BackendInterface.hpp

//------------------------------------------------------------------------------
/*
    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.
*/
//==============================================================================
 
#pragma once
 
#include "data/DBHelpers.hpp"
#include "data/LedgerCache.hpp"
#include "data/Types.hpp"
#include "etl/CorruptionDetector.hpp"
#include "util/log/Logger.hpp"
 
#include <boost/asio/executor_work_guard.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/spawn.hpp>
#include <boost/json.hpp>
#include <boost/json/object.hpp>
#include <boost/utility/result_of.hpp>
#include <xrpl/basics/base_uint.h>
#include <xrpl/protocol/AccountID.h>
#include <xrpl/protocol/Fees.h>
#include <xrpl/protocol/LedgerHeader.h>
 
#include <chrono>
#include <cstddef>
#include <cstdint>
#include <exception>
#include <optional>
#include <shared_mutex>
#include <string>
#include <thread>
#include <type_traits>
#include <utility>
#include <vector>
 
namespace data {
 
class DatabaseTimeout : public std::exception {
public:
    char const*
    what() const throw() override
    {
        return "Database read timed out. Please retry the request";
    }
};
 
static constexpr std::size_t kDEFAULT_WAIT_BETWEEN_RETRY = 500;
template <typename FnType>
auto
retryOnTimeout(FnType func, size_t waitMs = kDEFAULT_WAIT_BETWEEN_RETRY)
{
    static util::Logger const log{"Backend"};  // NOLINT(readability-identifier-naming)
 
    while (true) {
        try {
            return func();
        } catch (DatabaseTimeout const&) {
            LOG(log.error()) << "Database request timed out. Sleeping and retrying ... ";
            std::this_thread::sleep_for(std::chrono::milliseconds(waitMs));
        }
    }
}
 
template <typename FnType>
auto
synchronous(FnType&& func)
{
    boost::asio::io_context ctx;
 
    using R = typename boost::result_of<FnType(boost::asio::yield_context)>::type;
    if constexpr (!std::is_same_v<R, void>) {
        R res;
        boost::asio::spawn(ctx, [_ = boost::asio::make_work_guard(ctx), &func, &res](auto yield) {
            res = func(yield);
        });
 
        ctx.run();
        return res;
    } else {
        boost::asio::spawn(ctx, [_ = boost::asio::make_work_guard(ctx), &func](auto yield) { func(yield); });
        ctx.run();
    }
}
 
template <typename FnType>
auto
synchronousAndRetryOnTimeout(FnType&& func)
{
    return retryOnTimeout([&]() { return synchronous(func); });
}
 
class BackendInterface {
protected:
    mutable std::shared_mutex rngMtx_;
    std::optional<LedgerRange> range_;
    LedgerCache cache_;
    std::optional<etl::CorruptionDetector<LedgerCache>> corruptionDetector_;
 
public:
    BackendInterface() = default;
    virtual ~BackendInterface() = default;
 
    // TODO: Remove this hack. Cache should not be exposed thru BackendInterface
    LedgerCache const&
    cache() const
    {
        return cache_;
    }
 
    LedgerCache&
    cache()
    {
        return cache_;
    }
 
    void
    setCorruptionDetector(etl::CorruptionDetector<LedgerCache> detector)
    {
        corruptionDetector_ = std::move(detector);
    }
 
    virtual std::optional<ripple::LedgerHeader>
    fetchLedgerBySequence(std::uint32_t sequence, boost::asio::yield_context yield) const = 0;
 
    virtual std::optional<ripple::LedgerHeader>
    fetchLedgerByHash(ripple::uint256 const& hash, boost::asio::yield_context yield) const = 0;
 
    virtual std::optional<std::uint32_t>
    fetchLatestLedgerSequence(boost::asio::yield_context yield) const = 0;
 
    std::optional<LedgerRange>
    fetchLedgerRange() const;
 
    virtual std::vector<ripple::uint256>
    fetchAccountRoots(std::uint32_t number, std::uint32_t pageSize, std::uint32_t seq, boost::asio::yield_context yield)
        const = 0;
 
    void
    updateRange(uint32_t newMax);
 
    void
    setRange(uint32_t min, uint32_t max, bool force = false);
 
    std::optional<ripple::Fees>
    fetchFees(std::uint32_t seq, boost::asio::yield_context yield) const;
 
    virtual std::optional<TransactionAndMetadata>
    fetchTransaction(ripple::uint256 const& hash, boost::asio::yield_context yield) const = 0;
 
    virtual std::vector<TransactionAndMetadata>
    fetchTransactions(std::vector<ripple::uint256> const& hashes, boost::asio::yield_context yield) const = 0;
 
    virtual TransactionsAndCursor
    fetchAccountTransactions(
        ripple::AccountID const& account,
        std::uint32_t limit,
        bool forward,
        std::optional<TransactionsCursor> const& cursor,
        boost::asio::yield_context yield
    ) const = 0;
 
    virtual std::vector<TransactionAndMetadata>
    fetchAllTransactionsInLedger(std::uint32_t ledgerSequence, boost::asio::yield_context yield) const = 0;
 
    virtual std::vector<ripple::uint256>
    fetchAllTransactionHashesInLedger(std::uint32_t ledgerSequence, boost::asio::yield_context yield) const = 0;
 
    virtual std::optional<NFT>
    fetchNFT(ripple::uint256 const& tokenID, std::uint32_t ledgerSequence, boost::asio::yield_context yield) const = 0;
 
    virtual TransactionsAndCursor
    fetchNFTTransactions(
        ripple::uint256 const& tokenID,
        std::uint32_t limit,
        bool forward,
        std::optional<TransactionsCursor> const& cursorIn,
        boost::asio::yield_context yield
    ) const = 0;
 
    virtual NFTsAndCursor
    fetchNFTsByIssuer(
        ripple::AccountID const& issuer,
        std::optional<std::uint32_t> const& taxon,
        std::uint32_t ledgerSequence,
        std::uint32_t limit,
        std::optional<ripple::uint256> const& cursorIn,
        boost::asio::yield_context yield
    ) const = 0;
 
    virtual MPTHoldersAndCursor
    fetchMPTHolders(
        ripple::uint192 const& mptID,
        std::uint32_t const limit,
        std::optional<ripple::AccountID> const& cursorIn,
        std::uint32_t const ledgerSequence,
        boost::asio::yield_context yield
    ) const = 0;
 
    std::optional<Blob>
    fetchLedgerObject(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield) const;
 
    std::optional<std::uint32_t>
    fetchLedgerObjectSeq(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield) const;
 
    std::vector<Blob>
    fetchLedgerObjects(
        std::vector<ripple::uint256> const& keys,
        std::uint32_t sequence,
        boost::asio::yield_context yield
    ) const;
 
    virtual std::optional<Blob>
    doFetchLedgerObject(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield) const = 0;
 
    virtual std::optional<std::uint32_t>
    doFetchLedgerObjectSeq(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield)
        const = 0;
 
    virtual std::vector<Blob>
    doFetchLedgerObjects(
        std::vector<ripple::uint256> const& keys,
        std::uint32_t sequence,
        boost::asio::yield_context yield
    ) const = 0;
 
    virtual std::vector<LedgerObject>
    fetchLedgerDiff(std::uint32_t ledgerSequence, boost::asio::yield_context yield) const = 0;
 
    LedgerPage
    fetchLedgerPage(
        std::optional<ripple::uint256> const& cursor,
        std::uint32_t ledgerSequence,
        std::uint32_t limit,
        bool outOfOrder,
        boost::asio::yield_context yield
    );
 
    std::optional<LedgerObject>
    fetchSuccessorObject(ripple::uint256 key, std::uint32_t ledgerSequence, boost::asio::yield_context yield) const;
 
    std::optional<ripple::uint256>
    fetchSuccessorKey(ripple::uint256 key, std::uint32_t ledgerSequence, boost::asio::yield_context yield) const;
 
    virtual std::optional<ripple::uint256>
    doFetchSuccessorKey(ripple::uint256 key, std::uint32_t ledgerSequence, boost::asio::yield_context yield) const = 0;
 
    BookOffersPage
    fetchBookOffers(
        ripple::uint256 const& book,
        std::uint32_t ledgerSequence,
        std::uint32_t limit,
        boost::asio::yield_context yield
    ) const;
 
    virtual std::optional<std::string>
    fetchMigratorStatus(std::string const& migratorName, boost::asio::yield_context yield) const = 0;
 
    std::optional<LedgerRange>
    hardFetchLedgerRange() const;
 
    virtual std::optional<LedgerRange>
    hardFetchLedgerRange(boost::asio::yield_context yield) const = 0;
 
    std::optional<LedgerRange>
    hardFetchLedgerRangeNoThrow() const;
 
    virtual void
    writeLedger(ripple::LedgerHeader const& ledgerHeader, std::string&& blob) = 0;
 
    virtual void
    writeLedgerObject(std::string&& key, std::uint32_t seq, std::string&& blob);
 
    virtual void
    writeTransaction(
        std::string&& hash,
        std::uint32_t seq,
        std::uint32_t date,
        std::string&& transaction,
        std::string&& metadata
    ) = 0;
 
    virtual void
    writeNFTs(std::vector<NFTsData> const& data) = 0;
 
    virtual void
    writeAccountTransactions(std::vector<AccountTransactionsData> data) = 0;
 
    virtual void
    writeNFTTransactions(std::vector<NFTTransactionsData> const& data) = 0;
 
    virtual void
    writeMPTHolders(std::vector<MPTHolderData> const& data) = 0;
 
    virtual void
    writeSuccessor(std::string&& key, std::uint32_t seq, std::string&& successor) = 0;
 
    virtual void
    startWrites() const = 0;
 
    bool
    finishWrites(std::uint32_t ledgerSequence);
 
    virtual void
    waitForWritesToFinish() = 0;
 
    virtual void
    writeMigratorStatus(std::string const& migratorName, std::string const& status) = 0;
 
    virtual bool
    isTooBusy() const = 0;
 
    virtual boost::json::object
    stats() const = 0;
 
private:
    virtual void
    doWriteLedgerObject(std::string&& key, std::uint32_t seq, std::string&& blob) = 0;
 
    virtual bool
    doFinishWrites() = 0;
};
 
}  // namespace data
using BackendInterface = data::BackendInterface;