minor update

Signed-off-by: wbpcode <wbphub@live.com>

contrib/generic_proxy/filters/network/source/router/router.cc

@@ -94,7 +94,7 @@ void GenericUpstream::onPoolFailure(ConnectionPool::PoolFailureReason reason,
             host != nullptr ? host->address()->asStringView() : absl::string_view{});
 
   tcp_pool_handle_ = nullptr;
-  upstream_host_ = std::move(host);
+  mayUpdateUpstreamHost(std::move(host));
 
   onPoolFailureImpl(reason, transport_failure_reason);
 }
@@ -106,7 +106,7 @@ void GenericUpstream::onPoolReady(Tcp::ConnectionPool::ConnectionDataPtr&& conn_
             host->address()->asStringView());
 
   tcp_pool_handle_ = nullptr;
-  upstream_host_ = std::move(host);
+  mayUpdateUpstreamHost(std::move(host));
 
   owned_conn_data_ = std::move(conn_data);
   owned_conn_data_->addUpstreamCallbacks(*this);
@@ -355,15 +355,15 @@ UpstreamRequest::UpstreamRequest(RouterFilter& parent, GenericUpstreamSharedPtr
       stream_info_(parent.time_source_, nullptr, StreamInfo::FilterState::LifeSpan::FilterChain),
       upstream_info_(std::make_shared<StreamInfo::UpstreamInfoImpl>()) {
 
+  // Host is known at this point and set the initial upstream host.
+  onUpstreamHostSelected(generic_upstream_->upstreamHost());
+
   // Set the upstream info for the stream info.
   stream_info_.setUpstreamInfo(upstream_info_);
   parent_.callbacks_->streamInfo().setUpstreamInfo(upstream_info_);
   stream_info_.healthCheck(parent_.callbacks_->streamInfo().healthCheck());
   stream_info_.setUpstreamClusterInfo(parent_.cluster_);
 
-  // Host is known at this point.
-  onUpstreamHostSelected(generic_upstream_->upstreamHost());
-
   // Set request options.
   auto options = parent_.request_stream_->frameFlags().streamFlags();
   stream_id_ = options.streamId();
@@ -497,6 +497,7 @@ OptRef<const RouteEntry> UpstreamRequest::routeEntry() const {
 void UpstreamRequest::onUpstreamFailure(ConnectionPool::PoolFailureReason reason,
                                         absl::string_view transport_failure_reason) {
   ENVOY_LOG(debug, "upstream request: tcp connection (bound or owned) failure");
+  onUpstreamHostSelected(generic_upstream_->upstreamHost());
   onUpstreamConnectionReady();
 
   if (reason == ConnectionPool::PoolFailureReason::Overflow) {
@@ -509,6 +510,7 @@ void UpstreamRequest::onUpstreamFailure(ConnectionPool::PoolFailureReason reason
 void UpstreamRequest::onUpstreamSuccess() {
   ENVOY_LOG(debug, "upstream request: {} tcp connection has ready",
             parent_.config_->bindUpstreamConnection() ? "bound" : "owned");
+  onUpstreamHostSelected(generic_upstream_->upstreamHost());
   onUpstreamConnectionReady();
 
   const auto upstream_host = upstream_info_->upstream_host_.get();
@@ -588,9 +590,12 @@ void UpstreamRequest::onConnectionClose(Network::ConnectionEvent event) {
 }
 
 void UpstreamRequest::onUpstreamHostSelected(Upstream::HostDescriptionConstSharedPtr host) {
-  ENVOY_LOG(debug, "upstream request: selected upstream {}", host->address()->asString());
+  if (host == nullptr || host == upstream_info_->upstream_host_) {
+    return;
+  }
 
-  upstream_info_->setUpstreamHost(std::move(host));
+  ENVOY_LOG(debug, "upstream request: selected host {}", host->address()->asStringView());
+  upstream_info_->upstream_host_ = std::move(host);
 }
 
 void UpstreamRequest::onUpstreamConnectionReady() {

contrib/generic_proxy/filters/network/source/router/router.h

@@ -49,9 +49,9 @@ class GenericUpstream : public ClientCodecCallbacks,
                         public Envoy::Logger::Loggable<Envoy::Logger::Id::upstream> {
 public:
   GenericUpstream(Upstream::TcpPoolData&& tcp_pool_data, ClientCodecPtr&& client_codec)
-      : tcp_pool_data_(std::move(tcp_pool_data)), client_codec_(std::move(client_codec)) {
+      : tcp_pool_data_(std::move(tcp_pool_data)), client_codec_(std::move(client_codec)),
+        upstream_host_(tcp_pool_data_.host()) {
     client_codec_->setCodecCallbacks(*this);
-    upstream_host_ = tcp_pool_data_.host();
   }
   ~GenericUpstream() override;
 
@@ -71,15 +71,22 @@ class GenericUpstream : public ClientCodecCallbacks,
   void onEvent(Network::ConnectionEvent event) override { onEventImpl(event); }
 
   ClientCodec& clientCodec() { return *client_codec_; }
+  void mayUpdateUpstreamHost(Upstream::HostDescriptionConstSharedPtr real_host) {
+    if (real_host == nullptr || real_host == upstream_host_) {
+      return;
+    }
+
+    // Update the upstream host iff the connection pool callbacks provide a different
+    // value.
+    upstream_host_ = std::move(real_host);
+  }
   Upstream::HostDescriptionConstSharedPtr upstreamHost() const { return upstream_host_; }
 
   // ResponseDecoderCallback
   void writeToConnection(Buffer::Instance& buffer) override;
   OptRef<Network::Connection> connection() override;
   OptRef<const Upstream::ClusterInfo> upstreamCluster() const override {
-    if (upstream_host_ == nullptr) {
-      return {};
-    }
+    ASSERT(upstream_host_ != nullptr);
     return upstream_host_->cluster();
   }
 
@@ -93,15 +100,14 @@ class GenericUpstream : public ClientCodecCallbacks,
 protected:
   Upstream::TcpPoolData tcp_pool_data_;
   ClientCodecPtr client_codec_;
+  Upstream::HostDescriptionConstSharedPtr upstream_host_;
 
   // Whether the upstream connection is created. This will be set to true when the initialize()
   // is called.
   bool initialized_{};
 
   Tcp::ConnectionPool::Cancellable* tcp_pool_handle_{};
   Tcp::ConnectionPool::ConnectionDataPtr owned_conn_data_;
-
-  Upstream::HostDescriptionConstSharedPtr upstream_host_;
 };
 using GenericUpstreamSharedPtr = std::shared_ptr<GenericUpstream>;