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fd26d811 FT |
1 | ;;;; CHAR-CODE -- Conversions between characters and byte |
2 | ;;;; representations thereof | |
3 | ||
4 | (defpackage :charcode | |
5 | (:use :cl #+sbcl :sb-gray #-sbcl :gray) | |
6f9e13dc | 6 | (:export "MAKE-ENCODER" "MAKE-DECODER" "ENCODE-STRING" "DECODE-STRING" "SYSTEM-CHARSET" |
fd26d811 | 7 | "CODING-ERROR" |
ebf1ccf7 | 8 | "MAKE-CODEC-CHARACTER-STREAM" |
4dd02a73 | 9 | "ASCII" "LATIN-1" "LATIN1" "UTF-8" "UTF8")) |
fd26d811 FT |
10 | (in-package :charcode) |
11 | ||
12 | ;;; General stuff | |
13 | ||
14 | (define-condition coding-error (error) | |
15 | ((input :initarg :input) | |
16 | (position :initarg :position) | |
17 | (result :initarg :result))) | |
18 | ||
19 | (define-condition simple-coding-error (coding-error simple-error) ()) | |
20 | ||
21 | (defun coding-error (input position result format &rest format-args) | |
22 | (error 'simple-coding-error | |
23 | :input input :position position :result result | |
24 | :format-control format :format-arguments format-args)) | |
25 | ||
26 | (deftype decoder-fun () `(function ((array (unsigned-byte 8)) | |
27 | (array character) | |
28 | &key (start fixnum) (end fixnum)) | |
29 | (member t nil))) | |
30 | (deftype encoder-fun () `(function ((array character) | |
31 | (array (unsigned-byte 8)) | |
32 | &key (start fixnum) (end fixnum)) | |
33 | (member t nil))) | |
34 | ||
35 | (defmacro define-encoder ((name) &body make-encoder) | |
36 | `(setf (get ',name 'make-encoder) #'(lambda () ,@make-encoder))) | |
37 | ||
38 | (defmacro define-decoder ((name) &body make-decoder) | |
39 | `(setf (get ',name 'make-decoder) #'(lambda () ,@make-decoder))) | |
40 | ||
41 | (defmacro define-codec-synonyms (name &rest synonyms) | |
42 | `(eval-when (:load-toplevel :execute) | |
43 | ,@(mapcar #'(lambda (sym) | |
44 | `(setf (get ',sym 'make-encoder) (get ',name 'make-encoder) | |
45 | (get ',sym 'make-decoder) (get ',name 'make-decoder))) | |
46 | synonyms))) | |
47 | ||
48 | (defun make-encoder (name) | |
49 | (the encoder-fun (values (funcall (get name 'make-encoder))))) | |
50 | ||
51 | (defun make-decoder (name) | |
52 | (the decoder-fun (values (funcall (get name 'make-decoder))))) | |
53 | ||
6f9e13dc FT |
54 | (defun system-charset () |
55 | ;; XXX: Replace me with something perhaps more sensible. | |
56 | 'utf-8) | |
57 | ||
58 | (defun encode-string (string &optional (coding (system-charset))) | |
fd26d811 FT |
59 | (declare (type string string)) |
60 | (let ((encoder (make-encoder coding)) | |
61 | (buf (make-array (list (length string)) :element-type '(unsigned-byte 8) :adjustable t :fill-pointer 0))) | |
62 | (unless (funcall encoder string buf) | |
63 | (coding-error string (length string) buf "Encoding of string in ~A ended prematurely." coding)) | |
64 | buf)) | |
65 | ||
6f9e13dc | 66 | (defun decode-string (buffer &optional (coding (system-charset))) |
fd26d811 FT |
67 | (declare (type (array (unsigned-byte 8)) buffer)) |
68 | (let ((decoder (make-decoder coding)) | |
69 | (buf (make-array (list (length buffer)) :element-type 'character :adjustable t :fill-pointer 0))) | |
70 | (unless (funcall decoder buffer buf) | |
71 | (coding-error buffer (length buffer) buf "~A byte sequence ended prematurely." coding)) | |
72 | buf)) | |
73 | ||
74 | ;;; Gray stream implementation | |
75 | ||
76 | (defclass codec-character-stream (fundamental-character-input-stream fundamental-character-output-stream) | |
77 | ((decoder :initarg :decoder) | |
78 | (encoder :initarg :encoder) | |
79 | (back :initarg :back) | |
80 | (read-pos :initform 0) | |
81 | (buffer :initform (make-array '(64) :element-type 'character :adjustable t :fill-pointer 0)))) | |
82 | ||
6f9e13dc | 83 | (defun make-codec-character-stream (real-stream &optional (charset (system-charset))) |
ebf1ccf7 FT |
84 | (declare (type stream real-stream)) |
85 | (make-instance 'codec-character-stream :decoder (make-decoder charset) :encoder (make-encoder charset) :back real-stream)) | |
86 | ||
fd26d811 FT |
87 | (defmethod close ((stream codec-character-stream) &key abort) |
88 | (with-slots (back) stream | |
89 | (close back :abort abort)) | |
90 | (call-next-method)) | |
91 | ||
92 | (defmethod open-stream-p ((stream codec-character-stream)) | |
93 | (with-slots (back) stream | |
94 | (open-stream-p stream))) | |
95 | ||
96 | (defun ccs-ensure-buffer (stream len) | |
97 | (declare (type codec-character-stream stream) | |
98 | (type integer len)) | |
99 | (with-slots (decoder back buffer read-pos) stream | |
100 | (let ((readbuf (make-array (list len) :element-type '(unsigned-byte 8)))) | |
101 | (loop (unless (< (- (length buffer) read-pos) len) (return t)) | |
75545f66 | 102 | (let ((readlen (read-sequence readbuf back :end (- len (- (length buffer) read-pos))))) |
fd26d811 FT |
103 | (when (= readlen 0) |
104 | (return-from ccs-ensure-buffer nil)) | |
105 | (funcall decoder readbuf buffer :end readlen)))))) | |
106 | ||
107 | (defun ccs-clear-buffer (stream) | |
108 | (declare (type codec-character-stream stream)) | |
109 | (with-slots (read-pos buffer) stream | |
110 | (replace buffer buffer :start2 read-pos) | |
75545f66 FT |
111 | (setf (fill-pointer buffer) (- (fill-pointer buffer) read-pos) |
112 | read-pos 0))) | |
fd26d811 FT |
113 | |
114 | (defmethod stream-read-char ((stream codec-character-stream)) | |
115 | (unless (ccs-ensure-buffer stream 1) | |
116 | (return-from stream-read-char :eof)) | |
117 | (with-slots (read-pos buffer) stream | |
118 | (prog1 (aref buffer read-pos) | |
119 | (when (>= (incf read-pos) 16) | |
120 | (ccs-clear-buffer stream))))) | |
121 | ||
122 | (defmethod stream-unread-char ((stream codec-character-stream) char) | |
123 | (with-slots (read-pos buffer) stream | |
124 | (when (= read-pos 0) | |
125 | (let ((len (length buffer))) | |
126 | (when (< (array-dimension buffer 0) (+ len 16)) | |
127 | (adjust-array buffer (list (setf (fill-pointer buffer) | |
128 | (+ len 16))))) | |
129 | (replace buffer buffer :start1 16 :end2 len))) | |
75545f66 | 130 | (setf (aref buffer (decf read-pos)) char) |
fd26d811 FT |
131 | nil)) |
132 | ||
133 | (defun ccs-wont-hang-p (stream) | |
134 | (declare (type codec-character-stream stream)) | |
135 | (with-slots (read-pos back buffer) stream | |
136 | (or (and (< read-pos (length buffer)) (aref buffer read-pos)) | |
137 | (listen back)))) | |
138 | ||
139 | (defmethod stream-read-char-no-hang ((stream codec-character-stream)) | |
140 | (if (ccs-wont-hang-p stream) | |
141 | (stream-read-char stream) | |
142 | nil)) | |
143 | ||
144 | (defmethod stream-peek-char ((stream codec-character-stream)) | |
145 | (unless (ccs-ensure-buffer stream 1) | |
146 | (return-from stream-peek-char :eof)) | |
147 | (with-slots (read-pos buffer) stream | |
148 | (aref buffer read-pos))) | |
149 | ||
150 | (defmethod stream-listen ((stream codec-character-stream)) | |
151 | (if (ccs-wont-hang-p stream) | |
152 | (let ((peek (stream-peek-char stream))) | |
153 | (if (eq peek :eof) | |
154 | nil | |
155 | peek)) | |
156 | nil)) | |
157 | ||
158 | (defmethod stream-write-char ((stream codec-character-stream) char) | |
159 | (with-slots (encoder back) stream | |
160 | (let ((seq (make-array '(1) :element-type 'character :initial-element char)) | |
161 | (outbuf (make-array '(16) :element-type '(unsigned-byte 8) :adjustable t :fill-pointer 0))) | |
162 | (funcall encoder seq outbuf) | |
163 | (write-sequence outbuf back)))) | |
164 | ||
165 | (defmethod stream-finish-output ((stream codec-character-stream)) | |
166 | (finish-output (slot-value stream 'back))) | |
167 | ||
168 | (defmethod stream-force-output ((stream codec-character-stream)) | |
169 | (force-output (slot-value stream 'back))) | |
170 | ||
171 | (defmethod stream-read-sequence ((stream codec-character-stream) seq &optional (start 0) (end (length seq))) | |
172 | (ccs-ensure-buffer stream (- end start)) | |
173 | (with-slots (read-pos buffer) stream | |
174 | (replace seq buffer :start1 start :end1 end :start2 read-pos :end2 (length buffer)) | |
175 | (let ((len (min (- end start) (- (length buffer) read-pos)))) | |
176 | (when (>= (incf read-pos len) 128) | |
177 | (ccs-clear-buffer stream))))) | |
178 | ||
179 | (defmethod stream-write-sequence ((stream codec-character-stream) seq &optional (start 0) (end (length seq))) | |
180 | (with-slots (encoder back) stream | |
181 | (let ((outbuf (make-array (list (- end start)) :element-type '(unsigned-byte 8) :adjustable t :fill-pointer 0))) | |
182 | (funcall encoder seq outbuf) | |
183 | (write-sequence outbuf back)))) | |
184 | ||
185 | ;;; Implementation-specific functions | |
186 | ||
187 | #+(or (and clisp unicode) sbcl) | |
188 | (defun unicode->char (unicode) | |
189 | (declare (type (unsigned-byte 24) unicode)) | |
190 | (code-char unicode)) | |
191 | ||
192 | #+(or (and clisp unicode) sbcl) | |
193 | (defun char->unicode (char) | |
194 | (declare (type character char)) | |
195 | (char-code char)) | |
196 | ||
4dd02a73 FT |
197 | ;;; ASCII |
198 | ||
199 | (defun decode-ascii (byteseq charseq &key (start 0) (end (length byteseq))) | |
200 | (declare (type (array (unsigned-byte 8)) byteseq) | |
201 | (type (array character) charseq) | |
202 | (type fixnum start end)) | |
203 | (loop | |
204 | (restart-case | |
205 | (loop | |
206 | (unless (< start end) (return-from decode-ascii t)) | |
207 | (let ((byte (aref byteseq (prog1 start (incf start))))) | |
208 | (unless (< byte 128) | |
209 | (coding-error byteseq start charseq "Invalid byte ~D in ASCII stream." byte)) | |
210 | (vector-push-extend (unicode->char byte) charseq))) | |
211 | (:replace-char (&optional (replacement (unicode->char #xfffd))) | |
212 | :report "Replace the invalid byte with a character." | |
213 | (vector-push-extend replacement charseq)) | |
214 | (:skip-char () | |
215 | :report "Ignore the invalid byte." | |
216 | nil)))) | |
217 | ||
218 | (defun encode-ascii (charseq byteseq &key (start 0) (end (length charseq))) | |
219 | (declare (type (array (unsigned-byte 8)) byteseq) | |
220 | (type (array character) charseq) | |
221 | (type fixnum start end)) | |
222 | (loop | |
223 | (restart-case | |
224 | (loop | |
225 | (unless (< start end) (return-from encode-ascii t)) | |
226 | (vector-push-extend (let ((cp (char->unicode (aref charseq (prog1 start (incf start)))))) | |
227 | (unless (< cp 128) | |
228 | (coding-error charseq start byteseq "ASCII cannot encode code-points higher than 128.")) | |
229 | cp) | |
230 | byteseq)) | |
231 | (:replace-char (&optional (replacement #\?)) | |
232 | :report "Replace this character with another." | |
233 | (vector-push-extend (char->unicode replacement) byteseq)) | |
234 | (:skip-char () | |
235 | :report "Ignore this character." | |
236 | nil)))) | |
237 | ||
238 | (define-decoder (ascii) | |
239 | #'decode-ascii) | |
240 | ||
241 | (define-encoder (ascii) | |
242 | #'encode-ascii) | |
243 | ||
f8eaaa29 FT |
244 | (define-codec-synonyms ascii :ascii) |
245 | ||
fd26d811 FT |
246 | ;;; Latin-1 |
247 | ||
248 | (defun decode-latin-1 (byteseq charseq &key (start 0) (end (length byteseq))) | |
249 | (declare (type (array (unsigned-byte 8)) byteseq) | |
250 | (type (array character) charseq) | |
251 | (type fixnum start end)) | |
252 | (do ((i start (1+ i))) | |
253 | ((>= i end)) | |
254 | (vector-push-extend (unicode->char (aref byteseq i)) charseq)) | |
255 | t) | |
256 | ||
257 | (defun encode-latin-1 (charseq byteseq &key (start 0) (end (length charseq))) | |
258 | (declare (type (array (unsigned-byte 8)) byteseq) | |
259 | (type (array character) charseq) | |
260 | (type fixnum start end)) | |
261 | (loop | |
262 | (restart-case | |
263 | (loop | |
264 | (unless (< start end) (return-from encode-latin-1 t)) | |
265 | (vector-push-extend (let ((cp (char->unicode (aref charseq (prog1 start (incf start)))))) | |
266 | (unless (< cp 256) | |
267 | (coding-error charseq start byteseq "ISO-8859-1 cannot encode code-points higher than 256.")) | |
268 | cp) | |
269 | byteseq)) | |
270 | (:replace-char (&optional (replacement #\?)) | |
271 | :report "Replace this character with another." | |
272 | (vector-push-extend (char->unicode replacement) byteseq)) | |
273 | (:skip-char () | |
274 | :report "Ignore this character." | |
275 | nil)))) | |
276 | ||
277 | (define-decoder (latin-1) | |
278 | #'decode-latin-1) | |
279 | ||
280 | (define-encoder (latin-1) | |
281 | #'encode-latin-1) | |
282 | ||
f8eaaa29 | 283 | (define-codec-synonyms latin-1 latin1 iso-8859-1 :latin-1 :latin1 :iso-8859-1) |
fd26d811 FT |
284 | |
285 | ;;; UTF-8 | |
286 | ||
287 | (defun encode-utf-8 (charseq byteseq &key (start 0) (end (length charseq))) | |
288 | (declare (type (array (unsigned-byte 8)) byteseq) | |
289 | (type (array character) charseq) | |
290 | (type fixnum start end)) | |
291 | (do ((i start (1+ i))) | |
292 | ((>= i end)) | |
293 | (let ((cp (char->unicode (aref charseq i)))) | |
294 | (if (< cp 128) | |
295 | (vector-push-extend cp byteseq) | |
296 | (let ((nbytes 0) | |
297 | (bytes '())) | |
298 | (loop | |
299 | (push (logior (ldb (byte 6 0) cp) #x80) bytes) | |
300 | (setf cp (truncate cp 64)) | |
301 | (incf nbytes) | |
302 | (when (< cp (expt 2 (- 6 nbytes))) | |
303 | (push (logior (logand #xff (lognot (1- (expt 2 (- 7 nbytes))))) | |
304 | cp) | |
305 | bytes) | |
306 | (return))) | |
307 | (dolist (byte bytes) | |
308 | (vector-push-extend byte byteseq)))))) | |
309 | t) | |
310 | ||
311 | (define-encoder (utf-8) | |
312 | #'encode-utf-8) | |
313 | ||
314 | (define-decoder (utf-8) | |
315 | (let ((mbuf 0) | |
316 | (mlen 0)) | |
317 | (flet ((decode (byteseq charseq &key (start 0) (end (length byteseq))) | |
318 | (declare (type (array (unsigned-byte 8)) byteseq) | |
319 | (type (array character) charseq) | |
320 | (type fixnum start end)) | |
321 | (let ((i start)) | |
322 | (flet ((failure (format &rest args) | |
323 | (error 'simple-coding-error | |
324 | :input byteseq :position i :result charseq | |
325 | :format-control format :format-arguments args))) | |
326 | (loop | |
327 | (restart-case | |
328 | (progn | |
329 | (loop | |
330 | (unless (< i end) (return)) | |
331 | (let ((byte (aref byteseq (prog1 i (incf i))))) | |
332 | (if (= mlen 0) | |
333 | (if (< byte 128) | |
334 | (vector-push-extend (unicode->char byte) charseq) | |
335 | (setf mlen (block zero | |
336 | (dotimes (i 7) | |
337 | (when (= (ldb (byte 1 (- 7 i)) byte) 0) | |
338 | (when (< i 2) | |
339 | (failure "UTF-8 sequence started with continuation byte: ~D" byte)) | |
340 | (return-from zero (1- i)))) | |
341 | (failure "Invalid UTF-8 sequence start byte: ~D" byte)) | |
342 | mbuf (ldb (byte (- 6 mlen) 0) byte))) | |
343 | (progn (when (not (= (ldb (byte 2 6) byte) 2)) | |
344 | (failure "Invalid UTF-8 continuation byte: ~D" byte)) | |
345 | (setf mbuf (+ (* mbuf 64) (ldb (byte 6 0) byte))) | |
346 | (when (= (decf mlen) 0) | |
347 | (when (< mbuf 128) | |
348 | (with-simple-restart (:accept "Accept anyway.") | |
349 | (failure "UTF-8 multibyte sequence denoted an ASCII character ~S (either an encoding error or an attempt at breaking security)." (unicode->char mbuf)))) | |
350 | (vector-push-extend (unicode->char mbuf) charseq)))))) | |
351 | (return-from decode (= mlen 0))) | |
352 | (:replace-char (&optional (replacement (unicode->char #xfffd))) | |
353 | :report "Replace the invalid bytes with a character." | |
354 | (vector-push-extend replacement charseq) | |
355 | (loop (unless (and (< i end) (= (ldb (byte 2 6) (aref byteseq i)) 2)) | |
356 | (return)) | |
357 | (incf i)) | |
358 | (setf mlen 0)) | |
359 | (:skip-char () | |
360 | :report "Ignore the invalid byte sequence." | |
361 | (loop (unless (and (< i end) (= (ldb (byte 2 6) (aref byteseq i)) 2)) | |
362 | (return)) | |
363 | (incf i)) | |
364 | (setf mlen 0)))))))) | |
365 | #'decode))) | |
366 | ||
f8eaaa29 | 367 | (define-codec-synonyms utf-8 utf8 :utf-8 :utf8) |