101 lines
3.1 KiB
C++
101 lines
3.1 KiB
C++
/**
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*
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* @file SimpleReverseProxy.cc
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*
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*/
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#include "SimpleReverseProxy.h"
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using namespace drogon;
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using namespace my_plugin;
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void SimpleReverseProxy::initAndStart(const Json::Value &config)
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{
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/// Initialize and start the plugin
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if (config.isMember("backends") && config["backends"].isArray())
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{
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for (auto &backend : config["backends"])
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{
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backendAddrs_.emplace_back(backend.asString());
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}
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if (backendAddrs_.empty())
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{
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LOG_ERROR << "You must set at least one backend";
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abort();
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}
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}
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else
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{
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LOG_ERROR << "Error in configuration";
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abort();
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}
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pipeliningDepth_ = config.get("pipelining", 0).asInt();
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sameClientToSameBackend_ =
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config.get("same_client_to_same_backend", false).asBool();
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connectionFactor_ = config.get("connection_factor", 1).asInt();
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if (connectionFactor_ == 0 || connectionFactor_ > 100)
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{
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LOG_ERROR << "invalid number of connection factor";
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abort();
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}
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clients_.init(
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[this](std::vector<HttpClientPtr> &clients, size_t ioLoopIndex) {
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clients.resize(backendAddrs_.size() * connectionFactor_);
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});
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clientIndex_.init(
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[this](size_t &index, size_t ioLoopIndex) { index = ioLoopIndex; });
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drogon::app().registerPreRoutingAdvice([this](const HttpRequestPtr &req,
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AdviceCallback &&callback,
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AdviceChainCallback &&pass) {
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preRouting(req, std::move(callback), std::move(pass));
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});
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}
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void SimpleReverseProxy::shutdown()
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{
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}
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void SimpleReverseProxy::preRouting(const HttpRequestPtr &req,
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AdviceCallback &&callback,
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AdviceChainCallback &&)
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{
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size_t index;
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auto &clientsVector = *clients_;
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if (sameClientToSameBackend_)
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{
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index = std::hash<uint32_t>{}(req->getPeerAddr().ipNetEndian()) %
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clientsVector.size();
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index = (index + (++(*clientIndex_)) * backendAddrs_.size()) %
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clientsVector.size();
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}
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else
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{
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index = ++(*clientIndex_) % clientsVector.size();
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}
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auto &clientPtr = clientsVector[index];
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if (!clientPtr)
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{
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auto &addr = backendAddrs_[index % backendAddrs_.size()];
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clientPtr = HttpClient::newHttpClient(
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addr, trantor::EventLoop::getEventLoopOfCurrentThread());
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clientPtr->setPipeliningDepth(pipeliningDepth_);
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}
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req->setPassThrough(true);
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clientPtr->sendRequest(
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req,
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[callback = std::move(callback)](ReqResult result,
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const HttpResponsePtr &resp) {
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if (result == ReqResult::Ok)
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{
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resp->setPassThrough(true);
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callback(resp);
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}
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else
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{
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auto errResp = HttpResponse::newHttpResponse();
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errResp->setStatusCode(k500InternalServerError);
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callback(errResp);
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}
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});
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}
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