[FLINK-9751] [filesystem] Add fixes and tests for Persistent Resumabl…

…e Writers

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalRecoverableFsDataOutputStream.java

@@ -57,11 +57,11 @@ class LocalRecoverableFsDataOutputStream extends RecoverableFsDataOutputStream {
 		this.tempFile = checkNotNull(resumable.tempFile());
 
 		if (!tempFile.exists()) {
-			throw new FileNotFoundException("File Not Found: " + tempFile.getName());
+			throw new FileNotFoundException("File Not Found: " + tempFile);
 		}
 
 		if (tempFile.length() < resumable.offset()) {
-			throw new IOException("Missing data in tmp file: " + tempFile.getName());
+			throw new IOException("Missing data in tmp file: " + tempFile);
 		}
 
 		this.fos = new FileOutputStream(this.tempFile, true);
@@ -165,6 +165,8 @@ public void commitAfterRecovery() throws IOException {
 					try (FileOutputStream fos = new FileOutputStream(src, true)) {
 						fos.getChannel().truncate(expectedLength);
 					}
+				} else if (src.length() < expectedLength) {
+					throw new IOException("Missing data in tmp file: " + src);
 				}
 
 				// source still exists, so no renaming happened yet. do it!

flink-core/src/main/java/org/apache/flink/core/io/SimpleVersionedSerializer.java

@@ -18,6 +18,8 @@
 
 package org.apache.flink.core.io;
 
+import org.apache.flink.annotation.Internal;
+
 import java.io.IOException;
 
 /**
@@ -44,6 +46,7 @@
  * 
  * @param <E> The data type serialized / deserialized by this serializer.
  */
+@Internal
 public interface SimpleVersionedSerializer<E> extends Versioned {
 
 	/**