HHH-18513 fix wrong prePartialFlush calculation in Session Metrics log

hibernate-core/src/main/java/org/hibernate/engine/internal/StatisticalLoggingSessionEventListener.java

@@ -248,10 +248,10 @@ public class StatisticalLoggingSessionEventListener extends BaseSessionEventList
 
 	@Override
 	public void prePartialFlushEnd() {
-		assert prePartialFlushStart > 0 : "Unexpected call to partialFlushEnd; expecting partialFlushStart";
+		assert prePartialFlushStart > 0 : "Unexpected call to prePartialFlushEnd; expecting prePartialFlushStart";
 
 		prePartialFlushCount++;
-		prePartialFlushTime += ( System.nanoTime() - partialFlushStart );
+		prePartialFlushTime += ( System.nanoTime() - prePartialFlushStart );
 		prePartialFlushStart = -1;
 	}
 

hibernate-core/src/test/java/org/hibernate/engine/internal/StatisticalLoggingSessionEventListenerTest.java

@@ -0,0 +1,217 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.engine.internal;
+
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.hibernate.cfg.AvailableSettings;
+import org.hibernate.internal.CoreMessageLogger;
+
+import org.hibernate.testing.logger.LoggerInspectionRule;
+import org.hibernate.testing.logger.Triggerable;
+import org.hibernate.testing.orm.domain.gambit.BasicEntity;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.Jira;
+import org.hibernate.testing.orm.junit.ServiceRegistry;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.hibernate.testing.orm.junit.Setting;
+import org.junit.Rule;
+import org.junit.jupiter.api.Test;
+
+import org.jboss.logging.Logger;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * @author Christian Bürgi
+ */
+@DomainModel(annotatedClasses = {
+		BasicEntity.class
+})
+@SessionFactory(generateStatistics = true)
+@ServiceRegistry(settings = {
+		@Setting(name = AvailableSettings.STATEMENT_BATCH_SIZE, value = "10"),
+		@Setting(name = AvailableSettings.ORDER_INSERTS, value = "true"),
+		@Setting(name = AvailableSettings.USE_QUERY_CACHE, value = "true"),
+		@Setting(name = AvailableSettings.USE_SECOND_LEVEL_CACHE, value = "true")
+})
+@Jira("https://hibernate.atlassian.net/browse/HHH-18513")
+public class StatisticalLoggingSessionEventListenerTest {
+
+	@Rule
+	public LoggerInspectionRule logInspection = new LoggerInspectionRule(
+			Logger.getMessageLogger(
+					CoreMessageLogger.class,
+					StatisticalLoggingSessionEventListener.class.getName()
+			) );
+
+	@Test
+	void testSessionMetricsLog(SessionFactoryScope scope) {
+		Triggerable triggerable = logInspection.watchForLogMessages( "Session Metrics {" );
+		long startTime = System.nanoTime();
+
+		scope.inTransaction( session -> {
+			session.persist( new BasicEntity( 1, "fooData" ) );
+			session.persist( new BasicEntity( 2, "fooData2" ) );
+			session.flush();
+			session.clear();
+			for ( int i = 0; i < 2; i++ ) {
+				assertThat( session.createQuery( "select data from BasicEntity e where e.id=1", String.class )
+									.setCacheable( true )
+									.getSingleResult() ).isEqualTo( "fooData" );
+			}
+		} );
+		long sessionNanoDuration = System.nanoTime() - startTime;
+
+		List<String> messages = triggerable.triggerMessages();
+		assertThat( messages ).hasSize( 1 );
+		String sessionMetricsLog = messages.get( 0 );
+
+		// acquiring JDBC connections
+		SessionMetric acquiringJdbcConnectionsMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent acquiring ([0-9]+) JDBC connections"
+		);
+		assertThat( acquiringJdbcConnectionsMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// releasing JDBC connections
+		SessionMetric releasingJdbcConnectionsMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent releasing ([0-9]+) JDBC connections"
+		);
+		assertThat( releasingJdbcConnectionsMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// preparing JDBC statements
+		SessionMetric preparingJdbcStatmentsMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent preparing ([0-9]+) JDBC statements"
+		);
+		assertThat( preparingJdbcStatmentsMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// executing JDBC statements
+		SessionMetric executingJdbcStatmentsMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent executing ([0-9]+) JDBC statements"
+		);
+		assertThat( executingJdbcStatmentsMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// executing JDBC batches
+		SessionMetric executingJdbcBatchesMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent executing ([0-9]+) JDBC batches"
+		);
+		assertThat( executingJdbcBatchesMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// performing L2C puts
+		SessionMetric performingL2CPutsMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent performing ([0-9]+) L2C puts"
+		);
+		assertThat( performingL2CPutsMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// performing L2C hits
+		SessionMetric performingL2CHitsMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent performing ([0-9]+) L2C hits"
+		);
+		assertThat( performingL2CHitsMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// performing L2C misses
+		SessionMetric performingL2CMissesMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent performing ([0-9]+) L2C misses"
+		);
+		assertThat( performingL2CMissesMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// executing flushes
+		SessionMetric executingFlushesMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent executing ([0-9]+) flushes"
+		);
+		assertThat( executingFlushesMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// executing pre-partial-flushes
+		SessionMetric executingPrePartialFlushesMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent executing ([0-9]+) pre-partial-flushes"
+		);
+		assertThat( executingPrePartialFlushesMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// executing partial-flushes
+		SessionMetric executingPartialFlushesMetric = extractMetric(
+				sessionMetricsLog,
+				"([0-9]+) nanoseconds spent executing ([0-9]+) partial-flushes"
+		);
+		assertThat( executingPartialFlushesMetric.getDuration() ).isGreaterThan( 0L )
+				.isLessThan( sessionNanoDuration );
+
+		// Number of metrics
+		List<SessionMetric> metricList = List.of(
+				acquiringJdbcConnectionsMetric,
+				releasingJdbcConnectionsMetric,
+				preparingJdbcStatmentsMetric,
+				executingJdbcStatmentsMetric,
+				executingJdbcBatchesMetric,
+				performingL2CPutsMetric,
+				performingL2CHitsMetric,
+				performingL2CMissesMetric,
+				executingFlushesMetric,
+				executingPrePartialFlushesMetric,
+				executingPartialFlushesMetric
+		);
+		int numberOfMetrics = metricList.size();
+		// Number of lines
+		assertThat( sessionMetricsLog.lines().count() )
+				.as( "The StatisticalLoggingSessionEventListener should write a line per metric ("
+					 + numberOfMetrics + " lines) plus a header and a footer (2 lines)" )
+				.isEqualTo( numberOfMetrics + 2 );
+		// Total time
+		long sumDuration = metricList.stream().map( SessionMetric::getDuration ).mapToLong( Long::longValue ).sum();
+		assertThat( sumDuration ).isLessThanOrEqualTo( sessionNanoDuration );
+	}
+
+	private SessionMetric extractMetric(String logMessage, String regex) {
+		Pattern pattern = Pattern.compile( regex );
+		Matcher matcher = pattern.matcher( logMessage );
+		assertTrue( matcher.find() );
+		return new SessionMetric( Long.parseLong( matcher.group( 1 ) ), Integer.parseInt( matcher.group( 2 ) ) );
+	}
+
+	private static class SessionMetric {
+		private final long duration;
+		private final int count;
+
+		public SessionMetric(long duration, int count) {
+			this.duration = duration;
+			this.count = count;
+		}
+
+		public long getDuration() {
+			return duration;
+		}
+
+		public int getCount() {
+			return count;
+		}
+	}
+}