;;;;***************************************************************************
;;;;
;;;; FILE IDENTIFICATION
;;;;
;;;;  Name:           edge-table-storage.lisp
;;;;  Purpose:        Store precompiled edge table for reversi
;;;;  Programer:      Kevin Rosenberg
;;;;  Date Started:   1 Nov 2001
;;;;
;;;; $Id$
;;;;
;;;; This file is Copyright (c) 2001-2003 by Kevin M. Rosenberg
;;;;
;;;; Reversi users are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
;;;;***************************************************************************

(in-package #:reversi)

(defparameter *et-path* nil)

(eval-when (:load-toplevel :execute)
  (let ((precompiled-path (make-pathname
                           :directory '(:absolute "usr" "share" "common-lisp"
                                                  "source" "reversi")
                           :name "edge-table"
                           :type "dat")))
    (if (probe-file precompiled-path)
        (setq *et-path* precompiled-path)
      (setq *et-path* (make-pathname
                       :directory (pathname-directory *load-truename*)
                       :host (pathname-host *load-truename*)
                       :device (pathname-device *load-truename*)
                       :name "edge-table"
                       :type "dat"))))

  (defun store-edge-table (et &optional (path *et-path*))
    (declare (type edge-table et))
    (with-open-file (stream path :direction :output
                            :if-exists :supersede)
      (print (length et) stream)
      (dotimes (i (length et))
        (declare (fixnum i))
        (print (aref et i) stream))))

  (defun load-edge-table (&optional (path *et-path*))
    (when (probe-file path)
      (with-open-file (stream path :direction :input)
        (let* ((length (read stream))
               (et (make-array length :element-type 'fixnum)))
          (declare (type (simple-array fixnum (*)) et))
          (dotimes (i length)
            (declare (fixnum i))
            (setf (aref et i) (read stream)))
          et))))

  (unless (probe-file *et-path*)
    (format *trace-output* ";; Recompiling edge-table, this make take several minutes")
    (store-edge-table (make-edge-table)))

  (unless *edge-table*
    (setq *edge-table* (load-edge-table))))