basis/compression/snappy/snappy.factor

   1 ! Copyright (C) 2014 Doug Coleman.
   2 ! See http://factorcode.org/license.txt for BSD license.
   3 USING: alien.c-types alien.data byte-arrays compression.snappy.ffi
   4 kernel sequences ;
   5 IN: compression.snappy
   6
   7 ERROR: snappy-error error ;
   8
   9 <PRIVATE
  10
  11 : check-snappy ( ret -- )
  12     dup SNAPPY_OK = [ drop ] [ throw-snappy-error ] if ;
  13
  14 : n>outs ( n -- byte-array size_t* )
  15     [ <byte-array> ] [ size_t <ref> ] bi ;
  16
  17 PRIVATE>
  18
  19 : snappy-compress ( byte-array -- compressed )
  20     dup length
  21     dup snappy_max_compressed_length
  22     n>outs
  23     [ snappy_compress check-snappy ] 2keep size_t deref head ;
  24
  25 : snappy-uncompress ( compressed -- byte-array )
  26     dup length
  27     over
  28     dup length 0 size_t <ref>
  29     [ snappy_uncompressed_length check-snappy ] keep
  30     size_t deref
  31     n>outs
  32     [ snappy_uncompress check-snappy ] 2keep drop >byte-array ;