How NiFi writes data into HDFS? whats the internal process?

[#1]

How NiFi writes data into HDFS? whats the internal process it uses?

[#2]

If PutHDFS is used; https://github.com/apache/nifi/blob/master/nifi-nar-bundles/nifi-hadoop-bundle/nifi-hdfs-processors/...

In the above lines from the source we can see;
1. The flowfile is written to HDFS as a tmp file
2. The tmp file is renamed to the desired filename
3. A log entry is created, which looks as follows for a successful operation:

 getLogger().info("copied {} to HDFS at {} in {} milliseconds at a rate of {}"

Or in case of failure:

getLogger().error("Failed to write to HDFS due to {}", new Object[]{t});

In the top of the source code, import org.apache.hadoop.fs.FileSystem; is performed, which is used for the hdfs.create. More info on this base class; https://hadoop.apache.org/docs/r2.8.2/api/org/apache/hadoop/fs/FileSystem.html