No function to allow_compaction for FifoCompactOptions

When creating a new rocksdb database with FIFO compactions, I believe it is necessary to have compactions enabled to be able to actually delete old table files. In my OPTIONS file I can see that the allow_compactions paramater is by default set to false (see below).

compaction_options_fifo={allow_compaction=false;age_for_warm=0;max_table_files_size=20480;}

After looking through this codebase I do not see a public function to be able to set allow_compaction equal to true, meaning FIFO compactions don't work. i.e. old sst files are never deleted once set_max_table_files_size is reached. I tested this out by setting a low max_table_files_size size (20KB), and seeing that even with manual flushes/compactions happening in code the total_sst_files_size grows well beyond the 20KB and no sst files are ever deleted.

Is there a workaround to get FIFO compactions working in rocksdb crate?

Start with FifoCompactOptions and the compaction_options_fifo OPTIONS entry, then trace how allow_compaction and set_max_table_files_size are exposed. Done means a public way to enable allow_compaction and verification that old SST files are deleted when a low table-size limit is reached.