LanguageClient: Restructure request response handling

Instead of working on a Client member IContent now returns an optional
response handler that consists of an id, a name and a callback.

Change-Id: I5ca7dd4eaa7ae37f333f99c9fe60339db03ebf2c
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/languageserverprotocol/icontent.h

@@ -89,7 +89,13 @@ public:
     }
 };
 
-using ResponseHandler = std::function<void(const QByteArray &, QTextCodec *)>;
+struct ResponseHandler
+{
+    MessageId id;
+    using Callback = std::function<void(const QByteArray &, QTextCodec *)>;
+    Callback callback;
+};
+
 using ResponseHandlers = std::function<void(const MessageId &, const QByteArray &, QTextCodec *)>;
 using MethodHandler = std::function<void(const QString &, const MessageId &, const IContent *)>;
 
@@ -121,7 +127,8 @@ public:
     virtual QByteArray mimeType() const = 0;
     virtual bool isValid(QString *errorMessage) const = 0;
 
-    virtual void registerResponseHandler(QHash<MessageId, ResponseHandler> *) const { }
+    virtual Utils::optional<ResponseHandler> responseHandler() const
+    { return Utils::nullopt; }
 
     BaseMessage toBaseMessage() const
     { return BaseMessage(mimeType(), toRawData()); }

src/libs/languageserverprotocol/jsonrpcmessages.h

@@ -284,15 +284,15 @@ public:
     void setResponseCallback(const ResponseCallback &callback)
     { m_callBack = callback; }
 
-    void registerResponseHandler(QHash<MessageId, ResponseHandler> *handlers) const final
+    Utils::optional<ResponseHandler> responseHandler() const final
     {
-        auto callback = m_callBack;
-        handlers->insert(id(), [callback](const QByteArray &content, QTextCodec *codec){
+        auto callback = [callback = m_callBack](const QByteArray &content, QTextCodec *codec) {
             if (!callback)
                 return;
             QString parseError;
-            const QJsonObject &object =
-                    JsonRpcMessageHandler::toJsonObject(content, codec, parseError);
+            const QJsonObject &object = JsonRpcMessageHandler::toJsonObject(content,
+                                                                            codec,
+                                                                            parseError);
             Response response(object);
             if (object.isEmpty()) {
                 ResponseError<ErrorDataType> error;
@@ -300,7 +300,8 @@ public:
                 response.setError(error);
             }
             callback(Response(object));
-        });
+        };
+        return Utils::make_optional(ResponseHandler{id(), callback});
     }
 
     bool isValid(QString *errorMessage) const override

src/plugins/languageclient/client.cpp

@@ -245,7 +245,9 @@ void Client::initialize()
         initializeCallback(initResponse);
     });
     // directly send data otherwise the state check would fail;
-    initRequest.registerResponseHandler(&m_responseHandlers);
+    if (Utils::optional<ResponseHandler> responseHandler = initRequest.responseHandler())
+        m_responseHandlers[responseHandler->id] = responseHandler->callback;
+
     LanguageClientManager::logBaseMessage(LspLogMessage::ClientMessage,
                                           name(),
                                           initRequest.toBaseMessage());
@@ -321,7 +323,8 @@ void Client::sendContent(const IContent &content)
     QTC_ASSERT(m_clientInterface, return);
     QTC_ASSERT(m_state == Initialized, return);
     sendPostponedDocumentUpdates();
-    content.registerResponseHandler(&m_responseHandlers);
+    if (Utils::optional<ResponseHandler> responseHandler = content.responseHandler())
+        m_responseHandlers[responseHandler->id] = responseHandler->callback;
     QString error;
     if (!QTC_GUARD(content.isValid(&error)))
         Core::MessageManager::write(error);

src/plugins/languageclient/client.h

@@ -211,7 +211,8 @@ private:
                                               LanguageServerProtocol::MethodHandler)>;
 
     State m_state = Uninitialized;
-    QHash<LanguageServerProtocol::MessageId, LanguageServerProtocol::ResponseHandler> m_responseHandlers;
+    QHash<LanguageServerProtocol::MessageId,
+          LanguageServerProtocol::ResponseHandler::Callback> m_responseHandlers;
     QHash<QByteArray, ContentHandler> m_contentHandler;
     QString m_displayName;
     LanguageFilter m_languagFilter;