factor/basis/base64/base64.factor

103 lines
2.8 KiB
Factor

! Copyright (C) 2008 Doug Coleman, Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: arrays combinators fry io io.binary io.encodings.binary
io.streams.byte-array kernel literals math namespaces sbufs
sequences ;
IN: base64
ERROR: malformed-base64 ;
<PRIVATE
<<
CONSTANT: alphabet
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
: alphabet-inverse ( alphabet -- seq )
dup supremum 1 + f <array> [
'[ swap _ set-nth ] each-index
] keep ;
>>
: ch>base64 ( ch -- ch )
alphabet nth ; inline
: base64>ch ( ch -- ch )
$[ alphabet alphabet-inverse 0 CHAR: = pick set-nth ] nth
[ malformed-base64 ] unless* ; inline
: (write-lines) ( column byte-array -- column' )
output-stream get dup '[
_ stream-write1 1 + dup 76 = [
drop B{ CHAR: \r CHAR: \n } _ stream-write 0
] when
] each ; inline
: write-lines ( column byte-array -- column' )
over [ (write-lines) ] [ write ] if ; inline
: encode3 ( seq -- byte-array )
be> { -18 -12 -6 0 } '[
shift 0x3f bitand ch>base64
] with B{ } map-as ; inline
: encode-pad ( seq n -- byte-array )
[ 3 0 pad-tail encode3 ] [ 1 + ] bi* head-slice
4 CHAR: = pad-tail ; inline
: (encode-base64) ( stream column -- )
3 pick stream-read dup length {
{ 0 [ 3drop ] }
{ 3 [ encode3 write-lines (encode-base64) ] }
[ encode-pad write-lines (encode-base64) ]
} case ;
PRIVATE>
: encode-base64 ( -- )
input-stream get f (encode-base64) ;
: encode-base64-lines ( -- )
input-stream get 0 (encode-base64) ;
<PRIVATE
: read1-ignoring ( ignoring stream -- ch )
dup stream-read1 pick dupd member?
[ drop read1-ignoring ] [ 2nip ] if ; inline recursive
: push-ignoring ( accum ch -- accum )
dup { f 0 } member-eq? [ drop ] [ suffix! ] if ; inline
: read-into-ignoring ( accum n ignoring stream -- accum )
'[ _ _ read1-ignoring push-ignoring ] times ; inline
: read-ignoring ( n ignoring stream -- accum )
[ [ <sbuf> ] keep ] 2dip read-into-ignoring ; inline
: decode4 ( seq -- )
[ 0 [ base64>ch swap 6 shift bitor ] reduce 3 >be ]
[ [ CHAR: = = ] count ] bi
[ write ] [ head-slice* write ] if-zero ; inline
: (decode-base64) ( stream -- )
4 "\n\r" pick read-ignoring dup length {
{ 0 [ 2drop ] }
{ 4 [ decode4 (decode-base64) ] }
[ drop 4 CHAR: = pad-tail decode4 (decode-base64) ]
} case ;
PRIVATE>
: decode-base64 ( -- )
input-stream get (decode-base64) ;
: >base64 ( seq -- base64 )
binary [ binary [ encode-base64 ] with-byte-reader ] with-byte-writer ;
: base64> ( base64 -- seq )
binary [ binary [ decode-base64 ] with-byte-reader ] with-byte-writer ;
: >base64-lines ( seq -- base64 )
binary [ binary [ encode-base64-lines ] with-byte-reader ] with-byte-writer ;