factor/basis/compression/zlib/zlib.factor

49 lines
1.4 KiB
Factor
Executable File

! Copyright (C) 2009 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: alien alien.c-types alien.syntax byte-arrays combinators
kernel math math.functions sequences system accessors
libc ;
QUALIFIED: compression.zlib.ffi
IN: compression.zlib
TUPLE: compressed data length ;
: <compressed> ( data length -- compressed )
compressed new
swap >>length
swap >>data ;
ERROR: zlib-failed n string ;
: zlib-error-message ( n -- * )
dup compression.zlib.ffi:Z_ERRNO = [
drop errno "native libc error"
] [
dup {
"no error" "libc_error"
"stream error" "data error"
"memory error" "buffer error" "zlib version error"
} ?nth
] if zlib-failed ;
: zlib-error ( n -- )
dup compression.zlib.ffi:Z_OK = [ drop ] [ dup zlib-error-message zlib-failed ] if ;
: compressed-size ( byte-array -- n )
length 1001/1000 * ceiling 12 + ;
: compress ( byte-array -- compressed )
[
[ compressed-size <byte-array> dup length <ulong> ] keep [
dup length compression.zlib.ffi:compress zlib-error
] 3keep drop *ulong head
] keep length <compressed> ;
: uncompress ( compressed -- byte-array )
[
length>> [ <byte-array> ] keep <ulong> 2dup
] [
data>> dup length
compression.zlib.ffi:uncompress zlib-error
] bi *ulong head ;