fixes

Author: malkia

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_forward_proxy.h

@@ -22,17 +22,23 @@ class OPENTELEMETRY_EXPORT_TYPE OtlpGrpcForwardProxy
 {
     struct Impl;
     std::unique_ptr<Impl> impl;
+    OtlpGrpcForwardProxy() = delete;
 public:
-    explicit OtlpGrpcForwardProxy();
+    enum class ExportMode {
+        Unknown          = -1,
+        Sync             = 0,
+        // For async to work, options.max_concurrent_requests > 1.
+        AsyncBlockOnFull = 1, 
+        AsyncDropOnFull  = 2,
+    };
+    explicit OtlpGrpcForwardProxy(const OtlpGrpcClientOptions& options);
     ~OtlpGrpcForwardProxy();
     void SetActive(bool active);
     bool IsActive() const;
-    void SetAsync(bool async);
-    bool IsAsync() const;
     void AddListenAddress(const std::string& listenAddress);
-    void RegisterTraceExporter(const OtlpGrpcExporterOptions& options);
-    void RegisterMetricExporter(const OtlpGrpcMetricExporterOptions& options);
-    void RegisterLogRecordExporter(const OtlpGrpcLogRecordExporterOptions& options);
+    void RegisterTraceExporter( ExportMode exportMode );
+    void RegisterMetricExporter( ExportMode exportMode );
+    void RegisterLogRecordExporter( ExportMode exportMode );
     void Start();
     void Wait();
     void Shutdown();