Skip to content
Snippets Groups Projects
fd-stream.lisp 61.7 KiB
Newer Older
ram's avatar
ram committed
;;; -*- Log: code.log; Package: LISP -*-
ram's avatar
ram committed
;;; **********************************************************************
;;; This code was written as part of the CMU Common Lisp project at
;;; Carnegie Mellon University, and has been placed in the public domain.
;;;
(ext:file-comment
  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/fd-stream.lisp,v 1.81 2005/02/10 17:49:46 rtoy Exp $")
ram's avatar
ram committed
;;; **********************************************************************
;;;
;;; Streams for UNIX file descriptors.
;;;
;;; Written by William Lott, July 1989 - January 1990.
;;; Some tuning by Rob MacLachlan.
ram's avatar
ram committed
;;; 
;;; **********************************************************************


(in-package "SYSTEM")

(export '(fd-stream fd-stream-p fd-stream-fd make-fd-stream
          io-timeout beep *beep-function* output-raw-bytes
ram's avatar
ram committed
	  *tty* *stdin* *stdout* *stderr*))


(in-package "EXTENSIONS")

(export '(*backup-extension*))


(in-package "LISP")

(export '(file-stream file-string-length))
ram's avatar
ram committed

;;;; Buffer manipulation routines.

(defvar *available-buffers* ()
  "List of available buffers.  Each buffer is an sap pointing to
  bytes-per-buffer of memory.")
ram's avatar
ram committed

(defconstant bytes-per-buffer (* 4 1024)
  "Number of bytes per buffer.")

;; This limit is rather arbitrary
(defconstant max-stream-element-size 1024
  "The maximum supported byte size for a stream element-type.")

ram's avatar
ram committed
;;; NEXT-AVAILABLE-BUFFER -- Internal.
;;;
;;; Returns the next available buffer, creating one if necessary.
ram's avatar
ram committed
;;;
pw's avatar
pw committed
(declaim (inline next-available-buffer))
ram's avatar
ram committed
;;;
(defun next-available-buffer ()
  (if *available-buffers*
      (pop *available-buffers*)
      (allocate-system-memory bytes-per-buffer)))
ram's avatar
ram committed


;;;; The FD-STREAM structure.

moore's avatar
 
moore committed
;;;; Superclass defined by the ANSI Spec
(defstruct (file-stream
	     (:include lisp-stream)
	     (:constructor nil)
	     (:copier nil)))

ram's avatar
ram committed
(defstruct (fd-stream
	    (:print-function %print-fd-stream)
	    (:constructor %make-fd-stream)
moore's avatar
 
moore committed
	    (:include file-stream
ram's avatar
ram committed
		      (misc #'fd-stream-misc-routine)))

  (name nil)		      ; The name of this stream
  (file nil)		      ; The file this stream is for
  ;;
  ;; The backup file namestring for the old file, for :if-exists :rename or
  ;; :rename-and-delete.
  (original nil :type (or simple-string null))
ram's avatar
ram committed
  (delete-original nil)	      ; for :if-exists :rename-and-delete
  ;;
  ;;; Number of bytes per element.
  (element-size 1 :type index)
  (element-type 'base-char)   ; The type of element being transfered.
ram's avatar
ram committed
  (fd -1 :type fixnum)	      ; The file descriptor
  ;;
  ;; Controls when the output buffer is flushed.
  (buffering :full :type (member :full :line :none))
  ;;
  ;; Character position if known.
  (char-pos nil :type (or index null))
  ;;
  ;; T if input is waiting on FD.  :EOF if we hit EOF.
  (listen nil :type (member nil t :eof))
  ;;
ram's avatar
ram committed
  ;; The input buffer.
  (unread nil)
  (ibuf-sap nil :type (or system-area-pointer null))
  (ibuf-length nil :type (or index null))
  (ibuf-head 0 :type index)
  (ibuf-tail 0 :type index)
ram's avatar
ram committed

  ;; The output buffer.
  (obuf-sap nil :type (or system-area-pointer null))
  (obuf-length nil :type (or index null))
  (obuf-tail 0 :type index)
ram's avatar
ram committed

  ;; Output flushed, but not written due to non-blocking io.
  (output-later nil)
  (handler nil)
  ;;
  ;; Timeout specified for this stream, or NIL if none.
  (timeout nil :type (or index null))
  ;;
  ;; Pathname of the file this stream is opened to (returned by PATHNAME.)
  (pathname nil :type (or pathname null)))
ram's avatar
ram committed

(defun %print-fd-stream (fd-stream stream depth)
  (declare (ignore depth) (stream stream))
ram's avatar
ram committed
  (format stream "#<Stream for ~A>"
	  (fd-stream-name fd-stream)))


(define-condition io-timeout (stream-error)
  ((direction :reader io-timeout-direction :initarg :direction))
     (declare (stream stream))
     (format stream "Timeout ~(~A~)ing ~S."
	     (io-timeout-direction condition)
	     (stream-error-stream condition)))))

ram's avatar
ram committed

;;;; Output routines and related noise.

(defvar *output-routines* ()
  "List of all available output routines. Each element is a list of the
  element-type output, the kind of buffering, the function name, and the number
  of bytes per element.")

;;; DO-OUTPUT-LATER -- internal
;;;
;;;   Called by the server when we can write to the given file descriptor.
;;; Attempt to write the data again. If it worked, remove the data from the
ram's avatar
ram committed
;;; output-later list. If it didn't work, something is wrong.
;;;
(defun do-output-later (stream)
  (let* ((stuff (pop (fd-stream-output-later stream)))
	 (base (car stuff))
	 (start (cadr stuff))
	 (end (caddr stuff))
	 (reuse-sap (cadddr stuff))
ram's avatar
ram committed
	 (length (- end start)))
    (declare (type index start end length))
ram's avatar
ram committed
    (multiple-value-bind
	(count errno)
	(unix:unix-write (fd-stream-fd stream)
ram's avatar
ram committed
			 base
			 start
			 length)
      (cond ((not count)
	     (if (= errno unix:ewouldblock)
		 (error "Write would have blocked, but SERVER told us to go.")
		 (error "While writing ~S: ~A"
			stream (unix:get-unix-error-msg errno))))
	    ((eql count length) ; Hot damn, it worked.
	     (when reuse-sap
	       (push base *available-buffers*)))
ram's avatar
ram committed
	    ((not (null count)) ; Sorta worked.
	     (push (list base
			 (the index (+ start count))
		   (fd-stream-output-later stream))))))
ram's avatar
ram committed
  (unless (fd-stream-output-later stream)
    (system:remove-fd-handler (fd-stream-handler stream))
    (setf (fd-stream-handler stream) nil)))

;;; OUTPUT-LATER -- internal
;;;
;;;   Arrange to output the string when we can write on the file descriptor.
ram's avatar
ram committed
;;;
(defun output-later (stream base start end reuse-sap)
ram's avatar
ram committed
  (cond ((null (fd-stream-output-later stream))
	 (setf (fd-stream-output-later stream)
	       (list (list base start end reuse-sap)))
ram's avatar
ram committed
	 (setf (fd-stream-handler stream)
	       (system:add-fd-handler (fd-stream-fd stream)
				      :output
				      #'(lambda (fd)
					  (declare (ignore fd))
					  (do-output-later stream)))))
	(t
	 (nconc (fd-stream-output-later stream)
		(list (list base start end reuse-sap)))))
  (when reuse-sap
ram's avatar
ram committed
    (let ((new-buffer (next-available-buffer)))
      (setf (fd-stream-obuf-sap stream) new-buffer)
      (setf (fd-stream-obuf-length stream) bytes-per-buffer)))) 
ram's avatar
ram committed

;;; DO-OUTPUT -- internal
;;;
;;;   Output the given noise. Check to see if there are any pending writes. If
;;; so, just queue this one. Otherwise, try to write it. If this would block,
;;; queue it.
;;;
(defun do-output (stream base start end reuse-sap)
  (declare (type fd-stream stream)
	   (type (or system-area-pointer (simple-array * (*))) base)
	   (type index start end))
ram's avatar
ram committed
  (if (not (null (fd-stream-output-later stream))) ; something buffered.
      (progn
	(output-later stream base start end reuse-sap)
	;; ### check to see if any of this noise can be output
	)
      (let ((length (- end start)))
	(multiple-value-bind
	    (unix:unix-write (fd-stream-fd stream) base start length)
	  (cond ((not count)
		 (if (= errno unix:ewouldblock)
		     (output-later stream base start end reuse-sap)
emarsden's avatar
 
emarsden committed
		     (error 'simple-stream-error
                            :stream stream
                            :format-control "while writing: ~A"
			    :format-arguments (list (unix:get-unix-error-msg errno)))))
		((not (eql count length))
		 (output-later stream base (the index (+ start count))
			       end reuse-sap)))))))
ram's avatar
ram committed

;;; FLUSH-OUTPUT-BUFFER -- internal
;;;
;;;   Flush any data in the output buffer.
;;;
(defun flush-output-buffer (stream)
  (let ((length (fd-stream-obuf-tail stream)))
    (unless (= length 0)
      (do-output stream (fd-stream-obuf-sap stream) 0 length t)
ram's avatar
ram committed
      (setf (fd-stream-obuf-tail stream) 0))))

;;; DEF-OUTPUT-ROUTINES -- internal
;;;
;;;   Define output routines that output numbers size bytes long for the
;;; given bufferings. Use body to do the actual output.
;;;
(defmacro def-output-routines ((name size &rest bufferings) &body body)
  (declare (optimize (speed 1)))
ram's avatar
ram committed
  (cons 'progn
	(mapcar
	    #'(lambda (buffering)
		(let ((function
		       (intern (let ((*print-case* :upcase))
				 (format nil name (car buffering))))))
		  `(progn
		     (defun ,function (stream byte)
		       ,(unless (eq (car buffering) :none)
			  `(when (< (fd-stream-obuf-length stream)
				    (+ (fd-stream-obuf-tail stream)
				       ,size))
			     (flush-output-buffer stream)))
		       ;;
		       ;; If there is any input read from UNIX but not
		       ;; supplied to the user of the stream, reposition
		       ;; to the real file position as seen from Lisp.
		       ,(unless (eq (car buffering) :none)
			  `(when (> (fd-stream-ibuf-tail stream)
				    (fd-stream-ibuf-head stream))
			     (file-position stream (file-position stream))))
ram's avatar
ram committed
		       ,@body
		       (incf (fd-stream-obuf-tail stream) ,size)
		       ,(ecase (car buffering)
			  (:none
			   `(flush-output-buffer stream))
			  (:line
			   `(when (eq (char-code byte) (char-code #\Newline))
			      (flush-output-buffer stream)))
			  (:full
			   ))
		       (values))
		     (setf *output-routines*
			   (nconc *output-routines*
				  ',(mapcar
					#'(lambda (type)
					    (list type
						  (car buffering)
						  function
						  size))
				      (cdr buffering)))))))
	  bufferings)))

(def-output-routines ("OUTPUT-CHAR-~A-BUFFERED"
		      1
		      (:none character)
		      (:line character)
		      (:full character))
      (setf (fd-stream-char-pos stream) 0)
      (incf (fd-stream-char-pos stream)))
  (setf (sap-ref-8 (fd-stream-obuf-sap stream) (fd-stream-obuf-tail stream))
	(char-code byte)))

(def-output-routines ("OUTPUT-UNSIGNED-BYTE-~A-BUFFERED"
ram's avatar
ram committed
		      1
		      (:none (unsigned-byte 8))
		      (:full (unsigned-byte 8)))
  (setf (sap-ref-8 (fd-stream-obuf-sap stream) (fd-stream-obuf-tail stream))
	byte))
ram's avatar
ram committed

(def-output-routines ("OUTPUT-SIGNED-BYTE-~A-BUFFERED"
		      1
		      (:none (signed-byte 8))
		      (:full (signed-byte 8)))
  (setf (signed-sap-ref-8 (fd-stream-obuf-sap stream)
			  (fd-stream-obuf-tail stream))
	byte))

(def-output-routines ("OUTPUT-UNSIGNED-SHORT-~A-BUFFERED"
ram's avatar
ram committed
		      2
		      (:none (unsigned-byte 16))
		      (:full (unsigned-byte 16)))
  (setf (sap-ref-16 (fd-stream-obuf-sap stream) (fd-stream-obuf-tail stream))
(def-output-routines ("OUTPUT-SIGNED-SHORT-~A-BUFFERED"
		      2
		      (:none (signed-byte 16))
		      (:full (signed-byte 16)))
  (setf (signed-sap-ref-16 (fd-stream-obuf-sap stream)
			   (fd-stream-obuf-tail stream))
	byte))

(def-output-routines ("OUTPUT-UNSIGNED-LONG-~A-BUFFERED"
ram's avatar
ram committed
		      4
		      (:none (unsigned-byte 32))
		      (:full (unsigned-byte 32)))
  (setf (sap-ref-32 (fd-stream-obuf-sap stream) (fd-stream-obuf-tail stream))
ram's avatar
ram committed

(def-output-routines ("OUTPUT-SIGNED-LONG-~A-BUFFERED"
		      4
		      (:none (signed-byte 32))
		      (:full (signed-byte 32)))
  (setf (signed-sap-ref-32 (fd-stream-obuf-sap stream)
			   (fd-stream-obuf-tail stream))
	byte))


ram's avatar
ram committed
;;; OUTPUT-RAW-BYTES -- public
;;;
;;;   Does the actual output. If there is space to buffer the string, buffer
;;; it. If the string would normally fit in the buffer, but doesn't because
;;; of other stuff in the buffer, flush the old noise out of the buffer and
;;; put the string in it. Otherwise we have a very long string, so just
;;; send it directly (after flushing the buffer, of course).
;;;
(defun output-raw-bytes (stream thing &optional start end)
  "Output THING to stream.  THING can be any kind of vector or a sap.  If THING
  is a SAP, END must be supplied (as length won't work)."
  (let ((start (or start 0))
	(end (or end (length (the (simple-array * (*)) thing)))))
    (declare (type index start end))
    ;;
    ;; If there is any input read from UNIX but not
    ;; supplied to the user of the stream, reposition
    ;; to the real file position as seen from Lisp.
    (when (> (fd-stream-ibuf-tail stream)
	     (fd-stream-ibuf-head stream))
      (file-position stream (file-position stream)))
ram's avatar
ram committed
    (let* ((len (fd-stream-obuf-length stream))
	   (tail (fd-stream-obuf-tail stream))
	   (space (- len tail))
	   (bytes (- end start))
	   (newtail (+ tail bytes)))
      (cond ((minusp bytes) ; Error case
	     (cerror "Just go on as if nothing happened..."
		     "~S called with :END before :START!"
		     'output-raw-bytes))
	    ((zerop bytes)) ; Easy case
	    ((<= bytes space)
	     (if (system-area-pointer-p thing)
		 (system-area-copy thing
				   (* start vm:byte-bits)
				   (fd-stream-obuf-sap stream)
				   (* tail vm:byte-bits)
				   (* bytes vm:byte-bits))
		 (copy-to-system-area thing
				      (+ (* start vm:byte-bits)
					 (* vm:vector-data-offset vm:word-bits))
				      (fd-stream-obuf-sap stream)
				      (* tail vm:byte-bits)
				      (* bytes vm:byte-bits)))
ram's avatar
ram committed
	     (setf (fd-stream-obuf-tail stream) newtail))
	    ((<= bytes len)
	     (flush-output-buffer stream)
	     (if (system-area-pointer-p thing)
		 (system-area-copy thing
				   (* start vm:byte-bits)
				   (fd-stream-obuf-sap stream)
				   0
				   (* bytes vm:byte-bits))
		 (copy-to-system-area thing
				      (+ (* start vm:byte-bits)
					 (* vm:vector-data-offset vm:word-bits))
				      (fd-stream-obuf-sap stream)
				      0
				      (* bytes vm:byte-bits)))
ram's avatar
ram committed
	     (setf (fd-stream-obuf-tail stream) bytes))
	    (t
	     (flush-output-buffer stream)
	     (do-output stream thing start end nil))))))

;;; FD-SOUT -- internal
;;;
;;;   Routine to use to output a string. If the stream is unbuffered, slam
;;; the string down the file descriptor, otherwise use OUTPUT-RAW-BYTES to
;;; buffer the string. Update charpos by checking to see where the last newline
;;; was.
;;;
;;;   Note: some bozos (the FASL dumper) call write-string with things other
;;; than strings. Therefore, we must make sure we have a string before calling
;;; position on it.
;;; 
(defun fd-sout (stream thing start end)
  (let ((start (or start 0))
	(end (or end (length (the vector thing)))))
    (declare (type index start end))
ram's avatar
ram committed
    (if (stringp thing)
	(let ((last-newline (and (find #\newline (the simple-string thing)
				       :start start :end end)
				 (position #\newline (the simple-string thing)
					   :from-end t
					   :start start
					   :end end))))
	  (ecase (fd-stream-buffering stream)
	    (:full
	     (output-raw-bytes stream thing start end))
	    (:line
	     (output-raw-bytes stream thing start end)
	     (when last-newline
	       (flush-output-buffer stream)))
	    (:none
	     (do-output stream thing start end nil)))
	  (if last-newline
	      (setf (fd-stream-char-pos stream)
		    (- end last-newline 1))
	      (incf (fd-stream-char-pos stream)
		    (- end start))))
ram's avatar
ram committed
	(ecase (fd-stream-buffering stream)
	  ((:line :full)
ram's avatar
ram committed
	   (output-raw-bytes stream thing start end))
	  (:none
	   (do-output stream thing start end nil))))))
ram's avatar
ram committed

(defmacro output-wrapper ((stream size buffering) &body body)
  (let ((stream-var (gensym)))
    `(let ((,stream-var ,stream))
      ,(unless (eq (car buffering) :none)
	 `(when (< (fd-stream-obuf-length ,stream-var)
	           (+ (fd-stream-obuf-tail ,stream-var)
		       ,size))
            (flush-output-buffer ,stream-var)))
      ,(unless (eq (car buffering) :none)
	 `(when (> (fd-stream-ibuf-tail ,stream-var)
		   (fd-stream-ibuf-head ,stream-var))
            (file-position ,stream-var (file-position ,stream-var))))
    
      ,@body
      (incf (fd-stream-obuf-tail ,stream-var) ,size)
      ,(ecase (car buffering)
	 (:none
	  `(flush-output-buffer ,stream-var))
	 (:line
	  `(when (eq (char-code byte) (char-code #\Newline))
	     (flush-output-buffer ,stream-var)))
	 (:full))
      (values))))

ram's avatar
ram committed
;;; PICK-OUTPUT-ROUTINE -- internal
;;;
;;;   Find an output routine to use given the type and buffering. Return as
;;; multiple values the routine, the real type transfered, and the number of
;;; bytes per element.
;;;
(defun pick-output-routine (type buffering)
  (dolist (entry *output-routines*)
    (when (and (subtypep type (car entry))
	       (eq buffering (cadr entry)))
      (return-from pick-output-routine
	(values (symbol-function (caddr entry))
		(car entry)
		(cadddr entry)))))
  ;; KLUDGE: also see comments in PICK-INPUT-ROUTINE
  (loop for i from 40 by 8 to max-stream-element-size ; ARB (KLUDGE)
	if (subtypep type `(unsigned-byte ,i))
	do (return-from pick-output-routine
	     (values
	      (ecase buffering
		(:none
		 (lambda (stream byte)
		   (output-wrapper (stream (/ i 8) (:none))
		     (loop for j from 0 below (/ i 8)
			   do (setf (sap-ref-8 
				     (fd-stream-obuf-sap stream)
				     (+ j (fd-stream-obuf-tail stream)))
				    (ldb (byte 8 (- i 8 (* j 8))) byte))))))
		(:full
		 (lambda (stream byte)
		   (output-wrapper (stream (/ i 8) (:full))
		     (loop for j from 0 below (/ i 8)
			   do (setf (sap-ref-8 
				     (fd-stream-obuf-sap stream)
				     (+ j (fd-stream-obuf-tail stream)))
				    (ldb (byte 8 (- i 8 (* j 8))) byte)))))))
	      `(unsigned-byte ,i)
	      (/ i 8))))
  (loop for i from 40 by 8 to max-stream-element-size ; ARB (KLUDGE)
	if (subtypep type `(signed-byte ,i))
	do (return-from pick-output-routine
	     (values
	      (ecase buffering
		(:none
		 (lambda (stream byte)
		   (output-wrapper (stream (/ i 8) (:none))
		     (loop for j from 0 below (/ i 8)
			   do (setf (sap-ref-8 
				     (fd-stream-obuf-sap stream)
				     (+ j (fd-stream-obuf-tail stream)))
				    (ldb (byte 8 (- i 8 (* j 8))) byte))))))
		(:full
		 (lambda (stream byte)
		   (output-wrapper (stream (/ i 8) (:full))
		     (loop for j from 0 below (/ i 8)
			   do (setf (sap-ref-8 
				     (fd-stream-obuf-sap stream)
				     (+ j (fd-stream-obuf-tail stream)))
				    (ldb (byte 8 (- i 8 (* j 8))) byte)))))))
	      `(signed-byte ,i)
	      (/ i 8)))))
ram's avatar
ram committed

;;;; Input routines and related noise.

(defvar *input-routines* ()
  "List of all available input routines. Each element is a list of the
  element-type input, the function name, and the number of bytes per element.")

;;; DO-INPUT -- internal
;;;
;;;   Fills the input buffer, and returns the first character. Throws to
;;; eof-input-catcher if the eof was reached. Drops into system:server if
;;; necessary.
;;;
(defun do-input (stream)
  (let ((fd (fd-stream-fd stream))
	(ibuf-sap (fd-stream-ibuf-sap stream))
	(buflen (fd-stream-ibuf-length stream))
	(head (fd-stream-ibuf-head stream))
	(tail (fd-stream-ibuf-tail stream)))
    (declare (type index head tail))
ram's avatar
ram committed
    (unless (zerop head)
      (cond ((eql head tail)
ram's avatar
ram committed
	     (setf head 0)
	     (setf tail 0)
	     (setf (fd-stream-ibuf-head stream) 0)
	     (setf (fd-stream-ibuf-tail stream) 0))
	    (t
	     (decf tail head)
	     (system-area-copy ibuf-sap (* head vm:byte-bits)
			       ibuf-sap 0 (* tail vm:byte-bits))
ram's avatar
ram committed
	     (setf head 0)
	     (setf (fd-stream-ibuf-head stream) 0)
	     (setf (fd-stream-ibuf-tail stream) tail))))
    (setf (fd-stream-listen stream) nil)
    (multiple-value-bind
	  (count errno)
	(alien:with-alien ((read-fds (alien:struct unix:fd-set)))
	  (unix:fd-zero read-fds)
	  (unix:fd-set fd read-fds)
	  (unix:unix-fast-select (1+ fd) (alien:addr read-fds) nil nil 0 0))
      ;; Wait if input is not available or if interrupted.
      (when (or (eql count 0)
		(and (not count) (eql errno unix:eintr)))
	(unless #-mp (system:wait-until-fd-usable
		      fd :input (fd-stream-timeout stream))
		#+mp (mp:process-wait-until-fd-usable
		      fd :input (fd-stream-timeout stream))
	  (error 'io-timeout :stream stream :direction :read))))
ram's avatar
ram committed
    (multiple-value-bind
	(unix:unix-read fd
ram's avatar
ram committed
			(system:int-sap (+ (system:sap-int ibuf-sap) tail))
			(- buflen tail))
      (cond ((null count)
	     ;; What kinds of errors do we want to look at and what do
	     ;; we want them to do?
	     (cond ((eql errno unix:ewouldblock)
		    (unless #-mp (system:wait-until-fd-usable
				  fd :input (fd-stream-timeout stream))
			    #+mp (mp:process-wait-until-fd-usable
				  fd :input (fd-stream-timeout stream))
			    (error 'io-timeout :stream stream :direction :read))
		    (do-input stream))
		   ((eql errno unix:econnreset)
		    (error 'socket-error
			   :format-control "Socket connection reset: ~A"
			   :format-arguments (list (unix:get-unix-error-msg errno))
			   :errno errno))
		   (t
		    (error "Error reading ~S: ~A"
			   stream
			   (unix:get-unix-error-msg errno)))))
ram's avatar
ram committed
	    ((zerop count)
	     (setf (fd-stream-listen stream) :eof)
ram's avatar
ram committed
	     (throw 'eof-input-catcher nil))
	    (t
	     (incf (fd-stream-ibuf-tail stream) count))))))
			
;;; INPUT-AT-LEAST -- internal
;;;
;;;   Makes sure there are at least ``bytes'' number of bytes in the input
;;; buffer. Keeps calling do-input until that condition is met.
;;;
(defmacro input-at-least (stream bytes)
  (let ((stream-var (gensym))
	(bytes-var (gensym)))
    `(let ((,stream-var ,stream)
	   (,bytes-var ,bytes))
       (loop
	 (when (>= (- (fd-stream-ibuf-tail ,stream-var)
		      (fd-stream-ibuf-head ,stream-var))
		   ,bytes-var)
	   (return))
	 (do-input ,stream-var)))))

;;; INPUT-WRAPPER -- intenal
;;;
;;;   Macro to wrap around all input routines to handle eof-error noise.
ram's avatar
ram committed
;;;
(defmacro input-wrapper ((stream bytes eof-error eof-value) &body read-forms)
  (let ((stream-var (gensym))
	(element-var (gensym)))
    `(let ((,stream-var ,stream))
       (if (fd-stream-unread ,stream-var)
	   (prog1
	       (fd-stream-unread ,stream-var)
	     (setf (fd-stream-unread ,stream-var) nil)
	     (setf (fd-stream-listen ,stream-var) nil))
	   (let ((,element-var
		  (catch 'eof-input-catcher
		    (input-at-least ,stream-var ,bytes)
		    ,@read-forms)))
	     (cond (,element-var
		    (incf (fd-stream-ibuf-head ,stream-var) ,bytes)
		    ,element-var)
		   (t
		    (eof-or-lose ,stream-var ,eof-error ,eof-value))))))))
ram's avatar
ram committed

;;; DEF-INPUT-ROUTINE -- internal
;;;
;;;   Defines an input routine.
;;;
(defmacro def-input-routine (name
			     (type size sap head)
			     &rest body)
  `(progn
     (defun ,name (stream eof-error eof-value)
       (input-wrapper (stream ,size eof-error eof-value)
	 (let ((,sap (fd-stream-ibuf-sap stream))
	       (,head (fd-stream-ibuf-head stream)))
	   ,@body)))
     (setf *input-routines*
	   (nconc *input-routines*
		  (list (list ',type ',name ',size))))))

;;; INPUT-CHARACTER -- internal
ram's avatar
ram committed
;;;
;;;   Routine to use in stream-in slot for reading string chars.
;;;
(def-input-routine input-character
		   (character 1 sap head)
  (code-char (sap-ref-8 sap head)))
ram's avatar
ram committed

;;; INPUT-UNSIGNED-8BIT-BYTE -- internal
;;;
;;;   Routine to read in an unsigned 8 bit number.
;;;
(def-input-routine input-unsigned-8bit-byte
		   ((unsigned-byte 8) 1 sap head)
  (sap-ref-8 sap head))
ram's avatar
ram committed

;;; INPUT-SIGNED-8BIT-BYTE -- internal
;;;
;;;   Routine to read in a signed 8 bit number.
;;;
(def-input-routine input-signed-8bit-number
		   ((signed-byte 8) 1 sap head)
  (signed-sap-ref-8 sap head))
ram's avatar
ram committed

;;; INPUT-UNSIGNED-16BIT-BYTE -- internal
;;;
;;;   Routine to read in an unsigned 16 bit number.
;;;
(def-input-routine input-unsigned-16bit-byte
		   ((unsigned-byte 16) 2 sap head)
ram's avatar
ram committed

;;; INPUT-SIGNED-16BIT-BYTE -- internal
;;;
;;;   Routine to read in a signed 16 bit number.
;;;
(def-input-routine input-signed-16bit-byte
		   ((signed-byte 16) 2 sap head)
  (signed-sap-ref-16 sap head))
ram's avatar
ram committed

;;; INPUT-UNSIGNED-32BIT-BYTE -- internal
;;;
;;;   Routine to read in a unsigned 32 bit number.
;;;
(def-input-routine input-unsigned-32bit-byte
		   ((unsigned-byte 32) 4 sap head)
ram's avatar
ram committed

;;; INPUT-SIGNED-32BIT-BYTE -- internal
;;;
;;;   Routine to read in a signed 32 bit number.
;;;
(def-input-routine input-signed-32bit-byte
		   ((signed-byte 32) 4 sap head)
  (signed-sap-ref-32 sap head))
ram's avatar
ram committed

;;; PICK-INPUT-ROUTINE -- internal
;;;
;;;   Find an input routine to use given the type. Return as multiple values
;;; the routine, the real type transfered, and the number of bytes per element.
;;;
(defun pick-input-routine (type)
  (dolist (entry *input-routines*)
    (when (subtypep type (car entry))
      (return-from pick-input-routine
	(values (symbol-function (cadr entry))
		(car entry)
		(caddr entry)))))
  ;; FIXME: let's do it the hard way, then (but ignore things like
  ;; endianness, efficiency, and the necessary coupling between these
  ;; and the output routines).  -- CSR, 2004-02-09
  (loop for i from 40 by 8 to max-stream-element-size ; ARB (well, KLUDGE really)
	if (subtypep type `(unsigned-byte ,i))
	do (return-from pick-input-routine
	     (values
	      (lambda (stream eof-error eof-value)
		(input-wrapper (stream (/ i 8) eof-error eof-value)
		  (let ((sap (fd-stream-ibuf-sap stream))
			(head (fd-stream-ibuf-head stream)))
		    (loop for j from 0 below (/ i 8)
			  with result = 0
			  do (setf result
				   (+ (* 256 result)
				      (sap-ref-8 sap (+ head j))))
			  finally (return result)))))
	      `(unsigned-byte ,i)
	      (/ i 8))))
  (loop for i from 40 by 8 to max-stream-element-size ; ARB (well, KLUDGE really)
	if (subtypep type `(signed-byte ,i))
	do (return-from pick-input-routine
	     (values
	      (lambda (stream eof-error eof-value)
		(input-wrapper (stream (/ i 8) eof-error eof-value)
		  (let ((sap (fd-stream-ibuf-sap stream))
			(head (fd-stream-ibuf-head stream)))
		    (loop for j from 0 below (/ i 8)
			  with result = 0
			  do (setf result
				   (+ (* 256 result)
				      (sap-ref-8 sap (+ head j))))
		          finally (return (if (logbitp (1- i) result)
					      (dpb result (byte i 0) -1)
					      result))))))
	      `(signed-byte ,i)
	      (/ i 8)))))
ram's avatar
ram committed

;;; STRING-FROM-SAP -- internal
;;;
;;;   Returns a string constructed from the sap, start, and end.
;;;
(defun string-from-sap (sap start end)
  (declare (type index start end))
ram's avatar
ram committed
  (let* ((length (- end start))
	 (string (make-string length)))
    (copy-from-system-area sap (* start vm:byte-bits)
			   string (* vm:vector-data-offset vm:word-bits)
			   (* length vm:byte-bits))
ram's avatar
ram committed
    string))

ram's avatar
ram committed
;;; FD-STREAM-READ-N-BYTES -- internal
;;;
dtc's avatar
dtc committed
;;; This version waits using server.  I changed to the non-server version
;;; because it allows this method to be used by CLX w/o confusing serve-event.
;;; The non-server method is also significantly more efficient for large
;;; reads. -- Ram
;;;
ram's avatar
ram committed
;;; The n-bin routine.
;;; 
(defun fd-stream-read-n-bytes (stream buffer start requested eof-error-p)
dtc's avatar
dtc committed
  (declare (type stream stream) (type index start requested))
ram's avatar
ram committed
  (let* ((sap (fd-stream-ibuf-sap stream))
	 (elsize (fd-stream-element-size stream))
	 (offset (* elsize start))
	 (bytes (* elsize requested))
	 (result
	  (catch 'eof-input-catcher
	    (loop
	      (input-at-least stream 1)
	      (let* ((head (fd-stream-ibuf-head stream))
		     (tail (fd-stream-ibuf-tail stream))
		     (available (- tail head))
		     (copy (min available bytes)))
		(if (typep buffer 'system-area-pointer)
		    (system-area-copy sap (* head vm:byte-bits)
				      buffer (* offset vm:byte-bits)
				      (* copy vm:byte-bits))
		    (copy-from-system-area sap (* head vm:byte-bits)
					   buffer (+ (* offset vm:byte-bits)
						     (* vm:vector-data-offset
							vm:word-bits))
					   (* copy vm:byte-bits)))
		(incf (fd-stream-ibuf-head stream) copy)
		(incf offset copy)
		(decf bytes copy))
	      (when (zerop bytes)
		(return requested))))))
    (or result
	(eof-or-lose stream eof-error-p 
		     (- requested (/ bytes elsize))))))
dtc's avatar
dtc committed
;;;    The N-Bin method for FD-STREAMs.  This doesn't use the SERVER; it blocks
;;; in UNIX-READ.  This allows the method to be used to implementing reading
;;; for CLX.  It is generally used where there is a definite amount of reading
;;; to be done, so blocking isn't too problematical.
;;;
;;;    We copy buffered data into the buffer.  If there is enough, just return.
;;; Otherwise, we see if the amount of additional data needed will fit in the
;;; stream buffer.  If not, inhibit GCing (so we can have a SAP into the Buffer
;;; argument), and read directly into the user supplied buffer.  Otherwise,
;;; read a buffer-full into the stream buffer and then copy the amount we need
;;; out.
;;;
;;;    We loop doing the reads until we either get enough bytes or hit EOF.  We
;;; must loop when eof-errorp is T because some streams (like pipes) may return
;;; a partial amount without hitting EOF.
;;;
(defun fd-stream-read-n-bytes (stream buffer start requested eof-error-p)
  (declare (type stream stream) (type index start requested))
  (let* ((sap (fd-stream-ibuf-sap stream))
	 (offset start)
	 (head (fd-stream-ibuf-head stream))
	 (tail (fd-stream-ibuf-tail stream))
	 (available (- tail head))
	 (copy (min requested available)))
    (declare (type index offset head tail available copy))
    ;;
    ;; If something has been unread, put that at buffer + start,
    ;; and read the rest to start + 1.
    (when (fd-stream-unread stream)
      (etypecase buffer
	(system-area-pointer
	 (assert (= 1 (fd-stream-element-size stream)))
	 (setf (sap-ref-8 buffer start) (char-code (read-char stream))))
	(vector
	 (setf (aref buffer start) (read-char stream))))
      (return-from fd-stream-read-n-bytes
	(1+ (fd-stream-read-n-bytes stream buffer (1+ start) (1- requested)
				    eof-error-p))))
    ;;
    (unless (zerop copy)
      (if (typep buffer 'system-area-pointer)
	  (system-area-copy sap (* head vm:byte-bits)
			    buffer (* offset vm:byte-bits)
			    (* copy vm:byte-bits))
	  (copy-from-system-area sap (* head vm:byte-bits)
				 buffer (+ (* offset vm:byte-bits)
					   (* vm:vector-data-offset
					      vm:word-bits))
				 (* copy vm:byte-bits)))
      (incf (fd-stream-ibuf-head stream) copy))
    (cond
     ((or (= copy requested)
	  (and (not eof-error-p) (/= copy 0)))
      copy)
     (t
      (setf (fd-stream-ibuf-head stream) 0)
      (setf (fd-stream-ibuf-tail stream) 0)
      (setf (fd-stream-listen stream) nil)
      (let ((now-needed (- requested copy))
	    (len (fd-stream-ibuf-length stream)))
	(declare (type index now-needed len))
	(cond
	 ((> now-needed len)
	  ;;
	  ;; If the desired amount is greater than the stream buffer size, then
	  ;; read directly into the destination, incrementing the start
	  ;; accordingly.  In this case, we never leave anything in the stream
	  ;; buffer.
	  (system:without-gcing
	    (loop
	      (multiple-value-bind
		  (count err)
		  (unix:unix-read (fd-stream-fd stream)
				  (sap+ (if (typep buffer 'system-area-pointer)
					    buffer
					    (vector-sap buffer))
					(+ offset copy))
				  now-needed)
		(declare (type (or index null) count))
		(unless count
		  (error "Error reading ~S: ~A" stream
			 (unix:get-unix-error-msg err)))
		(decf now-needed count)
		(if eof-error-p
		    (when (zerop count)
		      (error 'end-of-file :stream stream))
		    (return (- requested now-needed)))
		(when (zerop now-needed) (return requested))
		(incf offset count)))))
	 (t
	  ;;
	  ;; If we want less than the buffer size, then loop trying to fill the
	  ;; stream buffer and copying what we get into the destination.  When
	  ;; we have enough, we leave what's left in the stream buffer.
		(unix:unix-read (fd-stream-fd stream) sap len)
	      (declare (type (or index null) count))
	      (unless count
		(error "Error reading ~S: ~A" stream
		       (unix:get-unix-error-msg err)))
	      (when (and eof-error-p (zerop count))
		(error 'end-of-file :stream stream))

	      (let* ((copy (min now-needed count))
		     (copy-bits (* copy vm:byte-bits))
		     (buffer-start-bits
		      (* (+ offset available) vm:byte-bits)))
		(declare (type index copy copy-bits buffer-start-bits))
		(if (typep buffer 'system-area-pointer)
		    (system-area-copy sap 0
				      buffer buffer-start-bits
				      copy-bits)
		    (copy-from-system-area sap 0 
					   buffer (+ buffer-start-bits
						     (* vm:vector-data-offset
							vm:word-bits))
					   copy-bits))
		(when (or (zerop now-needed) (not eof-error-p))
		  (setf (fd-stream-ibuf-head stream) copy)
		  (setf (fd-stream-ibuf-tail stream) count)
		  (return (- requested now-needed)))
		(incf offset copy)))))))))))
ram's avatar
ram committed


;;;; Utility functions (misc routines, etc)

;;; SET-ROUTINES -- internal
;;;
;;;   Fill in the various routine slots for the given type. Input-p and
;;; output-p indicate what slots to fill. The buffering slot must be set prior
;;; to calling this routine.
ram's avatar
ram committed
;;;
(defun set-routines (stream type input-p output-p buffer-p)
ram's avatar
ram committed
  (let ((target-type (case type
		       ((:default unsigned-byte)
			'(unsigned-byte 8))
		       (signed-byte
			'(signed-byte 8))
		       (t
			type)))
	(input-type nil)
	(output-type nil)
	(input-size nil)
	(output-size nil))
    
    (when (fd-stream-obuf-sap stream)
      (push (fd-stream-obuf-sap stream) *available-buffers*)
      (setf (fd-stream-obuf-sap stream) nil))
    (when (fd-stream-ibuf-sap stream)
      (push (fd-stream-ibuf-sap stream) *available-buffers*)
      (setf (fd-stream-ibuf-sap stream) nil))
ram's avatar
ram committed
    
    (when input-p
      (multiple-value-bind
	  (routine type size)
	  (pick-input-routine target-type)