Subscribe.hpp

//------------------------------------------------------------------------------
/*
    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 "data/BackendInterface.hpp"
#include "feed/SubscriptionManagerInterface.hpp"
#include "feed/Types.hpp"
#include "rpc/common/Specs.hpp"
#include "rpc/common/Types.hpp"
 
#include <boost/asio/spawn.hpp>
#include <boost/json/array.hpp>
#include <boost/json/conversion.hpp>
#include <boost/json/object.hpp>
#include <boost/json/value.hpp>
#include <boost/json/value_to.hpp>
#include <xrpl/beast/utility/Zero.h>
#include <xrpl/protocol/Book.h>
#include <xrpl/protocol/ErrorCodes.h>
#include <xrpl/protocol/jss.h>
 
#include <cstdint>
#include <memory>
#include <optional>
#include <string>
#include <vector>
 
namespace rpc {
 
class SubscribeHandler {
    std::shared_ptr<BackendInterface> sharedPtrBackend_;
    std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions_;
 
public:
    struct Output {
        // response of stream "ledger"
        // TODO: use better type than json, this type will be used in the stream as well
        std::optional<boost::json::object> ledger;
        // books returns nothing by default, if snapshot is true and both is false, offers go to offers list
        // TODO: use better type than json
        std::optional<boost::json::array> offers;
        // if snapshot is true and both is true, reversed book' offers go to asks list
        std::optional<boost::json::array> asks;
        // if snapshot is true and both is true, original book' offers go to bids list
        std::optional<boost::json::array> bids;
    };
 
    struct OrderBook {
        ripple::Book book;
        std::optional<std::string> taker;
        bool snapshot = false;
        bool both = false;
    };
 
    struct Input {
        std::optional<std::vector<std::string>> accounts;
        std::optional<std::vector<std::string>> streams;
        std::optional<std::vector<std::string>> accountsProposed;
        std::optional<std::vector<OrderBook>> books;
    };
 
    using Result = HandlerReturnType<Output>;
 
    SubscribeHandler(
        std::shared_ptr<BackendInterface> const& sharedPtrBackend,
        std::shared_ptr<feed::SubscriptionManagerInterface> const& subscriptions
    );
 
    static RpcSpecConstRef
    spec([[maybe_unused]] uint32_t apiVersion);
 
    Result
    process(Input input, Context const& ctx) const;
 
private:
    boost::json::object
    subscribeToStreams(
        boost::asio::yield_context yield,
        std::vector<std::string> const& streams,
        feed::SubscriberSharedPtr const& session
    ) const;
 
    void
    subscribeToAccounts(std::vector<std::string> const& accounts, feed::SubscriberSharedPtr const& session) const;
 
    void
    subscribeToAccountsProposed(std::vector<std::string> const& accounts, feed::SubscriberSharedPtr const& session)
        const;
 
    void
    subscribeToBooks(
        std::vector<OrderBook> const& books,
        feed::SubscriberSharedPtr const& session,
        boost::asio::yield_context yield,
        Output& output
    ) const;
 
    friend void
    tag_invoke(boost::json::value_from_tag, boost::json::value& jv, Output const& output);
 
    friend Input
    tag_invoke(boost::json::value_to_tag<Input>, boost::json::value const& jv);
};
 
}  // namespace rpc