X-Git-Url: https://git.distorted.org.uk/~mdw/lisp/blobdiff_plain/9224720f63a3a3f810ce03dc4018e23a0c6d8492..813da880d2d77f04ea623f426d543d298528f967:/safely.lisp diff --git a/safely.lisp b/safely.lisp index 0674429..9b39518 100644 --- a/safely.lisp +++ b/safely.lisp @@ -1,7 +1,5 @@ ;;; -*-lisp-*- ;;; -;;; $Id$ -;;; ;;; Safely modify collections of files ;;; ;;; (c) 2005 Straylight/Edgeware @@ -24,10 +22,7 @@ ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. (defpackage #:safely - (:use #:common-lisp #:mdw.base) - (:export #:safely #:safely-close #:safely-delete-file - #:safely-open-output-stream #:safely-bail #:safely-commit - #:safely-writing)) + (:use #:common-lisp #:mdw.base)) (in-package #:safely) #+(or cmu sbcl) @@ -41,15 +36,18 @@ (declare (ignore as-file)) (unix-namestring pathname nil))) -(defstruct (safely (:predicate safelyp)) +(export '(safely safelyp make-safely)) +(defstruct (safely (:predicate safelyp) (:constructor make-safely ())) "Stores information about how to commit or undo safe writes." (streams nil) (trail nil)) +(export 'safely-close) (defun safely-close (safe stream) "Make sure that STREAM is closed when SAFE is finished." (push stream (safely-streams safe))) +(export 'safely-delete-file) (defun safely-delete-file (safe file) "Delete FILE when SAFE is committed." (push `(:delete ,file) (safely-trail safe))) @@ -94,6 +92,7 @@ (when ret (return (values new ret))))))) +(export 'safely-open-output-stream) (defun safely-open-output-stream (safe file &rest open-args) "Create an output stream which will be named FILE when SAFE is committed. Other OPEN-ARGS are passed to open." @@ -114,6 +113,7 @@ (progn (ffi:def-call-out %rename (:name "rename") (:language :stdc) + (:library "libc.so.6") (:arguments (from ffi:c-string) (to ffi:c-string)) (:return-type ffi:int))) @@ -159,6 +159,7 @@ (setf (safely-streams safe) nil) (setf (safely-trail safe) nil)) +(export 'safely-bail) (defun safely-bail (safe) "Abort the operations in SAFE, unwinding all the things that have been done. Streams are closed, new files are removed." @@ -218,6 +219,7 @@ (return copy)))))) (close output))))) +(export 'safely-commit) (defun safely-commit (safe) "Commit SAFE. The files deleted by safely-delete-file are deleted; the files created by safely-open-output-stream are renamed over the old @@ -256,6 +258,7 @@ (safely-unwind cleanup) (safely-reset safe)))) +;; The symbol `safely' is already exported. (defmacro safely ((safe &key) &body body) "Do stuff within the BODY safely. If BODY completes without errors, the SAFE is committed; otherwise it's bailed." @@ -268,6 +271,7 @@ (when ,safe (safely-bail ,safe))))) +(export 'safely-writing) (defmacro safely-writing ((stream file &rest open-args) &body body) "Simple macro for writing a single file safely. STREAM is opened onto a temporary file, and if BODY completes, it is renamed to FILE."