extract_bitcask.erl

-module(extract_bitcask).

main([Dir, Output]) ->
  {ok, Fh} = file:open(Output,[write]),
  io:format("Dumping bucket/keys for partition: ~p to output file: ~p\n", [Dir,Output]),
  F = fun(Entry, _Acc) -> 
                case Entry of
                  {bitcask_entry, Key, _S, _T, _F, _U} ->
                    {B, K} = binary_to_term(Key),
                    erlang:put(extraction_counter, erlang:get(extraction_counter) + 1)  ,
                    io:format(Fh, "\"~s\",\"~s\"\n", [csv_encode(B),csv_encode(K)]);
                  _ ->
                    true
                end            
      end,
  erlang:put(extraction_counter, 0),
  Ref = bitcask:open(Dir),
  bitcask:fold_keys(Ref, F, true), 
  io:format("Extracted ~w records\n", [erlang:get(extraction_counter)]);

main(_) ->
  usage().

usage() ->
  io:format("usage: extract PATH_TO_PARTITION OUTPUT_FILE\n"),
  halt(1).

csv_encode(Bin) ->
    csv_encode(lists:reverse(binary_to_list(Bin)), []).

csv_encode([], Acc) ->
    list_to_binary(Acc);
csv_encode([$\n | Rest], Acc) ->
    csv_encode(Rest, [$\\, $n | Acc]);
csv_encode([$\\ | Rest], Acc) ->
    csv_encode(Rest, [$\\, $\\ | Acc]);
csv_encode([Char |Rest], Acc) ->
    csv_encode(Rest, [Char | Acc]).