From 08cdb1c4e4112823eb09876c83bc70d7fa62a888 Mon Sep 17 00:00:00 2001
From: Stelian Ionescu <sionescu@common-lisp.net>
Date: Tue, 15 Jul 2008 13:01:55 +0200
Subject: [PATCH] Fix DEVICE-POSITION for files.

Signed-off-by: Stelian Ionescu <sionescu@common-lisp.net>
---
 io.streams/zeta/device.lisp |  4 +---
 io.streams/zeta/file.lisp   | 25 +++++++------------------
 2 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/io.streams/zeta/device.lisp b/io.streams/zeta/device.lisp
index a3a6c5d..82e304e 100644
--- a/io.streams/zeta/device.lisp
+++ b/io.streams/zeta/device.lisp
@@ -15,9 +15,7 @@
   (:default-initargs :input-timeout nil
                      :output-timeout nil))
 
-(defclass single-channel-device (device)
-  ((position :initarg :position :accessor position-of))
-  (:default-initargs :position 0))
+(defclass single-channel-device (device) ())
 
 (defclass dual-channel-device (device) ())
 
diff --git a/io.streams/zeta/file.lisp b/io.streams/zeta/file.lisp
index 2a94271..d30c2b7 100644
--- a/io.streams/zeta/file.lisp
+++ b/io.streams/zeta/file.lisp
@@ -80,9 +80,7 @@
     (let ((fd (try-open)))
       (%set-fd-nonblock-mode fd t)
       (setf (input-handle-of device) fd
-            (output-handle-of device) fd)
-      (when (logtest flags nix:o-append)
-        (setf (position-of device) (device-length device)))))
+            (output-handle-of device) fd)))
   (values device))
 
 (defun process-file-direction (direction flags if-exists if-does-not-exist)
@@ -141,23 +139,14 @@
 ;;;-----------------------------------------------------------------------------
 
 (defmethod device-position ((device file-device))
-  (position-of device))
+  (nix:lseek (input-handle-of device) 0 nix:seek-cur))
 
 (defmethod (setf device-position) (position (device file-device) &key (from :start))
-  (ecase from
-    (:start
-     (nix:lseek (input-handle-of device) position nix:seek-set)
-     (setf (position-of device) position))
-    (:current
-     (nix:lseek (input-handle-of device) position nix:seek-cur)
-     (incf (position-of device) position))
-    (:end
-     (nix:lseek (input-handle-of device) position nix:seek-end)
-     ;; WARNING: possible race condition here: if betweek lseek() and fstat()
-     ;; the file size is modified, this calculation will be incorrect
-     ;; perhaps fcntl() or ioctl() can be used to find out the file offset
-     (setf (position-of device) (+ (device-length device) position))))
-  (position-of device))
+  (nix:lseek (input-handle-of device) position
+             (ecase from
+               (:start nix:seek-set)
+               (:current nix:seek-cur)
+               (:end nix:seek-end))))
 
 
 ;;;-----------------------------------------------------------------------------
-- 
2.11.4.GIT