Hadoop file streaming

[robertogiachetta]

The Hadoop Distributed File System (HDFS) is supported by the HadoopFileSystem type using HTTP requests. However, the file system also offers operations which return an open stream to the file allocated on the file system, which is not supported by the build-in HTTP handlers.

To simulate the open stream in the HTTP environment, add a custom Stream type named HadoopStream, which utilizes the already available file system operation types to perform read/write queries on the remote files. The type should hide all limitations of Hadoop, and should support standard exceptions.