[hermes] Introduce Sink class (#3570)

* [hermes] Introduce Sink class

This commit introduces Sink class which serves as a base class for all
log message consumers.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
* Update comment

diff --git a/contrib/hermes/include/hermes/core/Sink.h b/contrib/hermes/include/hermes/core/Sink.h
new file mode 100644 (file)
index 0000000..f53aff9
--- /dev/null
+++ b/contrib/hermes/include/hermes/core/Sink.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __HERMES_SINK_H__
+#define __HERMES_SINK_H__
+
+#include "hermes/core/Message.h"
+
+#include <memory>
+
+namespace hermes
+{
+
+/**
+ * @brief Message consumer interface
+ *
+ * All message consumers should inherit this interface.
+ */
+struct Sink
+{
+  struct Registry
+  {
+    virtual ~Registry() = default;
+
+    // NOTE SinkRegistry takes the ownership of all the appended Sink objects
+    virtual void append(std::unique_ptr<Sink> &&) = 0;
+  };
+
+  virtual ~Sink() = default;
+
+  virtual void notify(const Message *) = 0;
+};
+
+} // namespace hermes
+
+#endif // __HERMES_SINK_H__

diff --git a/contrib/hermes/src/core/Sink.cpp b/contrib/hermes/src/core/Sink.cpp
new file mode 100644 (file)
index 0000000..1677073
--- /dev/null
+++ b/contrib/hermes/src/core/Sink.cpp
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "hermes/core/Sink.h"
+
+// NOTE This empty file validates "Sink.h"