livetrax/tools/readtest.cc

/* g++ -o readtest readtest.cc `pkg-config --cflags --libs sndfile` `pkg-config --cflags --libs glibmm-2.4` */

#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <getopt.h>
#include <fcntl.h>

#include <glib.h>

char* data = 0;

int
read_one (int fd, ssize_t sz)
{

	return 0;
}

void
usage ()
{
	fprintf (stderr, "readtest [ -b BLOCKSIZE ] [ -s ] [ -D ] filename-template\n");
}

int
main (int argc, char* argv[])
{
        int* files;
	char optstring[] = "b:D";
	uint32_t block_size = 64 * 1024 * 4;
        bool direct = false;
	const struct option longopts[] = {
		{ "blocksize", 1, 0, 'b' },
		{ "direct", 0, 0, 'D' },
		{ 0, 0, 0, 0 }
	};

	int option_index = 0;
	int c = 0;
	char const * name_template = 0;
        int flags = O_RDONLY;
        int n = 0;
        int nfiles = 0;

	while (1) {
		if ((c = getopt_long (argc, argv, optstring, longopts, &option_index)) == -1) {
			break;
		}

		switch (c) {
		case 'b':
			block_size = atoi (optarg);
			break;
                case 'D':
                        direct = true;
                        break;
		default:
			usage ();
			return 0;
		}
	}

	if (optind < argc) {
		name_template = argv[optind];
	} else {
		usage ();
		return 1;
	}
        
        while (1) {
		char path[PATH_MAX+1];

		snprintf (path, sizeof (path), name_template, n+1);

		if (access (path, R_OK) != 0) {
			break;
		}

                ++n;
        }

        if (n == 0) {
                fprintf (stderr, "No matching files found for %s\n", name_template);
                return 1;
        }

	printf ("Discovered %d files using %s\n", n, name_template);
        
        nfiles = n;
        files = (int *) malloc (sizeof (int) * nfiles);

        for (n = 0; n < nfiles; ++n) {

		char path[PATH_MAX+1];
                int fd;

		snprintf (path, sizeof (path), name_template, n+1);

                if ((fd = open (path, flags, 0644)) < 0) {
			fprintf (stderr, "Could not open file #%d @ %s (%s)\n", n, path, strerror (errno));
                        return 1;
                }

#ifdef __APPLE__
                if (direct) {
                        /* Apple man pages say only that it returns "a value other than -1 on success",
                           which probably means zero, but you just can't be too careful with
                           those guys.
                        */
                        if (fcntl (fd, F_NOCACHE, 1) == -1) {
                                fprintf (stderr, "Cannot set F_NOCACHE on file #%d\n", n);
                        }
                }
#endif

                files[n] = fd;
	}

	data = new char[block_size];
	uint64_t read = 0;
	
	while (true) {
		gint64 before;
		before = g_get_monotonic_time();

		for (n = 0; n < nfiles; ++n) {

                        if (::read (files[n], (char*) data, block_size) != block_size) {
                                fprintf (stderr, "read failed on file %d (%s)\n", n, strerror (errno));
                                return -1;
                        }
		}

		read += block_size;
		gint64 elapsed = g_get_monotonic_time() - before;
                double bandwidth = ((nfiles * block_size)/1048576.0) / (elapsed/1000000.0);
		
                printf ("BW @ %Lu %.3f seconds bandwidth %.4f MB/sec\n", read, elapsed/1000000.0, bandwidth);
	}

	return 0;
}