Added a comment that describes a better way to implement garbage colletion

of texts.

src/server/ChangeLog

+Wed Oct  7 00:43:03 1992  Per Cederqvist  (ceder@mauritz)
+
+	* text-garb.c: Added a comment that describes a design for a
+	better way to implement garbage collection of texts.
+
 Sun Sep  6 20:30:01 1992  Per Cederqvist  (ceder@robert)
 
 	* version.incl: Version 1.2.5.

src/server/text-garb.c

 /*
- * $Id: text-garb.c,v 0.6 1992/02/26 18:44:57 ceder Exp $
+ * $Id: text-garb.c,v 0.7 1992/10/06 23:45:00 ceder Exp $
  * Copyright (C) 1991  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -28,7 +28,7 @@
  * Author: Per Cederqvist.
  */
 
-static char *rcsid = "$Id: text-garb.c,v 0.6 1992/02/26 18:44:57 ceder Exp $";
+static char *rcsid = "$Id: text-garb.c,v 0.7 1992/10/06 23:45:00 ceder Exp $";
 
 
 #include <time.h>
@@ -40,6 +40,38 @@ static char *rcsid = "$Id: text-garb.c,v 0.6 1992/02/26 18:44:57 ceder Exp $";
 #include "text-garb.h"
 #include <debug.h>
 
+/*
+ * This comment is a description of how this _could_ be done in a more
+ * efficient way.  It is not yet implemented.  Design by Inge Wallin
+ * and Per Cederqvist 1992-10-07.
+ *
+ * Today, all text statuses are read into the core during the garbage
+ * collection phase. Due to step 3 below we think that we can reduce
+ * the number of text-status-fetches by 95 %.
+ *
+ * 1) Allocate a bitmap with one bit for each text. Clear all bits.
+ *    This bit is set as soon as it is certain that this text should
+ *    not be deleted during this garbage collection pass.
+ * 2) Loop over all persons:
+ *	+ Set the bit for all his/her marked texts.
+ *    (This step may, or may not, be efficient. Profile your code!)
+ * 3) Loop over all conferences:
+ *	+ Loop over all texts in the conference:
+ *		+ If the bit is already set, skip the text.
+ *		+ Retrieve the text status from the data base.
+ *		+ If it is old enough (in all the recipient conferences)
+ *			delete it.
+ *		  else
+ *		        set the bit.
+ *		+ If it is too young to be deleted (only
+ *    		  considering this conferene)
+ *			+ Set the bit for this text and all subsequent
+ *    			  texts in this conference.
+ * 4) Loop over all remaining texts:
+ *	+ If the bit is not set,
+ *		+ delete the text. (It has no recipients).
+ * 5) Deallocate the bitmap and wait 24 hours.
+ */
 
 /*
  * Delete old texts.