From 8d15028ec03999fa6eca8dba7ef7cd4eb575486b Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Wed, 13 Jul 2011 15:16:08 +0200 Subject: [PATCH] Add iov_clear() Fill the spefified area with zeros. Signed-off-by: Gerd Hoffmann --- iov.c | 23 +++++++++++++++++++++++ iov.h | 2 ++ 2 files changed, 25 insertions(+) diff --git a/iov.c b/iov.c index 60553c7542..e7385c41f4 100644 --- a/iov.c +++ b/iov.c @@ -62,6 +62,29 @@ size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, return buf_off; } +size_t iov_clear(const struct iovec *iov, const unsigned int iov_cnt, + 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); + + memset(iov[i].iov_base + (iov_off - iovec_off), 0, 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; diff --git a/iov.h b/iov.h index c2c5b39b8d..94d2f78284 100644 --- a/iov.h +++ b/iov.h @@ -17,5 +17,7 @@ size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt, size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, void *buf, size_t iov_off, size_t size); size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt); +size_t iov_clear(const struct iovec *iov, const unsigned int iov_cnt, + size_t iov_off, size_t size); void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt, FILE *fp, const char *prefix, size_t limit);