examples/proto.cpp

#include <bitcoin/bitcoin.hpp>
using namespace bc;

using std::placeholders::_1;
using std::placeholders::_2;

// We don't have a database open, and aren't doing any critical file
// operations so we aren't worried about exiting suddenly.
void check_error(const std::error_code& ec)
{
    if (!ec)
        return;
    log_fatal() << ec.message();
    exit(-1);
}

// Needed for the C callback capturing the signals.
bool stopped = false;
void signal_handler(int sig)
{
    log_info() << "Caught signal: " << sig;
    stopped = true;
}

// Started protocol. Node discovery complete.
void handle_start(const std::error_code& ec);
// After number of connections is fetched, this completion handler is called
// and the number of connections is displayed.
void display_number_of_connections(
    const std::error_code& ec, size_t connection_count);

void handle_start(const std::error_code& ec)
{
    check_error(ec);
    log_debug() << "Started.";
}

void display_number_of_connections(
    const std::error_code& ec, size_t connection_count)
{
    check_error(ec);
    log_debug() << connection_count << " CONNECTIONS";
}

void connection_started(const std::error_code& ec, channel_ptr node,
    protocol& prot)
{
    if (ec)
    {
        log_warning() << "Couldn't start connection: " << ec.message();
        return;
    }
    log_info() << "Connection established.";
    // Resubscribe to new nodes.
    prot.subscribe_channel(
        std::bind(connection_started, _1, _2, std::ref(prot)));
}

int main()
{
    threadpool pool(1);
    // Create dependencies for our protocol object.
    hosts hst(pool);
    handshake hs(pool);
    network net(pool);
    // protocol service.
    protocol prot(pool, hst, hs, net);
    // Perform node discovery if needed and then creating connections.
    prot.start(handle_start);
    // Notify us of new connections.
    prot.subscribe_channel(
        std::bind(connection_started, _1, _2, std::ref(prot)));
    // Catch C signals for stopping the program.
    signal(SIGABRT, signal_handler);
    signal(SIGTERM, signal_handler);
    signal(SIGINT, signal_handler);
    while (!stopped)
    {
        prot.fetch_connection_count(display_number_of_connections);
        sleep(1);
    }
    // Safely close down.
    pool.stop();
    pool.join();
    return 0;
}