dcf6f5e15e
Reorder arguments to be more natural, readable and consistent with other iov_* functions, and change argument names, from: iov_from_buf(iov, iov_cnt, buf, iov_off, size) to iov_from_buf(iov, iov_cnt, offset, buf, bytes) The result becomes natural English: copy data to this `iov' vector with `iov_cnt' elements starting at byte offset `offset' from memory buffer `buf', processing `bytes' bytes max. (Try to read the original prototype this way). Also change iov_clear() to more general iov_memset() (it uses memset() internally anyway). While at it, add comments to the header file describing what the routines actually does. The patch only renames argumens in the header, but keeps old names in the implementation. The next patch will touch actual code to match. Now, it might look wrong to pay so much attention to so small things. But we've so many badly designed interfaces already so the whole thing becomes rather confusing or error prone. One example of this is previous commit and small discussion which emerged from it, with an outcome that the utility functions like these aren't well-understdandable, leading to strange usage cases. That's why I paid quite some attention to this set of functions and a few others in subsequent patches. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
132 lines
3.3 KiB
C
132 lines
3.3 KiB
C
/*
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* Helpers for getting linearized buffers from iov / filling buffers into iovs
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*
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* Copyright IBM, Corp. 2007, 2008
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* Copyright (C) 2010 Red Hat, Inc.
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*
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* Author(s):
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* Anthony Liguori <aliguori@us.ibm.com>
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* Amit Shah <amit.shah@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "iov.h"
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size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt, size_t iov_off,
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const void *buf, size_t size)
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{
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size_t iovec_off, buf_off;
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unsigned int i;
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iovec_off = 0;
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buf_off = 0;
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for (i = 0; i < iov_cnt && size; i++) {
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if (iov_off < (iovec_off + iov[i].iov_len)) {
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size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off, size);
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memcpy(iov[i].iov_base + (iov_off - iovec_off), buf + buf_off, len);
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buf_off += len;
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iov_off += len;
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size -= len;
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}
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iovec_off += iov[i].iov_len;
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}
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return buf_off;
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}
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size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, size_t iov_off,
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void *buf, size_t size)
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{
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uint8_t *ptr;
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size_t iovec_off, buf_off;
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unsigned int i;
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ptr = buf;
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iovec_off = 0;
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buf_off = 0;
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for (i = 0; i < iov_cnt && size; i++) {
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if (iov_off < (iovec_off + iov[i].iov_len)) {
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size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
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memcpy(ptr + buf_off, iov[i].iov_base + (iov_off - iovec_off), len);
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buf_off += len;
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iov_off += len;
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size -= len;
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}
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iovec_off += iov[i].iov_len;
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}
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return buf_off;
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}
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size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt,
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size_t iov_off, int fillc, size_t size)
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{
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size_t iovec_off, buf_off;
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unsigned int i;
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iovec_off = 0;
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buf_off = 0;
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for (i = 0; i < iov_cnt && size; i++) {
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if (iov_off < (iovec_off + iov[i].iov_len)) {
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size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
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memset(iov[i].iov_base + (iov_off - iovec_off), fillc, len);
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buf_off += len;
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iov_off += len;
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size -= len;
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}
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iovec_off += iov[i].iov_len;
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}
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return buf_off;
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}
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size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt)
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{
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size_t len;
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unsigned int i;
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len = 0;
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for (i = 0; i < iov_cnt; i++) {
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len += iov[i].iov_len;
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}
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return len;
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}
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void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt,
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FILE *fp, const char *prefix, size_t limit)
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{
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unsigned int i, v, b;
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uint8_t *c;
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c = iov[0].iov_base;
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for (i = 0, v = 0, b = 0; b < limit; i++, b++) {
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if (i == iov[v].iov_len) {
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i = 0; v++;
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if (v == iov_cnt) {
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break;
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}
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c = iov[v].iov_base;
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}
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if ((b % 16) == 0) {
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fprintf(fp, "%s: %04x:", prefix, b);
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}
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if ((b % 4) == 0) {
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fprintf(fp, " ");
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}
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fprintf(fp, " %02x", c[i]);
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if ((b % 16) == 15) {
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fprintf(fp, "\n");
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}
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}
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if ((b % 16) != 0) {
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fprintf(fp, "\n");
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}
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}
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