Function file_writev_once

lib_acl/src/stdlib/acl_vstream.c:1574–1633

}

static int file_writev_once(ACL_VSTREAM *fp, const struct iovec *vec, int count)
{
	int n = 0;

	if ((fp->oflags & O_APPEND)) {
#ifdef ACL_WINDOWS
		fp->sys_offset = acl_lseek(ACL_VSTREAM_FILE(fp), 0, SEEK_END);
		if (fp->sys_offset < 0) {
			fp->errnum = acl_last_error();
			fp->flag |= ACL_VSTREAM_FLAG_ERR;
			return ACL_VSTREAM_EOF;
		}
#endif
	} else if ((fp->flag & ACL_VSTREAM_FLAG_CACHE_SEEK)
			&& fp->offset != fp->sys_offset) {

		fp->sys_offset = acl_lseek(ACL_VSTREAM_FILE(fp),
					fp->offset, SEEK_SET);
		if (fp->sys_offset == -1) {
			acl_msg_error("%s, %s(%d): lseek error(%s), "
				"offset(" ACL_FMT_I64D "), sys_offset("
				ACL_FMT_I64D ")", __FUNCTION__, __FILE__,
				__LINE__, acl_last_serror(),
				fp->offset, fp->sys_offset);

			fp->errnum = acl_last_error();
			fp->flag |= ACL_VSTREAM_FLAG_ERR;
			return ACL_VSTREAM_EOF;
		}
	}

	if (fp->fwrite_fn == acl_file_write) {
		n = fp->fwritev_fn(ACL_VSTREAM_FILE(fp), vec, count,
				fp->rw_timeout, fp, fp->context);
	} else {
		int i, ret;

		for (i = 0; i < count; i++) {
			ret = write_once(fp, vec[i].iov_base,
				(int) vec[i].iov_len);
			if (ret == ACL_VSTREAM_EOF) {
				return ACL_VSTREAM_EOF;
			}
			n += ret;
			if (ret < (int) vec[i].iov_len) {
				break;
			}
		}
	}

	if (n > 0) {
		fp->sys_offset += n;
		fp->offset = fp->sys_offset;

		/* ��ֹ�������ڵ�������ʵ�ʲ�һ��, �����ļ�IO��Ч */
		fp->read_cnt = 0;
	}