1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

use super::msg_types::*;
use super::{handshake, reader};
use crate::configuration::middleware_configuration::Configuration;
use crate::graph::structs::message_type::ClientPeerMiddleware;
use bincode::deserialize_from;
use crossbeam::Sender;
use std::net::{TcpListener, TcpStream};
use std::sync::{Arc, Barrier};
use std::thread;

/**
 * Starts the Acceptor thread that waits for connections from other peers and
 * spawns a Reader for each. This function is called on a thread as to not
 * block the caller.
 *
 * # Arguments
 *
 * `local_id` - Local peer's globally unique id.
 *
 * `local_port` - Port where the middleware will be listening for connections.
 *
 * `peer_addresses` - Addresses the middleware will connect to.
 *
 * `middleware_channel` - Channel from the middleware to the peer.
 *
 * `configuration` - Middleware's configuration file.
 *
 * `setup_end_barrier` - Barrier signalling the middleware connected to every peer.
 */
pub fn start(
    local_id: usize,
    local_port: usize,
    peer_addresses: Vec<String>,
    middleware_channel: Sender<ClientPeerMiddleware>,
    configuration: Arc<Configuration>,
    setup_end_barrier: Arc<Barrier>,
) {
    //Binding middleware TCP listener and setting blocking behaviour
    let server = TcpListener::bind(format!("0.0.0.0:{}", local_port))
        .expect("ERROR: Stream failed to connect");

    server
        .set_nonblocking(false)
        .expect("ERROR: Failed to set stream non-blocking mode");

    let mut connected_peers = 0;

    loop {
        match server.accept() {
            Ok((stream, _)) => match deserialize_from::<_, StreamMessages>(&stream) {
                Ok(decoded_msg_type) => match decoded_msg_type {
                    StreamMessages::Handshake { index } => {
                        let setup_end_barrier_clone = Arc::clone(&setup_end_barrier);

                        handle_new_connection(
                            local_id,
                            &peer_addresses,
                            stream,
                            &middleware_channel,
                            index,
                            &mut connected_peers,
                            &configuration,
                            setup_end_barrier_clone,
                        );
                    }
                    m => {
                        println!("ERROR: Acceptor received unexpected type - {:?}", m);
                        break;
                    }
                },
                Err(e) => {
                    println!("{}", e);
                    break;
                }
            },
            Err(e) => {
                println!("{}", e);
                break;
            }
        }
    }
}

/**
 * Handles a new peer connection.
 */
fn handle_new_connection(
    local_id: usize,
    peer_addresses: &Vec<String>,
    stream: TcpStream,
    middleware_channel: &Sender<ClientPeerMiddleware>,
    peer_id: usize,
    connected_peers: &mut usize,
    configuration: &Arc<Configuration>,
    setup_end_barrier: Arc<Barrier>,
) {
    handshake::send_handshake(&stream, local_id);

    let middleware_channel_temp = middleware_channel.clone();

    let thread_name = format!("stream_reader_{}_{}", local_id, peer_id);
    let builder = thread::Builder::new()
        .name(thread_name)
        .stack_size(configuration.thread_stack_size);

    builder
        .spawn(move || {
            reader::start(
                stream,
                middleware_channel_temp,
                local_id,
                peer_id,
                setup_end_barrier,
            );
        })
        .unwrap();

    *connected_peers += 1;

    if *connected_peers == peer_addresses.len() {
        let setup = ClientPeerMiddleware::Setup;
        match middleware_channel.send(setup) {
            Ok(_) => {}
            Err(e) => {
                println!(
                    "ERROR: Failed to send the SETUP message to client\n\t- {}",
                    e
                );
            }
        }
    }
}