clio/src/rpc/handlers/Subscribe.cpp

//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2022, 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.
*/
//==============================================================================

#include <boost/json.hpp>
#include <subscriptions/SubscriptionManager.h>
#include <webserver/WsBase.h>

#include <rpc/RPCHelpers.h>

namespace RPC {

// these are the streams that take no arguments
static std::unordered_set<std::string>
    validCommonStreams{"ledger", "transactions", "transactions_proposed", "validations", "manifests", "book_changes"};

Status
validateStreams(boost::json::object const& request)
{
    for (auto const& streams = request.at(JS(streams)).as_array(); auto const& stream : streams)
    {
        if (!stream.is_string())
            return Status{RippledError::rpcINVALID_PARAMS, "streamNotString"};

        if (!validCommonStreams.contains(stream.as_string().c_str()))
            return Status{RippledError::rpcSTREAM_MALFORMED};
    }

    return OK;
}

boost::json::object
subscribeToStreams(
    boost::asio::yield_context& yield,
    boost::json::object const& request,
    std::shared_ptr<WsBase> session,
    SubscriptionManager& manager)
{
    boost::json::array const& streams = request.at(JS(streams)).as_array();

    boost::json::object response;
    for (auto const& stream : streams)
    {
        std::string s = stream.as_string().c_str();

        if (s == "ledger")
            response = manager.subLedger(yield, session);
        else if (s == "transactions")
            manager.subTransactions(session);
        else if (s == "transactions_proposed")
            manager.subProposedTransactions(session);
        else if (s == "validations")
            manager.subValidation(session);
        else if (s == "manifests")
            manager.subManifest(session);
        else if (s == "book_changes")
            manager.subBookChanges(session);
        else
            assert(false);
    }
    return response;
}

void
unsubscribeToStreams(boost::json::object const& request, std::shared_ptr<WsBase> session, SubscriptionManager& manager)
{
    boost::json::array const& streams = request.at(JS(streams)).as_array();

    for (auto const& stream : streams)
    {
        std::string s = stream.as_string().c_str();

        if (s == "ledger")
            manager.unsubLedger(session);
        else if (s == "transactions")
            manager.unsubTransactions(session);
        else if (s == "transactions_proposed")
            manager.unsubProposedTransactions(session);
        else if (s == "validations")
            manager.unsubValidation(session);
        else if (s == "manifests")
            manager.unsubManifest(session);
        else if (s == "book_changes")
            manager.unsubBookChanges(session);
        else
            assert(false);
    }
}

Status
validateAccounts(boost::json::array const& accounts)
{
    for (auto const& account : accounts)
    {
        if (!account.is_string())
            return Status{RippledError::rpcINVALID_PARAMS, "accountNotString"};

        if (!accountFromStringStrict(account.as_string().c_str()))
            return Status{RippledError::rpcACT_MALFORMED, "Account malformed."};
    }

    return OK;
}

void
subscribeToAccounts(boost::json::object const& request, std::shared_ptr<WsBase> session, SubscriptionManager& manager)
{
    boost::json::array const& accounts = request.at(JS(accounts)).as_array();

    for (auto const& account : accounts)
    {
        std::string s = account.as_string().c_str();

        auto accountID = accountFromStringStrict(s);

        if (!accountID)
        {
            assert(false);
            continue;
        }

        manager.subAccount(*accountID, session);
    }
}

void
unsubscribeToAccounts(boost::json::object const& request, std::shared_ptr<WsBase> session, SubscriptionManager& manager)
{
    boost::json::array const& accounts = request.at(JS(accounts)).as_array();

    for (auto const& account : accounts)
    {
        std::string s = account.as_string().c_str();

        auto accountID = accountFromStringStrict(s);

        if (!accountID)
        {
            assert(false);
            continue;
        }

        manager.unsubAccount(*accountID, session);
    }
}

void
subscribeToAccountsProposed(
    boost::json::object const& request,
    std::shared_ptr<WsBase> session,
    SubscriptionManager& manager)
{
    boost::json::array const& accounts = request.at(JS(accounts_proposed)).as_array();

    for (auto const& account : accounts)
    {
        std::string s = account.as_string().c_str();

        auto accountID = ripple::parseBase58<ripple::AccountID>(s);

        if (!accountID)
        {
            assert(false);
            continue;
        }

        manager.subProposedAccount(*accountID, session);
    }
}

void
unsubscribeToAccountsProposed(
    boost::json::object const& request,
    std::shared_ptr<WsBase> session,
    SubscriptionManager& manager)
{
    boost::json::array const& accounts = request.at(JS(accounts_proposed)).as_array();

    for (auto const& account : accounts)
    {
        std::string s = account.as_string().c_str();

        auto accountID = ripple::parseBase58<ripple::AccountID>(s);

        if (!accountID)
        {
            assert(false);
            continue;
        }

        manager.unsubProposedAccount(*accountID, session);
    }
}

std::variant<Status, std::pair<std::vector<ripple::Book>, boost::json::array>>
validateAndGetBooks(
    boost::asio::yield_context& yield,
    boost::json::object const& request,
    std::shared_ptr<Backend::BackendInterface const> const& backend)
{
    if (!request.at(JS(books)).is_array())
        return Status{RippledError::rpcINVALID_PARAMS, "booksNotArray"};
    boost::json::array const& books = request.at(JS(books)).as_array();

    std::vector<ripple::Book> booksToSub;
    std::optional<Backend::LedgerRange> rng;
    boost::json::array snapshot;
    for (auto const& book : books)
    {
        auto parsedBook = parseBook(book.as_object());
        if (auto status = std::get_if<Status>(&parsedBook))
            return *status;

        auto b = std::get<ripple::Book>(parsedBook);
        booksToSub.push_back(b);
        bool both = book.as_object().contains(JS(both));
        if (both)
            booksToSub.push_back(ripple::reversed(b));

        if (book.as_object().contains(JS(snapshot)))
        {
            if (!rng)
                rng = backend->fetchLedgerRange();
            ripple::AccountID takerID = beast::zero;
            if (book.as_object().contains(JS(taker)))
                if (auto const status = getTaker(book.as_object(), takerID); status)
                    return status;

            auto getOrderBook = [&snapshot, &backend, &rng, &takerID](auto book, boost::asio::yield_context& yield) {
                auto bookBase = getBookBase(book);
                auto [offers, _] = backend->fetchBookOffers(bookBase, rng->maxSequence, 200, yield);

                auto orderBook = postProcessOrderBook(offers, book, takerID, *backend, rng->maxSequence, yield);
                std::copy(orderBook.begin(), orderBook.end(), std::back_inserter(snapshot));
            };
            getOrderBook(b, yield);
            if (both)
                getOrderBook(ripple::reversed(b), yield);
        }
    }
    return std::make_pair(booksToSub, snapshot);
}

void
subscribeToBooks(std::vector<ripple::Book> const& books, std::shared_ptr<WsBase> session, SubscriptionManager& manager)
{
    for (auto const& book : books)
    {
        manager.subBook(book, session);
    }
}

void
unsubscribeToBooks(
    std::vector<ripple::Book> const& books,
    std::shared_ptr<WsBase> session,
    SubscriptionManager& manager)
{
    for (auto const& book : books)
    {
        manager.unsubBook(book, session);
    }
}

Result
doSubscribe(Context const& context)
{
    auto request = context.params;

    if (request.contains(JS(streams)))
    {
        if (!request.at(JS(streams)).is_array())
            return Status{RippledError::rpcINVALID_PARAMS, "streamsNotArray"};

        auto status = validateStreams(request);

        if (status)
            return status;
    }

    if (request.contains(JS(accounts)))
    {
        auto const& jsonAccounts = request.at(JS(accounts));
        if (!jsonAccounts.is_array())
            return Status{RippledError::rpcINVALID_PARAMS, "accountsNotArray"};

        auto const& accounts = jsonAccounts.as_array();
        if (accounts.empty())
            return Status{RippledError::rpcACT_MALFORMED, "Account malformed."};

        auto const status = validateAccounts(accounts);
        if (status)
            return status;
    }

    if (request.contains(JS(accounts_proposed)))
    {
        auto const& jsonAccounts = request.at(JS(accounts_proposed));
        if (!jsonAccounts.is_array())
            return Status{RippledError::rpcINVALID_PARAMS, "accountsProposedNotArray"};

        auto const& accounts = jsonAccounts.as_array();
        if (accounts.empty())
            return Status{RippledError::rpcACT_MALFORMED, "Account malformed."};

        auto const status = validateAccounts(accounts);
        if (status)
            return status;
    }

    std::vector<ripple::Book> books;
    boost::json::object response;

    if (request.contains(JS(books)))
    {
        auto parsed = validateAndGetBooks(context.yield, request, context.backend);
        if (auto status = std::get_if<Status>(&parsed))
            return *status;
        auto [bks, snap] = std::get<std::pair<std::vector<ripple::Book>, boost::json::array>>(parsed);
        books = std::move(bks);
        response[JS(offers)] = std::move(snap);
    }

    if (request.contains(JS(streams)))
        response = subscribeToStreams(context.yield, request, context.session, *context.subscriptions);

    if (request.contains(JS(accounts)))
        subscribeToAccounts(request, context.session, *context.subscriptions);

    if (request.contains(JS(accounts_proposed)))
        subscribeToAccountsProposed(request, context.session, *context.subscriptions);

    if (request.contains(JS(books)))
        subscribeToBooks(books, context.session, *context.subscriptions);

    return response;
}

Result
doUnsubscribe(Context const& context)
{
    auto request = context.params;

    if (request.contains(JS(streams)))
    {
        if (!request.at(JS(streams)).is_array())
            return Status{RippledError::rpcINVALID_PARAMS, "streamsNotArray"};

        auto status = validateStreams(request);

        if (status)
            return status;
    }

    if (request.contains(JS(accounts)))
    {
        auto const& jsonAccounts = request.at(JS(accounts));
        if (!jsonAccounts.is_array())
            return Status{RippledError::rpcINVALID_PARAMS, "accountsNotArray"};

        auto const& accounts = jsonAccounts.as_array();
        if (accounts.empty())
            return Status{RippledError::rpcACT_MALFORMED, "Account malformed."};

        auto const status = validateAccounts(accounts);
        if (status)
            return status;
    }

    if (request.contains(JS(accounts_proposed)))
    {
        auto const& jsonAccounts = request.at(JS(accounts_proposed));
        if (!jsonAccounts.is_array())
            return Status{RippledError::rpcINVALID_PARAMS, "accountsProposedNotArray"};

        auto const& accounts = jsonAccounts.as_array();
        if (accounts.empty())
            return Status{RippledError::rpcACT_MALFORMED, "Account malformed."};

        auto const status = validateAccounts(accounts);
        if (status)
            return status;
    }

    std::vector<ripple::Book> books;
    if (request.contains(JS(books)))
    {
        auto parsed = validateAndGetBooks(context.yield, request, context.backend);

        if (auto status = std::get_if<Status>(&parsed))
            return *status;

        auto [bks, snap] = std::get<std::pair<std::vector<ripple::Book>, boost::json::array>>(parsed);

        books = std::move(bks);
    }

    if (request.contains(JS(streams)))
        unsubscribeToStreams(request, context.session, *context.subscriptions);

    if (request.contains(JS(accounts)))
        unsubscribeToAccounts(request, context.session, *context.subscriptions);

    if (request.contains(JS(accounts_proposed)))
        unsubscribeToAccountsProposed(request, context.session, *context.subscriptions);

    if (request.contains("books"))
        unsubscribeToBooks(books, context.session, *context.subscriptions);

    return boost::json::object{};
}

}  // namespace RPC