ssize_t preadv()

in fs/httpfs/httpfs_v2.cpp [182:213]
32 lines of code
11 McCabe index (conditional complexity)

    ssize_t preadv(const struct iovec* iovec, int iovcnt,
                   off_t offset) override {
        Timeout tmo(m_conn_timeout);
        struct stat s;
        if (fstat(&s) < 0) LOG_ERROR_RETURN(0, -1, "Failed to get file length");
        if (offset >= s.st_size) return 0;
        iovector_view view((struct iovec*)iovec, iovcnt);
        auto count = std::min(view.sum(), (size_t)(s.st_size - offset));
        if (count == 0) return 0;
        HTTP_OP op;
        send_read_request(op, offset, count, tmo);
        if (op.status_code < 0) return -1;
        auto ret = op.status_code;
        if (ret != 200 && ret != 206) {
            if (ret == 401 || ret == 403) {
                m_authorized = false;
                LOG_ERROR_RETURN(EACCES, -1, "GET not authorized", VALUE(m_url));
            }
            LOG_ERROR_RETURN(ENOENT, -1, "GET response got unexpected stats ",
                             VALUE(m_url), VALUE(offset), VALUE(ret));
        }
        if (update_stat_from_resp(&op) < 0) {
            LOG_ERROR_RETURN(ENOENT, -1, "GET response got unexpected header ",
                             VALUE(m_url), VALUE(offset), VALUE(ret));
        }
        m_authorized = true;
        ret = op.resp.readv(iovec, iovcnt);
        if (ret < 0) {
            LOG_ERROR("HttpFs: read body failed, ", ERRNO());
        }
        return ret;
    }