[jena] branch main updated: use streams for more efficient iterator handling

[andy]

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andy pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/jena.git


The following commit(s) were added to refs/heads/main by this push:
     new 8ffa54889b use streams for more efficient iterator handling
     new d9dc97a4bb Merge pull request #1331 from 
LorenzBuehmann/improvement/gspf-iterator
8ffa54889b is described below

commit 8ffa54889b732facdea60799b91b649b15b3826b
Author: Lorenz Buehmann <buehm...@informatik.uni-leipzig.de>
AuthorDate: Mon May 23 14:32:52 2022 +0200

    use streams for more efficient iterator handling
---
 .../GenericSpatialPropertyFunction.java            | 34 +++++++---------------
 1 file changed, 11 insertions(+), 23 deletions(-)

diff --git 
a/jena-geosparql/src/main/java/org/apache/jena/geosparql/spatial/property_functions/GenericSpatialPropertyFunction.java
 
b/jena-geosparql/src/main/java/org/apache/jena/geosparql/spatial/property_functions/GenericSpatialPropertyFunction.java
index 8e59043d8a..0e47410bb4 100644
--- 
a/jena-geosparql/src/main/java/org/apache/jena/geosparql/spatial/property_functions/GenericSpatialPropertyFunction.java
+++ 
b/jena-geosparql/src/main/java/org/apache/jena/geosparql/spatial/property_functions/GenericSpatialPropertyFunction.java
@@ -20,6 +20,8 @@ package org.apache.jena.geosparql.spatial.property_functions;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.stream.Stream;
+
 import org.apache.commons.collections4.iterators.IteratorChain;
 import org.apache.jena.datatypes.DatatypeFormatException;
 import org.apache.jena.geosparql.implementation.GeometryWrapper;
@@ -38,8 +40,9 @@ import org.apache.jena.sparql.core.Var;
 import org.apache.jena.sparql.engine.ExecutionContext;
 import org.apache.jena.sparql.engine.QueryIterator;
 import org.apache.jena.sparql.engine.binding.Binding;
-import org.apache.jena.sparql.engine.iterator.QueryIterConcat;
+import org.apache.jena.sparql.engine.binding.BindingFactory;
 import org.apache.jena.sparql.engine.iterator.QueryIterNullIterator;
+import org.apache.jena.sparql.engine.iterator.QueryIterPlainWrapper;
 import org.apache.jena.sparql.engine.iterator.QueryIterSingleton;
 import org.apache.jena.sparql.expr.ExprEvalException;
 import org.apache.jena.sparql.pfunction.PFuncSimpleAndList;
@@ -175,7 +178,6 @@ public abstract class GenericSpatialPropertyFunction 
extends PFuncSimpleAndList
 
     private QueryIterator checkUnbound(Binding binding, ExecutionContext 
execCxt, Node subject, int limit) {
 
-        QueryIterConcat queryIterConcat = new QueryIterConcat(execCxt);
         if (limit < 0) {
             limit = Integer.MAX_VALUE;
         }
@@ -185,29 +187,15 @@ public abstract class GenericSpatialPropertyFunction 
extends PFuncSimpleAndList
         HashSet<Resource> features = searchEnvelope.check(spatialIndex);
 
         Var subjectVar = Var.alloc(subject.getName());
-        int count = 0;
-        for (Resource feature : features) {
-
-            boolean isMatched;
-
-            if (requireSecondFilter()) {
-                //Check all the GeometryLiterals of the Feature in a 
fine-grained test.
-                isMatched = checkBound(execCxt, feature.asNode());
-            } else {
-                //Second filter is not required so accept the case.
-                isMatched = true;
-            }
 
-            if (isMatched) {
-                count++; //Exit on limit of zero.
-                if (count > limit) {
-                    break;
-                }
-                QueryIterator queryIter = QueryIterSingleton.create(binding, 
subjectVar, feature.asNode(), execCxt);
-                queryIterConcat.add(queryIter);
-            }
+        Stream<Resource> stream = features.stream();
+        if (requireSecondFilter()) {
+            stream = stream.filter(feature -> checkBound(execCxt, 
feature.asNode()));
         }
-        return queryIterConcat;
+        Iterator<Binding> iterator = stream.map(feature -> 
BindingFactory.binding(binding, subjectVar, feature.asNode()))
+                .limit(limit)
+                .iterator();
+        return QueryIterPlainWrapper.create(iterator, execCxt);
     }
 
 }