title: What is the fastest bzip2 decompressor?
body: <p>Which implementation of bzip2 have the biggest decompression speed? </p>
  
  <p>There is a <a href="http://bitbucket.org/james_taylor/seek-bzip2/src/tip/micro-bunzip.c" rel="noreferrer">http://bitbucket.org/james_taylor/seek-bzip2/src/tip/micro-bunzip.c</a> which claims</p>
  
  <blockquote>
    <p>Size and speed optimizations by
    Manuel Novoa III  (mjn3@codepoet.org).
    More efficient reading of huffman
    codes, a streamlined read_bunzip() 
    function, and various other tweaks. 
    In (limited) tests, approximately  20%
    faster than bzcat on x86 and about 10%
    faster on arm.  Note that about 2/3 of
    the time is spent in read_unzip()
    reversing  the Burrows-Wheeler
    transformation.  Much of that time is
    delay  resulting from cache misses.</p>
  </blockquote>
  
  <p>A lot of cache misses have a chance to be optimized out by some techniques, so even faster implementations are possible.</p>
  
  <p>This one (seek-bzip2) have also an interesting feature of easy seeking in the input file.</p>
  
  <p>My program will consume output of bzip2 and (Theoretically) can do this in parallel on different parts of file. So, parallel bzip2 implementations are considered too.</p>
  
  <p>Thanks.</p>