diff options
Diffstat (limited to 'iov.c')
| -rw-r--r-- | iov.c | 51 |
1 files changed, 51 insertions, 0 deletions
@@ -198,6 +198,57 @@ void iov_memset(const struct iovec *iov, size_t iov_cnt, size_t offset, int c, } /** + * iov_memcpy() - Copy data between two iovec arrays + * @dst_iov: Destination iovec array + * @dst_iov_cnt: Number of elements in destination iovec array + * @dst_offset: Destination offset + * @src_iov: Source iovec array + * @src_iov_cnt: Number of elements in source iovec array + * @offs: Source offset + * @length: Number of bytes to copy + * + * Return: total number of bytes copied + */ +/* cppcheck-suppress unusedFunction */ +size_t iov_memcpy(struct iovec *dst_iov, size_t dst_iov_cnt, size_t dst_offset, + const struct iovec *src_iov, size_t src_iov_cnt, + size_t src_offset, size_t length) +{ + size_t i, j, total = 0; + + i = iov_skip_bytes(src_iov, src_iov_cnt, src_offset, &src_offset); + j = iov_skip_bytes(dst_iov, dst_iov_cnt, dst_offset, &dst_offset); + + /* copying data */ + while (length && i < src_iov_cnt && j < dst_iov_cnt) { + size_t n = MIN(dst_iov[j].iov_len - dst_offset, + src_iov[i].iov_len - src_offset); + + if (n > length) + n = length; + + memcpy((char *)dst_iov[j].iov_base + dst_offset, + (const char *)src_iov[i].iov_base + src_offset, n); + + dst_offset += n; + src_offset += n; + total += n; + length -= n; + + if (dst_offset == dst_iov[j].iov_len) { + dst_offset = 0; + j++; + } + if (src_offset == src_iov[i].iov_len) { + src_offset = 0; + i++; + } + } + + return total; +} + +/** * iov_tail_prune() - Remove any unneeded buffers from an IOV tail * @tail: IO vector tail (modified) * |