[FLINK-8116] [DataStream] Fix stale comments referring to Checkpointed interface

docs/ops/state/state_backends.md

@@ -26,7 +26,7 @@ Programs written in the [Data Stream API]({{ site.baseurl }}/dev/datastream_api.
 
 - Windows gather elements or aggregates until they are triggered
 - Transformation functions may use the key/value state interface to store values
-- Transformation functions may implement the `Checkpointed` interface to make their local variables fault tolerant
+- Transformation functions may implement the `CheckpointedFunction` interface to make their local variables fault tolerant
 
 See also [state section]({{ site.baseurl }}/dev/stream/state/index.html) in the streaming API guide.
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/source/SourceFunction.java

@@ -34,9 +34,9 @@ import java.io.Serializable;
  * The run method can run for as long as necessary. The source must, however, react to an
  * invocation of {@link #cancel()} by breaking out of its main loop.
  *
- * <h3>Checkpointed Sources</h3>
+ * <h3>CheckpointedFunction Sources</h3>
  *
- * <p>Sources that also implement the {@link org.apache.flink.streaming.api.checkpoint.Checkpointed}
+ * <p>Sources that also implement the {@link org.apache.flink.streaming.api.checkpoint.CheckpointedFunction}
  * interface must ensure that state checkpointing, updating of internal state and emission of
  * elements are not done concurrently. This is achieved by using the provided checkpointing lock
  * object to protect update of state and emission of elements in a synchronized block.
@@ -44,7 +44,7 @@ import java.io.Serializable;
  * <p>This is the basic pattern one should follow when implementing a (checkpointed) source:
  *
  * <pre>{@code
- *  public class ExampleSource<T> implements SourceFunction<T>, Checkpointed<Long> {
+ *  public class ExampleSource<T> implements SourceFunction<T>, CheckpointedFunction {
  *      private long count = 0L;
  *      private volatile boolean isRunning = true;
  *
@@ -61,9 +61,9 @@ import java.io.Serializable;
  *          isRunning = false;
  *      }
  *
- *      public Long snapshotState(long checkpointId, long checkpointTimestamp) { return count; }
+ *      public void snapshotState(FunctionSnapshotContext context) {  }
  *
- *      public void restoreState(Long state) { this.count = state; }
+ *      public void initializeState(FunctionInitializationContext context) {  }
  * }
  * }</pre>
  *
@@ -96,12 +96,12 @@ public interface SourceFunction<T> extends Function, Serializable {
 	 * Starts the source. Implementations can use the {@link SourceContext} emit
 	 * elements.
 	 *
-	 * <p>Sources that implement {@link org.apache.flink.streaming.api.checkpoint.Checkpointed}
+	 * <p>Sources that implement {@link org.apache.flink.streaming.api.checkpoint.CheckpointedFunction}
 	 * must lock on the checkpoint lock (using a synchronized block) before updating internal
 	 * state and emitting elements, to make both an atomic operation:
 	 *
 	 * <pre>{@code
-	 *  public class ExampleSource<T> implements SourceFunction<T>, Checkpointed<Long> {
+	 *  public class ExampleSource<T> implements SourceFunction<T>, CheckpointedFunction<Long> {
 	 *      private long count = 0L;
 	 *      private volatile boolean isRunning = true;
 	 *

flink-streaming-scala/src/main/scala/org/apache/flink/streaming/api/scala/StreamExecutionEnvironment.scala

@@ -229,7 +229,7 @@ class StreamExecutionEnvironment(javaEnv: JavaEnv) {
    * [[KeyedStream]] is maintained (heap, managed memory, externally), and where state
    * snapshots/checkpoints are stored, both for the key/value state, and for checkpointed
    * functions (implementing the interface 
-   * [[org.apache.flink.streaming.api.checkpoint.Checkpointed]].
+   * [[org.apache.flink.streaming.api.checkpoint.CheckpointedFunction]].
    *
    * <p>The [[org.apache.flink.runtime.state.memory.MemoryStateBackend]] for example
    * maintains the state in heap memory, as objects. It is lightweight without extra