OpenView.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 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_LEDGER_OPENVIEW_H_INCLUDED
#define RIPPLE_LEDGER_OPENVIEW_H_INCLUDED
 
#include <ripple/basics/XRPAmount.h>
#include <ripple/ledger/RawView.h>
#include <ripple/ledger/ReadView.h>
#include <ripple/ledger/detail/RawStateTable.h>
 
#include <boost/container/pmr/monotonic_buffer_resource.hpp>
#include <boost/container/pmr/polymorphic_allocator.hpp>
 
#include <functional>
#include <utility>
 
namespace ripple {
 
struct open_ledger_t
{
    explicit open_ledger_t() = default;
};
 
extern open_ledger_t const open_ledger;
 
//------------------------------------------------------------------------------
 
class OpenView final : public ReadView, public TxsRawView
{
private:
    // Initial size for the monotonic_buffer_resource used for allocations
    // The size was chosen from the old `qalloc` code (which this replaces).
    // It is unclear how the size initially chosen in qalloc.
    static constexpr size_t initialBufferSize = kilobytes(256);
 
    class txs_iter_impl;
 
    struct txData
    {
        std::shared_ptr<Serializer const> txn;
        std::shared_ptr<Serializer const> meta;
 
        // Constructor needed for emplacement in std::map
        txData(
            std::shared_ptr<Serializer const> const& txn_,
            std::shared_ptr<Serializer const> const& meta_)
            : txn(txn_), meta(meta_)
        {
        }
    };
 
    // List of tx, key order
    // Use boost::pmr functionality instead of std::pmr
    // functions b/c clang does not support pmr yet (as-of 9/2020)
    using txs_map = std::map<
        key_type,
        txData,
        std::less<key_type>,
        boost::container::pmr::polymorphic_allocator<
            std::pair<key_type const, txData>>>;
 
    // monotonic_resource_ must outlive `items_`. Make a pointer so it may be
    // easily moved.
    std::unique_ptr<boost::container::pmr::monotonic_buffer_resource>
        monotonic_resource_;
    txs_map txs_;
    Rules rules_;
    LedgerInfo info_;
    ReadView const* base_;
    detail::RawStateTable items_;
    std::shared_ptr<void const> hold_;
    bool open_ = true;
 
public:
    OpenView() = delete;
    OpenView&
    operator=(OpenView&&) = delete;
    OpenView&
    operator=(OpenView const&) = delete;
 
    OpenView(OpenView&&) = default;
 
    OpenView(OpenView const&);
 
    OpenView(
        open_ledger_t,
        ReadView const* base,
        Rules const& rules,
        std::shared_ptr<void const> hold = nullptr);
 
    OpenView(
        open_ledger_t,
        Rules const& rules,
        std::shared_ptr<ReadView const> const& base)
        : OpenView(open_ledger, &*base, rules, base)
    {
    }
    OpenView(ReadView const* base, std::shared_ptr<void const> hold = nullptr);
 
    bool
    open() const override
    {
        return open_;
    }
 
    std::size_t
    txCount() const;
 
    void
    apply(TxsRawView& to) const;
 
    // ReadView
 
    LedgerInfo const&
    info() const override;
 
    Fees const&
    fees() const override;
 
    Rules const&
    rules() const override;
 
    bool
    exists(Keylet const& k) const override;
 
    std::optional<key_type>
    succ(
        key_type const& key,
        std::optional<key_type> const& last = std::nullopt) const override;
 
    std::shared_ptr<SLE const>
    read(Keylet const& k) const override;
 
    std::unique_ptr<sles_type::iter_base>
    slesBegin() const override;
 
    std::unique_ptr<sles_type::iter_base>
    slesEnd() const override;
 
    std::unique_ptr<sles_type::iter_base>
    slesUpperBound(uint256 const& key) const override;
 
    std::unique_ptr<txs_type::iter_base>
    txsBegin() const override;
 
    std::unique_ptr<txs_type::iter_base>
    txsEnd() const override;
 
    bool
    txExists(key_type const& key) const override;
 
    tx_type
    txRead(key_type const& key) const override;
 
    // RawView
 
    void
    rawErase(std::shared_ptr<SLE> const& sle) override;
 
    void
    rawInsert(std::shared_ptr<SLE> const& sle) override;
 
    void
    rawReplace(std::shared_ptr<SLE> const& sle) override;
 
    void
    rawDestroyXRP(XRPAmount const& fee) override;
 
    // TxsRawView
 
    void
    rawTxInsert(
        key_type const& key,
        std::shared_ptr<Serializer const> const& txn,
        std::shared_ptr<Serializer const> const& metaData) override;
};
 
}  // namespace ripple
 
#endif