Add support for nested gRPC callouts. (#240)

Signed-off-by: andytesti <atesti@salesforce.com>

Author: andytesti

src/dispatcher.rs

@@ -453,7 +453,8 @@ impl Dispatcher {
     }
 
     fn on_grpc_receive(&self, token_id: u32, response_size: usize) {
-        if let Some(context_id) = self.grpc_callouts.borrow_mut().remove(&token_id) {
+        let context_id = self.grpc_callouts.borrow_mut().remove(&token_id);
+        if let Some(context_id) = context_id {
             if let Some(http_stream) = self.http_streams.borrow_mut().get_mut(&context_id) {
                 self.active_id.set(context_id);
                 hostcalls::set_effective_context(context_id).unwrap();
@@ -467,24 +468,26 @@ impl Dispatcher {
                 hostcalls::set_effective_context(context_id).unwrap();
                 root.on_grpc_call_response(token_id, 0, response_size);
             }
-        } else if let Some(context_id) = self.grpc_streams.borrow_mut().get(&token_id) {
-            let context_id = *context_id;
-            if let Some(http_stream) = self.http_streams.borrow_mut().get_mut(&context_id) {
-                self.active_id.set(context_id);
-                hostcalls::set_effective_context(context_id).unwrap();
-                http_stream.on_grpc_stream_message(token_id, response_size);
-            } else if let Some(stream) = self.streams.borrow_mut().get_mut(&context_id) {
-                self.active_id.set(context_id);
-                hostcalls::set_effective_context(context_id).unwrap();
-                stream.on_grpc_stream_message(token_id, response_size);
-            } else if let Some(root) = self.roots.borrow_mut().get_mut(&context_id) {
-                self.active_id.set(context_id);
-                hostcalls::set_effective_context(context_id).unwrap();
-                root.on_grpc_stream_message(token_id, response_size);
-            }
         } else {
-            // TODO: change back to a panic once underlying issue is fixed.
-            trace!("on_grpc_receive_initial_metadata: invalid token_id");
+            let context_id = self.grpc_streams.borrow().get(&token_id).cloned();
+            if let Some(context_id) = context_id {
+                if let Some(http_stream) = self.http_streams.borrow_mut().get_mut(&context_id) {
+                    self.active_id.set(context_id);
+                    hostcalls::set_effective_context(context_id).unwrap();
+                    http_stream.on_grpc_stream_message(token_id, response_size);
+                } else if let Some(stream) = self.streams.borrow_mut().get_mut(&context_id) {
+                    self.active_id.set(context_id);
+                    hostcalls::set_effective_context(context_id).unwrap();
+                    stream.on_grpc_stream_message(token_id, response_size);
+                } else if let Some(root) = self.roots.borrow_mut().get_mut(&context_id) {
+                    self.active_id.set(context_id);
+                    hostcalls::set_effective_context(context_id).unwrap();
+                    root.on_grpc_stream_message(token_id, response_size);
+                }
+            } else {
+                // TODO: change back to a panic once underlying issue is fixed.
+                trace!("on_grpc_receive_initial_metadata: invalid token_id");
+            }
         }
     }
 
@@ -514,7 +517,8 @@ impl Dispatcher {
     }
 
     fn on_grpc_close(&self, token_id: u32, status_code: u32) {
-        if let Some(context_id) = self.grpc_callouts.borrow_mut().remove(&token_id) {
+        let context_id = self.grpc_callouts.borrow_mut().remove(&token_id);
+        if let Some(context_id) = context_id {
             if let Some(http_stream) = self.http_streams.borrow_mut().get_mut(&context_id) {
                 self.active_id.set(context_id);
                 hostcalls::set_effective_context(context_id).unwrap();
@@ -528,23 +532,26 @@ impl Dispatcher {
                 hostcalls::set_effective_context(context_id).unwrap();
                 root.on_grpc_call_response(token_id, status_code, 0);
             }
-        } else if let Some(context_id) = self.grpc_streams.borrow_mut().remove(&token_id) {
-            if let Some(http_stream) = self.http_streams.borrow_mut().get_mut(&context_id) {
-                self.active_id.set(context_id);
-                hostcalls::set_effective_context(context_id).unwrap();
-                http_stream.on_grpc_stream_close(token_id, status_code)
-            } else if let Some(stream) = self.streams.borrow_mut().get_mut(&context_id) {
-                self.active_id.set(context_id);
-                hostcalls::set_effective_context(context_id).unwrap();
-                stream.on_grpc_stream_close(token_id, status_code)
-            } else if let Some(root) = self.roots.borrow_mut().get_mut(&context_id) {
-                self.active_id.set(context_id);
-                hostcalls::set_effective_context(context_id).unwrap();
-                root.on_grpc_stream_close(token_id, status_code)
-            }
         } else {
-            // TODO: change back to a panic once underlying issue is fixed.
-            trace!("on_grpc_close: invalid token_id, a non-connected stream has closed");
+            let context_id = self.grpc_streams.borrow_mut().remove(&token_id);
+            if let Some(context_id) = context_id {
+                if let Some(http_stream) = self.http_streams.borrow_mut().get_mut(&context_id) {
+                    self.active_id.set(context_id);
+                    hostcalls::set_effective_context(context_id).unwrap();
+                    http_stream.on_grpc_stream_close(token_id, status_code)
+                } else if let Some(stream) = self.streams.borrow_mut().get_mut(&context_id) {
+                    self.active_id.set(context_id);
+                    hostcalls::set_effective_context(context_id).unwrap();
+                    stream.on_grpc_stream_close(token_id, status_code)
+                } else if let Some(root) = self.roots.borrow_mut().get_mut(&context_id) {
+                    self.active_id.set(context_id);
+                    hostcalls::set_effective_context(context_id).unwrap();
+                    root.on_grpc_stream_close(token_id, status_code)
+                }
+            } else {
+                // TODO: change back to a panic once underlying issue is fixed.
+                trace!("on_grpc_close: invalid token_id, a non-connected stream has closed");
+            }
         }
     }
 }