;; This file is part of eris-cl. ;; Copyright (C) 2022 Piotr SzarmaƄski ;; eris-cl is free software: you can redistribute it and/or modify it under the ;; terms of the GNU Lesser General Public License as published by the Free ;; Software Foundation, either version 3 of the License, or (at your option) any ;; later version. ;; eris-cl is distributed in the hope that it will be useful, but WITHOUT ANY ;; WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR ;; A PARTICULAR PURPOSE. See the GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License along with ;; eris-cl. If not, see . (in-package :eris) (defclass file-backend (encoding-backend decoding-backend) ((directory :initarg :directory :type (or string pathname) :documentation "Directory containing ERIS data."))) (define-condition file-backend-error (error) ()) (define-condition directory-error (file-backend-error) ((message :type string :initarg :message)) (:report (lambda (condition stream) (format stream "~a" (slot-value condition 'message))))) (defmethod shared-initialize :after ((file-backend file-backend) slot-names &rest initargs &key (directory nil directory-p) &allow-other-keys) (declare (ignore initargs slot-names)) (when (or (null directory-p) (null (pathname-directory directory))) (error 'directory-error :message "Incorrectly specified directory.")) (with-slots (directory output-function fetch-function) file-backend (when (or (pathname-name directory))) (setf fetch-function (lambda (reference) (let* ((base32 (bytes-to-base32-unpadded reference)) (file (merge-pathnames directory base32))) (if (probe-file file) (alexandria:read-file-into-byte-vector file) (error 'missing-block :reference reference)))) output-function (lambda (block reference) (let* ((base32 (bytes-to-base32-unpadded reference)) (file (merge-pathnames directory base32))) (unless (probe-file file) (alexandria:write-byte-vector-into-file block file))) block))))