;; Copyright (c) 2002-2006, Edward Marco Baringer
;; All rights reserved.
(in-package :alexandria)
(defmacro with-open-file* ((stream filespec &key direction element-type
if-exists if-does-not-exist external-format)
&body body)
"Just like WITH-OPEN-FILE, but NIL values in the keyword arguments mean to use
the default value specified for OPEN."
(once-only (direction element-type if-exists if-does-not-exist external-format)
`(with-open-stream
(,stream (apply #'open ,filespec
(append
(when ,direction
(list :direction ,direction))
(when ,element-type
(list :element-type ,element-type))
(when ,if-exists
(list :if-exists ,if-exists))
(when ,if-does-not-exist
(list :if-does-not-exist ,if-does-not-exist))
(when ,external-format
(list :external-format ,external-format)))))
,@body)))
(defmacro with-input-from-file ((stream-name file-name &rest args
&key (direction nil direction-p)
&allow-other-keys)
&body body)
"Evaluate BODY with STREAM-NAME to an input stream on the file
FILE-NAME. ARGS is sent as is to the call to OPEN except EXTERNAL-FORMAT,
which is only sent to WITH-OPEN-FILE when it's not NIL."
(declare (ignore direction))
(when direction-p
(error "Can't specify :DIRECTION for WITH-INPUT-FROM-FILE."))
`(with-open-file* (,stream-name ,file-name :direction :input ,@args)
,@body))
(defmacro with-output-to-file ((stream-name file-name &rest args
&key (direction nil direction-p)
&allow-other-keys)
&body body)
"Evaluate BODY with STREAM-NAME to an output stream on the file
FILE-NAME. ARGS is sent as is to the call to OPEN except EXTERNAL-FORMAT,
which is only sent to WITH-OPEN-FILE when it's not NIL."
(declare (ignore direction))
(when direction-p
(error "Can't specify :DIRECTION for WITH-OUTPUT-TO-FILE."))
`(with-open-file* (,stream-name ,file-name :direction :output ,@args)
,@body))
(defun read-stream-content-into-string (stream &key (buffer-size 4096))
"Return the \"content\" of STREAM as a fresh string."
(check-type buffer-size positive-integer)
(let ((*print-pretty* nil))
(with-output-to-string (datum)
(let ((buffer (make-array buffer-size :element-type 'character)))
(loop
:for bytes-read = (read-sequence buffer stream)
:do (write-sequence buffer datum :start 0 :end bytes-read)
:while (= bytes-read buffer-size))))))
(defun read-file-into-string (pathname &key (buffer-size 4096) external-format)
"Return the contents of the file denoted by PATHNAME as a fresh string.
The EXTERNAL-FORMAT parameter will be passed directly to WITH-OPEN-FILE
unless it's NIL, which means the system default."
(with-input-from-file
(file-stream pathname :external-format external-format)
(read-stream-content-into-string file-stream :buffer-size buffer-size)))
(defun write-string-into-file (string pathname &key (if-exists :error)
if-does-not-exist
external-format)
"Write STRING to PATHNAME.
The EXTERNAL-FORMAT parameter will be passed directly to WITH-OPEN-FILE
unless it's NIL, which means the system default."
(with-output-to-file (file-stream pathname :if-exists if-exists
:if-does-not-exist if-does-not-exist
:external-format external-format)
(write-sequence string file-stream)))
(defun read-stream-content-into-byte-vector (stream &key ((%length length))
(initial-size 4096))
"Return \"content\" of STREAM as freshly allocated (unsigned-byte 8) vector."
(check-type length (or null non-negative-integer))
(check-type initial-size positive-integer)
(do ((buffer (make-array (or length initial-size)
:element-type '(unsigned-byte 8)))
(offset 0)
(offset-wanted 0))
((or (/= offset-wanted offset)
(and length (>= offset length)))
(if (= offset (length buffer))
buffer
(subseq buffer 0 offset)))
(unless (zerop offset)
(let ((new-buffer (make-array (* 2 (length buffer))
:element-type '(unsigned-byte 8))))
(replace new-buffer buffer)
(setf buffer new-buffer)))
(setf offset-wanted (length buffer)
offset (read-sequence buffer stream :start offset))))
(defun read-file-into-byte-vector (pathname)
"Read PATHNAME into a freshly allocated (unsigned-byte 8) vector."
(with-input-from-file (stream pathname :element-type '(unsigned-byte 8))
(read-stream-content-into-byte-vector stream '%length (file-length stream))))
(defun write-byte-vector-into-file (bytes pathname &key (if-exists :error)
if-does-not-exist)
"Write BYTES to PATHNAME."
(check-type bytes (vector (unsigned-byte 8)))
(with-output-to-file (stream pathname :if-exists if-exists
:if-does-not-exist if-does-not-exist
:element-type '(unsigned-byte 8))
(write-sequence bytes stream)))
(defun copy-file (from to &key (if-to-exists :supersede)
(element-type '(unsigned-byte 8)) finish-output)
(with-input-from-file (input from :element-type element-type)
(with-output-to-file (output to :element-type element-type
:if-exists if-to-exists)
(copy-stream input output
:element-type element-type
:finish-output finish-output))))
(defun copy-stream (input output &key (element-type (stream-element-type input))
(buffer-size 4096)
(buffer (make-array buffer-size :element-type element-type))
(start 0) end
finish-output)
"Reads data from INPUT and writes it to OUTPUT. Both INPUT and OUTPUT must
be streams, they will be passed to READ-SEQUENCE and WRITE-SEQUENCE and must have
compatible element-types."
(check-type start non-negative-integer)
(check-type end (or null non-negative-integer))
(check-type buffer-size positive-integer)
(when (and end
(< end start))
(error "END is smaller than START in ~S" 'copy-stream))
(let ((output-position 0)
(input-position 0))
(unless (zerop start)
;; FIXME add platform specific optimization to skip seekable streams
(loop while (< input-position start)
do (let ((n (read-sequence buffer input
:end (min (length buffer)
(- start input-position)))))
(when (zerop n)
(error "~@<Could not read enough bytes from the input to fulfill ~
the :START ~S requirement in ~S.~:@>" 'copy-stream start))
(incf input-position n))))
(assert (= input-position start))
(loop while (or (null end) (< input-position end))
do (let ((n (read-sequence buffer input
:end (when end
(min (length buffer)
(- end input-position))))))
(when (zerop n)
(if end
(error "~@<Could not read enough bytes from the input to fulfill ~
the :END ~S requirement in ~S.~:@>" 'copy-stream end)
(return)))
(incf input-position n)
(write-sequence buffer output :end n)
(incf output-position n)))
(when finish-output
(finish-output output))
output-position))
