ApplyView.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_APPLYVIEW_H_INCLUDED
#define RIPPLE_LEDGER_APPLYVIEW_H_INCLUDED
 
#include <ripple/basics/safe_cast.h>
#include <ripple/ledger/RawView.h>
#include <ripple/ledger/ReadView.h>
 
namespace ripple {
 
enum ApplyFlags : std::uint32_t {
    tapNONE = 0x00,
 
    // This is a local transaction with the
    // fail_hard flag set.
    tapFAIL_HARD = 0x10,
 
    // This is not the transaction's last pass
    // Transaction can be retried, soft failures allowed
    tapRETRY = 0x20,
 
    // Transaction must pay more than both the open ledger
    // fee and all transactions in the queue to get into the
    // open ledger
    tapPREFER_QUEUE = 0x40,
 
    // Transaction came from a privileged source
    tapUNLIMITED = 0x400,
};
 
constexpr ApplyFlags
operator|(ApplyFlags const& lhs, ApplyFlags const& rhs)
{
    return safe_cast<ApplyFlags>(
        safe_cast<std::underlying_type_t<ApplyFlags>>(lhs) |
        safe_cast<std::underlying_type_t<ApplyFlags>>(rhs));
}
 
static_assert(
    (tapPREFER_QUEUE | tapRETRY) == safe_cast<ApplyFlags>(0x60u),
    "ApplyFlags operator |");
static_assert(
    (tapRETRY | tapPREFER_QUEUE) == safe_cast<ApplyFlags>(0x60u),
    "ApplyFlags operator |");
 
constexpr ApplyFlags
operator&(ApplyFlags const& lhs, ApplyFlags const& rhs)
{
    return safe_cast<ApplyFlags>(
        safe_cast<std::underlying_type_t<ApplyFlags>>(lhs) &
        safe_cast<std::underlying_type_t<ApplyFlags>>(rhs));
}
 
static_assert((tapPREFER_QUEUE & tapRETRY) == tapNONE, "ApplyFlags operator &");
static_assert((tapRETRY & tapPREFER_QUEUE) == tapNONE, "ApplyFlags operator &");
 
constexpr ApplyFlags
operator~(ApplyFlags const& flags)
{
    return safe_cast<ApplyFlags>(
        ~safe_cast<std::underlying_type_t<ApplyFlags>>(flags));
}
 
static_assert(
    ~tapRETRY == safe_cast<ApplyFlags>(0xFFFFFFDFu),
    "ApplyFlags operator ~");
 
inline ApplyFlags
operator|=(ApplyFlags& lhs, ApplyFlags const& rhs)
{
    lhs = lhs | rhs;
    return lhs;
}
 
inline ApplyFlags
operator&=(ApplyFlags& lhs, ApplyFlags const& rhs)
{
    lhs = lhs & rhs;
    return lhs;
}
 
//------------------------------------------------------------------------------
 
class ApplyView : public ReadView
{
private:
    std::optional<std::uint64_t>
    dirAdd(
        bool preserveOrder,
        Keylet const& directory,
        uint256 const& key,
        std::function<void(std::shared_ptr<SLE> const&)> const& describe);
 
public:
    ApplyView() = default;
 
    virtual ApplyFlags
    flags() const = 0;
 
    virtual std::shared_ptr<SLE>
    peek(Keylet const& k) = 0;
 
    virtual void
    erase(std::shared_ptr<SLE> const& sle) = 0;
 
    virtual void
    insert(std::shared_ptr<SLE> const& sle) = 0;
 
    virtual void
    update(std::shared_ptr<SLE> const& sle) = 0;
 
    //--------------------------------------------------------------------------
 
    // Called when a credit is made to an account
    // This is required to support PaymentSandbox
    virtual void
    creditHook(
        AccountID const& from,
        AccountID const& to,
        STAmount const& amount,
        STAmount const& preCreditBalance)
    {
    }
 
    // Called when the owner count changes
    // This is required to support PaymentSandbox
    virtual void
    adjustOwnerCountHook(
        AccountID const& account,
        std::uint32_t cur,
        std::uint32_t next)
    {
    }
 
    std::optional<std::uint64_t>
    dirAppend(
        Keylet const& directory,
        Keylet const& key,
        std::function<void(std::shared_ptr<SLE> const&)> const& describe)
    {
        if (key.type != ltOFFER)
        {
            assert(!"Only Offers are appended to book directories.  "
                "Call dirInsert() instead.");
            return std::nullopt;
        }
        return dirAdd(true, directory, key.key, describe);
    }
    std::optional<std::uint64_t>
    dirInsert(
        Keylet const& directory,
        uint256 const& key,
        std::function<void(std::shared_ptr<SLE> const&)> const& describe)
    {
        return dirAdd(false, directory, key, describe);
    }
 
    std::optional<std::uint64_t>
    dirInsert(
        Keylet const& directory,
        Keylet const& key,
        std::function<void(std::shared_ptr<SLE> const&)> const& describe)
    {
        return dirAdd(false, directory, key.key, describe);
    }
    bool
    dirRemove(
        Keylet const& directory,
        std::uint64_t page,
        uint256 const& key,
        bool keepRoot);
 
    bool
    dirRemove(
        Keylet const& directory,
        std::uint64_t page,
        Keylet const& key,
        bool keepRoot)
    {
        return dirRemove(directory, page, key.key, keepRoot);
    }
    bool
    emptyDirDelete(Keylet const& directory);
};
 
}  // namespace ripple
 
#endif