GH-4790 describe iteration needs to close the source iteration

Author: hmottestad

core/queryalgebra/evaluation/src/main/java/org/eclipse/rdf4j/query/algebra/evaluation/impl/DefaultEvaluationStrategy.java

@@ -352,50 +352,58 @@ public TupleExpr optimize(TupleExpr expr, EvaluationStatistics evaluationStatist
 	public CloseableIteration<BindingSet, QueryEvaluationException> evaluate(TupleExpr expr, BindingSet bindings)
 			throws QueryEvaluationException {
 
-		CloseableIteration<BindingSet, QueryEvaluationException> ret;
+		CloseableIteration<BindingSet, QueryEvaluationException> ret = null;
 
-		if (expr instanceof StatementPattern) {
-			ret = evaluate((StatementPattern) expr, bindings);
-		} else if (expr instanceof UnaryTupleOperator) {
-			ret = evaluate((UnaryTupleOperator) expr, bindings);
-		} else if (expr instanceof BinaryTupleOperator) {
-			ret = evaluate((BinaryTupleOperator) expr, bindings);
-		} else if (expr instanceof SingletonSet) {
-			ret = evaluate((SingletonSet) expr, bindings);
-		} else if (expr instanceof EmptySet) {
-			ret = evaluate((EmptySet) expr, bindings);
-		} else if (expr instanceof ZeroLengthPath) {
-			ret = evaluate((ZeroLengthPath) expr, bindings);
-		} else if (expr instanceof ArbitraryLengthPath) {
-			ret = evaluate((ArbitraryLengthPath) expr, bindings);
-		} else if (expr instanceof BindingSetAssignment) {
-			ret = evaluate((BindingSetAssignment) expr, bindings);
-		} else if (expr instanceof TripleRef) {
-			ret = evaluate((TripleRef) expr, bindings);
-		} else if (expr instanceof TupleFunctionCall) {
-			if (getQueryEvaluationMode().compareTo(QueryEvaluationMode.STANDARD) < 0) {
-				throw new QueryEvaluationException(
-						"Tuple function call not supported in query evaluation mode " + getQueryEvaluationMode());
+		try {
+			if (expr instanceof StatementPattern) {
+				ret = evaluate((StatementPattern) expr, bindings);
+			} else if (expr instanceof UnaryTupleOperator) {
+				ret = evaluate((UnaryTupleOperator) expr, bindings);
+			} else if (expr instanceof BinaryTupleOperator) {
+				ret = evaluate((BinaryTupleOperator) expr, bindings);
+			} else if (expr instanceof SingletonSet) {
+				ret = evaluate((SingletonSet) expr, bindings);
+			} else if (expr instanceof EmptySet) {
+				ret = evaluate((EmptySet) expr, bindings);
+			} else if (expr instanceof ZeroLengthPath) {
+				ret = evaluate((ZeroLengthPath) expr, bindings);
+			} else if (expr instanceof ArbitraryLengthPath) {
+				ret = evaluate((ArbitraryLengthPath) expr, bindings);
+			} else if (expr instanceof BindingSetAssignment) {
+				ret = evaluate((BindingSetAssignment) expr, bindings);
+			} else if (expr instanceof TripleRef) {
+				ret = evaluate((TripleRef) expr, bindings);
+			} else if (expr instanceof TupleFunctionCall) {
+				if (getQueryEvaluationMode().compareTo(QueryEvaluationMode.STANDARD) < 0) {
+					throw new QueryEvaluationException(
+							"Tuple function call not supported in query evaluation mode " + getQueryEvaluationMode());
+				}
+				return evaluate(expr, bindings);
+			} else if (expr == null) {
+				throw new IllegalArgumentException("expr must not be null");
+			} else {
+				throw new QueryEvaluationException("Unsupported tuple expr type: " + expr.getClass());
 			}
-			return evaluate((TupleFunctionCall) expr, bindings);
-		} else if (expr == null) {
-			throw new IllegalArgumentException("expr must not be null");
-		} else {
-			throw new QueryEvaluationException("Unsupported tuple expr type: " + expr.getClass());
-		}
 
-		if (trackTime) {
-			// set resultsSizeActual to at least be 0 so we can track iterations that don't procude anything
-			expr.setTotalTimeNanosActual(Math.max(0, expr.getTotalTimeNanosActual()));
-			ret = new TimedIterator(ret, expr);
-		}
+			if (trackTime) {
+				// set resultsSizeActual to at least be 0 so we can track iterations that don't procude anything
+				expr.setTotalTimeNanosActual(Math.max(0, expr.getTotalTimeNanosActual()));
+				ret = new TimedIterator(ret, expr);
+			}
 
-		if (trackResultSize) {
-			// set resultsSizeActual to at least be 0 so we can track iterations that don't procude anything
-			expr.setResultSizeActual(Math.max(0, expr.getResultSizeActual()));
-			ret = new ResultSizeCountingIterator(ret, expr);
+			if (trackResultSize) {
+				// set resultsSizeActual to at least be 0 so we can track iterations that don't procude anything
+				expr.setResultSizeActual(Math.max(0, expr.getResultSizeActual()));
+				ret = new ResultSizeCountingIterator(ret, expr);
+			}
+			return ret;
+
+		} catch (Throwable t) {
+			if (ret != null) {
+				ret.close();
+			}
+			throw t;
 		}
-		return ret;
 	}
 
 	@Override

core/queryalgebra/evaluation/src/main/java/org/eclipse/rdf4j/query/algebra/evaluation/iterator/DescribeIteration.java

@@ -220,4 +220,21 @@ protected CloseableIteration<BindingSet, QueryEvaluationException> createNextIte
 		return strategy.evaluate(pattern, parentBindings);
 	}
 
+	@Override
+	protected void handleClose() throws QueryEvaluationException {
+		try {
+			super.handleClose();
+
+		} finally {
+			try {
+				if (currentDescribeExprIter != null)
+					currentDescribeExprIter.close();
+			} finally {
+
+			}
+			if (sourceIter instanceof CloseableIteration) {
+				((CloseableIteration<?, QueryEvaluationException>) sourceIter).close();
+			}
+		}
+	}
 }

tools/federation/src/main/java/org/eclipse/rdf4j/federated/evaluation/FederationEvalStrategy.java

@@ -872,10 +872,19 @@ public CloseableIteration<BindingSet, QueryEvaluationException> evaluate(Describ
 			throw new FedXRuntimeException(
 					"Expected a FedXDescribeOperator Node. Found " + operator.getClass() + " instead.");
 		}
-		CloseableIteration<BindingSet, QueryEvaluationException> iter = evaluate(operator.getArg(), bindings);
-		// Note: we need to evaluate the DESCRIBE over the entire federation
-		return new FederatedDescribeIteration(iter, this, operator.getBindingNames(), bindings,
-				((FederatedDescribeOperator) operator).getQueryInfo());
+		CloseableIteration<BindingSet, QueryEvaluationException> iter = null;
+		try {
+			iter = evaluate(operator.getArg(), bindings);
+			// Note: we need to evaluate the DESCRIBE over the entire federation
+			return new FederatedDescribeIteration(iter, this, operator.getBindingNames(), bindings,
+					((FederatedDescribeOperator) operator).getQueryInfo());
+		} catch (Throwable t) {
+			if (iter != null) {
+				iter.close();
+			}
+			throw t;
+		}
+
 	}
 
 	protected CloseableIteration<BindingSet, QueryEvaluationException> evaluateAtStatementSources(Object preparedQuery,