diff options
Diffstat (limited to 'io.lisp')
| -rw-r--r-- | io.lisp | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/io.lisp b/io.lisp new file mode 100644 index 0000000000..28bf5e6d82 --- /dev/null +++ b/io.lisp @@ -0,0 +1,172 @@ +;; 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)) |