Merge pull request #8618 from markdroth/channel_info_api

Add API for getting arbitrary state back from a channel

2 files changed, 18 insertions, 1 deletions

diff --git a/src/cpp/common/channel_filter.cc b/src/cpp/common/channel_filter.cc
index 25cd49cb7c..ad2c0f2295 100644
--- a/src/cpp/common/channel_filter.cc
+++ b/src/cpp/common/channel_filter.cc
@@ -57,6 +57,11 @@ void ChannelData::StartTransportOp(grpc_exec_ctx *exec_ctx,
   grpc_channel_next_op(exec_ctx, elem, op->op());
 }
 
+void ChannelData::GetInfo(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
+                          const grpc_channel_info *channel_info) {
+  grpc_channel_next_get_info(exec_ctx, elem, channel_info);
+}
+
 // CallData
 
 void CallData::StartTransportStreamOp(grpc_exec_ctx *exec_ctx,
diff --git a/src/cpp/common/channel_filter.h b/src/cpp/common/channel_filter.h
index fc0deff3b3..e420efc71c 100644
--- a/src/cpp/common/channel_filter.h
+++ b/src/cpp/common/channel_filter.h
@@ -224,9 +224,13 @@ class ChannelData {
   const char *peer() const { return peer_; }
 
   // TODO(roth): Find a way to avoid passing elem into these methods.
+
   virtual void StartTransportOp(grpc_exec_ctx *exec_ctx,
                                 grpc_channel_element *elem, TransportOp *op);
 
+  virtual void GetInfo(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
+                       const grpc_channel_info *channel_info);
+
  protected:
   /// Takes ownership of \a peer.
   ChannelData(const grpc_channel_args &args, const char *peer) : peer_(peer) {}
@@ -296,6 +300,13 @@ class ChannelFilter final {
     channel_data->StartTransportOp(exec_ctx, elem, &op_wrapper);
   }
 
+  static void GetChannelInfo(grpc_exec_ctx *exec_ctx,
+                             grpc_channel_element *elem,
+                             const grpc_channel_info *channel_info) {
+    ChannelDataType *channel_data = (ChannelDataType *)elem->channel_data;
+    channel_data->GetInfo(exec_ctx, elem, channel_info);
+  }
+
   static const size_t call_data_size = sizeof(CallDataType);
 
   static grpc_error *InitCallElement(grpc_exec_ctx *exec_ctx,
@@ -376,7 +387,8 @@ void RegisterChannelFilter(
        FilterType::call_data_size, FilterType::InitCallElement,
        FilterType::SetPollsetOrPollsetSet, FilterType::DestroyCallElement,
        FilterType::channel_data_size, FilterType::InitChannelElement,
-       FilterType::DestroyChannelElement, FilterType::GetPeer, name}};
+       FilterType::DestroyChannelElement, FilterType::GetPeer,
+       FilterType::GetChannelInfo, name}};
   internal::channel_filters->push_back(filter_record);
 }