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 * modification, are permitted provided that the following conditions
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 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in
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 *    distribution.
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 *    used to endorse or promote products derived from this software
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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/**
 * @file sd_bench.c
 *
 * SD Card benchmarking
 */

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

#include <px4_platform_common/px4_config.h>
#include <px4_platform_common/module.h>
#include <px4_platform_common/getopt.h>
#include <px4_platform_common/log.h>

#include <drivers/drv_hrt.h>

static void	usage(void);

/** sequential write speed test */
static void	write_test(int fd, uint8_t *block, int block_size);

/**
 * Measure the time for fsync.
 * @param fd
 * @return time in ms
 */
static inline unsigned int time_fsync(int fd);

__EXPORT int	sd_bench_main(int argc, char *argv[]);

static const char *BENCHMARK_FILE = PX4_STORAGEDIR"/benchmark.tmp";

static int num_runs; ///< number of runs
static int run_duration; ///< duration of a single run [ms]
static bool synchronized; ///< call fsync after each block?

static void
usage()
{
	PRINT_MODULE_DESCRIPTION("Test the speed of an SD Card");

	PRINT_MODULE_USAGE_NAME_SIMPLE("sd_bench", "command");
	PRINT_MODULE_USAGE_PARAM_INT('b', 4096, 1, 1000000, "Block size for each read/write", true);
	PRINT_MODULE_USAGE_PARAM_INT('r', 5, 1, 1000, "Number of runs", true);
	PRINT_MODULE_USAGE_PARAM_INT('d', 2000, 1, 100000, "Duration of a run in ms", true);
	PRINT_MODULE_USAGE_PARAM_FLAG('s', "Call fsync after each block (default=at end of each run)", true);
	PRINT_MODULE_USAGE_PARAM_FLAG('u', "Test performance with unaligned data)", true);
}


int
sd_bench_main(int argc, char *argv[])
{
	int block_size = 4096;
	int myoptind = 1;
	int ch;
	const char *myoptarg = NULL;
	synchronized = false;
	num_runs = 5;
	run_duration = 2000;
	bool aligned = true;
	uint8_t *block =  NULL;

	while ((ch = px4_getopt(argc, argv, "b:r:d:su", &myoptind, &myoptarg)) != EOF) {
		switch (ch) {
		case 'b':
			block_size = strtol(myoptarg, NULL, 0);
			break;

		case 'r':
			num_runs = strtol(myoptarg, NULL, 0);
			break;

		case 'd':
			run_duration = strtol(myoptarg, NULL, 0);
			break;

		case 's':
			synchronized = true;
			break;

		case 'u':
			aligned = false;
			break;

		default:
			usage();
			return -1;
			break;
		}
	}

	if (block_size <= 0 || num_runs <= 0) {
		PX4_ERR("invalid argument");
		return -1;
	}

	int bench_fd = open(BENCHMARK_FILE, O_CREAT | O_WRONLY | O_TRUNC, PX4_O_MODE_666);

	if (bench_fd < 0) {
		PX4_ERR("Can't open benchmark file %s", BENCHMARK_FILE);
		return -1;
	}

	//create some data block
	if (aligned) {
		block = (uint8_t *)px4_cache_aligned_alloc(block_size);

	} else {
		block = (uint8_t *)malloc(block_size);
	}

	if (!block) {
		PX4_ERR("Failed to allocate memory block");
		close(bench_fd);
		return -1;
	}

	for (int i = 0; i < block_size; ++i) {
		block[i] = (uint8_t)i;
	}

	PX4_INFO("Using block size = %i bytes, sync=%i", block_size, (int)synchronized);
	write_test(bench_fd, block, block_size);

	free(block);
	close(bench_fd);
	unlink(BENCHMARK_FILE);

	return 0;
}

unsigned int time_fsync(int fd)
{
	hrt_abstime fsync_start = hrt_absolute_time();
	fsync(fd);
	return hrt_elapsed_time(&fsync_start) / 1000;
}

void write_test(int fd, uint8_t *block, int block_size)
{
	PX4_INFO("");
	PX4_INFO("Testing Sequential Write Speed...");
	double total_elapsed = 0.;
	unsigned int total_blocks = 0;

	for (int run = 0; run < num_runs; ++run) {
		hrt_abstime start = hrt_absolute_time();
		unsigned int num_blocks = 0;
		unsigned int max_write_time = 0;
		unsigned int fsync_time = 0;

		while ((int64_t)hrt_elapsed_time(&start) < run_duration * 1000) {

			hrt_abstime write_start = hrt_absolute_time();
			size_t written = write(fd, block, block_size);
			unsigned int write_time = hrt_elapsed_time(&write_start) / 1000;

			if (write_time > max_write_time) {
				max_write_time = write_time;
			}

			if ((int)written != block_size) {
				PX4_ERR("Write error");
				return;
			}

			if (synchronized) {
				fsync_time += time_fsync(fd);
			}

			++num_blocks;
		}

		//Note: if testing a slow device (SD Card) and the OS buffers a lot (eg. Linux),
		//fsync can take really long, and it looks like the process hangs. But it does
		//not and the reported result will still be correct.
		fsync_time += time_fsync(fd);

		//report
		double elapsed = hrt_elapsed_time(&start) / 1.e6;
		PX4_INFO("  Run %2i: %8.2lf KB/s, max write time: %i ms (=%7.2lf KB/s), fsync: %i ms", run,
			 (double)block_size * num_blocks / elapsed / 1024.,
			 max_write_time, (double)block_size / max_write_time * 1000. / 1024., fsync_time);

		total_elapsed += elapsed;
		total_blocks += num_blocks;
	}

	PX4_INFO("  Avg   : %8.2lf KB/s", (double)block_size * total_blocks / total_elapsed / 1024.);
}