#include #include "legislator.hh" #include "misc/logger.hh" #include "message/message.hh" #include "events/register.hh" #include "events/send.hh" #include "vote.hh" namespace paxos { Legislator::Legislator(const LegislatorConfig& config) : config_(config), ledger(config.name) { log("created legislator " + config.name, blue); } void Legislator::initiate_ballot() { quorum_previous_votes.clear(); int new_ballot_number = ledger.last_tried() + 1; ledger.set_last_tried(new_ballot_number); log(config_.name + " is initiating ballot " + std::to_string(new_ballot_number), cyan); send_next_ballot(new_ballot_number); } void Legislator::send_next_ballot(int ballot) { std::string ballot_string = std::to_string(ballot); Message message; message.set_method("NextBallot"); message.add_header("ballot", ballot_string); message.add_header("sender", self->config_.name); for (auto legislator : legislators) SendEW::send_message(message, legislator.second); } void Legislator::receive_next_ballot(Message message) { std::string ballot_str = *message.get_header("ballot"); int ballot = std::stoi(ballot_str); receive_next_ballot(ballot, *message.get_header("sender")); } void Legislator::receive_next_ballot(int ballot, std::string sender) { log(config_.name + " has received a NextBallot(" + std::to_string(ballot) + ") from " + sender, cyan); int next_ballot = ledger.next_bal(); if (ballot <= next_ballot) { log("but it was discarded because ballot " + std::to_string(ballot) + " is inferior or equal to nextBallot " + std::to_string(next_ballot), red); return; } ledger.set_next_bal(ballot); Vote previous_vote = ledger.prev_vote(); previous_vote = previous_vote; send_last_vote(ballot, previous_vote, sender); } void Legislator::send_last_vote(int ballot, Vote previous_vote, std::string sender) { std::string ballot_string = std::to_string(ballot); std::string vote_ballot_id_string = std::to_string(previous_vote.ballot_id); std::string decree_string = std::to_string(previous_vote.decree.decree); Message message; message.set_method("LastVote"); message.add_header("ballot", ballot_string); message.add_header("vote_ballot_id", vote_ballot_id_string); message.add_header("decree", decree_string); message.add_header("sender", self->config_.name); SendEW::send_message(message, legislators[sender]); } void Legislator::receive_last_vote(Message message) { std::string ballot_str = *message.get_header("ballot"); std::string vote_ballot_id_str = *message.get_header("vote_ballot_id"); std::string sender = *message.get_header("sender"); log(config_.name + " has received a LastVote(" + ballot_str + ", " + vote_ballot_id_str + ") from " + sender, cyan); int ballot = std::stoi(ballot_str); int vote_ballot_id = std::stoi(vote_ballot_id_str); int vote_decree = std::stoi(*message.get_header("decree")); if (ballot != ledger.last_tried()) return; Decree decree; decree.decree = vote_decree; Vote vote; vote.decree = decree; vote.legislator = sender; vote.ballot_id = vote_ballot_id; quorum_previous_votes.insert(std::pair (sender, vote)); int nb_legislators = legislators.size(); int quorum_size = quorum_previous_votes.size(); if (quorum_size > nb_legislators / 2) receive_enough_last_vote(); } void Legislator::receive_enough_last_vote() { int ballot = ledger.last_tried(); std::string ballot_str = std::to_string(ballot); log(config_.name + " has received enough LastVote(" + ballot_str + ", v" + ")", green); Vote max_vote; max_vote.ballot_id = -1; for (auto legislator_vote_pair : quorum_previous_votes) { Vote current_vote = legislator_vote_pair.second; if (current_vote.ballot_id > max_vote.ballot_id) max_vote = current_vote; } Decree decree; if (max_vote.ballot_id != -1) decree = max_vote.decree; else decree.decree = ballot; send_begin_ballot(ballot, decree); } void Legislator::send_begin_ballot(int ballot, Decree decree) { std::string ballot_string = std::to_string(ballot); std::string decree_string = std::to_string(decree.decree); Message message; message.set_method("BeginBallot"); message.add_header("sender", self->config_.name); message.add_header("ballot", ballot_string); message.add_header("decree", decree_string); for (auto legislator_vote_pair : quorum_previous_votes) { std::string legislator = legislator_vote_pair.first; SendEW::send_message(message, legislators[legislator]); } } void Legislator::receive_begin_ballot(Message message) { std::string ballot_string = *message.get_header("ballot"); std::string decree_string = *message.get_header("decree"); std::string sender = *message.get_header("sender"); log(config_.name + " has received BeginBallot(" + ballot_string + ", " + decree_string + ") from " + sender, green); int ballot = std::stoi(ballot_string); int decree = std::stoi(decree_string); receive_begin_ballot(ballot, decree, sender); } void Legislator::receive_begin_ballot(int ballot, int decree_id, std::string sender) { if (ballot != ledger.next_bal()) return; Vote vote; vote.ballot_id = ballot; Decree decree; decree.decree = decree_id; vote.decree = decree; ledger.set_prev_vote(vote); send_voted(ballot, decree, sender); } void Legislator::send_voted(int ballot, Decree decree, std::string receiver) { Message message; message.set_method("Voted"); message.add_header("ballot", std::to_string(ballot)); message.add_header("sender", self->config_.name); message.add_header("decree", std::to_string(decree.decree)); SendEW::send_message(message, legislators[receiver]); } void Legislator::receive_voted(Message message) { std::string ballot_str = *message.get_header("ballot"); std::string sender = *message.get_header("sender"); std::string decree_str = *message.get_header("decree"); Decree decree; decree.decree = std::stoi(decree_str); log(config_.name + " has received Voted(" + ballot_str + ") from " + sender, cyan); receive_voted(std::stoi(ballot_str), decree, sender); } void Legislator::receive_voted(int ballot, Decree decree, std::string voter) { if (ballot != ledger.last_tried()) return; quorum_previous_votes.erase(voter); if (quorum_previous_votes.size() == 0) receive_enough_voted(ballot, decree); } void Legislator::receive_enough_voted(int ballot, Decree decree) { log(config_.name + " has received enough Voted(" + std::to_string(ballot) + "), saving decree: " + std::to_string(decree.decree), green); ledger.set_decree(decree); send_success(decree); } void Legislator::send_success(Decree decree) { Message message; message.set_method("Success"); message.add_header("decree", std::to_string(decree.decree)); for (auto legislator : legislators) SendEW::send_message(message, legislator.second); } void Legislator::receive_success(Message message) { std::string decree_str = *message.get_header("decree"); Decree decree; decree.decree = std::stoi(decree_str); receive_success(decree); } void Legislator::receive_success(Decree decree) { ledger.set_decree(decree); std::string new_decree= std::to_string(ledger.get_decree().decree); log("Received success, the new decree is now: " + new_decree, green); } void Legislator::handle_message(Message message) { std::string method = message.get_method(); if (method == "NextBallot") receive_next_ballot(message); else if (method == "LastVote") receive_last_vote(message); else if (method == "BeginBallot") receive_begin_ballot(message); else if (method == "Voted") receive_voted(message); else if (method == "Success") receive_success(message); } }