InboundLedgers.cpp

#include <xrpld/app/ledger/InboundLedgers.h>
#include <xrpld/app/ledger/LedgerMaster.h>
#include <xrpld/app/main/Application.h>
#include <xrpld/app/misc/NetworkOPs.h>
 
#include <xrpl/basics/DecayingSample.h>
#include <xrpl/basics/Log.h>
#include <xrpl/basics/scope.h>
#include <xrpl/beast/container/aged_map.h>
#include <xrpl/core/JobQueue.h>
#include <xrpl/core/PerfLog.h>
#include <xrpl/protocol/jss.h>
 
#include <exception>
#include <memory>
#include <mutex>
#include <vector>
 
namespace xrpl {
 
class InboundLedgersImp : public InboundLedgers
{
private:
    Application& app_;
    std::mutex fetchRateMutex_;
    // measures ledgers per second, constants are important
    DecayWindow<30, clock_type> fetchRate_;
    beast::Journal const j_;
 
public:
    // How long before we try again to acquire the same ledger
    static constexpr std::chrono::minutes const kReacquireInterval{5};
 
    InboundLedgersImp(
        Application& app,
        clock_type& clock,
        beast::insight::Collector::ptr const& collector,
        std::unique_ptr<PeerSetBuilder> peerSetBuilder)
        : app_(app)
        , fetchRate_(clock.now())
        , j_(app.journal("InboundLedger"))
        , m_clock(clock)
        , mRecentFailures(clock)
        , mCounter(collector->make_counter("ledger_fetches"))
        , mPeerSetBuilder(std::move(peerSetBuilder))
    {
    }
 
    std::shared_ptr<Ledger const>
    acquire(
        uint256 const& hash,
        std::uint32_t seq,
        InboundLedger::Reason reason) override
    {
        auto doAcquire = [&, seq, reason]() -> std::shared_ptr<Ledger const> {
            XRPL_ASSERT(
                hash.isNonZero(),
                "xrpl::InboundLedgersImp::acquire::doAcquire : nonzero hash");
 
            // probably not the right rule
            if (app_.getOPs().isNeedNetworkLedger() &&
                (reason != InboundLedger::Reason::GENERIC) &&
                (reason != InboundLedger::Reason::CONSENSUS))
                return {};
 
            bool isNew = true;
            std::shared_ptr<InboundLedger> inbound;
            {
                ScopedLockType sl(mLock);
                if (stopping_)
                {
                    return {};
                }
 
                auto it = mLedgers.find(hash);
                if (it != mLedgers.end())
                {
                    isNew = false;
                    inbound = it->second;
                }
                else
                {
                    inbound = std::make_shared<InboundLedger>(
                        app_,
                        hash,
                        seq,
                        reason,
                        std::ref(m_clock),
                        mPeerSetBuilder->build());
                    mLedgers.emplace(hash, inbound);
                    inbound->init(sl);
                    ++mCounter;
                }
            }
 
            if (inbound->isFailed())
                return {};
 
            if (!isNew)
                inbound->update(seq);
 
            if (!inbound->isComplete())
                return {};
 
            return inbound->getLedger();
        };
        using namespace std::chrono_literals;
        std::shared_ptr<Ledger const> ledger = perf::measureDurationAndLog(
            doAcquire, "InboundLedgersImp::acquire", 500ms, j_);
 
        return ledger;
    }
 
    void
    acquireAsync(
        uint256 const& hash,
        std::uint32_t seq,
        InboundLedger::Reason reason) override
    {
        std::unique_lock lock(acquiresMutex_);
        try
        {
            if (pendingAcquires_.contains(hash))
                return;
            pendingAcquires_.insert(hash);
            scope_unlock unlock(lock);
            acquire(hash, seq, reason);
        }
        catch (std::exception const& e)
        {
            JLOG(j_.warn())
                << "Exception thrown for acquiring new inbound ledger " << hash
                << ": " << e.what();
        }
        catch (...)
        {
            JLOG(j_.warn())
                << "Unknown exception thrown for acquiring new inbound ledger "
                << hash;
        }
        pendingAcquires_.erase(hash);
    }
 
    std::shared_ptr<InboundLedger>
    find(uint256 const& hash) override
    {
        XRPL_ASSERT(
            hash.isNonZero(), "xrpl::InboundLedgersImp::find : nonzero input");
 
        std::shared_ptr<InboundLedger> ret;
 
        {
            ScopedLockType sl(mLock);
 
            auto it = mLedgers.find(hash);
            if (it != mLedgers.end())
            {
                ret = it->second;
            }
        }
 
        return ret;
    }
 
    /*
    This gets called when
        "We got some data from an inbound ledger"
 
    inboundLedgerTrigger:
      "What do we do with this partial data?"
      Figures out what to do with the responses to our requests for information.
 
    */
    // means "We got some data from an inbound ledger"
 
    // VFALCO TODO Remove the dependency on the Peer object.
    bool
    gotLedgerData(
        LedgerHash const& hash,
        std::shared_ptr<Peer> peer,
        std::shared_ptr<protocol::TMLedgerData> packet) override
    {
        if (auto ledger = find(hash))
        {
            JLOG(j_.trace()) << "Got data (" << packet->nodes().size()
                             << ") for acquiring ledger: " << hash;
 
            // Stash the data for later processing and see if we need to
            // dispatch
            if (ledger->gotData(std::weak_ptr<Peer>(peer), packet))
                app_.getJobQueue().addJob(
                    jtLEDGER_DATA, "processLedgerData", [ledger]() {
                        ledger->runData();
                    });
 
            return true;
        }
 
        JLOG(j_.trace()) << "Got data for ledger " << hash
                         << " which we're no longer acquiring";
 
        // If it's state node data, stash it because it still might be
        // useful.
        if (packet->type() == protocol::liAS_NODE)
        {
            app_.getJobQueue().addJob(
                jtLEDGER_DATA, "gotStaleData", [this, packet]() {
                    gotStaleData(packet);
                });
        }
 
        return false;
    }
 
    void
    logFailure(uint256 const& h, std::uint32_t seq) override
    {
        ScopedLockType sl(mLock);
 
        mRecentFailures.emplace(h, seq);
    }
 
    bool
    isFailure(uint256 const& h) override
    {
        ScopedLockType sl(mLock);
 
        beast::expire(mRecentFailures, kReacquireInterval);
        return mRecentFailures.find(h) != mRecentFailures.end();
    }
 
    void
    gotStaleData(std::shared_ptr<protocol::TMLedgerData> packet_ptr) override
    {
        Serializer s;
        try
        {
            for (int i = 0; i < packet_ptr->nodes().size(); ++i)
            {
                auto const& node = packet_ptr->nodes(i);
 
                if (!node.has_nodeid() || !node.has_nodedata())
                    return;
 
                auto newNode =
                    SHAMapTreeNode::makeFromWire(makeSlice(node.nodedata()));
 
                if (!newNode)
                    return;
 
                s.erase();
                newNode->serializeWithPrefix(s);
 
                app_.getLedgerMaster().addFetchPack(
                    newNode->getHash().as_uint256(),
                    std::make_shared<Blob>(s.begin(), s.end()));
            }
        }
        catch (std::exception const&)
        {
        }
    }
 
    void
    clearFailures() override
    {
        ScopedLockType sl(mLock);
 
        mRecentFailures.clear();
        mLedgers.clear();
    }
 
    std::size_t
    fetchRate() override
    {
        std::lock_guard lock(fetchRateMutex_);
        return 60 * fetchRate_.value(m_clock.now());
    }
 
    // Should only be called with an inboundledger that has
    // a reason of history
    void
    onLedgerFetched() override
    {
        std::lock_guard lock(fetchRateMutex_);
        fetchRate_.add(1, m_clock.now());
    }
 
    Json::Value
    getInfo() override
    {
        Json::Value ret(Json::objectValue);
 
        std::vector<std::pair<uint256, std::shared_ptr<InboundLedger>>> acqs;
 
        {
            ScopedLockType sl(mLock);
 
            acqs.reserve(mLedgers.size());
            for (auto const& it : mLedgers)
            {
                XRPL_ASSERT(
                    it.second,
                    "xrpl::InboundLedgersImp::getInfo : non-null ledger");
                acqs.push_back(it);
            }
            for (auto const& it : mRecentFailures)
            {
                if (it.second > 1)
                    ret[std::to_string(it.second)][jss::failed] = true;
                else
                    ret[to_string(it.first)][jss::failed] = true;
            }
        }
 
        for (auto const& it : acqs)
        {
            // getJson is expensive, so call without the lock
            std::uint32_t seq = it.second->getSeq();
            if (seq > 1)
                ret[std::to_string(seq)] = it.second->getJson(0);
            else
                ret[to_string(it.first)] = it.second->getJson(0);
        }
 
        return ret;
    }
 
    void
    gotFetchPack() override
    {
        std::vector<std::shared_ptr<InboundLedger>> acquires;
        {
            ScopedLockType sl(mLock);
 
            acquires.reserve(mLedgers.size());
            for (auto const& it : mLedgers)
            {
                XRPL_ASSERT(
                    it.second,
                    "xrpl::InboundLedgersImp::gotFetchPack : non-null "
                    "ledger");
                acquires.push_back(it.second);
            }
        }
 
        for (auto const& acquire : acquires)
        {
            acquire->checkLocal();
        }
    }
 
    void
    sweep() override
    {
        auto const start = m_clock.now();
 
        // Make a list of things to sweep, while holding the lock
        std::vector<MapType::mapped_type> stuffToSweep;
        std::size_t total;
 
        {
            ScopedLockType sl(mLock);
            MapType::iterator it(mLedgers.begin());
            total = mLedgers.size();
 
            stuffToSweep.reserve(total);
 
            while (it != mLedgers.end())
            {
                auto const la = it->second->getLastAction();
 
                if (la > start)
                {
                    it->second->touch();
                    ++it;
                }
                else if ((la + std::chrono::minutes(1)) < start)
                {
                    stuffToSweep.push_back(it->second);
                    // shouldn't cause the actual final delete
                    // since we are holding a reference in the vector.
                    it = mLedgers.erase(it);
                }
                else
                {
                    ++it;
                }
            }
 
            beast::expire(mRecentFailures, kReacquireInterval);
        }
 
        JLOG(j_.debug())
            << "Swept " << stuffToSweep.size() << " out of " << total
            << " inbound ledgers. Duration: "
            << std::chrono::duration_cast<std::chrono::milliseconds>(
                   m_clock.now() - start)
                   .count()
            << "ms";
    }
 
    void
    stop() override
    {
        ScopedLockType lock(mLock);
        stopping_ = true;
        mLedgers.clear();
        mRecentFailures.clear();
    }
 
    std::size_t
    cacheSize() override
    {
        ScopedLockType lock(mLock);
        return mLedgers.size();
    }
 
private:
    clock_type& m_clock;
 
    using ScopedLockType = std::unique_lock<std::recursive_mutex>;
    std::recursive_mutex mLock;
 
    bool stopping_ = false;
    using MapType = hash_map<uint256, std::shared_ptr<InboundLedger>>;
    MapType mLedgers;
 
    beast::aged_map<uint256, std::uint32_t> mRecentFailures;
 
    beast::insight::Counter mCounter;
 
    std::unique_ptr<PeerSetBuilder> mPeerSetBuilder;
 
    std::set<uint256> pendingAcquires_;
    std::mutex acquiresMutex_;
};
 
//------------------------------------------------------------------------------
 
std::unique_ptr<InboundLedgers>
make_InboundLedgers(
    Application& app,
    InboundLedgers::clock_type& clock,
    beast::insight::Collector::ptr const& collector)
{
    return std::make_unique<InboundLedgersImp>(
        app, clock, collector, make_PeerSetBuilder(app));
}
 
}  // namespace xrpl