SLING-7540 SuppIterator improvement
Removed recursion on Option determination
diff --git a/src/main/java/org/apache/sling/query/iterator/SuppIterator.java b/src/main/java/org/apache/sling/query/iterator/SuppIterator.java
index fafd2a2..8fae602 100644
--- a/src/main/java/org/apache/sling/query/iterator/SuppIterator.java
+++ b/src/main/java/org/apache/sling/query/iterator/SuppIterator.java
@@ -26,9 +26,10 @@
import org.apache.sling.query.api.internal.Option;
/**
- * This iterator returns all elements of the input list which are mapped to non-empty values by the input
- * function. Name is inspired by the <a href="http://en.wikipedia.org/wiki/Support_(mathematics)">support of
- * the function</a>.
+ * This iterator returns all elements of the input list which are mapped to
+ * non-empty values by the input function. Name is inspired by the
+ * <a href="http://en.wikipedia.org/wiki/Support_(mathematics)">support of the
+ * function</a>.
*/
public class SuppIterator<T> extends AbstractIterator<Option<T>> {
@@ -46,29 +47,43 @@
}
/**
- * The idea behind this method is that index of each element in the input iterator is passed to the
- * function. Elements returned by the output iterator contains the same index, which can be used to assign
- * input to output elements. We check which indices are present in the output iterator and return only
- * related input elements.
+ * The idea behind this method is that index of each element in the input
+ * iterator is passed to the function. One or more Option<T> items for each
+ * index will be returned. If any Option<T> item in that index set is not
+ * empty then the corresponding element in the input will be returned.
*/
@Override
protected Option<T> getElement() {
- if (outputElement != null) {
- final int outputIndex = outputElement.getArgumentId();
- if (currentIndex < outputIndex) {
- return Option.empty(input.get(currentIndex++).getArgumentId());
- } else if (currentIndex == outputIndex && !outputElement.isEmpty()) {
- return input.get(currentIndex++);
+ if (outputElement == null) {
+ if (!output.hasNext()) {
+ return null;
}
+ outputElement = output.next();
}
- while (output.hasNext()) {
- outputElement = output.next();
- final int outputIndex = outputElement.getArgumentId();
- if ((outputIndex == currentIndex && !outputElement.isEmpty()) || outputIndex > currentIndex) {
- return getElement();
+ int outputIndex = outputElement.getArgumentId();
+ boolean emptyResponse = outputElement.isEmpty();
+
+ //loop to next index or end of list
+ while (outputIndex <= currentIndex && output.hasNext()) {
+ if (emptyResponse) {
+ emptyResponse = outputElement.isEmpty();
}
+ outputElement = output.next();
+ outputIndex = outputElement.getArgumentId();
}
- return null;
+
+ if (emptyResponse) {
+ if (outputIndex > currentIndex) {
+ return Option.empty(currentIndex++);
+ }
+ return null;
+ }
+
+ if (outputIndex <= currentIndex) {
+ outputElement = null;
+ }
+ return input.get(currentIndex++);
}
+
}
