MetricsTracker refactor.

src/main/java/com/zaxxer/hikari/metrics/IMetricsTracker.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 Brett Wooldridge
+ *
+ * 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 com.zaxxer.hikari.metrics;
+
+/**
+ * @author Brett Wooldridge
+ */
+public interface IMetricsTracker extends AutoCloseable
+{
+   default void recordConnectionCreatedMillis(long connectionCreatedMillis) {}
+
+   default void recordConnectionAcquiredNanos(final long elapsedAcquiredNanos) {}
+
+   default void recordConnectionUsageMillis(final long elapsedBorrowedMillis) {}
+
+   default void recordConnectionTimeout() {}
+
+   @Override
+   default void close() {}
+}

src/main/java/com/zaxxer/hikari/metrics/MetricsTracker.java

@@ -21,30 +21,7 @@ package com.zaxxer.hikari.metrics;
  *
  * @author Brett Wooldridge
  */
-public class MetricsTracker implements AutoCloseable
+@Deprecated
+public class MetricsTracker implements IMetricsTracker
 {
-   public MetricsTracker()
-   {
-   }
-
-   public void recordConnectionAcquiredNanos(final long elapsedAcquiredNanos)
-   {
-   }
-
-   public void recordConnectionUsageMillis(final long elapsedBorrowedMillis)
-   {
-   }
-
-   public void recordConnectionTimeout()
-   {
-   }
-
-   public void recordConnectionCreatedMillis(long connectionCreatedMillis)
-   {
-   }
-
-   @Override
-   public void close()
-   {
-   }
 }

src/main/java/com/zaxxer/hikari/metrics/MetricsTrackerFactory.java

@@ -19,11 +19,11 @@ package com.zaxxer.hikari.metrics;
 public interface MetricsTrackerFactory
 {
    /**
-    * Create an instance of a MetricsTracker.
+    * Create an instance of an IMetricsTracker.
     *
     * @param poolName the name of the pool
     * @param poolStats a PoolStats instance to use
-    * @return a MetricsTracker implementation instance
+    * @return a IMetricsTracker implementation instance
     */
-   MetricsTracker create(String poolName, PoolStats poolStats);
+   IMetricsTracker create(String poolName, PoolStats poolStats);
 }

src/main/java/com/zaxxer/hikari/metrics/dropwizard/CodaHaleMetricsTracker.java

@@ -23,10 +23,10 @@ import com.codahale.metrics.Histogram;
 import com.codahale.metrics.Meter;
 import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.Timer;
-import com.zaxxer.hikari.metrics.MetricsTracker;
+import com.zaxxer.hikari.metrics.IMetricsTracker;
 import com.zaxxer.hikari.metrics.PoolStats;
 
-public final class CodaHaleMetricsTracker extends MetricsTracker
+public final class CodaHaleMetricsTracker implements IMetricsTracker
 {
    private final String poolName;
    private final Timer connectionObtainTimer;

src/main/java/com/zaxxer/hikari/metrics/dropwizard/CodahaleMetricsTrackerFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013,2014 Brett Wooldridge
+ * Copyright (C) 2013 Brett Wooldridge
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,7 @@
 package com.zaxxer.hikari.metrics.dropwizard;
 
 import com.codahale.metrics.MetricRegistry;
-import com.zaxxer.hikari.metrics.MetricsTracker;
+import com.zaxxer.hikari.metrics.IMetricsTracker;
 import com.zaxxer.hikari.metrics.MetricsTrackerFactory;
 import com.zaxxer.hikari.metrics.PoolStats;
 
@@ -36,7 +36,7 @@ public final class CodahaleMetricsTrackerFactory implements MetricsTrackerFactor
    }
 
    @Override
-   public MetricsTracker create(String poolName, PoolStats poolStats)
+   public IMetricsTracker create(String poolName, PoolStats poolStats)
    {
       return new CodaHaleMetricsTracker(poolName, poolStats, registry);
    }

src/main/java/com/zaxxer/hikari/metrics/prometheus/PrometheusMetricsTracker.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013, 2014 Brett Wooldridge
+ * Copyright (C) 2013 Brett Wooldridge
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,14 +16,14 @@
 
 package com.zaxxer.hikari.metrics.prometheus;
 
-import com.zaxxer.hikari.metrics.MetricsTracker;
+import com.zaxxer.hikari.metrics.IMetricsTracker;
 
 import io.prometheus.client.Collector;
 import io.prometheus.client.CollectorRegistry;
 import io.prometheus.client.Counter;
 import io.prometheus.client.Summary;
 
-class PrometheusMetricsTracker extends MetricsTracker
+class PrometheusMetricsTracker implements IMetricsTracker
 {
    private final Counter.Child connectionTimeoutCounter;
    private final Summary.Child elapsedAcquiredSummary;

src/main/java/com/zaxxer/hikari/metrics/prometheus/PrometheusMetricsTrackerFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013, 2014 Brett Wooldridge
+ * Copyright (C) 2016 Brett Wooldridge
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 
 package com.zaxxer.hikari.metrics.prometheus;
 
-import com.zaxxer.hikari.metrics.MetricsTracker;
+import com.zaxxer.hikari.metrics.IMetricsTracker;
 import com.zaxxer.hikari.metrics.MetricsTrackerFactory;
 import com.zaxxer.hikari.metrics.PoolStats;
 
@@ -28,9 +28,11 @@ import io.prometheus.client.Collector;
  * config.setMetricsTrackerFactory(new PrometheusMetricsTrackerFactory());
  * }</pre>
  */
-public class PrometheusMetricsTrackerFactory implements MetricsTrackerFactory {
+public class PrometheusMetricsTrackerFactory implements MetricsTrackerFactory
+{
    @Override
-   public MetricsTracker create(String poolName, PoolStats poolStats) {
+   public IMetricsTracker create(String poolName, PoolStats poolStats)
+   {
       Collector collector = new HikariCPCollector(poolName, poolStats).register();
       return new PrometheusMetricsTracker(poolName, collector);
    }

src/main/java/com/zaxxer/hikari/pool/PoolBase.java

@@ -16,15 +16,6 @@
 
 package com.zaxxer.hikari.pool;
 
-import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_AUTOCOMMIT;
-import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_CATALOG;
-import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_ISOLATION;
-import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_NETTIMEOUT;
-import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_READONLY;
-import static com.zaxxer.hikari.util.ClockSource.currentTime;
-import static com.zaxxer.hikari.util.ClockSource.elapsedMillis;
-import static com.zaxxer.hikari.util.ClockSource.elapsedNanos;
-import static com.zaxxer.hikari.util.UtilityElf.createInstance;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
 
@@ -48,12 +39,22 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import com.zaxxer.hikari.HikariConfig;
-import com.zaxxer.hikari.metrics.MetricsTracker;
+import com.zaxxer.hikari.metrics.IMetricsTracker;
 import com.zaxxer.hikari.util.DriverDataSource;
 import com.zaxxer.hikari.util.PropertyElf;
 import com.zaxxer.hikari.util.UtilityElf;
 import com.zaxxer.hikari.util.UtilityElf.DefaultThreadFactory;
 
+import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_AUTOCOMMIT;
+import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_CATALOG;
+import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_ISOLATION;
+import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_NETTIMEOUT;
+import static com.zaxxer.hikari.pool.ProxyConnection.DIRTY_BIT_READONLY;
+import static com.zaxxer.hikari.util.ClockSource.currentTime;
+import static com.zaxxer.hikari.util.ClockSource.elapsedMillis;
+import static com.zaxxer.hikari.util.ClockSource.elapsedNanos;
+import static com.zaxxer.hikari.util.UtilityElf.createInstance;
+
 abstract class PoolBase
 {
    private final Logger LOGGER = LoggerFactory.getLogger(PoolBase.class);
@@ -62,7 +63,7 @@ abstract class PoolBase
    protected final String poolName;
    protected long connectionTimeout;
    protected long validationTimeout;
-   protected MetricsTrackerDelegate metricsTracker;
+   protected IMetricsTrackerDelegate metricsTracker;
 
    private static final String[] RESET_STATES = {"readOnly", "autoCommit", "isolation", "catalog", "netTimeout"};
    private static final int UNINITIALIZED = -1;
@@ -639,91 +640,69 @@ abstract class PoolBase
       }
    }
 
+   static interface IMetricsTrackerDelegate extends AutoCloseable
+   {
+      default void recordConnectionUsage(PoolEntry poolEntry) {}
+
+      default void recordConnectionCreated(long connectionCreatedMillis) {}
+
+      default void recordBorrowStats(final PoolEntry poolEntry, final long startTime) {}
+
+      default void recordConnectionTimeout() {}
+
+      @Override
+      default void close() {}
+   }
+
    /**
     * A class that delegates to a MetricsTracker implementation.  The use of a delegate
     * allows us to use the NopMetricsTrackerDelegate when metrics are disabled, which in
     * turn allows the JIT to completely optimize away to callsites to record metrics.
     */
-   static class MetricsTrackerDelegate implements AutoCloseable
+   static class MetricsTrackerDelegate implements IMetricsTrackerDelegate
    {
-      final MetricsTracker tracker;
-
-      protected MetricsTrackerDelegate()
-      {
-         this.tracker = null;
-      }
+      final IMetricsTracker tracker;
 
-      MetricsTrackerDelegate(MetricsTracker tracker)
+      MetricsTrackerDelegate(IMetricsTracker tracker)
       {
          this.tracker = tracker;
       }
 
       @Override
-      public void close()
-      {
-         tracker.close();
-      }
-
-      void recordConnectionUsage(final PoolEntry poolEntry)
+      public void recordConnectionUsage(final PoolEntry poolEntry)
       {
          tracker.recordConnectionUsageMillis(poolEntry.getMillisSinceBorrowed());
       }
 
-      void recordConnectionCreated(long connectionCreatedMillis)
+      @Override
+      public void recordConnectionCreated(long connectionCreatedMillis)
       {
          tracker.recordConnectionCreatedMillis(connectionCreatedMillis);
       }
 
-      /**
-       * @param poolEntry
-       * @param now
-       */
-      void recordBorrowStats(final PoolEntry poolEntry, final long startTime)
+      @Override
+      public void recordBorrowStats(final PoolEntry poolEntry, final long startTime)
       {
          final long now = currentTime();
          poolEntry.lastBorrowed = now;
          tracker.recordConnectionAcquiredNanos(elapsedNanos(startTime, now));
       }
 
-      void recordConnectionTimeout() {
-         tracker.recordConnectionTimeout();
-      }
-   }
-
-   /**
-    * A no-op implementation of the MetricsTrackerDelegate that is used when metrics capture is
-    * disabled.
-    */
-   static final class NopMetricsTrackerDelegate extends MetricsTrackerDelegate
-   {
       @Override
-      void recordConnectionUsage(final PoolEntry poolEntry)
-      {
-         // no-op
+      public void recordConnectionTimeout() {
+         tracker.recordConnectionTimeout();
       }
 
       @Override
       public void close()
       {
-         // no-op
-      }
-
-      @Override
-      void recordBorrowStats(final PoolEntry poolEntry, final long startTime)
-      {
-         // no-op
-      }
-
-      @Override
-      void recordConnectionTimeout()
-      {
-         // no-op
-      }
-
-      @Override
-      void recordConnectionCreated(long connectionCreatedMillis)
-      {
-         // no-op
+         tracker.close();
       }
    }
+
+   /**
+    * A no-op implementation of the IMetricsTrackerDelegate that is used when metrics capture is
+    * disabled.
+    */
+   static final class NopMetricsTrackerDelegate implements IMetricsTrackerDelegate {}
 }