peer_manager.cpp

#include "peer_manager.h"
#include "cidr_utils.h"
#include "peer_client.h"
#include <chrono>
#include <thread>
#include <iostream> // TODO : REMOVE

PeerManager::PeerManager(const std::string& cidr, uint16_t port, int interval_seconds, const std::string& our_ip)
: cidr_(cidr), port_(port + 200/*Adding 200 to peer port like seen in p2 handout*/), interval_(interval_seconds), our_ip_(our_ip), running_(true) 
{
    if (!cidr_.empty()) {
        worker_ = std::thread([this]{ scan_loop(); });
    } else {
        running_ = false;
    }
}

PeerManager::~PeerManager() { 
    stop(); 
}

void PeerManager::stop() { // TODO :
    if (running_.exchange(false)) {
        if (worker_.joinable()) 
            worker_.join();
    } else {
        if (worker_.joinable()) 
            worker_.join();
    }
}

std::vector<std::string> PeerManager::peers() const {
    std::lock_guard<std::mutex> lk(mu_);
    return std::vector<std::string>(alive_.begin(), alive_.end());
}

void PeerManager::scan_loop() { 
    while (running_) {
        one_scan();
        if (running_) {
            //std::cout << "Sleep for " << interval_ << " seconds" << std::endl; // TODO : REMOVE
            std::this_thread::sleep_for(std::chrono::seconds(interval_));
            //std::cout << "Woke up from sleep" << std::endl; // TODO : REMOVE
        }
    }
}

void PeerManager::one_scan() {
    //std::cout << "Peermngr: scan " << cidr_ << " : " << port_ << std::endl; // TODO : REMOVE

    auto hosts = netcidr::enumerate_ipv4_hosts(cidr_); // keep

    //std::cout << "Parsing " << hosts.size() << " hosts" << std::endl; // TODO : REMOVE

    std::set<std::string> new_alive;
    for (auto h : hosts) {
        auto ip = netcidr::ip_to_string(h);
        if (ip == our_ip_) // skip self
            continue;
        PeerClient pc(ip, port_ - 200 /*Peerclient adds its own 200*/, our_ip_);
        //std::cout << "Testing peer: " << ip << "   port:" << port_ << std::endl; // TODO : REMOVE
        if (pc.good()) {
            new_alive.insert(ip);
            //std::cout << "Peer found: " << ip << std::endl; // TODO : REMOVE
        }
    }
    std::lock_guard<std::mutex> lk(mu_); 
    alive_.swap(new_alive); // replace old set with new set
}