Add VSC stats for the key vector lengths of PH secondary hashes.

Fix rounding for h2strings_avg while we're here.

src/selector.vsc

@@ -58,7 +58,7 @@
 .. varnish_vsc:: hash_keylen
 	:type:  gauge
 	:level:  debug
-	:oneliner:      Hash key vector length
+	:oneliner:      Primary hash key vector length
 
 	Length of the hash key vectors, in blocks of 8 bytes
 
@@ -106,6 +106,28 @@
 	Average number of strings in a secondary hash table, rounded
 	to the nearest integer
 
+.. varnish_vsc:: hash_h2_klen_min
+	:type:  gauge
+	:level:  debug
+	:oneliner:      Minimum secondary hash key vector length
+
+	Minimum key vector length for a secondary hash
+
+.. varnish_vsc:: hash_h2_klen_max
+	:type:  gauge
+	:level:  debug
+	:oneliner:      Maximum secondary hash key vector length
+
+	Maximum key vector length for a secondary hash
+
+.. varnish_vsc:: hash_h2_klen_avg
+	:type:  gauge
+	:level:  debug
+	:oneliner:      Average secondary hash strings
+
+	Average key vector length for secondary hashes, rounded to the
+	nearest integer
+
 .. varnish_vsc:: trie_nodes
 	:type:  gauge
 	:level:  debug

src/tests/stats.vtc

@@ -41,6 +41,9 @@ varnish v1 -expect SELECTOR.vcl1.s.hash_h2_buckets_avg >= 0
 varnish v1 -expect SELECTOR.vcl1.s.hash_h2_strings_min >= 0
 varnish v1 -expect SELECTOR.vcl1.s.hash_h2_strings_max >= 0
 varnish v1 -expect SELECTOR.vcl1.s.hash_h2_strings_avg >= 0
+varnish v1 -expect SELECTOR.vcl1.s.hash_h2_klen_min >= 0
+varnish v1 -expect SELECTOR.vcl1.s.hash_h2_klen_max >= 0
+varnish v1 -expect SELECTOR.vcl1.s.hash_h2_klen_avg >= 0
 
 varnish v1 -vcl {
 	import ${vmod_selector};
@@ -95,6 +98,9 @@ varnish v1 -expect SELECTOR.vcl2.p.hash_h2_buckets_avg >= 0
 varnish v1 -expect SELECTOR.vcl2.p.hash_h2_strings_min >= 0
 varnish v1 -expect SELECTOR.vcl2.p.hash_h2_strings_max >= 0
 varnish v1 -expect SELECTOR.vcl2.p.hash_h2_strings_avg >= 0
+varnish v1 -expect SELECTOR.vcl2.p.hash_h2_klen_min >= 0
+varnish v1 -expect SELECTOR.vcl2.p.hash_h2_klen_max >= 0
+varnish v1 -expect SELECTOR.vcl2.p.hash_h2_klen_avg >= 0
 
 varnish v1 -expect SELECTOR.vcl2.e.elements == 0
 varnish v1 -expect SELECTOR.vcl2.e.setsz == 0
@@ -118,6 +124,9 @@ varnish v1 -expect SELECTOR.vcl2.e.hash_h2_buckets_avg == 0
 varnish v1 -expect SELECTOR.vcl2.e.hash_h2_strings_min >= 0
 varnish v1 -expect SELECTOR.vcl2.e.hash_h2_strings_max >= 0
 varnish v1 -expect SELECTOR.vcl2.e.hash_h2_strings_avg >= 0
+varnish v1 -expect SELECTOR.vcl2.e.hash_h2_klen_min >= 0
+varnish v1 -expect SELECTOR.vcl2.e.hash_h2_klen_max >= 0
+varnish v1 -expect SELECTOR.vcl2.e.hash_h2_klen_avg >= 0
 
 # When vcl1 is set to cold, stats for vcl2.p but not vcl1.s appear.
 varnish v1 -cliok "vcl.state vcl1 cold"
@@ -148,6 +157,9 @@ varnish v1 -expect SELECTOR.vcl1.s.hash_h2_buckets_avg >= 0
 varnish v1 -expect SELECTOR.vcl1.s.hash_h2_strings_min >= 0
 varnish v1 -expect SELECTOR.vcl1.s.hash_h2_strings_max >= 0
 varnish v1 -expect SELECTOR.vcl1.s.hash_h2_strings_avg >= 0
+varnish v1 -expect SELECTOR.vcl1.s.hash_h2_klen_min >= 0
+varnish v1 -expect SELECTOR.vcl1.s.hash_h2_klen_max >= 0
+varnish v1 -expect SELECTOR.vcl1.s.hash_h2_klen_avg >= 0
 
 # The same 100 words from /usr/share/dict/words as in match.vtc
 varnish v1 -vcl {
@@ -283,6 +295,9 @@ varnish v1 -expect SELECTOR.vcl3.words.hash_h2_buckets_avg >= 0
 varnish v1 -expect SELECTOR.vcl3.words.hash_h2_strings_min >= 0
 varnish v1 -expect SELECTOR.vcl3.words.hash_h2_strings_max >= 0
 varnish v1 -expect SELECTOR.vcl3.words.hash_h2_strings_avg >= 0
+varnish v1 -expect SELECTOR.vcl3.words.hash_h2_klen_min >= 0
+varnish v1 -expect SELECTOR.vcl3.words.hash_h2_klen_max >= 0
+varnish v1 -expect SELECTOR.vcl3.words.hash_h2_klen_avg >= 0
 
 varnish v1 -cliok "vcl.state vcl1 cold"
 varnish v1 -cli "vcl.discard vcl1"

src/vmod_selector.c

@@ -915,6 +915,9 @@ vmod_set_create_stats(VRT_CTX, struct vmod_selector_set *set,
 		assert(ph_stats.h2strings_min <= ph_stats.h2strings_max);
 		assert(ph_stats.h2strings_min <= ph_stats.h2strings_avg);
 		assert(ph_stats.h2strings_avg <= ph_stats.h2strings_max);
+		assert(ph_stats.h2klen_min <= ph_stats.h2klen_max);
+		assert(ph_stats.h2klen_min <= ph_stats.h2klen_avg);
+		assert(ph_stats.h2klen_avg <= ph_stats.h2klen_max);
 	}
 
 	vsc = VSC_selector_New(NULL, &vsc_seg, "%s.%s", VCL_Name(ctx->vcl),
@@ -943,7 +946,10 @@ vmod_set_create_stats(VRT_CTX, struct vmod_selector_set *set,
 	vsc->hash_h2_buckets_avg = (uint64_t)(ph_stats.h2buckets_avg + 0.5);
 	vsc->hash_h2_strings_min = ph_stats.h2strings_min;
 	vsc->hash_h2_strings_max = ph_stats.h2strings_max;
-	vsc->hash_h2_strings_avg = ph_stats.h2strings_avg;
+	vsc->hash_h2_strings_avg = (uint64_t)(ph_stats.h2strings_avg + 0.5);
+	vsc->hash_h2_klen_min = ph_stats.h2klen_min;
+	vsc->hash_h2_klen_max = ph_stats.h2klen_max;
+	vsc->hash_h2_klen_avg = (uint64_t)(ph_stats.h2klen_avg + 0.5);
 
 	ALLOC_OBJ(vsc_entry, VMOD_SELECTOR_VSC_MAGIC);
 	AN(vsc_entry);