncGauge.getAsInt()).isEqualTo(0);
 
     syncStatusListener.onSyncStatus(new SyncStatus(0, 2, 1));
     assertThat(provider.hasReachedSync()).isTrue();
-    assertThat(syncGauge.get()).isEqualTo(1);
+    assertThat(syncGauge.getAsInt()).isEqualTo(1);
 
     syncStatusListener.onSyncStatus(new SyncStatus(0, 2, 3));
     assertThat(provider.hasReachedSync()).isTrue();
-    assertThat(syncGauge.get()).isEqualTo(1);
+    assertThat(syncGauge.getAsInt()).isEqualTo(1);
   }
 
   @Test
   public void whenHasNotSyncedNonBootnodeShouldNotBePermitted() {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 2));
     assertThat(provider.hasReachedSync()).isFalse();
-    assertThat(syncGauge.get()).isEqualTo(0);
+    assertThat(syncGauge.getAsInt()).isEqualTo(0);
 
     boolean isPermitted = provider.isPermitted(enode1, enode2);
 
@@ -150,7 +150,7 @@ public class SyncStatusNodePermissioningProviderTest {
   public void whenHasNotSyncedBootnodeIncomingConnectionShouldNotBePermitted() {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 2));
     assertThat(provider.hasReachedSync()).isFalse();
-    assertThat(syncGauge.get()).isEqualTo(0);
+    assertThat(syncGauge.getAsInt()).isEqualTo(0);
 
     boolean isPermitted = provider.isPermitted(bootnode, enode1);
 
@@ -164,7 +164,7 @@ public class SyncStatusNodePermissioningProviderTest {
   public void whenHasNotSyncedBootnodeOutgoingConnectionShouldBePermitted() {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 2));
     assertThat(provider.hasReachedSync()).isFalse();
-    assertThat(syncGauge.get()).isEqualTo(0);
+    assertThat(syncGauge.getAsInt()).isEqualTo(0);
 
     boolean isPermitted = provider.isPermitted(enode1, bootnode);
 
@@ -178,7 +178,7 @@ public class SyncStatusNodePermissioningProviderTest {
   public void whenHasSyncedIsPermittedShouldReturnTrue() {
     syncStatusListener.onSyncStatus(new SyncStatus(0, 1, 1));
     assertThat(provider.hasReachedSync()).isTrue();
-    assertThat(syncGauge.get()).isEqualTo(1);
+    assertThat(syncGauge.getAsInt()).isEqualTo(1);
 
     boolean isPermitted = provider.isPermitted(enode1, enode2);
 

metrics/core/src/main/java/tech/pegasys/pantheon/metrics/MetricsSystem.java

@@ -12,7 +12,9 @@
  */
 package tech.pegasys.pantheon.metrics;
 
-import java.util.function.Supplier;
+import java.util.function.DoubleSupplier;
+import java.util.function.IntSupplier;
+import java.util.function.LongSupplier;
 import java.util.stream.Stream;
 
 public interface MetricsSystem {
@@ -33,23 +35,22 @@ public interface MetricsSystem {
   LabelledMetric<OperationTimer> createLabelledTimer(
       MetricCategory category, String name, String help, String... labelNames);
 
-  void createGauge(
+  void createGauge(MetricCategory category, String name, String help, DoubleSupplier valueSupplier);
-      MetricCategory category, String name, String help, Supplier<Double> valueSupplier);
 
   default void createIntegerGauge(
       final MetricCategory category,
       final String name,
       final String help,
-      final Supplier<Integer> valueSupplier) {
+      final IntSupplier valueSupplier) {
-    createGauge(category, name, help, () -> (double) valueSupplier.get());
+    createGauge(category, name, help, () -> (double) valueSupplier.getAsInt());
   }
 
   default void createLongGauge(
       final MetricCategory category,
       final String name,
       final String help,
-      final Supplier<Long> valueSupplier) {
+      final LongSupplier valueSupplier) {
-    createGauge(category, name, help, () -> (double) valueSupplier.get());
+    createGauge(category, name, help, () -> (double) valueSupplier.getAsLong());
   }
 
   Stream<Observation> streamObservations(MetricCategory category);

metrics/core/src/main/java/tech/pegasys/pantheon/metrics/noop/NoOpMetricsSystem.java

@@ -20,7 +20,7 @@ import tech.pegasys.pantheon.metrics.Observation;
 import tech.pegasys.pantheon.metrics.OperationTimer;
 import tech.pegasys.pantheon.metrics.OperationTimer.TimingContext;
 
-import java.util.function.Supplier;
+import java.util.function.DoubleSupplier;
 import java.util.stream.Stream;
 
 import com.google.common.base.Preconditions;
@@ -85,7 +85,7 @@ public class NoOpMetricsSystem implements MetricsSystem {
       final MetricCategory category,
       final String name,
       final String help,
-      final Supplier<Double> valueSupplier) {}
+      final DoubleSupplier valueSupplier) {}
 
   @Override
   public Stream<Observation> streamObservations(final MetricCategory category) {

metrics/core/src/main/java/tech/pegasys/pantheon/metrics/prometheus/CurrentValueCollector.java

@@ -16,7 +16,7 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 
 import java.util.List;
-import java.util.function.Supplier;
+import java.util.function.DoubleSupplier;
 
 import io.prometheus.client.Collector;
 import io.prometheus.client.Collector.MetricFamilySamples.Sample;
@@ -25,10 +25,10 @@ class CurrentValueCollector extends Collector {
 
   private final String metricName;
   private final String help;
-  private final Supplier<Double> valueSupplier;
+  private final DoubleSupplier valueSupplier;
 
   public CurrentValueCollector(
-      final String metricName, final String help, final Supplier<Double> valueSupplier) {
+      final String metricName, final String help, final DoubleSupplier valueSupplier) {
     this.metricName = metricName;
     this.help = help;
     this.valueSupplier = valueSupplier;
@@ -36,7 +36,8 @@ class CurrentValueCollector extends Collector {
 
   @Override
   public List<MetricFamilySamples> collect() {
-    final Sample sample = new Sample(metricName, emptyList(), emptyList(), valueSupplier.get());
+    final Sample sample =
+        new Sample(metricName, emptyList(), emptyList(), valueSupplier.getAsDouble());
     return singletonList(
         new MetricFamilySamples(metricName, Type.GAUGE, help, singletonList(sample)));
   }

metrics/core/src/main/java/tech/pegasys/pantheon/metrics/prometheus/PrometheusMetricsSystem.java

@@ -29,7 +29,7 @@ import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Supplier;
+import java.util.function.DoubleSupplier;
 import java.util.stream.Stream;
 
 import io.prometheus.client.Collector;
@@ -138,7 +138,7 @@ public class PrometheusMetricsSystem implements MetricsSystem {
       final MetricCategory category,
       final String name,
       final String help,
-      final Supplier<Double> valueSupplier) {
+      final DoubleSupplier valueSupplier) {
     final String metricName = convertToPrometheusName(category, name);
     if (enabledCategories.contains(category)) {
       final Collector collector = new CurrentValueCollector(metricName, help, valueSupplier);