io.streams/gray/buffer.lisp

   1 ;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Indent-tabs-mode: NIL -*-
   2 ;;;
   3 ;;; buffer.lisp --- Foreign memory buffers.
   4 ;;;
   5 ;;; Copyright (C) 2006-2007, Stelian Ionescu  <sionescu@common-lisp.net>
   6 ;;;
   7 ;;; This code is free software; you can redistribute it and/or
   8 ;;; modify it under the terms of the version 2.1 of
   9 ;;; the GNU Lesser General Public License as published by
  10 ;;; the Free Software Foundation, as clarified by the
  11 ;;; preamble found here:
  12 ;;;     http://opensource.franz.com/preamble.html
  13 ;;;
  14 ;;; This program is distributed in the hope that it will be useful,
  15 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;;; GNU General Public License for more details.
  18 ;;;
  19 ;;; You should have received a copy of the GNU Lesser General
  20 ;;; Public License along with this library; if not, write to the
  21 ;;; Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  22 ;;; Boston, MA 02110-1301, USA
  23
  24 (in-package :io.streams)
  25
  26 ;;;; Foreign Buffers
  27
  28 (define-constant +bytes-per-iobuf+ (* 4 1024))
  29
  30 ;;; FIXME: make this right
  31 ;;; probably not all SIMPLE-ARRAYs are admissible
  32 ;;; on all implementations
  33 (deftype compatible-lisp-array ()
  34   '(simple-array * (*)))
  35
  36 (declaim (inline allocate-iobuf free-iobuf
  37                  iobuf-length iobuf-start-pointer
  38                  iobuf-end-pointer iobuf-end-space-length
  39                  iobuf-empty-p iobuf-full-p
  40                  iobuf-reset iobuf-copy-data-to-start
  41                  bref (setf bref) iobuf-copy
  42                  iobuf-pop-octet iobuf-push-octet))
  43
  44 (defun allocate-iobuf (&optional (size +bytes-per-iobuf+))
  45   (let ((b (%make-iobuf)))
  46     (setf (iobuf-data b) (foreign-alloc :uint8 :count size)
  47           (iobuf-size b) size)
  48     (values b)))
  49
  50 (defun free-iobuf (iobuf)
  51   (foreign-free (iobuf-data iobuf))
  52   (setf (iobuf-data iobuf) (null-pointer))
  53   (values iobuf))
  54
  55 (defun iobuf-length (iobuf)
  56   (- (iobuf-end iobuf)
  57      (iobuf-start iobuf)))
  58
  59 (defun iobuf-start-pointer (iobuf)
  60   (inc-pointer (iobuf-data iobuf)
  61                (iobuf-start iobuf)))
  62
  63 (defun iobuf-end-pointer (iobuf)
  64   (inc-pointer (iobuf-data iobuf)
  65                (iobuf-end iobuf)))
  66
  67 (defun iobuf-empty-p (iobuf)
  68   (= (iobuf-end iobuf)
  69      (iobuf-start iobuf)))
  70
  71 (defun iobuf-full-p (iobuf)
  72   (= (iobuf-end iobuf)
  73      (iobuf-size iobuf)))
  74
  75 (defun iobuf-end-space-length (iobuf)
  76   (- (iobuf-size iobuf)
  77      (iobuf-end iobuf)))
  78
  79 (defun iobuf-reset (iobuf)
  80   (setf (iobuf-start iobuf) 0
  81         (iobuf-end iobuf)   0))
  82
  83 (defun iobuf-copy-data-to-start (iobuf)
  84   (declare (type iobuf iobuf))
  85   (nix:memmove
  86    (iobuf-data iobuf)
  87    (inc-pointer (iobuf-data iobuf)
  88                 (iobuf-start iobuf))
  89    (iobuf-length iobuf))
  90   (setf (iobuf-end iobuf) (iobuf-length iobuf))
  91   (setf (iobuf-start iobuf) 0))
  92
  93 ;;; BREF, (SETF BREF) and BUFFER-COPY *DO NOT* check boundaries
  94 ;;; that must be done by their callers
  95 (defun bref (iobuf index)
  96   (declare (type iobuf iobuf)
  97            (type buffer-index index))
  98   (mem-aref (iobuf-data iobuf) :uint8 index))
  99
 100 (defun (setf bref) (octet iobuf index)
 101   (declare (type (unsigned-byte 8) octet)
 102            (type iobuf iobuf)
 103            (type buffer-index index))
 104   (setf (mem-aref (iobuf-data iobuf) :uint8 index) octet))
 105
 106 (defun iobuf-copy-from-lisp-array (src soff dst doff length)
 107   (declare (type compatible-lisp-array src)
 108            (type iobuf dst)
 109            (type buffer-index soff doff length))
 110   (let ((dst-ptr (iobuf-data dst)))
 111     (with-pointer-to-vector-data (src-ptr src)
 112       (nix:memcpy
 113        (inc-pointer dst-ptr doff)
 114        (inc-pointer src-ptr soff)
 115        length))))
 116
 117 (defun iobuf-copy-into-lisp-array (src soff dst doff length)
 118   (declare (type iobuf src)
 119            (type compatible-lisp-array dst)
 120            (type buffer-index soff doff length))
 121   (let ((src-ptr (iobuf-data src)))
 122     (with-pointer-to-vector-data (dst-ptr dst)
 123       (nix:memcpy
 124        (inc-pointer dst-ptr doff)
 125        (inc-pointer src-ptr soff)
 126        length))))
 127
 128 (defun iobuf-pop-octet (iobuf)
 129   (declare (type iobuf iobuf))
 130   (let ((start (iobuf-start iobuf)))
 131     (prog1 (bref iobuf start)
 132       (incf (iobuf-start iobuf)))))
 133
 134 (defun iobuf-push-octet (iobuf octet)
 135   (declare (type iobuf iobuf)
 136            (type (unsigned-byte 8) octet))
 137   (let ((end (iobuf-end iobuf)))
 138     (prog1 (setf (bref iobuf end) octet)
 139       (incf (iobuf-end iobuf)))))