Rearrange sources (#4997)

include/xrpl/basics/LocalValue.h

@@ -0,0 +1,132 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_LOCALVALUE_H_INCLUDED
+#define RIPPLE_BASICS_LOCALVALUE_H_INCLUDED
+
+#include <boost/thread/tss.hpp>
+#include <memory>
+#include <unordered_map>
+
+namespace ripple {
+
+namespace detail {
+
+struct LocalValues
+{
+    explicit LocalValues() = default;
+
+    bool onCoro = true;
+
+    struct BasicValue
+    {
+        virtual ~BasicValue() = default;
+        virtual void*
+        get() = 0;
+    };
+
+    template <class T>
+    struct Value : BasicValue
+    {
+        T t_;
+
+        Value() = default;
+        explicit Value(T const& t) : t_(t)
+        {
+        }
+
+        void*
+        get() override
+        {
+            return &t_;
+        }
+    };
+
+    // Keys are the address of a LocalValue.
+    std::unordered_map<void const*, std::unique_ptr<BasicValue>> values;
+
+    static inline void
+    cleanup(LocalValues* lvs)
+    {
+        if (lvs && !lvs->onCoro)
+            delete lvs;
+    }
+};
+
+template <class = void>
+boost::thread_specific_ptr<detail::LocalValues>&
+getLocalValues()
+{
+    static boost::thread_specific_ptr<detail::LocalValues> tsp(
+        &detail::LocalValues::cleanup);
+    return tsp;
+}
+
+}  // namespace detail
+
+template <class T>
+class LocalValue
+{
+public:
+    template <class... Args>
+    LocalValue(Args&&... args) : t_(std::forward<Args>(args)...)
+    {
+    }
+
+    /** Stores instance of T specific to the calling coroutine or thread. */
+    T&
+    operator*();
+
+    /** Stores instance of T specific to the calling coroutine or thread. */
+    T*
+    operator->()
+    {
+        return &**this;
+    }
+
+private:
+    T t_;
+};
+
+template <class T>
+T&
+LocalValue<T>::operator*()
+{
+    auto lvs = detail::getLocalValues().get();
+    if (!lvs)
+    {
+        lvs = new detail::LocalValues();
+        lvs->onCoro = false;
+        detail::getLocalValues().reset(lvs);
+    }
+    else
+    {
+        auto const iter = lvs->values.find(this);
+        if (iter != lvs->values.end())
+            return *reinterpret_cast<T*>(iter->second->get());
+    }
+
+    return *reinterpret_cast<T*>(
+        lvs->values
+            .emplace(this, std::make_unique<detail::LocalValues::Value<T>>(t_))
+            .first->second->get());
+}
+}  // namespace ripple
+
+#endif