I impemented a potential solution to "[BEAM-64] General decompression registry". It still needs a bit more attention with some of the finer details, e.g. better error handling, better javadocs, adding unit tests.
However, before I spend more time on it, I would like a review of the general design. https://github.com/apache/incubator-beam/compare/master...fkautz:beam-64?expand=1 Design: I attempted to implement an approach that would require no code changes to the users. There is an SDK interface change, but it should be backwards compatible with existing code. TextIO.withCompression() is now capable of receiving a generic compressor operator which includes all of the enums from before (AUTO, UNCOMPRESSED, GZIP, BZIP2) but now can also receive a user or library implemented compressor. CompressionType also receives a new getRegistry() which allows the user to customize the behavior of AUTO. It allows the user to add, replace or remove registered compressors as necessary. Here's a short list of changes: * Create a new CompressorOperator, compatible with Java 8 lambda * CompressionType enum now implements CompressorType * withCompression now takes a CompressorOperator * Compression wrappers implementations moved from in-line code to CompressionType enum * Compression registry created * AUTO now supports compressors registered with the registry Can someone review the design and give me feedback? If the design looks good, I'll move forward on implementing tests, better exception error messages, and improve the javadocs. Thanks, Frederick
