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[ric-plt/sdl.git] / include / private / error.hpp

diff --git a/include/private/error.hpp b/include/private/error.hpp
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+/*
+   Copyright (c) 2018-2019 Nokia.
+
+   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 SHAREDDATALAYER_ERROR_HPP_
+#define SHAREDDATALAYER_ERROR_HPP_
+
+#include <system_error>
+
+/* Error codes defined here are for SDL internal usage only.
+ * Error codes meant to be used by SDL clients are defined in sdl/errorqueries.hpp.
+ *
+ * Error code handling in SDL goes following way:
+ *
+ * - Implementation sets so called implementation specific error codes (e.g AsyncRedisCommandDispatcherErrorCode
+ *   and AsyncRedisConnection::ErrorCode).
+ * - All implementation specific error codes have mapping to InternalErrors. This mapping is handled by overriding
+ *   std::error_category default_error_condition function in all implementation specific error code categories.
+ * - All InternalErrors are mapped to shareddatalayer::Errors which SDL client can conveniently use in
+ *   its error handling implemention. This mapping is handled by overriding std::error_category equivalent function in
+ *   SharedDataLayerErrorCategory.
+ * - Async API error codes have corresponding exceptions in sync API. When modifying other one (async API error codes or
+ *   sync API exceptions) check the need for similar modification to other one also.
+ *
+ * When adding a new implementation specific error code, do also needed updates to mappings described above.
+ * At least mapping from new implementation specific error code error code to InternalError is always needed.
+ */
+
+namespace shareddatalayer
+{
+    enum class InternalError
+    {
+        SUCCESS = 0,
+        SDL_NOT_READY,
+        SDL_NOT_CONNECTED_TO_BACKEND,
+        SDL_ERROR_CODE_LOGIC_ERROR,
+        SDL_RECEIVED_INVALID_PARAMETER,
+        BACKEND_CONNECTION_LOST,
+        BACKEND_NOT_READY,
+        BACKEND_REJECTED_REQUEST,
+        BACKEND_ERROR
+    };
+
+    std::error_condition make_error_condition(shareddatalayer::InternalError ec);
+
+    namespace redis
+    {
+        enum class AsyncRedisCommandDispatcherErrorCode
+        {
+            SUCCESS = 0,
+            UNKNOWN_ERROR,
+            CONNECTION_LOST,
+            PROTOCOL_ERROR,
+            OUT_OF_MEMORY,
+            DATASET_LOADING,
+            NOT_CONNECTED,
+            IO_ERROR,
+            //Keep this always as last item. Used in unit tests to loop all enum values.
+            END_MARKER
+        };
+
+        std::error_code make_error_code(AsyncRedisCommandDispatcherErrorCode errorCode);
+        AsyncRedisCommandDispatcherErrorCode& operator++ (AsyncRedisCommandDispatcherErrorCode& ecEnum);
+    }
+}
+
+namespace std
+{
+    template <>
+    struct is_error_condition_enum<shareddatalayer::InternalError> : public true_type { };
+
+    template <>
+    struct is_error_code_enum<shareddatalayer::redis::AsyncRedisCommandDispatcherErrorCode>: public true_type { };
+}
+
+#endif