/*
* gcc -Wall -O2 -D_GNU_SOURCE -o io_uring-cp io_uring-cp.c -luring
*/
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "../src/liburing.h"
#define QD 64
#define BS 4096
static struct io_uring in_ring;
static struct io_uring out_ring;
static void *bufs[QD];
static int setup_context(unsigned entries, struct io_uring *ring, int offload)
{
struct io_uring_params p;
int ret;
memset(&p, 0, sizeof(p));
if (offload)
p.flags = IORING_SETUP_SQWQ;
ret = io_uring_queue_init(entries, &p, NULL, ring);
if (ret < 0) {
fprintf(stderr, "queue_init: %s\n", strerror(-ret));
return -1;
}
return 0;
}
static int get_file_size(int fd, off_t *size)
{
struct stat st;
if (fstat(fd, &st) < 0)
return -1;
if (S_ISREG(st.st_mode)) {
*size = st.st_size;
return 0;
}
return -1;
}
static unsigned iocb_index(struct io_uring_iocb *iocb)
{
return iocb - in_ring.sq.iocbs;
}
static int queue_read(int fd, off_t size, off_t offset)
{
struct io_uring_iocb *iocb;
iocb = io_uring_get_iocb(&in_ring);
if (!iocb)
return 1;
iocb->opcode = IORING_OP_READ;
iocb->flags = 0;
iocb->ioprio = 0;
iocb->fd = fd;
iocb->off = offset;
iocb->addr = bufs[iocb_index(iocb)];
iocb->len = size;
return 0;
}
static int complete_writes(unsigned *writes)
{
int ret, nr;
ret = io_uring_submit(&out_ring);
if (ret < 0) {
fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret));
return 1;
}
nr = ret;
while (nr) {
struct io_uring_event *ev = NULL;
ret = io_uring_wait_completion(&out_ring, &ev);
if (ret < 0) {
fprintf(stderr, "io_uring_wait_completion: %s\n",
strerror(-ret));
return 1;
}
if (ev->res < 0) {
fprintf(stderr, "ev failed: %s\n", strerror(-ev->res));
return 1;
}
(*writes)--;
nr--;
}
return 0;
}
static void queue_write(int fd, off_t size, off_t offset, unsigned index)
{
struct io_uring_iocb *iocb;
iocb = io_uring_get_iocb(&out_ring);
iocb->opcode = IORING_OP_WRITE;
iocb->flags = 0;
iocb->ioprio = 0;
iocb->fd = fd;
iocb->off = offset;
iocb->addr = bufs[index];
iocb->len = size;
}
int main(int argc, char *argv[])
{
struct io_uring_event *ev;
off_t read_left, write_left, offset;
int i, infd, outfd, ret;
unsigned reads, writes;
if (argc < 3) {
printf("%s: infile outfile\n", argv[0]);
return 1;
}
infd = open(argv[1], O_RDONLY);
if (infd < 0) {
perror("open infile");
return 1;
}
outfd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (outfd < 0) {
perror("open outfile");
return 1;
}
for (i = 0; i < QD; i++)
if (posix_memalign(&bufs[i], BS, BS))
return 1;
if (setup_context(QD, &in_ring, 1))
return 1;
if (setup_context(QD, &out_ring, 0))
return 1;
if (get_file_size(infd, &read_left))
return 1;
offset = 0;
writes = reads = 0;
write_left = read_left;
while (read_left || write_left) {
off_t this_size = read_left;
struct io_uring_iocb *iocb;
if (this_size > BS)
this_size = BS;
else if (!this_size)
goto skip_read;
/*
* Queue up as many reads as we can
*/
while (read_left && !queue_read(infd, this_size, offset)) {
read_left -= this_size;
offset += this_size;
reads++;
}
skip_read:
ret = io_uring_submit(&in_ring);
if (ret < 0) {
fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret));
break;
}
/*
* read queue full, get at least one completion and queue up
* a write
*/
while (reads || write_left) {
if (reads)
ret = io_uring_wait_completion(&in_ring, &ev);
else
ret = io_uring_get_completion(&in_ring, &ev);
if (ret < 0) {
fprintf(stderr, "io_uring_get_completion: %s\n",
strerror(-ret));
return 1;
}
if (!ev)
break;
reads--;
if (ev->res < 0) {
fprintf(stderr, "ev failed: %s\n",
strerror(-ev->res));
return 1;
}
iocb = io_uring_iocb_from_ev(&in_ring, ev);
queue_write(outfd, ev->res, iocb->off, ev->index);
write_left -= ev->res;
writes++;
};
if (complete_writes(&writes))
break;
};
close(infd);
close(outfd);
io_uring_queue_exit(&in_ring);
io_uring_queue_exit(&out_ring);
return 0;
}