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/*
* Helpers for getting linearized buffers from iov / filling buffers into iovs
*
* Copyright IBM, Corp. 2007, 2008
* Copyright (C) 2010 Red Hat, Inc.
*
* Author(s):
* Anthony Liguori <aliguori@us.ibm.com>
* Amit Shah <amit.shah@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#include "iov.h"
size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt,
const void *buf, size_t iov_off, size_t size)
{
size_t iovec_off, buf_off;
unsigned int i;
iovec_off = 0;
buf_off = 0;
for (i = 0; i < iov_cnt && size; i++) {
if (iov_off < (iovec_off + iov[i].iov_len)) {
size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off, size);
memcpy(iov[i].iov_base + (iov_off - iovec_off), buf + buf_off, len);
buf_off += len;
iov_off += len;
size -= len;
}
iovec_off += iov[i].iov_len;
}
return buf_off;
}
size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
void *buf, size_t iov_off, size_t size)
{
uint8_t *ptr;
size_t iovec_off, buf_off;
unsigned int i;
ptr = buf;
iovec_off = 0;
buf_off = 0;
for (i = 0; i < iov_cnt && size; i++) {
if (iov_off < (iovec_off + iov[i].iov_len)) {
size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
memcpy(ptr + buf_off, iov[i].iov_base + (iov_off - iovec_off), len);
buf_off += len;
iov_off += len;
size -= len;
}
iovec_off += iov[i].iov_len;
}
return buf_off;
}
size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt)
{
size_t len;
unsigned int i;
len = 0;
for (i = 0; i < iov_cnt; i++) {
len += iov[i].iov_len;
}
return len;
}
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