zfs-builds-mm/zfs-0.8.2/tests/zfs-tests/cmd/randwritecomp/randwritecomp.c

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2019-10-24 23:13:56 +02:00
/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright (c) 2017 by Delphix. All rights reserved.
*/
/*
* The following is defined so the source can use
* lrand48() and srand48().
*/
#define __EXTENSIONS__
#include <stdint.h>
#include <string.h>
#include "../file_common.h"
/*
* The following sample was derived from real-world data
* of a production Oracle database.
*/
static uint64_t size_distribution[] = {
0,
1499018,
352084,
1503485,
4206227,
5626657,
5387001,
3733756,
2233094,
874652,
238635,
81434,
33357,
13106,
2009,
1,
23660,
};
static uint64_t distribution_n;
static uint8_t randbuf[BLOCKSZ];
static void
rwc_pwrite(int fd, const void *buf, size_t nbytes, off_t offset)
{
size_t nleft = nbytes;
ssize_t nwrite = 0;
nwrite = pwrite(fd, buf, nbytes, offset);
if (nwrite < 0) {
perror("pwrite");
exit(EXIT_FAILURE);
}
nleft -= nwrite;
if (nleft != 0) {
(void) fprintf(stderr, "warning: pwrite: "
"wrote %zu out of %zu bytes\n",
(nbytes - nleft), nbytes);
}
}
static void
fillbuf(char *buf)
{
uint64_t rv = lrand48() % distribution_n;
uint64_t sum = 0;
uint64_t i;
for (i = 0;
i < sizeof (size_distribution) / sizeof (size_distribution[0]);
i++) {
sum += size_distribution[i];
if (rv < sum)
break;
}
bcopy(randbuf, buf, BLOCKSZ);
if (i == 0)
bzero(buf, BLOCKSZ - 10);
else if (i < 16)
bzero(buf, BLOCKSZ - i * 512 + 256);
/*LINTED: E_BAD_PTR_CAST_ALIGN*/
((uint32_t *)buf)[0] = lrand48();
}
static void
exit_usage(void)
{
(void) printf("usage: ");
(void) printf("randwritecomp <file> [-s] [nwrites]\n");
exit(EXIT_FAILURE);
}
static void
sequential_writes(int fd, char *buf, uint64_t nblocks, int64_t n)
{
for (int64_t i = 0; n == -1 || i < n; i++) {
fillbuf(buf);
static uint64_t j = 0;
if (j == 0)
j = lrand48() % nblocks;
rwc_pwrite(fd, buf, BLOCKSZ, j * BLOCKSZ);
j++;
if (j >= nblocks)
j = 0;
}
}
static void
random_writes(int fd, char *buf, uint64_t nblocks, int64_t n)
{
for (int64_t i = 0; n == -1 || i < n; i++) {
fillbuf(buf);
rwc_pwrite(fd, buf, BLOCKSZ, (lrand48() % nblocks) * BLOCKSZ);
}
}
int
main(int argc, char *argv[])
{
int fd, err;
char *filename = NULL;
char buf[BLOCKSZ];
struct stat ss;
uint64_t nblocks;
int64_t n = -1;
int sequential = 0;
if (argc < 2)
exit_usage();
argv++;
if (strcmp("-s", argv[0]) == 0) {
sequential = 1;
argv++;
}
if (argv[0] == NULL)
exit_usage();
else
filename = argv[0];
argv++;
if (argv[0] != NULL)
n = strtoull(argv[0], NULL, 0);
fd = open(filename, O_RDWR|O_CREAT, 0666);
err = fstat(fd, &ss);
if (err != 0) {
(void) fprintf(stderr,
"error: fstat returned error code %d\n", err);
exit(EXIT_FAILURE);
}
nblocks = ss.st_size / BLOCKSZ;
if (nblocks == 0) {
(void) fprintf(stderr, "error: "
"file is too small (min allowed size is %d bytes)\n",
BLOCKSZ);
exit(EXIT_FAILURE);
}
srand48(getpid());
for (int i = 0; i < BLOCKSZ; i++)
randbuf[i] = lrand48();
distribution_n = 0;
for (uint64_t i = 0;
i < sizeof (size_distribution) / sizeof (size_distribution[0]);
i++) {
distribution_n += size_distribution[i];
}
if (sequential)
sequential_writes(fd, buf, nblocks, n);
else
random_writes(fd, buf, nblocks, n);
return (0);
}