expire: Add hits to EXP_Expired log statement

This makes it easier to estimate the popularity of expired objects.

bin/varnishd/cache/cache_expire.c

@@ -354,8 +354,9 @@ exp_expire(struct exp_priv *ep, vtim_real now)
 		assert(oc->timer_idx == VBH_NOIDX);
 
 		CHECK_OBJ_NOTNULL(oc->objhead, OBJHEAD_MAGIC);
-		VSLb(&ep->vsl, SLT_ExpKill, "EXP_Expired xid=%ju t=%.0f",
-		    VXID(ObjGetXID(ep->wrk, oc)), EXP_Ttl(NULL, oc) - now);
+		VSLb(&ep->vsl, SLT_ExpKill, "EXP_Expired x=%ju t=%.0f h=%ld",
+		    VXID(ObjGetXID(ep->wrk, oc)), EXP_Ttl(NULL, oc) - now,
+		    oc->hits);
 		ObjSendEvent(ep->wrk, oc, OEV_EXPIRE);
 		(void)HSH_DerefObjCore(ep->wrk, &oc, 0);
 	}

bin/varnishtest/tests/r02339.vtc

@@ -21,7 +21,7 @@ varnish v1 -vcl+backend {
 varnish v1 -cliok "param.set timeout_idle 2"
 
 logexpect l0 -v v1 -g raw {
-	expect * 0 ExpKill	"EXP_Expired xid=1002"
+	expect * 0 ExpKill	"EXP_Expired x=1002"
 } -start
 
 logexpect l2 -v v1 -g raw {
@@ -109,4 +109,4 @@ varnish v1 -errvcl "Not available in subroutine 'vcl_backend_response'" {
 	sub vcl_backend_response {
 		if (bereq.url == "response") { purge.hard(); }
 	}
-}
\ No newline at end of file
+}

include/tbl/vsl_tags.h

@@ -367,7 +367,7 @@ SLTM(ExpKill, 0, "Object expiry event",
 	"\tEXP_Inbox p=%p e=%f f=0x%x\n"
 	"\tEXP_Kill p=%p e=%f f=0x%x\n"
 	"\tEXP_When p=%p e=%f f=0x%x\n"
-	"\tEXP_Expired x=%u t=%f\n"
+	"\tEXP_Expired x=%u t=%f h=%u\n"
 	"\tLRU_Cand p=%p f=0x%x r=%d\n"
 	"\tLRU x=%u\n"
 	"\tLRU_Fail\n"
@@ -380,6 +380,7 @@ SLTM(ExpKill, 0, "Object expiry event",
 	"\tf=0x%x       Objcore flags\n"
 	"\tr=%d         Objcore refcount\n"
 	"\tx=%u         Object VXID\n"
+	"\th=%u         Objcore hits\n"
 	"\n"
 )
 

vmod/tests/purge_c00000.vtc

@@ -68,7 +68,7 @@ logexpect l2 -v v1 -q "Begin ~ bgfetch" {
 } -start
 
 logexpect l3 -v v1 -g raw -q "vxid == 0" {
-	expect * * ExpKill xid=1008
+	expect * * ExpKill x=1008
 } -start
 
 client c1 {