Commit caca70e6 authored by Ben Walker's avatar Ben Walker Committed by Konrad Sztyber
Browse files

util: Implement spdk_ioviter_next such that it could support N-way 


iteration

Somehow, this ends up far simpler.

Change-Id: I8a203a92e19d96950156abe602f4c0d4ab5a5942
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/18065


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarArtur Paszkiewicz <artur.paszkiewicz@intel.com>
Community-CI: Mellanox Build Bot
parent 068d93b1

lib/util/iov.c

+30 −49
Original line number Diff line number Diff line
@@ -59,62 +59,43 @@ spdk_ioviter_first(struct spdk_ioviter *iter, 
size_t

spdk_ioviter_next(struct spdk_ioviter *iter, void **src, void **dst)

{

	size_t len = 0;

	struct spdk_single_ioviter *siter;

	struct spdk_single_ioviter *diter;



	siter = &iter->iters[0];

	diter = &iter->iters[1];



	if (siter->idx == siter->iovcnt ||

	    diter->idx == diter->iovcnt ||

	    siter->iov_len == 0 ||

	    diter->iov_len == 0) {

	struct spdk_single_ioviter *it;

	size_t len;

	uint32_t i;



	/* Figure out the minimum size of each iovec's next segment */

	len = UINT32_MAX;

	for (i = 0; i < iter->count; i++) {

		it = &iter->iters[i];

		if (it->idx == it->iovcnt || it->iov_len == 0) {

			/* This element has 0 bytes remaining, so we're done. */

			return 0;

		}



	*src = siter->iov_base;

	*dst = diter->iov_base;

	len = spdk_min(siter->iov_len, diter->iov_len);



	if (siter->iov_len == diter->iov_len) {

		/* Advance both iovs to the next element */

		siter->idx++;

		if (siter->idx == siter->iovcnt) {

			return len;

		len = spdk_min(len, iter->iters[i].iov_len);

	}



		diter->idx++;

		if (diter->idx == diter->iovcnt) {

			return len;

		}

	*src = iter->iters[0].iov_base;

	*dst = iter->iters[1].iov_base;



		siter->iov_len = siter->iov[siter->idx].iov_len;

		siter->iov_base = siter->iov[siter->idx].iov_base;

		diter->iov_len = diter->iov[diter->idx].iov_len;

		diter->iov_base = diter->iov[diter->idx].iov_base;

	} else if (siter->iov_len < diter->iov_len) {

		/* Advance only the source to the next element */

		siter->idx++;

		if (siter->idx == siter->iovcnt) {

			return len;

		}

	for (i = 0; i < iter->count; i++) {

		it = &iter->iters[i];



		diter->iov_base += siter->iov_len;

		diter->iov_len -= siter->iov_len;

		siter->iov_len = siter->iov[siter->idx].iov_len;

		siter->iov_base = siter->iov[siter->idx].iov_base;

		assert(it->iov_len >= len);



		if (it->iov_len == len) {

			/* Advance to next element */

			it->idx++;

			if (it->idx != it->iovcnt) {

				/* Set up for next element */

				it->iov_len = it->iov[it->idx].iov_len;

				it->iov_base = it->iov[it->idx].iov_base;

			}

		} else {

		/* Advance only the destination to the next element */

		diter->idx++;

		if (diter->idx == diter->iovcnt) {

			return len;

			/* Partial buffer */

			it->iov_base += len;

			it->iov_len -= len;

		}



		siter->iov_base += diter->iov_len;

		siter->iov_len -= diter->iov_len;

		diter->iov_len = diter->iov[diter->idx].iov_len;

		diter->iov_base = diter->iov[diter->idx].iov_base;

	}



	return len;