ccan/ccan/htable/tools/stringspeed.c

/* Simple speed tests for a hash of strings. */
#include <ccan/htable/htable_type.h>
#include <ccan/htable/htable.c>
#include <ccan/str_talloc/str_talloc.h>
#include <ccan/grab_file/grab_file.h>
#include <ccan/talloc/talloc.h>
#include <ccan/hash/hash.h>
#include <ccan/time/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/time.h>

static size_t hashcount;

static const char *strkey(const char *str)
{
	return str;
}

static size_t hash_str(const char *key)
{
	hashcount++;
	return hash(key, strlen(key), 0);
}

static bool cmp(const char *obj, const char *key)
{
	return strcmp(obj, key) == 0;
}

HTABLE_DEFINE_TYPE(char, strkey, hash_str, cmp, str);

/* Nanoseconds per operation */
static size_t normalize(const struct timeval *start,
			const struct timeval *stop,
			unsigned int num)
{
	struct timeval diff;

	timersub(stop, start, &diff);

	/* Floating point is more accurate here. */
	return (double)(diff.tv_sec * 1000000 + diff.tv_usec)
		/ num * 1000;
}

int main(int argc, char *argv[])
{
	size_t i, j, num;
	struct timeval start, stop;
	struct htable_str *ht;
	char **words, **misswords;

	words = strsplit(NULL, grab_file(NULL,
					 argv[1] ? argv[1] : "/usr/share/dict/words",
					 NULL), "\n");
	ht = htable_str_new();
	num = talloc_array_length(words) - 1;
	printf("%zu words\n", num);

	/* Append and prepend last char for miss testing. */
	misswords = talloc_array(words, char *, num);
	for (i = 0; i < num; i++) {
		char lastc;
		if (strlen(words[i]))
			lastc = words[i][strlen(words[i])-1];
		else
			lastc = 'z';
		misswords[i] = talloc_asprintf(misswords, "%c%s%c%c",
					       lastc, words[i], lastc, lastc);
	}

	printf("#01: Initial insert: ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++)
		htable_str_add(ht, words[i]);
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("Bytes allocated: %zu\n",
	       sizeof(((struct htable *)ht)->table[0])
	       << ((struct htable *)ht)->bits);

	printf("#02: Initial lookup (match): ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++)
		if (htable_str_get(ht, words[i]) != words[i])
			abort();
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#03: Initial lookup (miss): ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++) {
		if (htable_str_get(ht, misswords[i]))
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	/* Lookups in order are very cache-friendly for judy; try random */
	printf("#04: Initial lookup (random): ");
	fflush(stdout);
	start = time_now();
	for (i = 0, j = 0; i < num; i++, j = (j + 10007) % num)
		if (htable_str_get(ht, words[j]) != words[j])
			abort();
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	hashcount = 0;
	printf("#05: Initial delete all: ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++)
		if (!htable_str_del(ht, words[i]))
			abort();
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#06: Initial re-inserting: ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++)
		htable_str_add(ht, words[i]);
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	hashcount = 0;
	printf("#07: Deleting first half: ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i+=2)
		if (!htable_str_del(ht, words[i]))
			abort();
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#08: Adding (a different) half: ");
	fflush(stdout);

	start = time_now();
	for (i = 0; i < num; i+=2)
		htable_str_add(ht, misswords[i]);
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#09: Lookup after half-change (match): ");
	fflush(stdout);
	start = time_now();
	for (i = 1; i < num; i+=2)
		if (htable_str_get(ht, words[i]) != words[i])
			abort();
	for (i = 0; i < num; i+=2) {
		if (htable_str_get(ht, misswords[i]) != misswords[i])
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#10: Lookup after half-change (miss): ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i+=2)
		if (htable_str_get(ht, words[i]))
			abort();
	for (i = 1; i < num; i+=2) {
		if (htable_str_get(ht, misswords[i]))
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	/* Hashtables with delete markers can fill with markers over time.
	 * so do some changes to see how it operates in long-term. */
	printf("#11: Churn 1: ");
	start = time_now();
	for (j = 0; j < num; j+=2) {
		if (!htable_str_del(ht, misswords[j]))
			abort();
		if (!htable_str_add(ht, words[j]))
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#12: Churn 2: ");
	start = time_now();
	for (j = 1; j < num; j+=2) {
		if (!htable_str_del(ht, words[j]))
			abort();
		if (!htable_str_add(ht, misswords[j]))
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#13: Churn 3: ");
	start = time_now();
	for (j = 1; j < num; j+=2) {
		if (!htable_str_del(ht, misswords[j]))
			abort();
		if (!htable_str_add(ht, words[j]))
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	/* Now it's back to normal... */
	printf("#14: Post-Churn lookup (match): ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++)
		if (htable_str_get(ht, words[i]) != words[i])
			abort();
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	printf("#15: Post-Churn lookup (miss): ");
	fflush(stdout);
	start = time_now();
	for (i = 0; i < num; i++) {
		if (htable_str_get(ht, misswords[i]))
			abort();
	}
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	/* Lookups in order are very cache-friendly for judy; try random */
	printf("#16: Post-Churn lookup (random): ");
	fflush(stdout);
	start = time_now();
	for (i = 0, j = 0; i < num; i++, j = (j + 10007) % num)
		if (htable_str_get(ht, words[j]) != words[j])
			abort();
	stop = time_now();
	printf(" %zu ns\n", normalize(&start, &stop, num));

	return 0;
}