Function copy_file

examples/io_uring-cp.c:119–247

}

static int copy_file(struct io_uring *ring, off_t insize)
{
	unsigned long reads, writes;
	struct io_uring_cqe *cqe;
	off_t write_left, offset;
	int ret;

	write_left = insize;
	writes = reads = offset = 0;

	while (insize || write_left) {
		unsigned long had_reads;
		int got_comp;
	
		/*
		 * Queue up as many reads as we can
		 */
		had_reads = reads;
		while (insize) {
			off_t this_size = insize;

			if (reads + writes >= QD)
				break;
			if (this_size > BS)
				this_size = BS;
			else if (!this_size)
				break;

			if (queue_read(ring, this_size, offset))
				break;

			insize -= this_size;
			offset += this_size;
			reads++;
		}

		if (had_reads != reads) {
			ret = io_uring_submit(ring);
			if (ret < 0) {
				fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret));
				break;
			}
		}

		/*
		 * Queue is full at this point. Find at least one completion.
		 */
		got_comp = 0;
		while (write_left) {
			struct io_data *data;

			if (!got_comp) {
				ret = io_uring_wait_cqe(ring, &cqe);
				got_comp = 1;
			} else {
				ret = io_uring_peek_cqe(ring, &cqe);
				if (ret == -EAGAIN) {
					cqe = NULL;