[MINOR] add a weight divisor to the struct proxy

Under some circumstances, it will be useful to be able to have
a server's effective weight bigger than the user weight, and this
is particularly true for dynamic weight-based algorithms. In order
to support this, we add a "wdiv" member to the lbprm structure
which will always be used to divide the weights before reporting
them.

include/proto/backend.h

@@ -42,6 +42,7 @@ int backend_parse_balance(const char **args, char *err,
 void recount_servers(struct proxy *px);
 void recalc_server_map(struct proxy *px);
 int be_downtime(struct proxy *px);
+void init_server_map(struct proxy *p);
 
 /*
  * This function tries to find a running server with free connection slots for

include/types/proxy.h

@@ -86,6 +86,7 @@ struct proxy {
 		int tot_weight;			/* total effective weight of servers participating to LB */
 		int tot_used;			/* total number of servers used for LB */
 		int wmult;			/* ratio between user weight and effective weight */
+		int wdiv;			/* ratio between effective weight and user weight */
 		struct {
 			struct server **srv;	/* the server map used to apply weights */
 			int rr_idx;		/* next server to be elected in round robin mode */

src/backend.c

@@ -161,6 +161,59 @@ void recalc_server_map(struct proxy *px)
 	px->lbprm.map.state &= ~PR_MAP_RECALC;
 }
 
+/* This function is responsible of building the server MAP for map-based LB
+ * algorithms, allocating the map, and setting p->lbprm.wmult to the GCD of the
+ * weights if applicable. It should be called only once per proxy, at config
+ * time.
+ */
+void init_server_map(struct proxy *p)
+{
+	struct server *srv;
+	int pgcd;
+	int act, bck;
+
+	if (!p->srv)
+		return;
+
+	/* We will factor the weights to reduce the table,
+	 * using Euclide's largest common divisor algorithm
+	 */
+	pgcd = p->srv->uweight;
+	for (srv = p->srv->next; srv && pgcd > 1; srv = srv->next) {
+		int w = srv->uweight;
+		while (w) {
+			int t = pgcd % w;
+			pgcd = w;
+			w = t;
+		}
+	}
+
+	/* It is sometimes useful to know what factor to apply
+	 * to the backend's effective weight to know its real
+	 * weight.
+	 */
+	p->lbprm.wmult = pgcd;
+
+	act = bck = 0;
+	for (srv = p->srv; srv; srv = srv->next) {
+		srv->eweight = srv->uweight / pgcd;
+		if (srv->state & SRV_BACKUP)
+			bck += srv->eweight;
+		else
+			act += srv->eweight;
+	}
+
+	/* this is the largest map we will ever need for this servers list */
+	if (act < bck)
+		act = bck;
+
+	p->lbprm.map.srv = (struct server **)calloc(act, sizeof(struct server *));
+	/* recounts servers and their weights */
+	p->lbprm.map.state = PR_MAP_RECALC;
+	recount_servers(p);
+	recalc_server_map(p);
+}
+
 /* 
  * This function tries to find a running server for the proxy <px> following
  * the URL parameter hash method. It looks for a specific parameter in the

src/cfgparse.c

@@ -2653,53 +2653,9 @@ int readcfgfile(const char *file)
 		}
 
 		curproxy->lbprm.wmult = 1; /* default weight multiplier */
+		curproxy->lbprm.wdiv  = 1; /* default weight divider */
 
-		/* now, newsrv == curproxy->srv */
-		if (newsrv) {
-			struct server *srv;
-			int pgcd;
-			int act, bck;
-
-			/* We will factor the weights to reduce the table,
-			 * using Euclide's largest common divisor algorithm
-			 */
-			pgcd = newsrv->uweight;
-			for (srv = newsrv->next; srv && pgcd > 1; srv = srv->next) {
-				int t, w;
-		
-				w = srv->uweight;
-				while (w) {
-					t = pgcd % w;
-					pgcd = w;
-					w = t;
-				}
-			}
-
-			/* It is sometimes useful to know what factor to apply
-			 * to the backend's effective weight to know its real
-			 * weight.
-			 */
-			curproxy->lbprm.wmult = pgcd;
-
-			act = bck = 0;
-			for (srv = newsrv; srv; srv = srv->next) {
-				srv->eweight = srv->uweight / pgcd;
-				if (srv->state & SRV_BACKUP)
-					bck += srv->eweight;
-				else
-					act += srv->eweight;
-			}
-
-			/* this is the largest map we will ever need for this servers list */
-			if (act < bck)
-				act = bck;
-
-			curproxy->lbprm.map.srv = (struct server **)calloc(act, sizeof(struct server *));
-			/* recounts servers and their weights */
-			curproxy->lbprm.map.state = PR_MAP_RECALC;
-			recount_servers(curproxy);
-			recalc_server_map(curproxy);
-		}
+		init_server_map(curproxy);
 
 		if (curproxy->options & PR_O_LOGASAP)
 			curproxy->to_log &= ~LW_BYTES;

src/dumpstats.c

@@ -756,7 +756,7 @@ int stats_dump_proxy(struct session *s, struct proxy *px, struct uri_auth *uri,
 				     /* act, bck */
 				     "<td>%s</td><td>%s</td>"
 				     "",
-				     sv->uweight,
+				     sv->eweight * px->lbprm.wmult / px->lbprm.wdiv,
 				     (sv->state & SRV_BACKUP) ? "-" : "Y",
 				     (sv->state & SRV_BACKUP) ? "Y" : "-");
 
@@ -808,7 +808,7 @@ int stats_dump_proxy(struct session *s, struct proxy *px, struct uri_auth *uri,
 				     /* weight, active, backup */
 				     "%d,%d,%d,"
 				     "",
-				     sv->uweight,
+				     sv->eweight * px->lbprm.wmult / px->lbprm.wdiv,
 				     (sv->state & SRV_BACKUP) ? 0 : 1,
 				     (sv->state & SRV_BACKUP) ? 1 : 0);
 
@@ -872,7 +872,7 @@ int stats_dump_proxy(struct session *s, struct proxy *px, struct uri_auth *uri,
 				     px->retries, px->redispatches,
 				     human_time(now.tv_sec - px->last_change, 1),
 				     (px->lbprm.tot_weight > 0 || !px->srv) ? "UP" : "DOWN",
-				     px->lbprm.tot_weight * px->lbprm.wmult,
+				     px->lbprm.tot_weight * px->lbprm.wmult / px->lbprm.wdiv,
 				     px->srv_act, px->srv_bck);
 
 				chunk_printf(&msg, sizeof(trash),
@@ -918,7 +918,7 @@ int stats_dump_proxy(struct session *s, struct proxy *px, struct uri_auth *uri,
 				     px->failed_conns, px->failed_resp,
 				     px->retries, px->redispatches,
 				     (px->lbprm.tot_weight > 0 || !px->srv) ? "UP" : "DOWN",
-				     px->lbprm.tot_weight * px->lbprm.wmult,
+				     px->lbprm.tot_weight * px->lbprm.wmult / px->lbprm.wdiv,
 				     px->srv_act, px->srv_bck,
 				     px->down_trans, now.tv_sec - px->last_change,
 				     px->srv?be_downtime(px):0,