/[cffi-objects]/struct.lisp
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Contents of /struct.lisp

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Revision 18 - (show annotations)
Sat Jan 12 21:26:46 2013 UTC (15 months ago) by rklochkov
File size: 12131 byte(s)
Added support for MESSAGE-OO and (lisp-name . c-name) syntax for structure fields
1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
2 ;;;
3 ;;; struct.lisp --- CFFI wrapper for structs. We need to save on lisp
4 ;;; side only values of struct field, not pointer on
5 ;;; the struct to be able to garbage collect it
6 ;;;
7 ;;; Copyright (C) 2011, Roman Klochkov <kalimehtar@mail.ru>
8 ;;;
9
10 (in-package :cffi-objects)
11
12 (defclass struct (object)
13 ((value :documentation "plist ({field-name field-value}*)"))
14 (:documentation "If value bound, use it, else use pointer.
15 Struct may be used in OBJECT cffi-type or STRUCT cffi-type"))
16
17 (defgeneric new-struct (class)
18 (:method (class)
19 (foreign-alloc class)))
20
21 (defgeneric free-struct (class value)
22 (:method (class value)
23 (declare (ignore class))
24 ; (break)
25 ;(format t "Free ~a ~a~%" class value)
26 (foreign-free value)))
27
28 (if (find-symbol "MEM-APTR" "CFFI") ;; new cffi
29 (defun struct-type (type)
30 (list :struct type))
31 (defun struct-type (type)
32 type))
33
34 (defmethod gconstructor ((struct struct) &rest initargs
35 &key new-struct &allow-other-keys)
36 (let ((class-name (class-name (class-of struct)))
37 (pointer (null-pointer)))
38 (if new-struct
39 (setf pointer (new-struct class-name))
40 (progn
41 (setf (slot-value struct 'value) nil
42 (slot-value struct 'free-after) nil)))
43 (mapc
44 (lambda (field)
45 (let ((val (getf initargs (alexandria:make-keyword field) :default)))
46 (unless (eq val :default)
47 (if new-struct
48 (setf (foreign-slot-value pointer
49 (struct-type class-name) field) val)
50 (setf (getf (slot-value struct 'value) field) val)))))
51 (foreign-slot-names (struct-type class-name)))
52 pointer))
53
54 (defun pair (maybe-pair)
55 (if (consp maybe-pair) maybe-pair (cons maybe-pair maybe-pair)))
56
57 (defun slot-accessor (designator)
58 (flet ((count-args (list)
59 (do ((list list (cdr list))
60 (count 0 (1+ count)))
61 ((or (null list)
62 (char= (char (string (car list)) 0) #\&))
63 count))))
64 (let ((lambda-list
65 (closer-mop:generic-function-lambda-list (fdefinition designator))))
66 (= (count-args lambda-list) (if (listp designator) 2 1)))))
67
68 (defmacro defaccessor (name c-name class &body body)
69 #-message-oo (declare (ignore c-name))
70 (let ((val* (when (listp name) (list 'val))))
71 `(progn
72 (unless (fboundp ',name)
73 (defgeneric ,name (,@val* ,class)))
74 (if (slot-accessor ',name)
75 (defmethod ,name (,@val* (,class ,class))
76 . ,body)
77 (warn 'style-warning
78 "~a is not a slot accessor" ',name))
79 #+message-oo
80 ,(if val*
81 `(defmessage ,class (,(alexandria:format-symbol
82 :keyword "~A=" c-name)
83 val)
84 . ,body)
85 `(defmessage ,class ,(alexandria:make-keyword c-name)
86 . ,body)))))
87
88
89 (defmacro defcstruct-accessors (class &rest fields)
90 "CLASS may be symbol = class-name = struct name,
91 or may be cons (class-name . struct-name)"
92 (destructuring-bind (class-name . struct-name) (pair class)
93 `(progn
94 (clear-setters ,class-name)
95 ,@(mapcar
96 (lambda (field)
97 (destructuring-bind (lisp-name . c-name) (pair field)
98 `(progn
99 (defaccessor ,lisp-name ,c-name ,class-name
100 (if (slot-boundp ,class-name 'value)
101 (getf (slot-value ,class-name 'value) ',c-name)
102 (foreign-slot-value (pointer ,class-name)
103 ',(struct-type struct-name)
104 ',c-name)))
105 (defaccessor (setf ,lisp-name) ,c-name ,class-name
106 (if (slot-boundp ,class-name 'value)
107 (setf (getf (slot-value ,class-name 'value)
108 ',c-name)
109 val)
110 (setf (foreign-slot-value
111 (pointer ,class-name)
112 ',(struct-type struct-name) ',c-name)
113 val)))
114 (save-setter ,class-name ,lisp-name))))
115 (or (mapcan (lambda (field)
116 (unless (stringp field) (list (car field))))
117 fields)
118 (foreign-slot-names (struct-type struct-name)))))))
119
120 (defmacro defbitaccessors (class slot &rest fields)
121 (let ((pos 0))
122 (flet ((build-field (field)
123 (destructuring-bind (name type size) field
124 (destructuring-bind (lisp-name . c-name) (pair name)
125 (prog1
126 `(progn
127 (defaccessor ,lisp-name ,c-name ,class
128 (convert-from-foreign
129 (ldb (byte ,size ,pos) (slot-value ,class ',slot))
130 ,type))
131 (defaccessor (setf ,lisp-name) ,c-name ,class
132 (setf (ldb (byte ,size ,pos)
133 (slot-value ,class ',slot))
134 (convert-to-foreign val ,type))))
135 (incf pos size))))))
136 (cons 'progn (mapcar #'build-field fields)))))
137
138 (defun parse-struct (body)
139 (flet ((struct? (type)
140 (and (consp type) (eq (car type) :struct)))
141 (cname (name)
142 (destructuring-bind (lisp-name . c-name) (pair name)
143 (declare (ignore lisp-name))
144 c-name)))
145 (mapcar (lambda (str)
146 (if (stringp str) str
147 (list*
148 (cname (first str))
149 (let ((type (second str)))
150 (if (struct? type)
151 (struct-type (second type))
152 type))
153 (cddr str))))
154 body)))
155
156 (defmacro defcstruct* (class &body body)
157 `(progn
158 (defclass ,class (struct) ())
159 (defcstruct ,class ,@(parse-struct body))
160 (defcstruct-accessors ,class)
161 (init-slots ,class)))
162
163 (defun clos->struct (class object struct)
164 (let ((default (gensym)))
165 (mapc (lambda (slot)
166 (let ((val (getf (slot-value object 'value) slot default)))
167 (unless (eq val default)
168 (setf (foreign-slot-value struct (struct-type class) slot)
169 val))))
170 (foreign-slot-names (struct-type class)))))
171
172 (defun clos->new-struct (class object)
173 (if (slot-boundp object 'value)
174 ;; use make-instance, not new-struct, because gconstructor
175 ;; may be redefined
176 (let ((res (make-instance class :new-struct t :free-after nil)))
177 (clos->struct class object (pointer res))
178 (pointer res))
179 (pointer object)))
180
181 (defun struct->clos (class struct &optional object)
182 "Translates pointer STRUCT to object OBJECT (if not supplied, then to new
183 object).
184 I suppose, that by default it should convert data from pointer to struct.
185 Only exception is the presence of OBJECT with not boundp value"
186 (let ((%object (or object
187 (unless (null-pointer-p struct)
188 (make-instance class)))))
189 (when %object
190 (if (slot-boundp %object 'value)
191 (progn
192 (setf (slot-value %object 'value) nil)
193 (unless (null-pointer-p struct)
194 (dolist (slot (foreign-slot-names (struct-type class)))
195 (setf (getf (slot-value %object 'value) slot)
196 (foreign-slot-value struct (struct-type class) slot)))))
197 (setf (pointer %object) struct))
198 %object)))
199
200 (define-foreign-type cffi-struct (cffi-object freeable-out)
201 ()
202 (:actual-type :pointer))
203
204 (defmethod free-sent-ptr ((type cffi-struct) ptr place)
205 (when (and (not (null-pointer-p ptr)) (slot-boundp place 'value))
206 (free-struct (object-class type) ptr)))
207
208 (defmethod free-returned-ptr ((type cffi-struct) ptr)
209 (unless (null-pointer-p ptr)
210 (free-struct (object-class type) ptr)))
211
212
213 (defmethod foreign-type-size ((type cffi-struct))
214 "Return the size in bytes of a foreign typedef."
215 (foreign-type-size (struct-type (object-class type))))
216
217 (define-parse-method struct (class &rest rest)
218 (apply #'make-instance 'cffi-struct :class class rest))
219
220 (defun %class (type value)
221 (or (object-class type) (class-name (class-of value))))
222
223 (defmethod copy-from-foreign ((type cffi-object) ptr place)
224 (when (slot-boundp place 'value)
225 (struct->clos (%class type place) ptr place)))
226
227 ;; cffi-object is not tyoo. It is for use struct with object designator
228 (defmethod translate-to-foreign ((value struct) (type cffi-object))
229 (values (clos->new-struct (%class type value) value) value))
230
231 (defmethod translate-from-foreign (value (type cffi-struct))
232 (struct->clos (object-class type) value))
233
234 ;;; Allowed use with object designator
235 ;; object == (struct nil)
236
237
238 ;; to allow using array of structs
239 ;; (eval-when (:compile-toplevel :load-toplevel :execute)
240 ;; (unless (get 'mem-ref 'struct)
241 ;; (let ((old (fdefinition 'mem-ref)))
242 ;; (fmakunbound 'mem-ref)
243 ;; (defun mem-ref (ptr type &optional (offset 0))
244 ;; (let ((ptype (cffi::parse-type type)))
245 ;; (if (subtypep (type-of ptype) 'cffi-struct)
246 ;; (translate-from-foreign (inc-pointer ptr offset) ptype)
247 ;; (funcall old ptr type offset)))))
248 ;; (setf (get 'mem-ref 'struct) t)))
249
250 (defun struct-p (type)
251 (and (consp type) (eq (car type) 'struct)))
252
253 (defun ptr-struct (ptr type i)
254 (inc-pointer ptr (* i (foreign-type-size type))))
255
256 (defun from-foreign (var type count)
257 "VAR - symbol; type - symbol or list -- CFFI type; count -- integer"
258 (if count
259 (let ((res (make-array count)))
260 (if (struct-p type)
261 (dotimes (i count)
262 (setf (aref res i)
263 (convert-from-foreign (ptr-struct var type i) type)))
264 (dotimes (i count)
265 (setf (aref res i)
266 (mem-aref var type i))))
267 res)
268 (mem-ref var type)))
269
270
271 (defmacro with-foreign-out ((var type &optional count) return-result &body body)
272 "The same as WITH-FOREIGN-OBJECT, but returns value of object"
273 (let ((value `(from-foreign ,var ,type ,count)))
274 `(with-foreign-object (,var ,type ,@(when count (list count)))
275 ,(if (eq return-result :ignore)
276 `(progn ,@body ,value)
277 `(let ((res ,@body))
278 ,(ecase return-result
279 (:if-success `(when res ,value))
280 (:return `(values res ,value))))))))
281
282 (flet
283 ((make-with-foreign-outs (res-fun bindings return-result body)
284 (let ((values-form (mapcar (lambda (x)
285 (destructuring-bind
286 (var type &optional count) x
287 `(from-foreign ,var ,type ,count)))
288 bindings)))
289 `(with-foreign-objects ,bindings
290 ,(if (eq return-result :ignore)
291 `(progn ,@body (,res-fun ,@values-form))
292 `(let ((res ,@body))
293 ,(ecase return-result
294 (:if-success
295 `(when res (,res-fun ,@values-form)))
296 (:return
297 `(,res-fun res ,@values-form)))))))))
298
299 (defmacro with-foreign-outs (bindings return-result &body body)
300 "The same as WITH-FOREIGN-OBJECTS, but returns (values ...)
301 of result and binded vars, RETURN-RESULT may be
302 :RETURN - return result and values
303 :IF-SUCCESS - return values if result t
304 :IGNORE - discard result"
305 (make-with-foreign-outs 'values bindings return-result body))
306
307 (defmacro with-foreign-outs-list (bindings return-result &body body)
308 "The same as WITH-FOREIGN-OBJECTS, but returns list"
309 (make-with-foreign-outs 'list bindings return-result body)))

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