intmap: add benchmarks.

I wrote these a while ago, dig them out.

On my laptop, min-max(avg+/-stdev) of 5 runs:

make && for i in `seq 5`; do ./speed 10000000; done | stats
make: Nothing to be done for 'all'.
10000000,random generation (nsec),3-4(3.2+/-0.4)
10000000,critbit insert (nsec),1530-1751(1633.2+/-80)
10000000,critbit successful lookup (nsec),1723-1993(1806.8+/-97)
10000000,critbit failed lookup (nsec),1763-2104(1933.6+/-1.3e+02)
10000000,critbit iteration (nsec),208-266(242.2+/-19)
10000000,critbit memory (bytes),48
10000000,critbit delete (nsec),1747-1861(1803.8+/-42)
10000000,critbit consecutive iteration (nsec),182-228(210+/-18)
10000000,hash insert (nsec),396-424(412+/-9.6)
10000000,hash successful lookup (nsec),150-164(157.4+/-5.5)
10000000,hash failed lookup (nsec),163-178(170+/-5.5)
10000000,hash iteration (nsec),21-26(23.2+/-1.7)
10000000,hash memory (bytes),45
10000000,hash delete (nsec),179-194(183.6+/-5.3)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan/intmap/benchmark/Makefile

+CCANDIR=../../..
+CFLAGS=-Wall -Werror -O3 -I$(CCANDIR) -flto
+#CFLAGS=-Wall -Werror -g3 -I$(CCANDIR)
+LDFLAGS := -flto -O3
+
+all: speed
+
+CCAN_OBJS:=ccan-intmap.o ccan-time.o ccan-isaac64.o ccan-htable.o ccan-siphash24.o
+
+speed: speed.o $(CCAN_OBJS)
+
+clean:
+	rm -f speed *.o
+
+ccan-time.o: $(CCANDIR)/ccan/time/time.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+ccan-intmap.o: $(CCANDIR)/ccan/intmap/intmap.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+ccan-isaac64.o: $(CCANDIR)/ccan/isaac/isaac64.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+ccan-htable.o: $(CCANDIR)/ccan/htable/htable.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+ccan-siphash24.o: $(CCANDIR)/ccan/crypto/siphash24/siphash24.c
+	$(CC) $(CFLAGS) -c -o $@ $<

ccan/intmap/benchmark/speed.c

+/* Test speed of intmap */
+#include <ccan/time/time.h>
+#include <ccan/intmap/intmap.h>
+#include <ccan/isaac/isaac64.h>
+#include <ccan/htable/htable_type.h>
+#include <ccan/crypto/siphash24/siphash24.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+#include <inttypes.h>
+
+/* hack to let us gather span. */
+struct node {
+	/* These point to strings or nodes. */
+	struct intmap child[2];
+	/* The bit where these children differ (0 == lsb) */
+	uint8_t bit_num;
+};
+
+static void update_span(const void *p, size_t s, uintptr_t *min, uintptr_t *max)
+{
+	if ((uintptr_t)p < *min)
+		*min = (uintptr_t)p;
+	if ((uintptr_t)p + s > *max)
+		*max = (uintptr_t)p + s;
+}
+
+static void getspan(const struct intmap *m, uintptr_t *min, uintptr_t *max)
+{
+	struct node *n;
+	/* Leaf node? */
+	if (m->v)
+		return;
+
+	n = m->u.n;
+	update_span(n, sizeof(*n), min, max);
+	getspan(&n->child[0], min, max);
+	getspan(&n->child[1], min, max);
+}
+
+struct htable_elem {
+	uint64_t index;
+	uint64_t *v;
+};
+
+static struct siphash_seed sipseed;
+
+static uint64_t keyof(const struct htable_elem *elem)
+{
+	return elem->index;
+}
+
+static size_t hashfn(const uint64_t index)
+{
+	return siphash24(&sipseed, &index, sizeof(index));
+}
+
+static bool eqfn(const struct htable_elem *elem, const uint64_t index)
+{
+	return elem->index == index;
+}
+HTABLE_DEFINE_TYPE(struct htable_elem, keyof, hashfn, eqfn, hash);
+
+int main(int argc, char *argv[])
+{
+	uint64_t i, total = 0, seed, *v;
+	size_t max = argv[1] ? atol(argv[1]) : 100000000;
+	isaac64_ctx isaac;
+	struct timeabs start, end;
+	UINTMAP(uint64_t *) map;
+	struct hash hash;
+	struct htable_elem *e;
+	struct hash_iter it;
+	uintptr_t span_min, span_max;
+
+	uintmap_init(&map);
+	hash_init(&hash);
+
+	/* We don't want our randomness function to dominate the time,
+	 * nor deal with duplicates (just abort, that's v. unlikely) */
+	seed = time_now().ts.tv_sec + time_now().ts.tv_nsec;
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+
+	start = time_now();
+	for (i = 0; i < max; i++)
+		total += isaac64_next_uint64(&isaac);
+	end = time_now();
+	printf("%zu,random generation (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		if (!uintmap_add(&map, isaac64_next_uint64(&isaac), &i))
+			abort();
+	}
+	end = time_now();
+	printf("%zu,critbit insert (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		if (uintmap_get(&map, isaac64_next_uint64(&isaac)) != &i)
+			abort();
+	}
+	end = time_now();
+	printf("%zu,critbit successful lookup (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		if (uintmap_get(&map, isaac64_next_uint64(&isaac)))
+			abort();
+	}
+	end = time_now();
+	printf("%zu,critbit failed lookup (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (v = uintmap_first(&map, &i); v; v = uintmap_after(&map, &i)) {
+		if (v != &i)
+			abort();
+	}
+	end = time_now();
+	printf("%zu,critbit iteration (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	span_min = -1ULL;
+	span_max = 0;
+	getspan(uintmap_unwrap_(&map), &span_min, &span_max);
+	printf("%zu,critbit memory (bytes),%zu\n",
+	       max, (size_t)(span_max - span_min + max / 2) / max);
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		if (!uintmap_del(&map, isaac64_next_uint64(&isaac)))
+			abort();
+	}
+	end = time_now();
+	printf("%zu,critbit delete (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	/* Fill with consecutive values */
+	for (i = 0; i < max; i++) {
+		if (!uintmap_add(&map, i, &i))
+			abort();
+	}
+	start = time_now();
+	for (v = uintmap_first(&map, &i); v; v = uintmap_after(&map, &i)) {
+		if (v != &i)
+			abort();
+	}
+	end = time_now();
+	printf("%zu,critbit consecutive iteration (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	sipseed.u.u64[0] = isaac64_next_uint64(&isaac);
+	sipseed.u.u64[1] = isaac64_next_uint64(&isaac);
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		e = malloc(sizeof(*e));
+		e->v = &i;
+		e->index = isaac64_next_uint64(&isaac);
+		hash_add(&hash, e);
+	}
+	end = time_now();
+	printf("%zu,hash insert (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		if (hash_get(&hash, isaac64_next_uint64(&isaac))->v != &i)
+			abort();
+	}
+	end = time_now();
+	printf("%zu,hash successful lookup (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		if (hash_get(&hash, isaac64_next_uint64(&isaac)))
+			abort();
+	}
+	end = time_now();
+	printf("%zu,hash failed lookup (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (e = hash_first(&hash, &it); e; e = hash_next(&hash, &it)) {
+		if (e->v != &i)
+			abort();
+	}
+	end = time_now();
+	printf("%zu,hash iteration (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	span_min = -1ULL;
+	span_max = 0;
+	for (e = hash_first(&hash, &it); e; e = hash_next(&hash, &it))
+		update_span(e, sizeof(*e), &span_min, &span_max);
+	/* table itself tends to be allocated in separate memory. */
+	span_max += (sizeof(uintptr_t) << hash.raw.bits);
+	printf("%zu,hash memory (bytes),%zu\n",
+	       max, (size_t)(span_max - span_min + max / 2) / max);
+
+	isaac64_init(&isaac, (unsigned char *)&seed, sizeof(seed));
+	start = time_now();
+	for (i = 0; i < max; i++) {
+		e = hash_get(&hash, isaac64_next_uint64(&isaac));
+		if (!hash_del(&hash, e))
+			abort();
+		free(e);
+	}
+	end = time_now();
+	printf("%zu,hash delete (nsec),%"PRIu64"\n", max,
+	       time_to_nsec(time_divide(time_between(end, start), max)));
+
+	/* Use total, but "never happens". */
+	return (total == 0);
+}