cl-stream/utf8-stream/babel-stream.lisp

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• Hash : f10e99df
  Author : Thomas de Grivel
  Date : 2017-06-18T14:37:26
  

  optimize write

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• babel-stream.lisp

• ;;
  ;;  babel-stream  -  charset encoding/decoding layer for cl-stream
  ;;
  ;;  Copyright 2017 Thomas de Grivel <thoxdg@gmail.com>
  ;;
  ;;  Permission to use, copy, modify, and distribute this software for any
  ;;  purpose with or without fee is hereby granted, provided that the above
  ;;  copyright notice and this permission notice appear in all copies.
  ;;
  ;;  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  ;;  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  ;;  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ;;  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  ;;  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ;;  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  ;;  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  ;;
  
  (in-package :babel-stream)
  
  (defclass babel-stream (stream)
    ((underlying-stream :initarg :stream
                        :accessor stream-underlying-stream
                        :type stream)
     (external-format :initarg :external-format
                      :initform :utf-8
                      :accessor stream-external-format
                      :type symbol)))
  
  (defmethod initialize-instance :after ((stream babel-stream)
                                         &rest initargs
                                         &key &allow-other-keys)
    (declare (ignore initargs))
    (assert (equal '(unsigned-byte 8)
                   (stream-element-type (stream-underlying-stream stream)))))
  
  (defmethod stream-element-type ((stream babel-stream))
    'character)
  
  (defclass babel-input-stream (babel-stream input-stream)
    ((bytes :initform (make-array '(8) :element-type '(unsigned-byte 8))
            :reader stream-bytes
            :type (array (unsigned-byte 8)))
     (bytes-length :initform 0
                   :accessor stream-bytes-length
                   :type fixnum+)))
  
  (defmethod read ((stream babel-input-stream))
    (let* ((underlying-stream (stream-underlying-stream stream))
           (bytes (stream-bytes stream))
           (encoding (stream-external-format stream))
           (mapping (babel::lookup-mapping babel::*string-vector-mappings*
                                           encoding)))
      (loop
         (multiple-value-bind (element state) (read underlying-stream)
           (case state
             ((nil)
              (setf (aref bytes (stream-bytes-length stream)) element)
              (incf (stream-bytes-length stream))
              (handler-case
                  (let ((string (make-string 1)))
                    (when (= 1 (funcall (the function (babel::decoder mapping))
                                        bytes 0 (stream-bytes-length stream)
                                        string 0))
                      (setf (stream-bytes-length stream) 0)
                      (return (values (char string 0) nil))))
                (babel-encodings:end-of-input-in-character ())))
             ((:eof)
              (return (values nil :eof)))
             ((:non-blocking)
              (return (values nil :non-blocking)))
             (otherwise
              (error 'stream-input-error :stream stream)))))))
  
  (defclass babel-output-stream (babel-stream output-stream)
    ())
  
  (defmethod write ((stream babel-output-stream) (element fixnum))
    (assert (typep element '(unsigned-byte 8)))
    (write (stream-underlying-stream stream) element))
  
  (defmethod write ((stream babel-output-stream) (element character))
    (let* ((encoding (stream-external-format stream))
           (mapping (babel::lookup-mapping babel::*string-vector-mappings*
                                           encoding))
           (string (make-string 1 :initial-element element))
           (bytes (make-array '(8) :element-type '(unsigned-byte 8)))
           (length (funcall (the function (babel::encoder mapping))
                            string 0 1 bytes 0)))
      (write-sequence (stream-underlying-stream stream)
                      bytes :end length)))
  
  (defmethod flush ((stream babel-output-stream))
    (flush (stream-underlying-stream stream)))
  
  #+test
  (let ((s (make-instance 'babel-input-stream
                          :stream (fd-stream:fd-input-stream 0))))
    (read-line s))
  
  #+test
  (let ((s (make-instance 'babel-output-stream
                          :stream (fd-stream:fd-output-stream 1))))
    (write-sequence s "Hello, world ! ÉÀÖÛŸ")
    (flush s))
  

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