Add some more stats.

src/ph.c

@@ -444,14 +444,24 @@ PH_Stats(const struct ph * const restrict ph,
 	stats->minlen = ph->minlen;
 	stats->maxlen = ph->maxlen;
 
+	stats->h2buckets_min = UINT64_MAX;
 	for (unsigned i = 0; i <= ph->h1->mask; i++)
 		if (vbit_test(ph->collision, i)) {
 			struct hash *h2;
+			uint64_t sz;
 
 			h2 = ph->tbl[i].h2;
 			CHECK_OBJ_NOTNULL(h2, HASH_MAGIC);
+			sz = h2->mask + 1;
 
 			stats->collisions++;
+			if (sz < stats->h2buckets_min)
+				stats->h2buckets_min = sz;
+			if (sz > stats->h2buckets_max)
+				stats->h2buckets_max = sz;
+			stats->h2buckets_avg +=
+				(sz - stats->h2buckets_avg)
+				/ stats->collisions;
 		}
 }
 

src/ph.h

@@ -50,6 +50,9 @@ struct ph_stats {
 	uint64_t	klen;
 	uint64_t	minlen;
 	uint64_t	maxlen;
+	uint64_t	h2buckets_min;
+	uint64_t	h2buckets_max;
+	double		h2buckets_avg;
 };
 
 /*

src/tests/bench/bench_ph.c

@@ -329,6 +329,9 @@ main(int argc, char *argv[])
 	printf("%lu key vector length\n", stats.klen);
 	printf("%lu min string length\n", stats.minlen);
 	printf("%lu max string length\n", stats.maxlen);
+	printf("%lu h2 min buckets\n", stats.h2buckets_min);
+	printf("%lu h2 max buckets\n", stats.h2buckets_max);
+	printf("%.1f h2 mean buckets\n", stats.h2buckets_avg);
 
 	if (do_iters == 0)
 		exit(EXIT_SUCCESS);