SField.h

#pragma once
 
#include <xrpl/basics/safe_cast.h>
#include <xrpl/json/json_value.h>
#include <xrpl/protocol/Units.h>
 
#include <cstdint>
#include <map>
 
namespace xrpl {
 
/*
 
Some fields have a different meaning for their
    default value versus not present.
        Example:
            QualityIn on a TrustLine
 
*/
 
//------------------------------------------------------------------------------
 
// Forwards
class STAccount;
class STAmount;
class STIssue;
class STBlob;
template <int>
class STBitString;
template <class>
class STInteger;
class STNumber;
class STXChainBridge;
class STVector256;
class STCurrency;
 
#pragma push_macro("XMACRO")
#undef XMACRO
 
#define XMACRO(STYPE)                             \
    /* special types */                           \
    STYPE(STI_UNKNOWN, -2)                        \
    STYPE(STI_NOTPRESENT, 0)                      \
    STYPE(STI_UINT16, 1)                          \
                                                  \
    /* types (common) */                          \
    STYPE(STI_UINT32, 2)                          \
    STYPE(STI_UINT64, 3)                          \
    STYPE(STI_UINT128, 4)                         \
    STYPE(STI_UINT256, 5)                         \
    STYPE(STI_AMOUNT, 6)                          \
    STYPE(STI_VL, 7)                              \
    STYPE(STI_ACCOUNT, 8)                         \
    STYPE(STI_NUMBER, 9)                          \
    STYPE(STI_INT32, 10)                          \
    STYPE(STI_INT64, 11)                          \
                                                  \
    /* 12-13 are reserved */                      \
    STYPE(STI_OBJECT, 14)                         \
    STYPE(STI_ARRAY, 15)                          \
                                                  \
    /* types (uncommon) */                        \
    STYPE(STI_UINT8, 16)                          \
    STYPE(STI_UINT160, 17)                        \
    STYPE(STI_PATHSET, 18)                        \
    STYPE(STI_VECTOR256, 19)                      \
    STYPE(STI_UINT96, 20)                         \
    STYPE(STI_UINT192, 21)                        \
    STYPE(STI_UINT384, 22)                        \
    STYPE(STI_UINT512, 23)                        \
    STYPE(STI_ISSUE, 24)                          \
    STYPE(STI_XCHAIN_BRIDGE, 25)                  \
    STYPE(STI_CURRENCY, 26)                       \
                                                  \
    /* high-level types */                        \
    /* cannot be serialized inside other types */ \
    STYPE(STI_TRANSACTION, 10001)                 \
    STYPE(STI_LEDGERENTRY, 10002)                 \
    STYPE(STI_VALIDATION, 10003)                  \
    STYPE(STI_METADATA, 10004)
 
#pragma push_macro("TO_ENUM")
#undef TO_ENUM
#pragma push_macro("TO_MAP")
#undef TO_MAP
 
#define TO_ENUM(name, value) name = value,
#define TO_MAP(name, value) {#name, value},
 
enum SerializedTypeID { XMACRO(TO_ENUM) };
 
static std::map<std::string, int> const sTypeMap = {XMACRO(TO_MAP)};
 
#undef XMACRO
#undef TO_ENUM
 
#pragma pop_macro("XMACRO")
#pragma pop_macro("TO_ENUM")
#pragma pop_macro("TO_MAP")
 
// constexpr
inline int
field_code(SerializedTypeID id, int index)
{
    return (safe_cast<int>(id) << 16) | index;
}
 
// constexpr
inline int
field_code(int id, int index)
{
    return (id << 16) | index;
}
 
class SField
{
public:
    enum {
        sMD_Never = 0x00,
        sMD_ChangeOrig = 0x01,     // original value when it changes
        sMD_ChangeNew = 0x02,      // new value when it changes
        sMD_DeleteFinal = 0x04,    // final value when it is deleted
        sMD_Create = 0x08,         // value when it's created
        sMD_Always = 0x10,         // value when node containing it is affected at all
        sMD_BaseTen = 0x20,        // value is treated as base 10, overriding behavior
        sMD_PseudoAccount = 0x40,  // if this field is set in an ACCOUNT_ROOT
                                   // _only_, then it is a pseudo-account
        sMD_NeedsAsset = 0x80,     // This field needs to be associated with an
                                   // asset before it is serialized as a ledger
                                   // object. Intended for STNumber.
        sMD_Default = sMD_ChangeOrig | sMD_ChangeNew | sMD_DeleteFinal | sMD_Create
    };
 
    enum class IsSigning : unsigned char { no, yes };
    static IsSigning const notSigning = IsSigning::no;
 
    int const fieldCode;               // (type<<16)|index
    SerializedTypeID const fieldType;  // STI_*
    int const fieldValue;              // Code number for protocol
    std::string const fieldName;
    int const fieldMeta;
    int const fieldNum;
    IsSigning const signingField;
    Json::StaticString const jsonName;
 
    SField(SField const&) = delete;
    SField&
    operator=(SField const&) = delete;
    SField(SField&&) = delete;
    SField&
    operator=(SField&&) = delete;
 
public:
    struct private_access_tag_t;  // public, but still an implementation detail
 
    // These constructors can only be called from SField.cpp
    SField(
        private_access_tag_t,
        SerializedTypeID tid,
        int fv,
        char const* fn,
        int meta = sMD_Default,
        IsSigning signing = IsSigning::yes);
    explicit SField(private_access_tag_t, int fc, char const* fn);
 
    static SField const&
    getField(int fieldCode);
    static SField const&
    getField(std::string const& fieldName);
    static SField const&
    getField(int type, int value)
    {
        return getField(field_code(type, value));
    }
 
    static SField const&
    getField(SerializedTypeID type, int value)
    {
        return getField(field_code(type, value));
    }
 
    std::string const&
    getName() const
    {
        return fieldName;
    }
 
    bool
    hasName() const
    {
        return fieldCode > 0;
    }
 
    Json::StaticString const&
    getJsonName() const
    {
        return jsonName;
    }
 
    operator Json::StaticString const&() const
    {
        return jsonName;
    }
 
    bool
    isInvalid() const
    {
        return fieldCode == -1;
    }
 
    bool
    isUseful() const
    {
        return fieldCode > 0;
    }
 
    bool
    isBinary() const
    {
        return fieldValue < 256;
    }
 
    // A discardable field is one that cannot be serialized, and
    // should be discarded during serialization,like 'hash'.
    // You cannot serialize an object's hash inside that object,
    // but you can have it in the JSON representation.
    bool
    isDiscardable() const
    {
        return fieldValue > 256;
    }
 
    int
    getCode() const
    {
        return fieldCode;
    }
    int
    getNum() const
    {
        return fieldNum;
    }
    static int
    getNumFields()
    {
        return num;
    }
 
    bool
    shouldMeta(int c) const
    {
        return (fieldMeta & c) != 0;
    }
 
    bool
    shouldInclude(bool withSigningField) const
    {
        return (fieldValue < 256) && (withSigningField || (signingField == IsSigning::yes));
    }
 
    bool
    operator==(SField const& f) const
    {
        return fieldCode == f.fieldCode;
    }
 
    bool
    operator!=(SField const& f) const
    {
        return fieldCode != f.fieldCode;
    }
 
    static int
    compare(SField const& f1, SField const& f2);
 
    static std::unordered_map<int, SField const*> const&
    getKnownCodeToField()
    {
        return knownCodeToField;
    }
 
private:
    static int num;
    static std::unordered_map<int, SField const*> knownCodeToField;
    static std::unordered_map<std::string, SField const*> knownNameToField;
};
 
template <class T>
struct TypedField : SField
{
    using type = T;
 
    template <class... Args>
    explicit TypedField(private_access_tag_t pat, Args&&... args);
};
 
template <class T>
struct OptionaledField
{
    TypedField<T> const* f;
 
    explicit OptionaledField(TypedField<T> const& f_) : f(&f_)
    {
    }
};
 
template <class T>
inline OptionaledField<T>
operator~(TypedField<T> const& f)
{
    return OptionaledField<T>(f);
}
 
//------------------------------------------------------------------------------
 
//------------------------------------------------------------------------------
 
using SF_UINT8 = TypedField<STInteger<std::uint8_t>>;
using SF_UINT16 = TypedField<STInteger<std::uint16_t>>;
using SF_UINT32 = TypedField<STInteger<std::uint32_t>>;
using SF_UINT64 = TypedField<STInteger<std::uint64_t>>;
using SF_UINT96 = TypedField<STBitString<96>>;
using SF_UINT128 = TypedField<STBitString<128>>;
using SF_UINT160 = TypedField<STBitString<160>>;
using SF_UINT192 = TypedField<STBitString<192>>;
using SF_UINT256 = TypedField<STBitString<256>>;
using SF_UINT384 = TypedField<STBitString<384>>;
using SF_UINT512 = TypedField<STBitString<512>>;
 
using SF_INT32 = TypedField<STInteger<std::int32_t>>;
using SF_INT64 = TypedField<STInteger<std::int64_t>>;
 
using SF_ACCOUNT = TypedField<STAccount>;
using SF_AMOUNT = TypedField<STAmount>;
using SF_ISSUE = TypedField<STIssue>;
using SF_CURRENCY = TypedField<STCurrency>;
using SF_NUMBER = TypedField<STNumber>;
using SF_VL = TypedField<STBlob>;
using SF_VECTOR256 = TypedField<STVector256>;
using SF_XCHAIN_BRIDGE = TypedField<STXChainBridge>;
 
//------------------------------------------------------------------------------
 
// Use macros for most SField construction to enforce naming conventions.
#pragma push_macro("UNTYPED_SFIELD")
#undef UNTYPED_SFIELD
#pragma push_macro("TYPED_SFIELD")
#undef TYPED_SFIELD
 
#define UNTYPED_SFIELD(sfName, stiSuffix, fieldValue, ...) extern SField const sfName;
#define TYPED_SFIELD(sfName, stiSuffix, fieldValue, ...) extern SF_##stiSuffix const sfName;
 
extern SField const sfInvalid;
extern SField const sfGeneric;
 
#include <xrpl/protocol/detail/sfields.macro>
 
#undef TYPED_SFIELD
#pragma pop_macro("TYPED_SFIELD")
#undef UNTYPED_SFIELD
#pragma pop_macro("UNTYPED_SFIELD")
 
}  // namespace xrpl