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(in-package #:3bz)
(defmacro with-vector-context ((context) &body body)
(with-gensyms (boxes vector)
(once-only (context)
`(let* ((,boxes (boxes ,context))
(,vector (octet-vector ,context)))
(declare (optimize speed)
(ignorable ,vector ,boxes)
(type context-boxes ,boxes))
(check-type ,vector octet-vector)
(locally (declare (type octet-vector ,vector))
(context-common (,boxes)
(macrolet (;; read up to 8 octets in LE order, return
;; result + # of octets read as multiple
;; values
(word64 ()
(with-gensyms (available result)
`(let ((,available (octets-left)))
(if (>= ,available 8)
(let ((,result (ub64ref/le
,',vector (pos))))
(incf (pos) 8)
(values ,result 8))
(let ((,result 0))
(loop
for i fixnum below ,available
do (setf ,result
(ldb (byte 64 0)
(logior
,result
(ash
(aref ,',vector
(+ (pos) i))
(* i 8))))))
(incf (pos) ,available)
(values ,result ,available))))))
(word32 ()
(with-gensyms (available result)
`(let ((,available (octets-left)))
(if (>= ,available 4)
(let ((,result (ub32ref/le
,',vector (pos))))
(incf (pos) 4)
(values ,result 4))
(let ((,result 0))
(loop
for i of-type (unsigned-byte 2) below (min 4 ,available)
do (setf ,result
(ldb (byte 32 0)
(logior
,result
(ash
(aref ,',vector
(+ (pos) i))
(* i 8))))))
(incf (pos) ,available)
(values ,result ,available)))))))
,@body)))))))
(defmacro with-stream-context ((context) &body body)
(with-gensyms (boxes stream)
(once-only (context)
`(let* ((,boxes (boxes ,context))
(,stream (octet-stream ,context)))
(declare (optimize speed)
(ignorable ,stream ,boxes)
(type context-boxes ,boxes))
(assert (valid-octet-stream ,stream))
(context-common (,boxes)
(macrolet (;; override POS/SET-POS for streams
(pos ()
`(file-position ,',stream))
(word64 ()
(with-gensyms (available result)
`(locally (declare (optimize (speed 1)))
(let ((,available (- (end) (pos))))
(if (>= ,available 8)
(values (nibbles:read-ub64/le ,',stream) 8)
(let ((,result 0))
(declare (type (unsigned-byte 64) ,result)
(type (mod 8) ,available))
(loop
for i fixnum below (min 8 ,available)
do (setf (ldb (byte 8 (* i 8))
,result)
(read-byte ,',stream)))
(values ,result ,available)))))))
(word32 ()
(with-gensyms (available result)
`(locally (declare (optimize (speed 1)))
(let ((,available (- (end) (pos))))
(if (>= ,available 4)
(values (nibbles:read-ub32/le ,',stream) 4)
(let ((,result 0))
(declare (type (unsigned-byte 64) ,result)
(type (mod 4) ,available))
(loop
for i fixnum below (min 4 ,available)
do (setf (ldb (byte 8 (* i 8))
,result)
(read-byte ,',stream)))
(values ,result ,available))))))))
,@body))))))
(defmacro defun-with-reader-contexts (base-name lambda-list (in) &body body)
`(progn
,@(with-standard-io-syntax
(loop for cc in '(vector stream pointer)
for w = (find-symbol (format nil "~a-~a-~a" 'with cc 'context)
(find-package :3bz))
for n = (intern (format nil "~a/~a" base-name cc)
(find-package :3bz))
collect `(defun ,n ,lambda-list
(,w (,in)
(let ()
,@body)))))
(defun ,base-name ,lambda-list
(etypecase ,in
,@(with-standard-io-syntax
(loop for cc in '(vector stream pointer)
for ct = (find-symbol (format nil "~a-~a-~a" 'octet cc 'context)
(find-package :3bz))
for n = (find-symbol (format nil "~a/~a" base-name cc)
(find-package :3bz))
collect `(,ct (,n ,@lambda-list))))))))
(defmacro with-reader-contexts ((context) &body body)
`(etypecase ,context
(octet-vector-context
(with-vector-context (,context)
,@body))
(octet-pointer-context
(with-pointer-context (,context)
,@body))
(octet-stream-context
(with-stream-context (,context)
,@body))))
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