TokyoCabinet's Ruby C interface can't bzip

Question

I'm using the Ruby official Ruby C interface and am not able to bzip working. It did build with bzip support, ./configure said:

checking bzlib.h usability... yes
checking bzlib.h presence... yes
checking for bzlib.h... yes

So I wrote this example program that just writes an entry to two files, one supposedly bzip'd and one not. Neither is compressed; aside from the simple file size test at the end I can edit the with_bzip.tcb file and see the raw string text there.

require 'tokyocabinet'
include TokyoCabinet

def write filename, options
  File.unlink filename if File.exists? filename
  bdb = BDB::new
  bdb.tune(0, 0, 0, -1 -1, options) or raise "Couldn't tune"
  bdb.open(filename, BDB::OWRITER | BDB::OCREAT | BDB::OLCKNB) or raise "Couldn't open"
  bdb["test"] = "This string should be compressed and not appear raw.\n" * 10000
  bdb.close
end

write 'without_bzip.tcb', 0
write 'with_bzip.tcb', BDB::TBZIP
puts "Not actually compressed" unless File.size('with_bzip.tcb') < File.size('without_bzip.tcb')

What makes it worse is that if I try a preview release of Oklahoma Mixer (example following - though I don't have the reputation to add the new tag), it compresses fine. When I tucked some debugging into its try() call, it seems to be making the same call to tune(0, 0, 0, -1, -1, 4). I'm pretty completely stumped - can anyone tell me what my code above is doing wrong?

require 'oklahoma_mixer'
OklahomaMixer.open("minimal_om.tcb", :opts => 'lb') do |db|
  db["test"] = "This string should be compressed and not appear raw.\n" * 10000
end 

Answer 1

It is an evil, subtle bug. I left out a comma in the tune() call and wrote -1 -1 instead of -1, -1. All the arguments are optional, so it was quietly not bzipping. Argh.