--- irchat.el.old	Wed Jul 23 12:44:12 2003
+++ irchat.el	Mon Mar 15 21:51:53 2004
@@ -1241,6 +1241,17 @@
   (irchat-insert
    string (cons irchat-Private-buffer (pure-irc-users-get-chan irchat-nickname))  pattern))
 
+(defun irchat-pj-expire-lines (threshold lines)
+  (and
+   (numberp threshold)
+   (<= threshold (count-lines (point-min) (point-max)))
+   (or (numberp lines) (setq lines (/ threshold 10)))
+   (let ((buffer-read-only nil))
+     (save-excursion
+       (goto-line (1+ lines))
+       (beginning-of-line)
+       (delete-region (point-min) (point))))))
+
 (defun irchat-insert (body &optional chans pattern flag head)
   (let (opoint chan buf win visible)
     (while chans
@@ -1250,6 +1261,7 @@
       (if (setq buf (if (bufferp chan) chan (irchat-Channel-exist chan)))
 	  (save-excursion
 	    (set-buffer buf)
+	    (irchat-pj-expire-lines irchat-pj-expire-chanbuf-threshold irchat-pj-expire-chanbuf-lines)
 	    (setq opoint (point))
 	    (goto-char (point-max))
 	    (if (setq win (get-buffer-window buf))
@@ -1261,7 +1273,6 @@
                        (stringp irchat-previous-pattern)
 		       (string= pattern irchat-previous-pattern))
 		  (progn
-		    ;;(previous-line 1)
 		    (forward-line -1)
 		    (if flag
 			(if irchat-print-time (forward-char 6))
@@ -1293,9 +1304,11 @@
     (or visible
 	(save-excursion
 	  (set-buffer irchat-Others-buffer)
-	  (if (> (point-max) irchat-others-high-watermark)
-	      (let ((buffer-read-only nil))
-		(delete-region 1 (- (point-max) irchat-others-low-watermark))))
+	  (if irchat-pj-expire-other-threshold
+	      (irchat-pj-expire-lines irchat-pj-expire-other-threshold irchat-pj-expire-other-lines)
+	    (if (> (point-max) irchat-others-high-watermark)
+		(let ((buffer-read-only nil))
+		  (delete-region 1 (- (point-max) irchat-others-low-watermark)))))
 	  (goto-char (point-max))
 	  (let ((buffer-read-only nil))
 	    (if irchat-print-time
@@ -1320,6 +1333,7 @@
           ;; end
     (save-excursion
       (set-buffer irchat-Dialogue-buffer)
+      (irchat-pj-expire-lines irchat-pj-expire-dialogue-threshold irchat-pj-expire-dialogue-lines)
       (let ((opoint (point)))
 	(goto-char (point-max))
 	(let ((buffer-read-only nil))
--- irchat-vars.el.old	Tue Mar 16 01:01:34 2004
+++ irchat-vars.el	Tue Mar 16 00:53:50 2004
@@ -336,6 +336,26 @@
 
 (defvar irchat-pj-startup-interval 2)
 
+(defvar irchat-pj-expire-chanbuf-threshold nil
+  "Delete channel buffer if buffer line number is more than this value")
+
+(defvar irchat-pj-expire-chanbuf-lines nil
+  "Delete lines of channel buffer")
+
+(defvar irchat-pj-expire-other-threshold nil
+  "Delete other buffer if buffer line number is more than this value
+If nil, use irchat-others-high-watermark as maximal characters")
+
+(defvar irchat-pj-expire-other-lines nil
+  "Delete lines of other buffer
+This variable is used only when `irchat-pj-expire-other-threshold' is non-nil")
+
+(defvar irchat-pj-expire-dialogue-threshold nil
+  "Delete channel buffer if buffer line number is more than this value")
+
+(defvar irchat-pj-expire-dialogue-lines nil
+  "Delete lines of dialogue buffer")
+
 ;; That's all
 (provide 'irchat-vars)