Github user arunmahadevan commented on a diff in the pull request:
https://github.com/apache/storm/pull/1086#discussion_r52136638
--- Diff: storm-core/src/jvm/org/apache/storm/trident/Stream.java ---
@@ -436,8 +444,91 @@ public Stream partitionAggregate(Fields inputFields,
ReducerAggregator agg, Fiel
return chainedAgg()
.partitionAggregate(inputFields, agg, functionFields)
.chainEnd();
- }
-
+ }
+
+ /**
+ * This aggregator operation computes the minimum of tuples by the
given {@code inputFieldName} and it is
+ * assumed that its value is an instance of {@code Comparable}.
+ *
+ * @param inputFieldName input field name
+ * @return
+ */
+ public Stream minBy(String inputFieldName) {
+ Aggregator<ComparisonAggregator.State> min = new
Min(inputFieldName);
+ return comparableAggregateStream(inputFieldName, min);
+ }
+
+ /**
+ * This aggregator operation computes the minimum of tuples by the
given {@code inputFieldName} in a stream by
+ * using the given {@code comparator}.
+ *
+ * @param inputFieldName input field name
+ * @param comparator comparator used in for finding minimum of two
tuple values of {@code inputFieldName}.
+ * @param <T> type of tuple's given input field value.
+ * @return
+ */
+ public <T> Stream minBy(String inputFieldName, Comparator<T>
comparator) {
+ Aggregator<ComparisonAggregator.State> min = new
MinWithComparator<>(inputFieldName, comparator);
+ return comparableAggregateStream(inputFieldName, min);
+ }
+
+ /**
+ * This aggregator operation computes the minimum of tuples in a
stream by using the given {@code comparator} with
+ * {@code TridentTuple}s.
+ *
+ * @param comparator comparator used in for finding minimum of two
tuple values.
+ * @return
+ */
+ public Stream min(Comparator<TridentTuple> comparator) {
+ Aggregator<ComparisonAggregator.State> min = new
MinWithComparator<>(comparator);
+ return comparableAggregateStream(null, min);
+ }
+
+ /**
+ * This aggregator operation computes the maximum of tuples by the
given {@code inputFieldName} and it is
+ * assumed that its value is an instance of {@code Comparable}.
--- End diff --
What would be the behavior if the values are not `Comparable` ? Maybe
document that as well.
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