[GitHub] [incubator-pekko] He-Pin commented on a diff in pull request #582: =str Add IterableSource.

["He-Pin (via GitHub)" <gi...@apache.org>]

He-Pin commented on code in PR #582:
URL: https://github.com/apache/incubator-pekko/pull/582#discussion_r1301374770


##########
stream/src/main/scala/org/apache/pekko/stream/impl/fusing/IterableSource.scala:
##########
@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.pekko.stream.impl.fusing
+
+import scala.collection.immutable
+import scala.util.control.NonFatal
+
+import org.apache.pekko
+import pekko.stream.{ Attributes, Outlet, SourceShape, Supervision }
+import pekko.stream.ActorAttributes.SupervisionStrategy
+import pekko.stream.impl.ReactiveStreamsCompliance
+import pekko.stream.impl.Stages.DefaultAttributes
+import pekko.stream.stage.{ GraphStage, GraphStageLogic, OutHandler }
+
+private[pekko] final class IterableSource[T](val elements: immutable.Iterable[T]) extends GraphStage[SourceShape[T]] {
+  ReactiveStreamsCompliance.requireNonNullElement(elements)
+
+  override protected def initialAttributes: Attributes = DefaultAttributes.iterableSource
+
+  private val out = Outlet[T]("IterableSource.out")
+  override val shape: SourceShape[T] = SourceShape(out)
+
+  override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
+    new GraphStageLogic(shape) with OutHandler {
+      private lazy val decider = inheritedAttributes.mandatoryAttribute[SupervisionStrategy].decider
+      private var currentIterator: Iterator[T] = _
+
+      override def onPull(): Unit =
+        try {
+          if (currentIterator eq null) {

Review Comment:
   There are some cases where the `iterator` method call invoving some underling resources creation, that's why I defer the creation in the first place.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: notifications-unsubscribe@pekko.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: notifications-unsubscribe@pekko.apache.org
For additional commands, e-mail: notifications-help@pekko.apache.org