-(defun string-to-base64 (string &key (uri nil) (columns 0) (stream nil))
- "Encode a string array to base64. If columns is > 0, designates
-maximum number of columns in a line and the string will be terminated
-with a #\Newline."
- (declare (string string)
- (fixnum columns)
- (optimize (speed 3)))
- (let ((pad (if uri *uri-pad-char* *pad-char*))
- (encode-table (if uri *uri-encode-table* *encode-table*)))
- (declare (simple-string encode-table)
- (character pad))
- (let* ((string-length (length string))
- (complete-group-count (truncate string-length 3))
- (remainder (nth-value 1 (truncate string-length 3)))
- (padded-length (* 4 (truncate (+ string-length 2) 3)))
- (num-lines (if (plusp columns)
- (truncate (+ padded-length (1- columns)) columns)
- 0))
- (num-breaks (if (plusp num-lines)
- (1- num-lines)
- 0))
- (strlen (if stream
- 0
- (+ padded-length num-breaks)))
- (result (make-string strlen))
- (col (if (plusp columns)
- 0
- (1+ padded-length)))
- (ioutput 0))
- (declare (fixnum string-length padded-length col ioutput)
- (simple-string result))
- (labels ((output-char (ch)
- (if (= col columns)
- (progn
- (if stream
- (write-char #\Newline stream)
- (progn
- (setf (schar result ioutput) #\Newline)
- (incf ioutput)))
- (setq col 1))
- (incf col))
- (if stream
- (write-char ch stream)
- (progn
- (setf (schar result ioutput) ch)
- (incf ioutput))))
- (output-group (svalue chars)
- (declare (fixnum svalue chars))
- (output-char
- (schar encode-table
- (the fixnum
- (logand #x3f
- (the fixnum (ash svalue -18))))))
- (output-char
- (schar encode-table
- (the fixnum
- (logand #x3f
- (the fixnum (ash svalue -12))))))
- (if (> chars 2)
- (output-char
- (schar encode-table
- (the fixnum
- (logand #x3f
- (the fixnum (ash svalue -6))))))
- (output-char pad))
- (if (> chars 3)
- (output-char
- (schar encode-table
- (the fixnum
- (logand #x3f svalue))))
- (output-char pad))))
- (do ((igroup 0 (1+ igroup))
- (isource 0 (+ isource 3)))
- ((= igroup complete-group-count)
- (cond
- ((= remainder 2)
- (output-group
- (the fixnum
- (+
- (the fixnum
- (ash (the fixnum
- (char-code (the character
- (char string isource))))
- 16))
- (the fixnum
- (ash (the fixnum
- (char-code (the character
- (char string (1+ isource)))))
- 8))))
- 3))
- ((= remainder 1)
- (output-group
- (the fixnum
- (ash
- (the fixnum
- (char-code (the character (char string isource))))
- 16))
- 2)))
- result)
- (declare (fixnum igroup isource))
- (output-group
- (the fixnum
- (+
- (the fixnum
- (ash (char-code (the character
- (char string isource))) 16))
- (the fixnum
- (ash (char-code (the character (char string (1+ isource)))) 8))
- (the fixnum
- (char-code (the character (char string (+ 2 isource)))))))
- 4))))))
-