[mhc:00530] Re: スピード狂への道

[TSUCHIYA Masatoshi <tsuchiya@xxxxxxxxxxxxxxxxxxxxxxx>]

>> On Fri, 21 Apr 2000 21:45:13 +0900
>> 「土」== tsuchiya@xxxxxxxxxxxxxxxxxxxxxxx (TSUCHIYA Masatoshi) said as follows:

土> mhc を高速化するべく小細工を始めました。

小細工その2。(ddate-days) や (ddate-ww) が時間を食っていそうだなぁ、と
思ったので、計算結果を cache するようにしてみました。

Index: mhc-date.el
===================================================================
RCS file: /home/tsuchiya/CVS/projects/mhc/mhc-date.el,v
retrieving revision 1.1.1.1
diff -u -u -r1.1.1.1 mhc-date.el
--- mhc-date.el	2000/04/18 00:16:25	1.1.1.1
+++ mhc-date.el	2000/04/21 14:04:49
@@ -15,7 +15,7 @@
 ;;
 ;; 1999-04-30 corresponds to  (1999 4 30)
 ;;
-;; ddate is also simple. It expresses a time by a list of integer.
+;; dtime is also simple. It expresses a time by a list of integer.
 ;; for example:
 ;;
 ;; 12:30 (12 30)
@@ -111,6 +111,8 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; ddate
 
+(defvar ddate-cache-obarray (make-vector 1023 0))
+
 ;;
 ;; create new object, access method to each element.
 ;;
@@ -199,15 +201,19 @@
 (defun ddate-yy (ddate) (nth 0 ddate))
 (defun ddate-mm (ddate) (nth 1 ddate))
 (defun ddate-dd (ddate) (nth 2 ddate))
+
 (defun ddate-ww (ddate)
-  ;;  (0:Sun, 2:Mon, ... , 6:Sat)
-  (let ((xx (1- (ddate-yy ddate))))
-    (% (+ (ddate-day-of-yy ddate)
-	  (* xx  365)
-	  (/ xx    4)
-	  (/ xx -100)
-	  (/ xx  400))
-       7)))
+  (let ((symbol (intern (ddate-to-s ddate) ddate-cache-obarray)))
+    (or (get symbol 'ddate-ww)
+	(put symbol 'ddate-ww
+	     ;;  (0:Sun, 2:Mon, ... , 6:Sat)
+	     (let ((xx (1- (ddate-yy ddate))))
+	       (% (+ (ddate-day-of-yy ddate)
+		     (* xx  365)
+		     (/ xx    4)
+		     (/ xx -100)
+		     (/ xx  400))
+		  7))))))
 
 (defun ddate-oo (ddate)
   (/ (1- (ddate-dd ddate)) 7))
@@ -414,24 +420,30 @@
 ;;      ; 1994-7-1 is the 182nd day of the year.
 ;;
 (defun ddate-day-of-yy (ddate)
-  (let (yy mm dd xx)
-    (setq yy (ddate-yy ddate) mm (ddate-mm ddate) dd (ddate-dd ddate)
-	  xx (if (and (ddate-leap-year-p yy) (> mm 2)) 1 0))
-    (- (+ dd (* (1- mm) 31) xx)
-       (nth (1- mm) '(0 0 3 3 4 4 5 5 5 6 6 7)))))
+  (let ((symbol (intern (ddate-to-s ddate) ddate-cache-obarray)))
+    (or (get symbol 'ddate-day-of-yy)
+	(put symbol 'ddate-day-of-yy
+	     (let (yy mm dd xx)
+	       (setq yy (ddate-yy ddate) mm (ddate-mm ddate) dd (ddate-dd ddate)
+		     xx (if (and (ddate-leap-year-p yy) (> mm 2)) 1 0))
+	       (- (+ dd (* (1- mm) 31) xx)
+		  (nth (1- mm) '(0 0 3 3 4 4 5 5 5 6 6 7))))))))
 
 
 ;;
 ;; days from 1970-01-01
 ;;
 (defun ddate-days (ddate)
-  (let ((xx (1- (ddate-yy ddate))))
-    (- (+ (ddate-day-of-yy ddate)
-	  (* xx  365)
-	  (/ xx    4)
-	  (/ xx -100)
-	  (/ xx  400))
-       719163)))
+  (let ((symbol (intern (ddate-to-s ddate) ddate-cache-obarray)))
+    (or (get symbol 'ddate-days)
+	(put symbol 'ddate-days
+	     (let ((xx (1- (ddate-yy ddate))))
+	       (- (+ (ddate-day-of-yy ddate)
+		     (* xx  365)
+		     (/ xx    4)
+		     (/ xx -100)
+		     (/ xx  400))
+		  719163))))))
 
 ;;
 ;; check if date is the last week of the month.

と言っても、4ヶ月くらいの予定を見たときに、0.5 秒くらい変わるだけなん
ですけど。

-- 
土屋 雅稔  ( TSUCHIYA Masatoshi )
    http://www-nagao.kuee.kyoto-u.ac.jp/member/tsuchiya/