Core/DBLayer: Added new async query callback api

src/server/database/Database/QueryCallback.cpp

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2008-2017 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "QueryCallback.h"
+
+QueryCallbackNew::QueryCallbackNew(std::future<QueryResult>&& result) : _string(std::move(result)), _isPrepared(false)
+{
+}
+
+QueryCallbackNew::QueryCallbackNew(std::future<PreparedQueryResult>&& result) : _prepared(std::move(result)), _isPrepared(true)
+{
+}
+
+QueryCallbackNew::QueryCallbackNew(QueryCallbackNew&& right)
+{
+    MoveFrom(std::move(right));
+}
+
+QueryCallbackNew& QueryCallbackNew::operator=(QueryCallbackNew&& right)
+{
+    MoveFrom(std::move(right));
+    return *this;
+}
+
+QueryCallbackNew::~QueryCallbackNew()
+{
+    DestroyCurrentMember();
+}
+
+QueryCallbackNew&& QueryCallbackNew::WithCallback(std::function<void(QueryResult)>&& callback)
+{
+    ASSERT(!_isPrepared, "Attempted to set callback function for string query on a prepared async query");
+    _string.Callback = std::move(callback);
+    return std::move(*this);
+}
+
+QueryCallbackNew&& QueryCallbackNew::WithPreparedCallback(std::function<void(PreparedQueryResult)>&& callback)
+{
+    ASSERT(_isPrepared, "Attempted to set callback function for prepared query on a string async query");
+    _prepared.Callback = std::move(callback);
+    return std::move(*this);
+}
+
+QueryCallbackNew::Status QueryCallbackNew::InvokeIfReady()
+{
+    if (!_isPrepared)
+    {
+        if (_string.Result.valid() && _string.Result.wait_for(std::chrono::seconds(0)) == std::future_status::ready)
+        {
+            std::function<void(QueryResult)> cb(std::move(_string.Callback));
+            cb(_string.Result.get());
+            return !_string.Callback ? Completed : NextStep;
+        }
+    }
+    else
+    {
+        if (_prepared.Result.valid() && _prepared.Result.wait_for(std::chrono::seconds(0)) == std::future_status::ready)
+        {
+            std::function<void(PreparedQueryResult)> cb(std::move(_prepared.Callback));
+            cb(_prepared.Result.get());
+            return !_prepared.Callback ? Completed : NextStep;
+        }
+    }
+
+    return NotReady;
+}
+
+void QueryCallbackNew::MoveFrom(QueryCallbackNew&& other)
+{
+    DestroyCurrentMember();
+    _isPrepared = other._isPrepared;
+    if (!_isPrepared)
+        _string = std::move(other._string);
+    else
+        _prepared = std::move(other._prepared);
+}
+
+void QueryCallbackNew::DestroyCurrentMember()
+{
+    if (!_isPrepared)
+        _string.~String();
+    else
+        _prepared.~Prepared();
+}

src/server/database/Database/QueryCallback.h

@@ -28,6 +28,61 @@ typedef std::promise<PreparedQueryResult> PreparedQueryResultPromise;
 
 #define CALLBACK_STAGE_INVALID uint8(-1)
 
+class TC_DATABASE_API QueryCallbackNew
+{
+    struct String
+    {
+        explicit String(std::future<QueryResult>&& result) : Result(std::move(result)) { }
+        String(String&&) = default;
+        String& operator=(String&&) = default;
+        ~String() { }
+
+        std::future<QueryResult> Result;
+        std::function<void(QueryResult)> Callback;
+    };
+
+    struct Prepared
+    {
+        explicit Prepared(std::future<PreparedQueryResult>&& result) : Result(std::move(result)) { }
+        Prepared(Prepared&&) = default;
+        Prepared& operator=(Prepared&&) = default;
+        ~Prepared() { }
+
+        std::future<PreparedQueryResult> Result;
+        std::function<void(PreparedQueryResult)> Callback;
+    };
+
+public:
+    explicit QueryCallbackNew(std::future<QueryResult>&& result);
+    explicit QueryCallbackNew(std::future<PreparedQueryResult>&& result);
+    QueryCallbackNew(QueryCallbackNew&& right);
+    QueryCallbackNew& operator=(QueryCallbackNew&& right);
+    ~QueryCallbackNew();
+
+    QueryCallbackNew&& WithCallback(std::function<void(QueryResult)>&& callback);
+    QueryCallbackNew&& WithPreparedCallback(std::function<void(PreparedQueryResult)>&& callback);
+
+    enum Status
+    {
+        NotReady,
+        NextStep,
+        Completed
+    };
+
+    Status InvokeIfReady();
+
+private:
+    void MoveFrom(QueryCallbackNew&& other);
+    void DestroyCurrentMember();
+
+    union
+    {
+        String _string;
+        Prepared _prepared;
+    };
+    bool _isPrepared;
+};
+
 template <typename Result, typename ParamType, bool chain = false>
 class QueryCallback
 {

src/server/database/Database/QueryCallbackProcessor.cpp

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2008-2017 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "QueryCallbackProcessor.h"
+#include "QueryCallback.h"
+#include <algorithm>
+
+QueryCallbackProcessor::QueryCallbackProcessor()
+{
+}
+
+QueryCallbackProcessor::~QueryCallbackProcessor()
+{
+}
+
+void QueryCallbackProcessor::AddQuery(QueryCallbackNew&& query)
+{
+    _callbacks.emplace_back(std::move(query));
+}
+
+void QueryCallbackProcessor::ProcessReadyQueries()
+{
+    _callbacks.erase(std::remove_if(_callbacks.begin(), _callbacks.end(), [](QueryCallbackNew& callback)
+    {
+        return callback.InvokeIfReady() == QueryCallbackNew::Completed;
+    }), _callbacks.end());
+}

src/server/database/Database/QueryCallbackProcessor.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2008-2017 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef QueryCallbackProcessor_h__
+#define QueryCallbackProcessor_h__
+
+#include "Define.h"
+#include <vector>
+
+class QueryCallbackNew;
+
+class TC_DATABASE_API QueryCallbackProcessor
+{
+public:
+    QueryCallbackProcessor();
+    ~QueryCallbackProcessor();
+
+    void AddQuery(QueryCallbackNew&& query);
+    void ProcessReadyQueries();
+
+private:
+    std::vector<QueryCallbackNew> _callbacks;
+};
+
+#endif // QueryCallbackProcessor_h__