[haberman]

I think the open-source equivalent of RecordIO is the leveldb log format:

https://github.com/google/leveldb/blob/master/doc/log_format...

https://github.com/google/leveldb/blob/master/db/log_reader....

https://github.com/google/leveldb/blob/master/db/log_writer....

I think the decision not to open-source RecordIO is likely related to legacy baggage that's baked into the format. The LevelDB format above avoids that.

It doesn't appear that the headers for this are public though.