Commit 068d93b1 authored by Ben Walker's avatar Ben Walker Committed by Konrad Sztyber
Browse files

util: Change spdk_ioviter to hold an array 



Prepare for supporting N-way iteration. This is still strictly
2-way as of this patch, but reorganizes the data structure to prepare
for the upcoming change.

Change-Id: I9392d9f9a4f59b1bad95af049cc7ecbcead91730
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/18064


Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Community-CI: Mellanox Build Bot
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
parent 20370a5d

include/spdk/util.h

+10 −13
Original line number Diff line number Diff line
@@ -105,21 +105,18 @@ spdk_divide_round_up(uint64_t num, uint64_t divisor) 
}



/**

 * An iovec iterator. Can be allocated on the stack.

 * A 2-way iovec iterator. Can be allocated on the stack.

 */

struct spdk_ioviter {

	struct iovec	*siov;

	size_t		siovcnt;



	struct iovec	*diov;

	size_t		diovcnt;



	size_t		sidx;

	size_t		didx;

	int		siov_len;

	uint8_t		*siov_base;

	int		diov_len;

	uint8_t		*diov_base;

	uint32_t	count;



	struct spdk_single_ioviter {

		struct iovec	*iov;

		size_t		iovcnt;

		size_t		idx;

		size_t		iov_len;

		uint8_t		*iov_base;

	} iters[2];

};



/**

lib/util/iov.c

+52 −39
Original line number Diff line number Diff line
@@ -32,18 +32,26 @@ spdk_ioviter_first(struct spdk_ioviter *iter, 
		   struct iovec *diov, size_t diovcnt,

		   void **src, void **dst)

{

	iter->siov = siov;

	iter->siovcnt = siovcnt;

	struct spdk_single_ioviter *siter;

	struct spdk_single_ioviter *diter;



	iter->diov = diov;

	iter->diovcnt = diovcnt;

	iter->count = 2;



	iter->sidx = 0;

	iter->didx = 0;

	iter->siov_len = siov[0].iov_len;

	iter->siov_base = siov[0].iov_base;

	iter->diov_len = diov[0].iov_len;

	iter->diov_base = diov[0].iov_base;

	siter = &iter->iters[0];

	diter = &iter->iters[1];



	siter->iov = siov;

	siter->iovcnt = siovcnt;



	diter->iov = diov;

	diter->iovcnt = diovcnt;



	siter->idx = 0;

	diter->idx = 0;

	siter->iov_len = siov[0].iov_len;

	siter->iov_base = siov[0].iov_base;

	diter->iov_len = diov[0].iov_len;

	diter->iov_base = diov[0].iov_base;



	return spdk_ioviter_next(iter, src, dst);

}
@@ -52,56 +60,61 @@ 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 (iter->sidx == iter->siovcnt ||

	    iter->didx == iter->diovcnt ||

	    iter->siov_len == 0 ||

	    iter->diov_len == 0) {

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

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

	    siter->iov_len == 0 ||

	    diter->iov_len == 0) {

		return 0;

	}



	*src = iter->siov_base;

	*dst = iter->diov_base;

	len = spdk_min(iter->siov_len, iter->diov_len);

	*src = siter->iov_base;

	*dst = diter->iov_base;

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



	if (iter->siov_len == iter->diov_len) {

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

		/* Advance both iovs to the next element */

		iter->sidx++;

		if (iter->sidx == iter->siovcnt) {

		siter->idx++;

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

			return len;

		}



		iter->didx++;

		if (iter->didx == iter->diovcnt) {

		diter->idx++;

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

			return len;

		}



		iter->siov_len = iter->siov[iter->sidx].iov_len;

		iter->siov_base = iter->siov[iter->sidx].iov_base;

		iter->diov_len = iter->diov[iter->didx].iov_len;

		iter->diov_base = iter->diov[iter->didx].iov_base;

	} else if (iter->siov_len < iter->diov_len) {

		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 */

		iter->sidx++;

		if (iter->sidx == iter->siovcnt) {

		siter->idx++;

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

			return len;

		}



		iter->diov_base += iter->siov_len;

		iter->diov_len -= iter->siov_len;

		iter->siov_len = iter->siov[iter->sidx].iov_len;

		iter->siov_base = iter->siov[iter->sidx].iov_base;

		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;

	} else {

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

		iter->didx++;

		if (iter->didx == iter->diovcnt) {

		diter->idx++;

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

			return len;

		}



		iter->siov_base += iter->diov_len;

		iter->siov_len -= iter->diov_len;

		iter->diov_len = iter->diov[iter->didx].iov_len;

		iter->diov_base = iter->diov[iter->didx].iov_base;

		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;