perf: add PropertyIteratorImpl.EMPTY_ITERATOR when iterating over an …

…empty collection
apache · Jun 14, 2023 · 9793459 · 9793459
1 parent cabc3fb
commit 9793459
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diff --git a/src/core/src/main/java/org/apache/jmeter/testelement/AbstractTestElement.java b/src/core/src/main/java/org/apache/jmeter/testelement/AbstractTestElement.java
@@ -589,6 +589,9 @@ public PropertyIterator propertyIterator() {
         // Note: can't use ConcurrentMap here as it would return elements in unpredictable order
         readLock();
         try {
+            if (propMap.isEmpty()) {
+                return PropertyIteratorImpl.EMPTY_ITERATOR;
+            }
             // TODO: copy the contents of the iterator to avoid ConcurrentModificationException?
             return new PropertyIteratorImpl(this, propMap.values());
         } finally {

diff --git a/src/core/src/main/java/org/apache/jmeter/testelement/property/AbstractProperty.java b/src/core/src/main/java/org/apache/jmeter/testelement/property/AbstractProperty.java
@@ -77,6 +77,9 @@ public void setRunningVersion(boolean runningVersion) {
     }
 
     protected PropertyIterator getIterator(Collection<JMeterProperty> values) {
+        if (values.isEmpty()) {
+            return PropertyIteratorImpl.EMPTY_ITERATOR;
+        }
         return new PropertyIteratorImpl(values);
     }
 

diff --git a/src/core/src/main/java/org/apache/jmeter/testelement/property/PropertyIteratorImpl.java b/src/core/src/main/java/org/apache/jmeter/testelement/property/PropertyIteratorImpl.java
@@ -18,11 +18,13 @@
 package org.apache.jmeter.testelement.property;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 
 import org.apache.jmeter.testelement.TestElement;
 
 public class PropertyIteratorImpl implements PropertyIterator {
+    public static final PropertyIterator EMPTY_ITERATOR = new PropertyIteratorImpl(Collections.emptyList());
 
     private final TestElement owner;
     private final Iterator<? extends JMeterProperty> iter;