Rename headers to .hpp (#1154)

Fixes #1153

src/rpc/common/APIVersion.hpp

@@ -0,0 +1,66 @@
+//------------------------------------------------------------------------------
+/*
+    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/Expected.hpp"
+
+#include <boost/json.hpp>
+#include <boost/json/object.hpp>
+
+#include <cstdint>
+#include <string>
+
+namespace rpc {
+
+/**
+ * @brief Default API version to use if no version is specified by clients
+ */
+static constexpr uint32_t API_VERSION_DEFAULT = 1u;
+
+/**
+ * @brief Minimum API version supported by this build
+ *
+ * Note: Clio does not natively support v1 and only supports v2 or newer.
+ * However, Clio will forward all v1 requests to rippled for backward compatibility.
+ */
+static constexpr uint32_t API_VERSION_MIN = 1u;
+
+/**
+ * @brief Maximum API version supported by this build
+ */
+static constexpr uint32_t API_VERSION_MAX = 2u;
+
+/**
+ * @brief A baseclass for API version helper
+ */
+class APIVersionParser {
+public:
+    virtual ~APIVersionParser() = default;
+
+    /**
+     * @brief Extracts API version information from a JSON object.
+     *
+     * @param request A JSON object representing the request
+     * @return The specified API version if contained in the JSON object; error string otherwise
+     */
+    util::Expected<uint32_t, std::string> virtual parse(boost::json::object const& request) const = 0;
+};
+
+}  // namespace rpc