ledgers.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012-2017 Ripple Labs Inc
 
    Permission to use, copy, modify, and/or 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.
*/
//==============================================================================
#ifndef RIPPLE_TEST_CSF_LEDGERS_H_INCLUDED
#define RIPPLE_TEST_CSF_LEDGERS_H_INCLUDED
 
#include <test/csf/Tx.h>
#include <xrpld/consensus/LedgerTiming.h>
#include <xrpl/basics/UnorderedContainers.h>
#include <xrpl/basics/chrono.h>
#include <xrpl/basics/comparators.h>
#include <xrpl/basics/tagged_integer.h>
#include <xrpl/json/json_value.h>
#include <boost/bimap/bimap.hpp>
#include <optional>
#include <set>
 
namespace ripple {
namespace test {
namespace csf {
 
class Ledger
{
    friend class LedgerOracle;
 
public:
    struct SeqTag;
    using Seq = tagged_integer<std::uint32_t, SeqTag>;
 
    struct IdTag;
    using ID = tagged_integer<std::uint32_t, IdTag>;
 
    struct MakeGenesis
    {
    };
 
private:
    // The instance is the common immutable data that will be assigned a unique
    // ID by the oracle
    struct Instance
    {
        Instance()
        {
        }
 
        // Sequence number
        Seq seq{0};
 
        // Transactions added to generate this ledger
        TxSetType txs;
 
        // Resolution used to determine close time
        NetClock::duration closeTimeResolution = ledgerDefaultTimeResolution;
 
        NetClock::time_point closeTime;
 
        bool closeTimeAgree = true;
 
        ID parentID{0};
 
        NetClock::time_point parentCloseTime;
 
        std::vector<Ledger::ID> ancestors;
 
        auto
        asTie() const
        {
            return std::tie(
                seq,
                txs,
                closeTimeResolution,
                closeTime,
                closeTimeAgree,
                parentID,
                parentCloseTime);
        }
 
        friend bool
        operator==(Instance const& a, Instance const& b)
        {
            return a.asTie() == b.asTie();
        }
 
        friend bool
        operator!=(Instance const& a, Instance const& b)
        {
            return a.asTie() != b.asTie();
        }
 
        friend bool
        operator<(Instance const& a, Instance const& b)
        {
            return a.asTie() < b.asTie();
        }
 
        template <class Hasher>
        friend void
        hash_append(Hasher& h, Ledger::Instance const& instance)
        {
            using beast::hash_append;
            hash_append(h, instance.asTie());
        }
    };
 
    // Single common genesis instance
    static const Instance genesis;
 
    Ledger(ID id, Instance const* i) : id_{id}, instance_{i}
    {
    }
 
public:
    Ledger(MakeGenesis) : instance_(&genesis)
    {
    }
 
    // This is required by the generic Consensus for now and should be
    // migrated to the MakeGenesis approach above.
    Ledger() : Ledger(MakeGenesis{})
    {
    }
 
    ID
    id() const
    {
        return id_;
    }
 
    Seq
    seq() const
    {
        return instance_->seq;
    }
 
    NetClock::duration
    closeTimeResolution() const
    {
        return instance_->closeTimeResolution;
    }
 
    bool
    closeAgree() const
    {
        return instance_->closeTimeAgree;
    }
 
    NetClock::time_point
    closeTime() const
    {
        return instance_->closeTime;
    }
 
    NetClock::time_point
    parentCloseTime() const
    {
        return instance_->parentCloseTime;
    }
 
    ID
    parentID() const
    {
        return instance_->parentID;
    }
 
    TxSetType const&
    txs() const
    {
        return instance_->txs;
    }
 
    bool
    isAncestor(Ledger const& ancestor) const;
 
    ID
    operator[](Seq seq) const;
 
    friend Ledger::Seq
    mismatch(Ledger const& a, Ledger const& o);
 
    Json::Value
    getJson() const;
 
    friend bool
    operator<(Ledger const& a, Ledger const& b)
    {
        return a.id() < b.id();
    }
 
private:
    ID id_{0};
    Instance const* instance_;
};
 
class LedgerOracle
{
    using InstanceMap = boost::bimaps::bimap<
        boost::bimaps::set_of<Ledger::Instance, ripple::less<Ledger::Instance>>,
        boost::bimaps::set_of<Ledger::ID, ripple::less<Ledger::ID>>>;
    using InstanceEntry = InstanceMap::value_type;
 
    // Set of all known ledgers; note this is never pruned
    InstanceMap instances_;
 
    // ID for the next unique ledger
    Ledger::ID
    nextID() const;
 
public:
    LedgerOracle();
 
    std::optional<Ledger>
    lookup(Ledger::ID const& id) const;
 
    Ledger
    accept(
        Ledger const& curr,
        TxSetType const& txs,
        NetClock::duration closeTimeResolution,
        NetClock::time_point const& consensusCloseTime);
 
    Ledger
    accept(Ledger const& curr, Tx tx)
    {
        using namespace std::chrono_literals;
        return accept(
            curr,
            TxSetType{tx},
            curr.closeTimeResolution(),
            curr.closeTime() + 1s);
    }
 
    std::size_t
    branches(std::set<Ledger> const& ledgers) const;
};
 
struct LedgerHistoryHelper
{
    LedgerOracle oracle;
    Tx::ID nextTx{0};
    std::unordered_map<std::string, Ledger> ledgers;
    std::set<char> seen;
 
    LedgerHistoryHelper()
    {
        ledgers[""] = Ledger{Ledger::MakeGenesis{}};
    }
 
    Ledger const&
    operator[](std::string const& s)
    {
        auto it = ledgers.find(s);
        if (it != ledgers.end())
            return it->second;
 
        // enforce that the new suffix has never been seen
        assert(seen.emplace(s.back()).second);
 
        Ledger const& parent = (*this)[s.substr(0, s.size() - 1)];
        return ledgers.emplace(s, oracle.accept(parent, Tx{++nextTx}))
            .first->second;
    }
};
 
}  // namespace csf
}  // namespace test
}  // namespace ripple
 
#endif