factor/basis/compression/zlib/zlib.factor

69 lines
2.0 KiB
Factor

! Copyright (C) 2009 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors alien alien.c-types alien.data alien.syntax
byte-arrays byte-vectors combinators continuations destructors
fry kernel libc math math.functions math.ranges sequences system ;
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
neg ! zlib error codes are negative
{
"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-vector> dup underlying>> ] keep ulong <ref>
] keep [
dup length compression.zlib.ffi:compress zlib-error
] 2keep drop ulong deref >>length B{ } like
] keep length <compressed> ;
GENERIC: uncompress ( obj -- byte-array )
M: compressed uncompress
[
length>> [ <byte-vector> dup underlying>> ] keep
ulong <ref>
] [
data>> dup length pick
[ compression.zlib.ffi:uncompress zlib-error ] dip
] bi ulong deref >>length B{ } like ;
: (uncompress) ( length byte-array -- byte-array )
[
[ drop [ malloc &free ] [ ulong <ref> ] bi ]
[ nip dup length ] 2bi
[ compression.zlib.ffi:uncompress zlib-error ] 4keep
2drop ulong deref memory>byte-array
] with-destructors ;
M: byte-array uncompress
[ length 5 [0,b) [ 2^ * ] with map ] keep
'[ _ (uncompress) ] attempt-all ;