You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/ntex/ntex-tls/src/openssl
    
    the code of the file until where you have to start completion: //! An implementation of SSL streams for ntex backed by OpenSSL
use std::{any, cell::RefCell, cmp, error::Error, io, task::Poll};

use ntex_bytes::{BufMut, BytesVec};
use ntex_io::{types, Filter, FilterLayer, Io, Layer, ReadBuf, WriteBuf};
use tls_openssl::ssl::{self, NameType, SslStream};
use tls_openssl::x509::X509;

use crate::{PskIdentity, Servername};

mod accept;
pub use self::accept::{SslAcceptor, SslAcceptorService};

/// Connection's peer cert
#[derive(Debug)]
pub struct PeerCert(pub X509);

/// Connection's peer cert chain
#[derive(Debug)]
pub struct PeerCertChain(pub Vec<X509>);

/// An implementation of SSL streams
#[derive(Debug)]
pub struct SslFilter {
    inner: RefCell<SslStream<IoInner>>,
}

#[derive(Debug)]
struct IoInner {
    source: Option<BytesVec>,
    destination: Option<BytesVec>,
}

impl io::Read for IoInner {
    fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> {
        if let Some(ref mut buf) = self.source {
            if buf.is_empty() {
                Err(io::Error::from(io::ErrorKind::WouldBlock))
            } else {
                let len = cmp::min(buf.len(), dst.len()
    
    fn query(&self, id: any::TypeId) -> Option<Box<dyn any::Any>> {
        const H2: &[u8] = b"h2";

        if id == any::TypeId::of::<types::HttpProtocol>() {
            let h2 = self
                .inner
                .borrow()
                .ssl()
                .selected_alpn_protocol()
                .map(|protos| protos.windows(2).any(|w| w == H2))
                .unwrap_or(false);
            let proto = if h2 {
                types::HttpProtocol::Http2
            } else {
                types::HttpProtocol::Http1
            };
            Some(Box::new(proto))
        } else if id == any::TypeId::of::<PeerCert>() {
            if let Some(cert) = self.inner.borrow().ssl().peer_certificate() {
                Some(Box::new(PeerCert(cert)))
            } else {
                None
            }
        } else if id == any::TypeId::of::<PeerCertChain>() {
            if let Some(cert_chain) = self.inner.borrow().ssl().peer_cert_chain() {
                Some(Box::new(PeerCertChain(
                    cert_chain.iter().map(|c| c.to_owned()).collect(),
                )))
            } else {
                None
            }
        } else if id == any::TypeId::of::<Servername>() {
            if let Some(name) = self.inner.borrow().ssl().servername(NameType::HOST_NAME) {
                Some(Box::new(Servername(name.to_string())))
            } else {
                None
            }
        } else if id == any::TypeId::of::<PskIdentity>() {
            if let Some(psk_id) = self.inner.borrow().ssl().psk_identity() {
                Some(Box::new(PskIdentity(psk_id.to_vec())))
            } else {
                None
            }
        } else {
            None
        }
    }