diff options
Diffstat (limited to 'iov.h')
| -rw-r--r-- | iov.h | 12 |
1 files changed, 10 insertions, 2 deletions
@@ -1,10 +1,11 @@ /* - * Helpers for getting linearized buffers from iov / filling buffers into iovs + * Helpers for using (partial) iovecs. * * Copyright (C) 2010 Red Hat, Inc. * * Author(s): * Amit Shah <amit.shah@redhat.com> + * Michael Tokarev <mjt@tls.msk.ru> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. @@ -28,6 +29,12 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt); * only part of data will be copied, up to the end of the iovec. * Number of bytes actually copied will be returned, which is * min(bytes, iov_size(iov)-offset) + * `Offset' must point to the inside of iovec. + * It is okay to use very large value for `bytes' since we're + * limited by the size of the iovec anyway, provided that the + * buffer pointed to by buf has enough space. One possible + * such "large" value is -1 (sinice size_t is unsigned), + * so specifying `-1' as `bytes' means 'up to the end of iovec'. */ size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt, size_t offset, const void *buf, size_t bytes); @@ -37,11 +44,12 @@ size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, /** * Set data bytes pointed out by iovec `iov' of size `iov_cnt' elements, * starting at byte offset `start', to value `fillc', repeating it - * `bytes' number of times. + * `bytes' number of times. `Offset' must point to the inside of iovec. * If `bytes' is large enough, only last bytes portion of iovec, * up to the end of it, will be filled with the specified value. * Function return actual number of bytes processed, which is * min(size, iov_size(iov) - offset). + * Again, it is okay to use large value for `bytes' to mean "up to the end". */ size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt, size_t offset, int fillc, size_t bytes); |