+;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
+;;;; *************************************************************************
+;;;; FILE IDENTIFICATION
+;;;;
+;;;; Name: encode.lisp
+;;;; Purpose: cl-base64 encoding routines
+;;;; Programmer: Kevin M. Rosenberg
+;;;; Date Started: Dec 2002
+;;;;
+;;;; $Id: encode.lisp,v 1.1 2003/01/12 20:25:26 kevin Exp $
+;;;;
+;;;; This file implements the Base64 transfer encoding algorithm as
+;;;; defined in RFC 1521 by Borensten & Freed, September 1993.
+;;;; See: http://www.ietf.org/rfc/rfc1521.txt
+;;;;
+;;;; Based on initial public domain code by Juri Pakaste <juri@iki.fi>
+;;;;
+;;;; Copyright 2002-2003 Kevin M. Rosenberg
+;;;; Permission to use with BSD-style license included in the COPYING file
+;;;; *************************************************************************
+
+(declaim (optimize (debug 3) (speed 3) (safety 1) (compilation-speed 0)))
+
+;;;; Extended by Kevin M. Rosenberg <kevin@rosenberg.net>:
+;;;; - .asd file
+;;;; - numerous speed optimizations
+;;;; - conversion to and from integers
+;;;; - Renamed functions now that supporting integer conversions
+;;;; - URI-compatible encoding using :uri key
+;;;;
+;;;; $Id: encode.lisp,v 1.1 2003/01/12 20:25:26 kevin Exp $
+
+(in-package #:cl-base64)
+
+
+(defun round-next-multiple (x n)
+ "Round x up to the next highest multiple of n."
+ (declare (fixnum n)
+ (optimize (speed 3)))
+ (let ((remainder (mod x n)))
+ (declare (fixnum remainder))
+ (if (zerop remainder)
+ x
+ (the fixnum (+ x (the fixnum (- n remainder)))))))
+
+(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 (char-code (the character
+ (char string isource))) 16))
+ (the fixnum
+ (ash (char-code (the character
+ (char string (1+ isource)))) 8))))
+ 3))
+ ((= remainder 1)
+ (output-group
+ (the fixnum
+ (ash (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))))))
+
+(defun integer-to-base64 (input &key (uri nil) (columns 0) (stream nil))
+ (if stream
+ (integer-to-base64-stream input stream :uri uri :columns columns)
+ (integer-to-base64-string input :uri uri :columns columns)))
+
+(defun integer-to-base64-string (input &key (uri nil) (columns 0))
+ "Encode an integer to base64 format."
+ (declare (integer input)
+ (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* ((input-bits (integer-length input))
+ (byte-bits (round-next-multiple input-bits 8))
+ (padded-bits (round-next-multiple byte-bits 6))
+ (remainder-padding (mod padded-bits 24))
+ (padding-bits (if (zerop remainder-padding)
+ 0
+ (- 24 remainder-padding)))
+ (padding-chars (/ padding-bits 6))
+ (padded-length (/ (+ padded-bits padding-bits) 6))
+ (last-line-len (if (plusp columns)
+ (- padded-length (* columns
+ (truncate
+ padded-length columns)))
+ 0))
+ (num-lines (if (plusp columns)
+ (truncate (+ padded-length (1- columns)) columns)
+ 0))
+ (num-breaks (if (plusp num-lines)
+ (1- num-lines)
+ 0))
+ (strlen (+ padded-length num-breaks))
+ (last-char (1- strlen))
+ (str (make-string strlen))
+ (col (if (zerop last-line-len)
+ columns
+ last-line-len)))
+ (declare (fixnum padded-length num-lines col last-char
+ padding-chars last-line-len))
+ (unless (plusp columns)
+ (setq col -1)) ;; set to flag to optimize in loop
+
+ (dotimes (i padding-chars)
+ (declare (fixnum i))
+ (setf (schar str (the fixnum (- last-char i))) pad))
+
+ (do* ((strpos (- last-char padding-chars) (1- strpos))
+ (int (ash input (/ padding-bits 3))))
+ ((minusp strpos)
+ str)
+ (declare (fixnum strpos) (integer int))
+ (cond
+ ((zerop col)
+ (setf (schar str strpos) #\Newline)
+ (setq col columns))
+ (t
+ (setf (schar str strpos)
+ (schar encode-table (the fixnum (logand int #x3f))))
+ (setq int (ash int -6))
+ (decf col)))))))
+
+(defun integer-to-base64-stream (input stream &key (uri nil) (columns 0))
+ "Encode an integer to base64 format."
+ (declare (integer input)
+ (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* ((input-bits (integer-length input))
+ (byte-bits (round-next-multiple input-bits 8))
+ (padded-bits (round-next-multiple byte-bits 6))
+ (remainder-padding (mod padded-bits 24))
+ (padding-bits (if (zerop remainder-padding)
+ 0
+ (- 24 remainder-padding)))
+ (padding-chars (/ padding-bits 6))
+ (padded-length (/ (+ padded-bits padding-bits) 6))
+ (strlen padded-length)
+ (nonpad-chars (- strlen padding-chars))
+ (last-nonpad-char (1- nonpad-chars))
+ (str (make-string strlen)))
+ (declare (fixnum padded-length last-nonpad-char))
+ (do* ((strpos 0 (1+ strpos))
+ (int (ash input (/ padding-bits 3)) (ash int -6))
+ (6bit-value (logand int #x3f) (logand int #x3f)))
+ ((= strpos nonpad-chars)
+ (let ((col 0))
+ (declare (fixnum col))
+ (dotimes (i nonpad-chars)
+ (declare (fixnum i))
+ (write-char (schar str i) stream)
+ (when (plusp columns)
+ (incf col)
+ (when (= col columns)
+ (write-char #\Newline stream)
+ (setq col 0))))
+ (dotimes (ipad padding-chars)
+ (declare (fixnum ipad))
+ (write-char pad stream)
+ (when (plusp columns)
+ (incf col)
+ (when (= col columns)
+ (write-char #\Newline stream)
+ (setq col 0)))))
+ stream)
+ (declare (fixnum 6bit-value strpos)
+ (integer int))
+ (setf (schar str (- last-nonpad-char strpos))
+ (schar encode-table 6bit-value))
+ ))))
+
projects / cl-base64.git / blobdiff