Add cpp_entity_index

include/cppast/cpp_entity_index.hpp

@@ -0,0 +1,76 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#ifndef CPPAST_CPP_ENTITY_INDEX_HPP_INCLUDED
+#define CPPAST_CPP_ENTITY_INDEX_HPP_INCLUDED
+
+#include <map>
+#include <mutex>
+#include <string>
+
+#include <type_safe/optional_ref.hpp>
+#include <type_safe/reference.hpp>
+#include <type_safe/strong_typedef.hpp>
+
+#include <cppast/detail/assert.hpp>
+
+namespace cppast
+{
+    class cpp_entity;
+
+    /// A [ts::strong_typedef]() representing the unique id of a [cppast::cpp_entity]().
+    ///
+    /// It is fully comparable.
+    struct cpp_entity_id : type_safe::strong_typedef<cpp_entity_id, std::string>,
+                           type_safe::strong_typedef_op::equality_comparison<cpp_entity_id, bool>,
+                           type_safe::strong_typedef_op::relational_comparison<cpp_entity_id, bool>
+    {
+        using strong_typedef::strong_typedef;
+    };
+
+    inline namespace literals
+    {
+        /// \returns A new [cppast::cpp_entity_id]() created from the given string.
+        inline cpp_entity_id operator""_id(const char* str, std::size_t size)
+        {
+            return cpp_entity_id(std::string(str, size));
+        }
+    }
+
+    /// An index of all [cppast::cpp_entity]() objects created.
+    ///
+    /// It maps [cppast::cpp_entity_id]() to references to the [cppast::cpp_entity]() objects.
+    class cpp_entity_index
+    {
+    public:
+        /// \effects Registers a new [cppast::cpp_entity]() also giving its [cppast::cpp_entity_id]().
+        /// \requires The entity must not have been registered before,
+        /// and it must live as long as the index lives.
+        /// \notes This operation is thread safe.
+        void register_entity(cpp_entity_id id, type_safe::object_ref<const cpp_entity> entity) const
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            auto                        result = map_.emplace(std::move(id), std::move(entity));
+            DEBUG_ASSERT(result.second, detail::precondition_error_handler{},
+                         "duplicate index registration");
+        }
+
+        /// \returns A [ts::optional_ref]() corresponding to the entity of the given [cppast::cpp_entity_id]().
+        /// \notes This operation is thread safe.
+        type_safe::optional_ref<const cpp_entity> lookup(const cpp_entity_id& id) const noexcept
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            auto                        iter = map_.find(id);
+            if (iter == map_.end())
+                return {};
+            return iter->second.get();
+        }
+
+    private:
+        mutable std::mutex mutex_;
+        mutable std::map<cpp_entity_id, type_safe::object_ref<const cpp_entity>> map_;
+    };
+} // namespace cppast
+
+#endif // CPPAST_CPP_ENTITY_INDEX_HPP_INCLUDED