cleanups in implementations of ScrollableResults

Author: gavinking

hibernate-core/src/main/java/org/hibernate/internal/AbstractScrollableResults.java

@@ -44,7 +44,6 @@ public AbstractScrollableResults(
 		this.persistenceContext = persistenceContext;
 	}
 
-
 	@Override
 	public final R get() throws HibernateException {
 		if ( closed ) {
@@ -85,26 +84,22 @@ protected void afterScrollOperation() {
 
 	@Override
 	public void setFetchSize(int fetchSize) {
-		getJdbcValues().setFetchSize(fetchSize);
+		getJdbcValues().setFetchSize( fetchSize );
 	}
 
 	@Override
 	public final void close() {
-		if ( this.closed ) {
-			// noop if already closed
-			return;
+		if ( !closed ) {
+			rowReader.finishUp( rowProcessingState );
+			jdbcValues.finishUp( persistenceContext );
+			getPersistenceContext().getJdbcCoordinator().afterStatementExecution();
+			closed = true;
 		}
-
-		rowReader.finishUp( rowProcessingState );
-		jdbcValues.finishUp( persistenceContext );
-
-		getPersistenceContext().getJdbcCoordinator().afterStatementExecution();
-
-		this.closed = true;
+		// noop if already closed
 	}
 
 	@Override
 	public boolean isClosed() {
-		return this.closed;
+		return closed;
 	}
 }

hibernate-core/src/main/java/org/hibernate/internal/EmptyScrollableResults.java

@@ -4,29 +4,28 @@
  */
 package org.hibernate.internal;
 
-import org.hibernate.internal.util.collections.ArrayHelper;
 import org.hibernate.query.spi.ScrollableResultsImplementor;
 
 /**
  * @author Andrea Boriero
  */
-public class EmptyScrollableResults implements ScrollableResultsImplementor {
+public class EmptyScrollableResults<R> implements ScrollableResultsImplementor<R> {
 
-	public static final ScrollableResultsImplementor INSTANCE = new EmptyScrollableResults();
+	@SuppressWarnings("rawtypes")
+	private static final ScrollableResultsImplementor INSTANCE = new EmptyScrollableResults();
+
+	@SuppressWarnings("unchecked")
+	public static <R> EmptyScrollableResults<R> instance() {
+		return (EmptyScrollableResults<R>) INSTANCE;
+	}
 
 	@Override
 	public boolean isClosed() {
 		return true;
 	}
 
-//	@Override
-//	public int getNumberOfTypes() {
-//		return 0;
-//	}
-
 	@Override
 	public void close() {
-
 	}
 
 	@Override
@@ -61,12 +60,10 @@ public boolean first() {
 
 	@Override
 	public void beforeFirst() {
-
 	}
 
 	@Override
 	public void afterLast() {
-
 	}
 
 	@Override
@@ -93,112 +90,7 @@ public boolean setRowNumber(int rowNumber) {
 	public void setFetchSize(int fetchSize) {}
 
 	@Override
-	public Object[] get() {
-		return ArrayHelper.EMPTY_OBJECT_ARRAY;
-	}
-
-//	@Override
-//	public Object get(int i) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Type getType(int i) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Integer getInteger(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Long getLong(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Float getFloat(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Boolean getBoolean(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Double getDouble(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Short getShort(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Byte getByte(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Character getCharacter(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public byte[] getBinary(int col) {
-//		return new byte[0];
-//	}
-//
-//	@Override
-//	public String getText(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Blob getBlob(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Clob getClob(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public String getString(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public BigDecimal getBigDecimal(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public BigInteger getBigInteger(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Date getDate(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Locale getLocale(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public Calendar getCalendar(int col) {
-//		return null;
-//	}
-//
-//	@Override
-//	public TimeZone getTimeZone(int col) {
-//		return null;
-//	}
+	public R get() {
+		throw new UnsupportedOperationException( "Empty result set" );
+	}
 }

hibernate-core/src/main/java/org/hibernate/internal/FetchingScrollableResultsImpl.java

@@ -73,7 +73,7 @@ else if ( beforeFirst ) {
 			}
 		}
 
-		boolean last = prepareCurrentRow();
+		final boolean last = prepareCurrentRow();
 
 		beforeFirst = false;
 		currentPosition++;
@@ -130,15 +130,12 @@ else if ( currentPosition == 1 ) {
 				// we are interested in processing
 				boolean firstPass = true;
 				final EntityKey lastKey = getEntityKey();
-
 				while ( getRowProcessingState().previous() ) {
-					EntityKey checkKey = getEntityKey();
-
+					final EntityKey checkKey = getEntityKey();
 					if ( firstPass ) {
 						firstPass = false;
 						keyToRead = checkKey;
 					}
-
 					if ( !lastKey.equals( checkKey ) ) {
 						break;
 					}
@@ -148,8 +145,7 @@ else if ( currentPosition == 1 ) {
 			// Read backwards until we read past the first physical sequential
 			// row with the key we are interested in loading
 			while ( getRowProcessingState().previous() ) {
-				EntityKey checkKey = getEntityKey();
-
+				final EntityKey checkKey = getEntityKey();
 				if ( !keyToRead.equals( checkKey ) ) {
 					break;
 				}
@@ -223,7 +219,6 @@ public boolean last() {
 			}
 		}
 		else {
-			final RowProcessingStateStandardImpl rowProcessingState = getRowProcessingState();
 			if ( isResultSetEmpty() || afterLast ) {
 				// should not be able to reach last without maxPosition being set
 				// unless there are no results
@@ -243,10 +238,8 @@ public boolean last() {
 	@Override
 	public boolean first() {
 		beforeFirst();
-		boolean more = next();
-
+		final boolean more = next();
 		afterScrollOperation();
-
 		return more;
 	}
 

hibernate-core/src/main/java/org/hibernate/internal/ScrollableResultsImpl.java

@@ -117,32 +117,30 @@ public boolean setRowNumber(int rowNumber) throws HibernateException {
 	}
 
 	private void prepareCurrentRow(boolean underlyingScrollSuccessful) {
-		if ( !underlyingScrollSuccessful ) {
-			currentRow = null;
-			return;
-		}
-
-		final PersistenceContext persistenceContext = getPersistenceContext().getPersistenceContext();
-		final LoadContexts loadContexts = persistenceContext.getLoadContexts();
-		loadContexts.register( getJdbcValuesSourceProcessingState() );
-		persistenceContext.beforeLoad();
-		try {
+		if ( underlyingScrollSuccessful ) {
+			final PersistenceContext persistenceContext = getPersistenceContext().getPersistenceContext();
+			final LoadContexts loadContexts = persistenceContext.getLoadContexts();
+			loadContexts.register( getJdbcValuesSourceProcessingState() );
+			persistenceContext.beforeLoad();
 			try {
-				currentRow = getRowReader().readRow( getRowProcessingState() );
-
-				getRowProcessingState().finishRowProcessing( true );
-				getJdbcValuesSourceProcessingState().finishUp( false );
+				try {
+					currentRow = getRowReader().readRow( getRowProcessingState() );
+					getRowProcessingState().finishRowProcessing( true );
+					getJdbcValuesSourceProcessingState().finishUp( false );
+				}
+				finally {
+					persistenceContext.afterLoad();
+				}
+				persistenceContext.initializeNonLazyCollections();
 			}
 			finally {
-				persistenceContext.afterLoad();
+				loadContexts.deregister( getJdbcValuesSourceProcessingState() );
 			}
-			persistenceContext.initializeNonLazyCollections();
+			afterScrollOperation();
 		}
-		finally {
-			loadContexts.deregister( getJdbcValuesSourceProcessingState() );
+		else {
+			currentRow = null;
 		}
-
-		afterScrollOperation();
 	}
 
 }

hibernate-core/src/main/java/org/hibernate/query/sql/internal/NativeSelectQueryPlanImpl.java

@@ -144,8 +144,7 @@ public List<R> performList(DomainQueryExecutionContext executionContext) {
 	@Override
 	public ScrollableResultsImplementor<R> performScroll(ScrollMode scrollMode, DomainQueryExecutionContext executionContext) {
 		if ( executionContext.getQueryOptions().getEffectiveLimit().getMaxRowsJpa() == 0 ) {
-			//noinspection unchecked
-			return EmptyScrollableResults.INSTANCE;
+			return EmptyScrollableResults.instance();
 		}
 		final List<JdbcParameterBinder> jdbcParameterBinders;
 		final JdbcParameterBindings jdbcParameterBindings;

hibernate-core/src/main/java/org/hibernate/query/sqm/internal/AggregatedSelectQueryPlanImpl.java

@@ -76,7 +76,7 @@ else if ( elementsToSkip > 0 ) {
 	@Override
 	public ScrollableResultsImplementor<R> performScroll(ScrollMode scrollMode, DomainQueryExecutionContext executionContext) {
 		if ( executionContext.getQueryOptions().getEffectiveLimit().getMaxRowsJpa() == 0 ) {
-			return EmptyScrollableResults.INSTANCE;
+			return EmptyScrollableResults.instance();
 		}
 		throw new UnsupportedOperationException();
 	}

hibernate-core/src/main/java/org/hibernate/query/sqm/internal/ConcreteSqmSelectQueryPlan.java

@@ -371,7 +371,7 @@ public List<R> performList(DomainQueryExecutionContext executionContext) {
 	@Override
 	public ScrollableResultsImplementor<R> performScroll(ScrollMode scrollMode, DomainQueryExecutionContext executionContext) {
 		if ( executionContext.getQueryOptions().getEffectiveLimit().getMaxRowsJpa() == 0 ) {
-			return EmptyScrollableResults.INSTANCE;
+			return EmptyScrollableResults.instance();
 		}
 		return withCacheableSqmInterpretation( executionContext, scrollMode, scrollInterpreter );
 	}