router: ensure route using doesn't modify metric, PR #282

This is an alternative take to the original PR.  Instead of having
ch_get_nodes copy the metric into the destinations struct
(undocumented), perform the copy in router_route_intern, like for all
other cases.  This is more transparent, and ensures that the correct
metric is added to the send queue.

ChangeLog.md

@@ -28,6 +28,8 @@
   regex matching slow on glibc due to lock contention
 * [Issue #287](https://github.com/grobian/carbon-c-relay/issues/287)
   unexpected warning about rejected socket bufsize
+* [PR #282](https://github.com/grobian/carbon-c-relay/pull/282)
+  route using should not change the metric key sent
 
 
 # 3.1 (29-04-2017)

consistent-hash.c

@@ -333,7 +333,6 @@ ch_get_nodes(
 				j = jump_bucketpos(hash, i);
 
 				(*ret).dest = bcklst[j];
-				(*ret).metric = strdup(metric);
 				ret++;
 
 				if (--pos == 0)
@@ -403,7 +402,6 @@ ch_get_nodes(
 			continue;
 		}
 		ret[i].dest = ring->entrylist[t].server;
-		ret[i].metric = strdup(metric);
 	}
 }
 

router.c

@@ -2521,6 +2521,7 @@ router_route_intern(
 					case CARBON_CH:
 					case FNV1A_CH:
 					case JUMP_CH: {
+						size_t i;
 						/* let the ring(bearer) decide */
 						failif(retsize,
 								*curlen + d->cl->members.ch->repl_factor);
@@ -2544,7 +2545,8 @@ router_route_intern(
 								d->cl->members.ch->repl_factor,
 								w->masq ? newmetric : metric,
 								w->masq ? newfirstspace : firstspace);
-						*curlen += d->cl->members.ch->repl_factor;
+						for (i = 0; i < d->cl->members.ch->repl_factor; i++)
+							ret[(*curlen)++].metric = strdup(metric);
 						wassent = 1;
 					}	break;
 					case AGGREGATION: {
@@ -2903,7 +2905,6 @@ router_test_intern(char *metric, char *firstspace, route *routes)
 							fprintf(stdout, "        %s:%d\n",
 									serverip(dst[i].dest),
 									server_port(dst[i].dest));
-							free((char *)dst[i].metric);
 						}
 					}	break;
 					case FAILOVER: