/*   SPDX-License-Identifier: BSD-3-Clause
 *   Copyright (C) 2017 Intel Corporation.
 *   All rights reserved.
 */

#include "spdk_cunit.h"

#include "spdk/histogram_data.h"
#include "spdk/util.h"

uint64_t g_values[] = {
	1,
	10,
	1000,
	50000,
	(1ULL << 63),
	UINT64_MAX
};

uint64_t *g_values_end = &g_values[SPDK_COUNTOF(g_values)];
uint64_t g_total;
uint64_t g_number_of_merged_histograms;

static void
check_values(void *ctx, uint64_t start, uint64_t end, uint64_t count,
	     uint64_t total, uint64_t so_far)
{
	uint64_t **values = ctx;

	if (count == 0) {
		return;
	}

	CU_ASSERT(so_far == (g_total + count));

	/*
	 * The bucket for this iteration does not include end, but
	 *  subtract one anyways to account for the last bucket
	 *  which will have end = 0x0 (UINT64_MAX + 1).
	 */
	end--;

	while (1) {
		CU_ASSERT(**values >= start);
		/*
		 * We subtracted one from end above, so it's OK here for
		 *  **values to equal end.
		 */
		CU_ASSERT(**values <= end);
		g_total += g_number_of_merged_histograms;
		count -= g_number_of_merged_histograms;
		(*values)++;
		if (*values == g_values_end || **values > end) {
			break;
		}
	}
	CU_ASSERT(count == 0);
}

static void
histogram_test(void)
{
	struct spdk_histogram_data *h;
	uint64_t *values = g_values;
	uint32_t i;

	h = spdk_histogram_data_alloc();

	for (i = 0; i < SPDK_COUNTOF(g_values); i++) {
		spdk_histogram_data_tally(h, g_values[i]);
	}
	g_total = 0;
	g_number_of_merged_histograms = 1;
	spdk_histogram_data_iterate(h, check_values, &values);

	spdk_histogram_data_free(h);
}

static void
histogram_merge(void)
{
	struct spdk_histogram_data *h1, *h2;
	uint64_t *values = g_values;
	uint32_t i;

	h1 = spdk_histogram_data_alloc();
	h2 = spdk_histogram_data_alloc();

	for (i = 0; i < SPDK_COUNTOF(g_values); i++) {
		spdk_histogram_data_tally(h1, g_values[i]);
		spdk_histogram_data_tally(h2, g_values[i]);
	}

	spdk_histogram_data_merge(h1, h2);

	g_total = 0;
	g_number_of_merged_histograms = 2;
	spdk_histogram_data_iterate(h1, check_values, &values);

	spdk_histogram_data_free(h1);
	spdk_histogram_data_free(h2);
}

int
main(int argc, char **argv)
{
	CU_pSuite	suite = NULL;
	unsigned int	num_failures;

	if (CU_initialize_registry() != CUE_SUCCESS) {
		return CU_get_error();
	}

	suite = CU_add_suite("histogram", NULL, NULL);
	if (suite == NULL) {
		CU_cleanup_registry();
		return CU_get_error();
	}

	if (
		CU_add_test(suite, "histogram_test", histogram_test) == NULL ||
		CU_add_test(suite, "histogram_merge", histogram_merge) == NULL
	) {
		CU_cleanup_registry();
		return CU_get_error();
	}

	CU_basic_set_mode(CU_BRM_VERBOSE);
	CU_basic_run_tests();
	num_failures = CU_get_number_of_failures();
	CU_cleanup_registry();
	return num_failures;
}