Summary:
The methods in convenience.h are used to compare/convert objects to/from strings. There is a mishmash of parameters in use here with more needed in the future. This PR replaces those parameters with a single structure.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6389
Reviewed By: siying
Differential Revision: D21163707
Pulled By: zhichao-cao
fbshipit-source-id: f807b4cc7e2b0af3871536b69546b2604dfa81bd
