Refactor namespaces part 2 (#820)

Part 2 of refactoring effort

src/web/interface/Concepts.h

@@ -0,0 +1,43 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2023, the clio developers.
+
+    Permission to use, copy, modify, and 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.
+*/
+//==============================================================================
+
+#pragma once
+
+#include <web/interface/ConnectionBase.h>
+
+#include <boost/beast.hpp>
+
+#include <memory>
+
+namespace web {
+
+/**
+ * @brief Each executor fulfills this interface
+ */
+// clang-format off
+template <typename T>
+concept ServerHandler = requires(T handler, std::string const& req, std::shared_ptr<ConnectionBase> const& ws, boost::beast::error_code ec) {
+    // the callback when server receives a request
+    { handler(req, ws) };
+    // the callback when there is an error
+    { handler(ec, ws) };
+};
+// clang-format on
+
+}  // namespace web

src/web/interface/ConnectionBase.h

@@ -0,0 +1,79 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2023, the clio developers.
+
+    Permission to use, copy, modify, and 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.
+*/
+//==============================================================================
+
+#pragma once
+
+#include <util/Taggable.h>
+
+#include <boost/beast/http.hpp>
+
+namespace web {
+
+namespace http = boost::beast::http;
+
+/**
+ * @brief Base class for all connections
+ * This class is used to represent a connection in RPC executor and subscription manager
+ */
+struct ConnectionBase : public util::Taggable
+{
+protected:
+    boost::system::error_code ec_;
+
+public:
+    std::string const clientIp;
+    bool upgraded = false;
+
+    ConnectionBase(util::TagDecoratorFactory const& tagFactory, std::string ip) : Taggable(tagFactory), clientIp(ip)
+    {
+    }
+
+    /**
+     * @brief Send the response to the client
+     * @param msg The message to send
+     */
+    virtual void
+    send(std::string&& msg, http::status status = http::status::ok) = 0;
+
+    /**
+     * @brief Send via shared_ptr of string, that enables SubscriptionManager to publish to clients
+     * @param msg The message to send
+     */
+    virtual void
+    send(std::shared_ptr<std::string> msg)
+    {
+        throw std::runtime_error("web server can not send the shared payload");
+    }
+
+    /**
+     * @brief Indicates whether the connection had an error and is considered
+     * dead
+     *
+     * @return true
+     * @return false
+     */
+    bool
+    dead()
+    {
+        return ec_ != boost::system::error_code{};
+    }
+
+    virtual ~ConnectionBase() = default;
+};
+}  // namespace web