小E浅谈丨EOCS中继网络源码剖析
EOCS中继网络实现了两种模式，分别是eoc模式和icp模式，今天小E先为大家介绍eoc模式。
eoc_relay_plugin 源码剖析
在eoc_relay_plugin.cpp中
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static appbase::abstract_plugin& _eoc_relay_plugin = app().register_plugin
向appbase中注册了eoc_relay_plugin插件。
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void eoc_relay_plugin::set_program_options(options_description&, options_description& cfg);
该函数将config中配置的参数设置导入eoc_relay_plugin中，内部调用了plugin_initialize和init_eoc_relay_plugin函数，设置eoc_relay_plugin必备的参数。
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接着调用
voideoc_relay_plugin::plugin_startup()
{
ilog("starting eoc_relay_plugin");
//sendstartaction();
auto&chain = app().get_plugin().chain();
FC_ASSERT(chain.get_read_mode() != chain::db_read_mode::IRREVERSIBLE,"icp is not compatible with \"irreversible\" read_mode");
relay_->start();
chain::controller &cc = relay_->chain_plug->chain();
{
cc.applied_transaction.connect(boost::bind(&eoc_icp::relay::on_applied_transaction, relay_.get(), _1));
cc.accepted_block_with_action_digests.connect(boost::bind(&eoc_icp::relay::on_accepted_block, relay_.get(), _1));
cc.irreversible_block.connect(boost::bind(&eoc_icp::relay::on_irreversible_block, relay_.get(), _1));
}
relay_->start_monitors();
for(autoseed_node : relay_->connect_to_peers_)
{
connect(seed_node);
}
if(fc::get_logger_map().find(icp_logger_name) != fc::get_logger_map().end())
icp_logger = fc::get_logger_map()[icp_logger_name];
// Make the magic happen
}
该函数主要是实现插件的启动，内部绑定了controller的applied_transaction,accepted_block_with_action_digests,irreversible_block信号，当收到这些信号，就会自动调用relay的三个函数。
上面就是eoc_relay_plugin的核心通信代码，内部的网络消息流程和net_plugin类似，通过icp_relay类完成网络消息的控制，以及回调函数的逻辑处理。
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voidrelay::start_monitors( )
{
connector_check.reset(newboost::asio::steady_timer( app().get_io_service()));
start_conn_timer(connector_period,std::weak_ptr());
}
该函数设置了定时器，检测连接是否成功，不成功则定时重连。
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voidrelay::start() {
ioc_ =std::make_unique(num_threads_);
timer_ =std::make_shared(app().get_io_service());
autoaddress = boost::asio::ip::make_address(endpoint_address_);
update_local_head();
if( acceptor ) {
acceptor->open(listen_endpoint.protocol());
acceptor->set_option(tcp::acceptor::reuse_address(true));
try{
acceptor->bind(listen_endpoint);
}catch(conststd::exception& e) {
ilog("eoc_relay_plugin::plugin_startup failed to bind to port ${port}",
("port", listen_endpoint.port()));
throwe;
}
acceptor->listen();
ilog("starting listener, max clients is ${mc}",("mc",max_client_count));
start_listen_loop();
}
}
该函数启动了eoc插件的网络监听事件，start_listen_loop就是控制的网络事件循环监听。
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voidrelay::send_icp_net_msg(consticp_net_message& msg)
{
send_icp_notice_msg(icp_notice_message{local_head_});
for(constauto& c : connections )
{
c->send_icp_net_msg(msg);
}
}
中继间通信是通过网络tcp点对点发送的，该函数就是封装了icp_net_message发送的功能。
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voidrelay::on_applied_transaction(consttransaction_trace_ptr& t) {
//ilog("on applied transaction");
//......
for(auto& action: t->action_traces) {
if(action.receipt.receiver != action.act.account)
{
ilog("action.receipt.receiver != action.act.account");
continue;
}
if(action.act.account != local_contract_oraction.act.name == ACTION_DUMMY) {// thirdparty contract call or icp contract dummy call
//ilog("on applied transaction action dumy!!!");
for(auto& in: action.inline_traces) {
if(in.receipt.receiver != in.act.account)continue;
if(in.act.account == local_contract_andin.act.name == ACTION_SENDACTION) {
for(auto&inin: in.inline_traces) {
if(inin.receipt.receiver != inin.act.account)continue;
if(inin.act.name == ACTION_ISPACKET) {
autoseq = icp_packet::get_seq(inin.act.data, st.start_packet_seq);
st.packet_actions[seq] = send_transaction_internal{ACTION_ONPACKET, inin.act, inin.receipt};
}
}
}
}
}elseif(action.act.account == local_contract_) {
if(action.act.name == ACTION_ADDBLOCKSoraction.act.name == ACTION_OPENCHANNEL) {
ilog("on_applied_transaction ,action name is ${p}",("p", action.act.name) );
app().get_io_service().post([this] {
update_local_head();
});
}else
{
//....
}
}
if(st.empty())return;
//send_transactions_.insert(st);
update_send_transaction_index(st);
}
该函数是跨链交易处理的核心逻辑，分别处理了不同类型的action，如ACTION_ADDBLOCKS，ACTION_OPENCHANNEL等。
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同样，由于eoc_relay既要发送消息，也要接收消息，所以封装了几个消息处理函数如：
voidrelay::handle_message( icp_connection_ptr c,consticp_notice_message & msg)
{
ilog("received icp_notice_message");
if(notmsg.local_head_.valid())return;
app().get_io_service().post([=, self=shared_from_this()] {
if(notpeer_head_.valid()) {
clear_cache_block_state();
}
peer_head_ = msg.local_head_;
});
// TODO: check validity
icp_peer_ilog(c,"received icp_notice_message");
ilog("received icp_notice_message");
}
该函数处理icp_notice_message。详细细节，大家可以下载源码仔细参阅，eoc_relay_plugin核心代码剖析就介绍到这里，欢迎大家关注EOCS官方微信公众号及EOCS小秘书共同探讨交流更多技术。
