Github user mbalassi commented on a diff in the pull request:
https://github.com/apache/flink/pull/659#discussion_r29854598
--- Diff:
flink-staging/flink-streaming/flink-streaming-core/src/main/java/org/apache/flink/streaming/api/functions/source/Source.java
---
@@ -0,0 +1,87 @@
+/*
+ * 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.flink.streaming.api.functions.source;
+
+import org.apache.flink.api.common.functions.Function;
+import org.joda.time.Instant;
+
+import java.io.Serializable;
+
+/**
+ * Base interface for all stream data sources in Flink. The contract of a
stream source
+ * is similar to an iterator - it is consumed as in the following pseudo
code:
+ *
+ * <pre>{@code
+ * StreamSource<T> source = ...;
+ * Collector<T> out = ...;
+ * while (!source.reachedEnd()) {
+ * out.collect(source.next());
+ * }
+ * }
+ * </pre>
+ *
+ * <b>Note about blocking behavior</b>
+ * <p>This implementations of the methods in the stream sources must have
certain guarantees about
+ * blocking behavior. One of the two characteristics must be fulfilled.</p>
+ * <ul>
+ * <li>The methods must react to thread interrupt calls and break out
of blocking calls with
+ * an {@link InterruptedException}.</li>
+ * <li>The method may ignore interrupt calls and/or swallow
InterruptedExceptions, if it is guaranteed
+ * that the method returns quasi immediately irrespectively of the
input. This is true for example
+ * for file streams, where the call is guaranteed to return after
a very short I/O delay in
+ * the order of milliseconds.</li>
+ * </ul>
+ *
+ * @param <T> The type of the records produced by this source.
+ */
+public interface Source<T> extends Function, Serializable {
--- End diff --
`StreamSource` or `SourceFunction`.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
