numam-spdk/lib/util/iov.c
Ben Walker e475586b2a util: Add spdk_iovcpy, an iovec to iovec copy function.
Like memcpy, but works on two iovecs.

Change-Id: Ia1cf462a95690286f0c19325fc10937b9ba6baf3
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/473976
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
2019-11-20 09:35:32 +00:00

112 lines
3.2 KiB
C

/*-
* BSD LICENSE
*
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "spdk/util.h"
size_t
spdk_iovcpy(struct iovec *siov, size_t siovcnt, struct iovec *diov, size_t diovcnt)
{
size_t total_sz;
size_t sidx;
size_t didx;
int siov_len;
uint8_t *siov_base;
int diov_len;
uint8_t *diov_base;
/* d prefix = destination. s prefix = source. */
assert(diovcnt > 0);
assert(siovcnt > 0);
total_sz = 0;
sidx = 0;
didx = 0;
siov_len = siov[0].iov_len;
siov_base = siov[0].iov_base;
diov_len = diov[0].iov_len;
diov_base = diov[0].iov_base;
while (siov_len > 0 && diov_len > 0) {
if (siov_len == diov_len) {
memcpy(diov_base, siov_base, siov_len);
total_sz += siov_len;
/* Advance both iovs to the next element */
sidx++;
if (sidx == siovcnt) {
break;
}
didx++;
if (didx == diovcnt) {
break;
}
siov_len = siov[sidx].iov_len;
siov_base = siov[sidx].iov_base;
diov_len = diov[didx].iov_len;
diov_base = diov[didx].iov_base;
} else if (siov_len < diov_len) {
memcpy(diov_base, siov_base, siov_len);
total_sz += siov_len;
/* Advance only the source to the next element */
sidx++;
if (sidx == siovcnt) {
break;
}
diov_base += siov_len;
diov_len -= siov_len;
siov_len = siov[sidx].iov_len;
siov_base = siov[sidx].iov_base;
} else {
memcpy(diov_base, siov_base, diov_len);
total_sz += diov_len;
/* Advance only the destination to the next element */
didx++;
if (didx == diovcnt) {
break;
}
siov_base += diov_len;
siov_len -= diov_len;
diov_len = diov[didx].iov_len;
diov_base = diov[didx].iov_base;
}
}
return total_sz;
}