/* SPDX-License-Identifier: MIT */

#include <errno.h>

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <string.h>

#include <fcntl.h>

#include <sys/types.h>

#include <sys/poll.h>

#include "liburing.h"

#define BUF_SIZE 4096

#define FILE_SIZE 1024

static int create_file(const char *file)

{

	ssize_t ret;

	char *buf;

	int fd;

	buf = malloc(FILE_SIZE);

	memset(buf, 0xaa, FILE_SIZE);

	fd = open(file, O_WRONLY | O_CREAT, 0644);

	if (fd < 0) {

		perror("open file");

		return 1;

	}

	ret = write(fd, buf, FILE_SIZE);

	close(fd);

	return ret != FILE_SIZE;

}

int main(int argc, char *argv[])

{

	int ret, fd, save_errno;

	struct io_uring ring;

	struct io_uring_sqe *sqe;

	struct io_uring_cqe *cqe;

	struct iovec vec;

	if (argc > 1)

		return 0;

	vec.iov_base = malloc(BUF_SIZE);

	vec.iov_len = BUF_SIZE;

	if (create_file(".short-read")) {

		fprintf(stderr, "file creation failed\n");

		return 1;

	}

	fd = open(".short-read", O_RDONLY);

	save_errno = errno;

	unlink(".short-read");

	errno = save_errno;

	if (fd < 0) {

		perror("file open");

		return 1;

	}

	ret = io_uring_queue_init(32, &ring, 0);

	if (ret) {

		fprintf(stderr, "queue init failed: %d\n", ret);

		return ret;

	}

	sqe = io_uring_get_sqe(&ring);

	if (!sqe) {

		fprintf(stderr, "sqe get failed\n");

		return 1;

	}

	io_uring_prep_readv(sqe, fd, &vec, 1, 0);

	ret = io_uring_submit(&ring);

	if (ret != 1) {

		fprintf(stderr, "submit failed: %d\n", ret);

 		return 1;

	}

	ret = io_uring_wait_cqes(&ring, &cqe, 1, 0, 0);

	if (ret) {

		fprintf(stderr, "wait_cqe failed: %d\n", ret);

		return 1;

	}

	if (cqe->res != FILE_SIZE) {

		fprintf(stderr, "Read failed: %d\n", cqe->res);

		return 1;

	}

	io_uring_cqe_seen(&ring, cqe);

	return 0;

}