routing_simulator.h

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/*
 * Copyright (c) 2024 Oracle and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2.0,
 * as published by the Free Software Foundation.
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 * designated in a particular file or component or in included license
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#ifndef ROUTER_SRC_ROUTING_GUIDELINES_SRC_ROUTING_SIMULATOR_H_
#define ROUTER_SRC_ROUTING_GUIDELINES_SRC_ROUTING_SIMULATOR_H_
 
#include <memory>
#include <string>
#include <string_view>
#include <unordered_map>
 
#ifdef RAPIDJSON_NO_SIZETYPEDEFINE
#include "my_rapidjson_size_t.h"
#endif
 
#include <rapidjson/document.h>
#include <rapidjson/error/en.h>
 
#include "routing_guidelines/routing_guidelines.h"
#include "rpn.h"
 
namespace routing_guidelines {
 
class Routing_simulator {
 public:
  explicit Routing_simulator(
      rpn::Context *external_context = nullptr,
      Routing_guidelines_engine::ResolveCache *external_cache = nullptr);
 
  stdx::expected<void, std::string> process_document(const std::string &s);
 
 private:
  stdx::expected<void, std::string> parse_router(const rapidjson::Document &d);
  stdx::expected<void, std::string> parse_destination(
      const rapidjson::Document &d, std::string_view expected_name);
  stdx::expected<void, std::string> parse_source(
      const rapidjson::Document &d, std::string_view expected_name);
  stdx::expected<void, std::string> parse_sql(const rapidjson::Document &d,
                                              std::string_view expected_name);
 
  std::unique_ptr<Routing_guidelines_engine> rpd_;
 
  // External context + variables to keep it valid
  rpn::Context *external_context_{nullptr};
  Routing_guidelines_engine::ResolveCache *external_cache_{nullptr};
  Router_info router_;
  Session_info session_;
  Sql_info sql_;
  Server_info server_;
 
  // Tracking many destinations and sources
  std::unordered_map<std::string, Server_info> destinations_;
  std::string last_destination_;
  std::unordered_map<int, Session_info> sources_;
  int64_t last_source_{-1};
};
 
}  // namespace routing_guidelines
 
#endif  // ROUTER_SRC_ROUTING_GUIDELINES_SRC_ROUTING_SIMULATOR_H_