factor/basis/base64/base64.factor

101 lines
2.8 KiB
Factor

! Copyright (C) 2008 Doug Coleman, Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: combinators fry io io.binary io.encodings.binary
io.streams.byte-array kernel math namespaces
sequences strings ;
IN: base64
ERROR: malformed-base64 ;
<PRIVATE
: read1-ignoring ( ignoring stream -- ch )
dup stream-read1 pick dupd member?
[ drop read1-ignoring ] [ 2nip ] if ;
: read-ignoring ( n ignoring stream -- str )
'[ _ _ read1-ignoring ] replicate
[ { f 0 } member-eq? not ] "" filter-as
[ f ] when-empty ;
: ch>base64 ( ch -- ch )
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
nth ; inline
: base64>ch ( ch -- ch )
{
f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f
f f f f f f f f f f 62 f f f 63 52 53 54 55 56 57 58 59 60 61 f f
f 0 f f f 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 f f f f f f 26 27 28 29 30 31 32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47 48 49 50 51
} nth [ malformed-base64 ] unless* ; inline
SYMBOL: column
: write1-lines ( column/f ch stream -- column' )
[ stream-write1 ] keep swap [
1 + swap
'[ 76 = [ B{ CHAR: \r CHAR: \n } _ stream-write ] when ]
[ 76 mod ] bi
] [ drop f ] if* ;
: write-lines ( str -- )
column output-stream get '[
swap [ _ write1-lines ] each
] change ;
: encode3 ( seq -- )
column output-stream get '[
swap be> { 3 2 1 0 } [
-6 * shift 0x3f bitand ch>base64 _ write1-lines
] with each
] change ; inline
: encode-pad ( seq n -- )
[ 3 0 pad-tail binary [ encode3 ] with-byte-writer ]
[ 1 + ] bi* head-slice 4 CHAR: = pad-tail write-lines ; inline
: decode4 ( seq -- )
[ 0 [ base64>ch swap 6 shift bitor ] reduce 3 >be ]
[ [ CHAR: = = ] count ] bi head-slice*
output-stream get '[ _ stream-write1 ] each ; inline
: (encode-base64) ( stream -- )
3 over stream-read dup length {
{ 0 [ 2drop ] }
{ 3 [ encode3 (encode-base64) ] }
[ encode-pad (encode-base64) ]
} case ;
PRIVATE>
: encode-base64 ( -- )
input-stream get (encode-base64) ;
: encode-base64-lines ( -- )
0 column [ encode-base64 ] with-variable ;
<PRIVATE
: (decode-base64) ( stream -- )
4 "\n\r" pick read-ignoring dup length {
{ 0 [ 2drop ] }
{ 4 [ decode4 (decode-base64) ] }
[ malformed-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 ;