davidw pointed out that the holdtime calculation used by

app_queue does not use "boxcar" filtering as the comments
say. The term "boxcar" means that the number of samples used
to calculate stays constant, with new samples replacing the
oldest ones. The queue holdtime calculation uses all holdtime
samples collected since the queue was loaded, so the comment
has been changed to be accurate.

(closes issue #12781)
Reported by: davidw



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@123274 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_queue.c

@@ -394,7 +394,7 @@ struct call_queue {
 	int announcefrequency;              /*!< How often to announce their position */
 	int periodicannouncefrequency;      /*!< How often to play periodic announcement */
 	int roundingseconds;                /*!< How many seconds do we round to? */
-	int holdtime;                       /*!< Current avg holdtime, based on recursive boxcar filter */
+	int holdtime;                       /*!< Current avg holdtime, based on an exponential average */
 	int callscompleted;                 /*!< Number of queue calls completed */
 	int callsabandoned;                 /*!< Number of queue calls abandoned */
 	int servicelevel;                   /*!< seconds setting for servicelevel*/
@@ -1627,7 +1627,7 @@ static void recalc_holdtime(struct queue_ent *qe, int newholdtime)
 {
 	int oldvalue;
 
-	/* Calculate holdtime using a recursive boxcar filter */
+	/* Calculate holdtime using an exponential average */
 	/* Thanks to SRT for this contribution */
 	/* 2^2 (4) is the filter coefficient; a higher exponent would give old entries more weight */