serialize.h

Go to the documentation of this file.

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef BITCOIN_SERIALIZE_H
#define BITCOIN_SERIALIZE_H
 
#include <attributes.h>
#include <compat/assumptions.h>
#include <compat/endian.h>
#include <prevector.h>
#include <rcu.h>
#include <span.h>
 
#include <algorithm>
#include <array>
#include <concepts>
#include <cstdint>
#include <cstring>
#include <ios>
#include <limits>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include <vector>
 
static constexpr uint64_t MAX_SIZE = 0x02000000;
 
static const unsigned int MAX_VECTOR_ALLOCATE = 5000000;
 
struct deserialize_type {};
constexpr deserialize_type deserialize{};
 
template <typename Stream> inline void ser_writedata8(Stream &s, uint8_t obj) {
    s.write(AsBytes(Span{&obj, 1}));
}
template <typename Stream>
inline void ser_writedata16(Stream &s, uint16_t obj) {
    obj = htole16_internal(obj);
    s.write(AsBytes(Span{&obj, 1}));
}
template <typename Stream>
inline void ser_writedata16be(Stream &s, uint16_t obj) {
    obj = htobe16_internal(obj);
    s.write(AsBytes(Span{&obj, 1}));
}
template <typename Stream>
inline void ser_writedata32(Stream &s, uint32_t obj) {
    obj = htole32_internal(obj);
    s.write(AsBytes(Span{&obj, 1}));
}
template <typename Stream>
inline void ser_writedata32be(Stream &s, uint32_t obj) {
    obj = htobe32_internal(obj);
    s.write(AsBytes(Span{&obj, 1}));
}
template <typename Stream>
inline void ser_writedata64(Stream &s, uint64_t obj) {
    obj = htole64_internal(obj);
    s.write(AsBytes(Span{&obj, 1}));
}
template <typename Stream> inline uint8_t ser_readdata8(Stream &s) {
    uint8_t obj;
    s.read(AsWritableBytes(Span{&obj, 1}));
    return obj;
}
template <typename Stream> inline uint16_t ser_readdata16(Stream &s) {
    uint16_t obj;
    s.read(AsWritableBytes(Span{&obj, 1}));
    return le16toh_internal(obj);
}
template <typename Stream> inline uint16_t ser_readdata16be(Stream &s) {
    uint16_t obj;
    s.read(AsWritableBytes(Span{&obj, 1}));
    return be16toh_internal(obj);
}
template <typename Stream> inline uint32_t ser_readdata32(Stream &s) {
    uint32_t obj;
    s.read(AsWritableBytes(Span{&obj, 1}));
    return le32toh_internal(obj);
}
template <typename Stream> inline uint32_t ser_readdata32be(Stream &s) {
    uint32_t obj;
    s.read(AsWritableBytes(Span{&obj, 1}));
    return be32toh_internal(obj);
}
template <typename Stream> inline uint64_t ser_readdata64(Stream &s) {
    uint64_t obj;
    s.read(AsWritableBytes(Span{&obj, 1}));
    return le64toh_internal(obj);
}
inline uint64_t ser_double_to_uint64(double x) {
    uint64_t tmp;
    std::memcpy(&tmp, &x, sizeof(x));
    static_assert(sizeof(tmp) == sizeof(x),
                  "double and uint64_t assumed to have the same size");
    return tmp;
}
inline uint32_t ser_float_to_uint32(float x) {
    uint32_t tmp;
    std::memcpy(&tmp, &x, sizeof(x));
    static_assert(sizeof(tmp) == sizeof(x),
                  "float and uint32_t assumed to have the same size");
    return tmp;
}
inline double ser_uint64_to_double(uint64_t y) {
    double tmp;
    std::memcpy(&tmp, &y, sizeof(y));
    static_assert(sizeof(tmp) == sizeof(y),
                  "double and uint64_t assumed to have the same size");
    return tmp;
}
inline float ser_uint32_to_float(uint32_t y) {
    float tmp;
    std::memcpy(&tmp, &y, sizeof(y));
    static_assert(sizeof(tmp) == sizeof(y),
                  "float and uint32_t assumed to have the same size");
    return tmp;
}
 
//
// Templates for serializing to anything that looks like a stream,
// i.e. anything that supports .read(Span<std::byte>) and .write(Span<const
// std::byte>)
//
class CSizeComputer;
 
enum {
    // primary actions
    SER_NETWORK = (1 << 0),
    SER_DISK = (1 << 1),
    SER_GETHASH = (1 << 2),
};
 
template <class Out, class In> Out &AsBase(In &x) {
    static_assert(std::is_base_of_v<Out, In>);
    return x;
}
template <class Out, class In> const Out &AsBase(const In &x) {
    static_assert(std::is_base_of_v<Out, In>);
    return x;
}
 
#define READWRITE(...) (::SerReadWriteMany(s, ser_action, __VA_ARGS__))
#define SER_READ(obj, code)                                                    \
    ::SerRead(                                                                 \
        s, ser_action, obj,                                                    \
        [&](Stream &s, typename std::remove_const<Type>::type &obj) { code; })
#define SER_WRITE(obj, code)                                                   \
    ::SerWrite(s, ser_action, obj, [&](Stream &s, const Type &obj) { code; })
 
#define FORMATTER_METHODS(cls, obj)                                            \
    template <typename Stream> static void Ser(Stream &s, const cls &obj) {    \
        SerializationOps(obj, s, ActionSerialize());                           \
    }                                                                          \
    template <typename Stream> static void Unser(Stream &s, cls &obj) {        \
        SerializationOps(obj, s, ActionUnserialize());                         \
    }                                                                          \
    template <typename Stream, typename Type, typename Operation>              \
    static void SerializationOps(Type &obj, Stream &s, Operation ser_action)
 
#define FORMATTER_METHODS_PARAMS(cls, obj, paramcls, paramobj)                 \
    template <typename Stream> static void Ser(Stream &s, const cls &obj) {    \
        SerializationOps(obj, s, ActionSerialize{}, s.GetParams());            \
    }                                                                          \
    template <typename Stream> static void Unser(Stream &s, cls &obj) {        \
        SerializationOps(obj, s, ActionUnserialize{}, s.GetParams());          \
    }                                                                          \
    template <typename Stream, typename Type, typename Operation>              \
    static void SerializationOps(Type &obj, Stream &s, Operation ser_action,   \
                                 const paramcls &paramobj)
 
#define BASE_SERIALIZE_METHODS(cls)                                            \
    template <typename Stream> void Serialize(Stream &s) const {               \
        static_assert(std::is_same<const cls &, decltype(*this)>::value,       \
                      "Serialize type mismatch");                              \
        Ser(s, *this);                                                         \
    }                                                                          \
    template <typename Stream> void Unserialize(Stream &s) {                   \
        static_assert(std::is_same<cls &, decltype(*this)>::value,             \
                      "Unserialize type mismatch");                            \
        Unser(s, *this);                                                       \
    }
 
#define SERIALIZE_METHODS(cls, obj)                                            \
    BASE_SERIALIZE_METHODS(cls)                                                \
    FORMATTER_METHODS(cls, obj)
 
#define SERIALIZE_METHODS_PARAMS(cls, obj, paramcls, paramobj)                 \
    BASE_SERIALIZE_METHODS(cls)                                                \
    FORMATTER_METHODS_PARAMS(cls, obj, paramcls, paramobj)
 
// Typically int8_t and char are distinct types, but some systems may define
// int8_t in terms of char. Forbid serialization of char in the typical case,
// but allow it if it's the only way to describe an int8_t.
template <class T>
concept CharNotInt8 = std::same_as<T, char> && !std::same_as<T, int8_t>;
 
// char serialization forbidden. Use uint8_t or int8_t
template <typename Stream, CharNotInt8 V> void Serialize(Stream &, V) = delete;
template <typename Stream> void Serialize(Stream &s, std::byte a) {
    ser_writedata8(s, uint8_t(a));
}
template <typename Stream> inline void Serialize(Stream &s, int8_t a) {
    ser_writedata8(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, uint8_t a) {
    ser_writedata8(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, int16_t a) {
    ser_writedata16(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, uint16_t a) {
    ser_writedata16(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, int32_t a) {
    ser_writedata32(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, uint32_t a) {
    ser_writedata32(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, int64_t a) {
    ser_writedata64(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, uint64_t a) {
    ser_writedata64(s, a);
}
template <typename Stream> inline void Serialize(Stream &s, float a) {
    ser_writedata32(s, ser_float_to_uint32(a));
}
template <typename Stream> inline void Serialize(Stream &s, double a) {
    ser_writedata64(s, ser_double_to_uint64(a));
}
template <typename Stream, size_t N>
inline void Serialize(Stream &s, const int8_t (&a)[N]) {
    s.write(a, N);
}
template <typename Stream, BasicByte B, size_t N>
void Serialize(Stream &s, const B (&a)[N]) {
    s.write(MakeByteSpan(a));
}
template <typename Stream, size_t N>
inline void Serialize(Stream &s, const std::array<int8_t, N> &a) {
    s.write(a.data(), N);
}
template <typename Stream, size_t N>
inline void Serialize(Stream &s, const std::array<uint8_t, N> &a) {
    s.write(MakeByteSpan(a));
}
template <typename Stream, BasicByte B, std::size_t N>
void Serialize(Stream &s, const std::array<B, N> &a) {
    s.write(MakeByteSpan(a));
}
template <typename Stream, BasicByte B>
void Serialize(Stream &s, Span<B> span) {
    s.write(AsBytes(span));
}
 
// char serialization forbidden. Use uint8_t or int8_t
template <typename Stream, CharNotInt8 V>
void Unserialize(Stream &, V) = delete;
template <typename Stream> void Unserialize(Stream &s, std::byte &a) {
    a = std::byte{ser_readdata8(s)};
}
template <typename Stream> inline void Unserialize(Stream &s, int8_t &a) {
    a = ser_readdata8(s);
}
template <typename Stream> inline void Unserialize(Stream &s, uint8_t &a) {
    a = ser_readdata8(s);
}
template <typename Stream> inline void Unserialize(Stream &s, int16_t &a) {
    a = ser_readdata16(s);
}
template <typename Stream> inline void Unserialize(Stream &s, uint16_t &a) {
    a = ser_readdata16(s);
}
template <typename Stream> inline void Unserialize(Stream &s, int32_t &a) {
    a = ser_readdata32(s);
}
template <typename Stream> inline void Unserialize(Stream &s, uint32_t &a) {
    a = ser_readdata32(s);
}
template <typename Stream> inline void Unserialize(Stream &s, int64_t &a) {
    a = ser_readdata64(s);
}
template <typename Stream> inline void Unserialize(Stream &s, uint64_t &a) {
    a = ser_readdata64(s);
}
template <typename Stream> inline void Unserialize(Stream &s, float &a) {
    a = ser_uint32_to_float(ser_readdata32(s));
}
template <typename Stream> inline void Unserialize(Stream &s, double &a) {
    a = ser_uint64_to_double(ser_readdata64(s));
}
template <typename Stream, size_t N>
inline void Unserialize(Stream &s, int8_t (&a)[N]) {
    s.read(MakeWritableByteSpan(a));
}
template <typename Stream, BasicByte B, size_t N>
void Unserialize(Stream &s, B (&a)[N]) {
    s.read(MakeWritableByteSpan(a));
}
 
template <typename Stream> inline void Serialize(Stream &s, bool a) {
    char f = a;
    ser_writedata8(s, f);
}
template <typename Stream> inline void Unserialize(Stream &s, bool &a) {
    char f = ser_readdata8(s);
    a = f;
}
template <typename Stream, BasicByte B, std::size_t N>
void Unserialize(Stream &s, std::array<B, N> &a) {
    s.read(MakeWritableByteSpan(a));
}
template <typename Stream, BasicByte B>
void Unserialize(Stream &s, Span<B> span) {
    s.read(AsWritableBytes(span));
}
 
inline uint32_t GetSizeOfCompactSize(uint64_t nSize) {
    if (nSize < 253) {
        return sizeof(uint8_t);
    }
    if (nSize <= std::numeric_limits<uint16_t>::max()) {
        return sizeof(uint8_t) + sizeof(uint16_t);
    }
    if (nSize <= std::numeric_limits<uint32_t>::max()) {
        return sizeof(uint8_t) + sizeof(uint32_t);
    }
 
    return sizeof(uint8_t) + sizeof(uint64_t);
}
 
inline void WriteCompactSize(CSizeComputer &os, uint64_t nSize);
 
template <typename Stream> void WriteCompactSize(Stream &os, uint64_t nSize) {
    if (nSize < 253) {
        ser_writedata8(os, nSize);
    } else if (nSize <= std::numeric_limits<uint16_t>::max()) {
        ser_writedata8(os, 253);
        ser_writedata16(os, nSize);
    } else if (nSize <= std::numeric_limits<uint32_t>::max()) {
        ser_writedata8(os, 254);
        ser_writedata32(os, nSize);
    } else {
        ser_writedata8(os, 255);
        ser_writedata64(os, nSize);
    }
    return;
}
 
template <typename Stream>
uint64_t ReadCompactSize(Stream &is, bool range_check = true) {
    uint8_t chSize = ser_readdata8(is);
    uint64_t nSizeRet = 0;
    if (chSize < 253) {
        nSizeRet = chSize;
    } else if (chSize == 253) {
        nSizeRet = ser_readdata16(is);
        if (nSizeRet < 253) {
            throw std::ios_base::failure("non-canonical ReadCompactSize()");
        }
    } else if (chSize == 254) {
        nSizeRet = ser_readdata32(is);
        if (nSizeRet < 0x10000u) {
            throw std::ios_base::failure("non-canonical ReadCompactSize()");
        }
    } else {
        nSizeRet = ser_readdata64(is);
        if (nSizeRet < 0x100000000ULL) {
            throw std::ios_base::failure("non-canonical ReadCompactSize()");
        }
    }
    if (range_check && nSizeRet > MAX_SIZE) {
        throw std::ios_base::failure("ReadCompactSize(): size too large");
    }
    return nSizeRet;
}
 
enum class VarIntMode { DEFAULT, NONNEGATIVE_SIGNED };
 
template <VarIntMode Mode, typename I> struct CheckVarIntMode {
    constexpr CheckVarIntMode() {
        static_assert(Mode != VarIntMode::DEFAULT || std::is_unsigned<I>::value,
                      "Unsigned type required with mode DEFAULT.");
        static_assert(Mode != VarIntMode::NONNEGATIVE_SIGNED ||
                          std::is_signed<I>::value,
                      "Signed type required with mode NONNEGATIVE_SIGNED.");
    }
};
 
template <VarIntMode Mode, typename I>
inline unsigned int GetSizeOfVarInt(I n) {
    CheckVarIntMode<Mode, I>();
    int nRet = 0;
    while (true) {
        nRet++;
        if (n <= 0x7F) {
            return nRet;
        }
        n = (n >> 7) - 1;
    }
}
 
template <typename I> inline void WriteVarInt(CSizeComputer &os, I n);
 
template <typename Stream, VarIntMode Mode, typename I>
void WriteVarInt(Stream &os, I n) {
    CheckVarIntMode<Mode, I>();
    uint8_t tmp[(sizeof(n) * 8 + 6) / 7];
    int len = 0;
    while (true) {
        tmp[len] = (n & 0x7F) | (len ? 0x80 : 0x00);
        if (n <= 0x7F) {
            break;
        }
        n = (n >> 7) - 1;
        len++;
    }
    do {
        ser_writedata8(os, tmp[len]);
    } while (len--);
}
 
template <typename Stream, VarIntMode Mode, typename I>
I ReadVarInt(Stream &is) {
    CheckVarIntMode<Mode, I>();
    I n = 0;
    while (true) {
        uint8_t chData = ser_readdata8(is);
        if (n > (std::numeric_limits<I>::max() >> 7)) {
            throw std::ios_base::failure("ReadVarInt(): size too large");
        }
        n = (n << 7) | (chData & 0x7F);
        if ((chData & 0x80) == 0) {
            return n;
        }
        if (n == std::numeric_limits<I>::max()) {
            throw std::ios_base::failure("ReadVarInt(): size too large");
        }
        n++;
    }
}
 
template <typename Formatter, typename T> class Wrapper {
    static_assert(std::is_lvalue_reference<T>::value,
                  "Wrapper needs an lvalue reference type T");
 
protected:
    T m_object;
 
public:
    explicit Wrapper(T obj) : m_object(obj) {}
    template <typename Stream> void Serialize(Stream &s) const {
        Formatter().Ser(s, m_object);
    }
    template <typename Stream> void Unserialize(Stream &s) {
        Formatter().Unser(s, m_object);
    }
};
 
template <typename Formatter, typename T>
static inline Wrapper<Formatter, T &> Using(T &&t) {
    return Wrapper<Formatter, T &>(t);
}
 
#define VARINT_MODE(obj, mode) Using<VarIntFormatter<mode>>(obj)
#define VARINT(obj) Using<VarIntFormatter<VarIntMode::DEFAULT>>(obj)
#define COMPACTSIZE(obj) Using<CompactSizeFormatter<true>>(obj)
#define LIMITED_STRING(obj, n) Using<LimitedStringFormatter<n>>(obj)
 
template <VarIntMode Mode> struct VarIntFormatter {
    template <typename Stream, typename I> void Ser(Stream &s, I v) {
        WriteVarInt<Stream, Mode, typename std::remove_cv<I>::type>(s, v);
    }
 
    template <typename Stream, typename I> void Unser(Stream &s, I &v) {
        v = ReadVarInt<Stream, Mode, typename std::remove_cv<I>::type>(s);
    }
};
 
template <int Bytes, bool BigEndian = false> struct CustomUintFormatter {
    static_assert(Bytes > 0 && Bytes <= 8,
                  "CustomUintFormatter Bytes out of range");
    static constexpr uint64_t MAX = 0xffffffffffffffff >> (8 * (8 - Bytes));
 
    template <typename Stream, typename I> void Ser(Stream &s, I v) {
        if (v < 0 || v > MAX) {
            throw std::ios_base::failure(
                "CustomUintFormatter value out of range");
        }
        if (BigEndian) {
            uint64_t raw = htobe64_internal(v);
            s.write({BytePtr(&raw) + 8 - Bytes, Bytes});
        } else {
            uint64_t raw = htole64_internal(v);
            s.write({BytePtr(&raw), Bytes});
        }
    }
 
    template <typename Stream, typename I> void Unser(Stream &s, I &v) {
        using U = typename std::conditional<std::is_enum<I>::value,
                                            std::underlying_type<I>,
                                            std::common_type<I>>::type::type;
        static_assert(std::numeric_limits<U>::max() >= MAX &&
                          std::numeric_limits<U>::min() <= 0,
                      "Assigned type too small");
        uint64_t raw = 0;
        if (BigEndian) {
            s.read({BytePtr(&raw) + 8 - Bytes, Bytes});
            v = static_cast<I>(be64toh_internal(raw));
        } else {
            s.read({BytePtr(&raw), Bytes});
            v = static_cast<I>(le64toh_internal(raw));
        }
    }
};
 
template <int Bytes>
using BigEndianFormatter = CustomUintFormatter<Bytes, true>;
 
template <bool RangeCheck> struct CompactSizeFormatter {
    template <typename Stream, typename I> void Unser(Stream &s, I &v) {
        uint64_t n = ReadCompactSize<Stream>(s, RangeCheck);
        if (n < std::numeric_limits<I>::min() ||
            n > std::numeric_limits<I>::max()) {
            throw std::ios_base::failure("CompactSize exceeds limit of type");
        }
        v = n;
    }
 
    template <typename Stream, typename I> void Ser(Stream &s, I v) {
        static_assert(std::is_unsigned<I>::value,
                      "CompactSize only supported for unsigned integers");
        static_assert(std::numeric_limits<I>::max() <=
                          std::numeric_limits<uint64_t>::max(),
                      "CompactSize only supports 64-bit integers and below");
 
        WriteCompactSize<Stream>(s, v);
    }
};
 
template <typename U, bool LOSSY = false> struct ChronoFormatter {
    template <typename Stream, typename Tp> void Unser(Stream &s, Tp &tp) {
        U u;
        s >> u;
        // Lossy deserialization does not make sense, so force Wnarrowing
        tp = Tp{typename Tp::duration{typename Tp::duration::rep{u}}};
    }
    template <typename Stream, typename Tp> void Ser(Stream &s, Tp tp) {
        if constexpr (LOSSY) {
            s << U(tp.time_since_epoch().count());
        } else {
            s << U{tp.time_since_epoch().count()};
        }
    }
};
template <typename U> using LossyChronoFormatter = ChronoFormatter<U, true>;
 
template <size_t Limit> struct LimitedStringFormatter {
    template <typename Stream> void Unser(Stream &s, std::string &v) {
        size_t size = ReadCompactSize(s);
        if (size > Limit) {
            throw std::ios_base::failure("String length limit exceeded");
        }
        v.resize(size);
        if (size != 0) {
            s.read(MakeWritableByteSpan(v));
        }
    }
 
    template <typename Stream> void Ser(Stream &s, const std::string &v) {
        s << v;
    }
};
 
template <class Formatter> struct VectorFormatter {
    template <typename Stream, typename V> void Ser(Stream &s, const V &v) {
        Formatter formatter;
        WriteCompactSize(s, v.size());
        for (const typename V::value_type &elem : v) {
            formatter.Ser(s, elem);
        }
    }
 
    template <typename Stream, typename V> void Unser(Stream &s, V &v) {
        Formatter formatter;
        v.clear();
        size_t size = ReadCompactSize(s);
        size_t allocated = 0;
        while (allocated < size) {
            // For DoS prevention, do not blindly allocate as much as the stream
            // claims to contain. Instead, allocate in 5MiB batches, so that an
            // attacker actually needs to provide X MiB of data to make us
            // allocate X+5 Mib.
            static_assert(sizeof(typename V::value_type) <= MAX_VECTOR_ALLOCATE,
                          "Vector element size too large");
            allocated =
                std::min(size, allocated + MAX_VECTOR_ALLOCATE /
                                               sizeof(typename V::value_type));
            v.reserve(allocated);
            while (v.size() < allocated) {
                v.emplace_back();
                formatter.Unser(s, v.back());
            }
        }
    };
};
 
class DifferenceFormatter {
    uint64_t m_shift = 0;
 
public:
    template <typename Stream, typename I> void Ser(Stream &s, I v) {
        if (v < m_shift || v >= std::numeric_limits<uint64_t>::max()) {
            throw std::ios_base::failure("differential value overflow");
        }
        WriteCompactSize(s, v - m_shift);
        m_shift = uint64_t(v) + 1;
    }
    template <typename Stream, typename I> void Unser(Stream &s, I &v) {
        uint64_t n = ReadCompactSize(s);
        m_shift += n;
        if (m_shift < n || m_shift >= std::numeric_limits<uint64_t>::max() ||
            m_shift < std::numeric_limits<I>::min() ||
            m_shift > std::numeric_limits<I>::max()) {
            throw std::ios_base::failure("differential value overflow");
        }
        v = I(m_shift++);
    }
};
 
struct DifferentialIndexedItemFormatter : public DifferenceFormatter {
    template <typename Stream, typename T> void Ser(Stream &s, T v) {
        DifferenceFormatter::Ser(s, v.index);
        v.SerData(s);
    }
 
    template <typename Stream, typename T> void Unser(Stream &s, T &v) {
        DifferenceFormatter::Unser(s, v.index);
        v.UnserData(s);
    }
};
 
template <typename Stream, typename C>
void Serialize(Stream &os, const std::basic_string<C> &str);
template <typename Stream, typename C>
void Unserialize(Stream &is, std::basic_string<C> &str);
 
template <typename Stream, unsigned int N, typename T>
inline void Serialize(Stream &os, const prevector<N, T> &v);
template <typename Stream, unsigned int N, typename T>
inline void Unserialize(Stream &is, prevector<N, T> &v);
 
template <typename Stream, typename T, typename A>
inline void Serialize(Stream &os, const std::vector<T, A> &v);
template <typename Stream, typename T, typename A>
inline void Unserialize(Stream &is, std::vector<T, A> &v);
 
template <typename Stream, typename K, typename T>
void Serialize(Stream &os, const std::pair<K, T> &item);
template <typename Stream, typename K, typename T>
void Unserialize(Stream &is, std::pair<K, T> &item);
 
template <typename Stream, typename K, typename T, typename Pred, typename A>
void Serialize(Stream &os, const std::map<K, T, Pred, A> &m);
template <typename Stream, typename K, typename T, typename Pred, typename A>
void Unserialize(Stream &is, std::map<K, T, Pred, A> &m);
 
template <typename Stream, typename K, typename Pred, typename A>
void Serialize(Stream &os, const std::set<K, Pred, A> &m);
template <typename Stream, typename K, typename Pred, typename A>
void Unserialize(Stream &is, std::set<K, Pred, A> &m);
 
template <typename Stream, typename T>
void Serialize(Stream &os, const std::shared_ptr<const T> &p);
template <typename Stream, typename T>
void Unserialize(Stream &os, std::shared_ptr<const T> &p);
 
template <typename Stream, typename T>
void Serialize(Stream &os, const std::unique_ptr<const T> &p);
template <typename Stream, typename T>
void Unserialize(Stream &os, std::unique_ptr<const T> &p);
 
template <typename Stream, typename T>
void Serialize(Stream &os, const RCUPtr<const T> &p);
template <typename Stream, typename T>
void Unserialize(Stream &os, RCUPtr<const T> &p);
 
template <class T, class Stream>
concept Serializable = requires(T a, Stream s) { a.Serialize(s); };
template <typename Stream, typename T>
    requires Serializable<T, Stream>
void Serialize(Stream &os, const T &a) {
    a.Serialize(os);
}
 
template <class T, class Stream>
concept Unserializable = requires(T a, Stream s) { a.Unserialize(s); };
template <typename Stream, typename T>
    requires Unserializable<T, Stream>
void Unserialize(Stream &is, T &&a) {
    a.Unserialize(is);
}
 
struct DefaultFormatter {
    template <typename Stream, typename T>
    static void Ser(Stream &s, const T &t) {
        Serialize(s, t);
    }
 
    template <typename Stream, typename T> static void Unser(Stream &s, T &t) {
        Unserialize(s, t);
    }
};
 
template <typename Stream, typename C>
void Serialize(Stream &os, const std::basic_string<C> &str) {
    WriteCompactSize(os, str.size());
    if (!str.empty()) {
        os.write(MakeByteSpan(str));
    }
}
 
template <typename Stream, typename C>
void Unserialize(Stream &is, std::basic_string<C> &str) {
    size_t nSize = ReadCompactSize(is);
    str.resize(nSize);
    if (nSize != 0) {
        is.read(MakeWritableByteSpan(str));
    }
}
 
template <typename Stream, unsigned int N, typename T>
void Serialize(Stream &os, const prevector<N, T> &v) {
    if constexpr (BasicByte<T>) {
        // Use optimized version for unformatted basic bytes
        WriteCompactSize(os, v.size());
        if (!v.empty()) os.write(MakeByteSpan(v));
    } else {
        Serialize(os, Using<VectorFormatter<DefaultFormatter>>(v));
    }
}
 
template <typename Stream, unsigned int N, typename T>
void Unserialize(Stream &is, prevector<N, T> &v) {
    if constexpr (BasicByte<T>) {
        // Use optimized version for unformatted basic bytes
        // Limit size per read so bogus size value won't cause out of memory
        v.clear();
        size_t nSize = ReadCompactSize(is);
        size_t i = 0;
        while (i < nSize) {
            size_t blk = std::min(nSize - i, size_t(1 + 4999999 / sizeof(T)));
            v.resize_uninitialized(i + blk);
            is.read(AsWritableBytes(Span{&v[i], blk}));
            i += blk;
        }
    } else {
        Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v));
    }
}
 
template <typename Stream, typename T, typename A>
void Serialize(Stream &os, const std::vector<T, A> &v) {
    if constexpr (BasicByte<T>) {
        // Use optimized version for unformatted basic bytes
        WriteCompactSize(os, v.size());
        if (!v.empty()) {
            os.write(MakeByteSpan(v));
        }
    } else if constexpr (std::is_same_v<T, bool>) {
        // A special case for std::vector<bool>, as dereferencing
        // std::vector<bool>::const_iterator does not result in a const bool&
        // due to std::vector's special casing for bool arguments.
        WriteCompactSize(os, v.size());
        for (bool elem : v) {
            ::Serialize(os, elem);
        }
    } else {
        Serialize(os, Using<VectorFormatter<DefaultFormatter>>(v));
    }
}
 
template <typename Stream, typename T, typename A>
void Unserialize(Stream &is, std::vector<T, A> &v) {
    if constexpr (BasicByte<T>) {
        // Use optimized version for unformatted basic bytes
        // Limit size per read so bogus size value won't cause out of memory
        v.clear();
        size_t nSize = ReadCompactSize(is);
        size_t i = 0;
        while (i < nSize) {
            size_t blk = std::min(nSize - i, size_t(1 + 4999999 / sizeof(T)));
            v.resize(i + blk);
            is.read(AsWritableBytes(Span{&v[i], blk}));
            i += blk;
        }
    } else {
        Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v));
    }
}
 
template <typename Stream, typename K, typename T>
void Serialize(Stream &os, const std::pair<K, T> &item) {
    Serialize(os, item.first);
    Serialize(os, item.second);
}
 
template <typename Stream, typename K, typename T>
void Unserialize(Stream &is, std::pair<K, T> &item) {
    Unserialize(is, item.first);
    Unserialize(is, item.second);
}
 
template <typename Stream, typename K, typename T, typename Pred, typename A>
void Serialize(Stream &os, const std::map<K, T, Pred, A> &m) {
    WriteCompactSize(os, m.size());
    for (const auto &entry : m) {
        Serialize(os, entry);
    }
}
 
template <typename Stream, typename K, typename T, typename Pred, typename A>
void Unserialize(Stream &is, std::map<K, T, Pred, A> &m) {
    m.clear();
    size_t nSize = ReadCompactSize(is);
    typename std::map<K, T, Pred, A>::iterator mi = m.begin();
    for (size_t i = 0; i < nSize; i++) {
        std::pair<K, T> item;
        Unserialize(is, item);
        mi = m.insert(mi, item);
    }
}
 
template <typename Stream, typename K, typename Pred, typename A>
void Serialize(Stream &os, const std::set<K, Pred, A> &m) {
    WriteCompactSize(os, m.size());
    for (const K &i : m) {
        Serialize(os, i);
    }
}
 
template <typename Stream, typename K, typename Pred, typename A>
void Unserialize(Stream &is, std::set<K, Pred, A> &m) {
    m.clear();
    size_t nSize = ReadCompactSize(is);
    typename std::set<K, Pred, A>::iterator it = m.begin();
    for (size_t i = 0; i < nSize; i++) {
        K key;
        Unserialize(is, key);
        it = m.insert(it, key);
    }
}
 
template <typename Stream, typename T>
void Serialize(Stream &os, const std::unique_ptr<const T> &p) {
    Serialize(os, *p);
}
 
template <typename Stream, typename T>
void Unserialize(Stream &is, std::unique_ptr<const T> &p) {
    p.reset(new T(deserialize, is));
}
 
template <typename Stream, typename T>
void Serialize(Stream &os, const std::shared_ptr<const T> &p) {
    Serialize(os, *p);
}
 
template <typename Stream, typename T>
void Unserialize(Stream &is, std::shared_ptr<const T> &p) {
    p = std::make_shared<const T>(deserialize, is);
}
 
template <typename Stream, typename T>
void Serialize(Stream &os, const RCUPtr<const T> &p) {
    Serialize(os, *p);
}
 
template <typename Stream, typename T>
void Unserialize(Stream &is, RCUPtr<const T> &p) {
    p = RCUPtr<const T>::make(deserialize, is);
}
 
struct ActionSerialize {
    constexpr bool ForRead() const { return false; }
};
struct ActionUnserialize {
    constexpr bool ForRead() const { return true; }
};
 
class CSizeComputer {
protected:
    size_t nSize;
 
    const int nVersion;
 
public:
    explicit CSizeComputer(int nVersionIn) : nSize(0), nVersion(nVersionIn) {}
 
    void write(Span<const std::byte> src) { this->nSize += src.size(); }
 
    void seek(size_t _nSize) { this->nSize += _nSize; }
 
    template <typename T> CSizeComputer &operator<<(const T &obj) {
        ::Serialize(*this, obj);
        return (*this);
    }
 
    size_t size() const { return nSize; }
 
    int GetVersion() const { return nVersion; }
};
 
template <typename Stream> void SerializeMany(Stream &s) {}
 
template <typename Stream, typename Arg, typename... Args>
void SerializeMany(Stream &s, const Arg &arg, const Args &...args) {
    ::Serialize(s, arg);
    ::SerializeMany(s, args...);
}
 
template <typename Stream> inline void UnserializeMany(Stream &s) {}
 
template <typename Stream, typename Arg, typename... Args>
inline void UnserializeMany(Stream &s, Arg &&arg, Args &&...args) {
    ::Unserialize(s, arg);
    ::UnserializeMany(s, args...);
}
 
template <typename Stream, typename... Args>
inline void SerReadWriteMany(Stream &s, ActionSerialize ser_action,
                             const Args &...args) {
    ::SerializeMany(s, args...);
}
 
template <typename Stream, typename... Args>
inline void SerReadWriteMany(Stream &s, ActionUnserialize ser_action,
                             Args &&...args) {
    ::UnserializeMany(s, args...);
}
 
template <typename Stream, typename Type, typename Fn>
inline void SerRead(Stream &s, ActionSerialize ser_action, Type &&, Fn &&) {}
 
template <typename Stream, typename Type, typename Fn>
inline void SerRead(Stream &s, ActionUnserialize ser_action, Type &&obj,
                    Fn &&fn) {
    fn(s, std::forward<Type>(obj));
}
 
template <typename Stream, typename Type, typename Fn>
inline void SerWrite(Stream &s, ActionSerialize ser_action, Type &&obj,
                     Fn &&fn) {
    fn(s, std::forward<Type>(obj));
}
 
template <typename Stream, typename Type, typename Fn>
inline void SerWrite(Stream &s, ActionUnserialize ser_action, Type &&, Fn &&) {}
 
template <typename I> inline void WriteVarInt(CSizeComputer &s, I n) {
    s.seek(GetSizeOfVarInt<I>(n));
}
 
inline void WriteCompactSize(CSizeComputer &s, uint64_t nSize) {
    s.seek(GetSizeOfCompactSize(nSize));
}
 
template <typename T> size_t GetSerializeSize(const T &t, int nVersion = 0) {
    return (CSizeComputer(nVersion) << t).size();
}
 
template <typename... T>
size_t GetSerializeSizeMany(int nVersion, const T &...t) {
    CSizeComputer sc(nVersion);
    SerializeMany(sc, t...);
    return sc.size();
}
 
template <typename Params, typename SubStream> class ParamsStream {
    const Params &m_params;
    // private to avoid leaking version/type into serialization code that
    // shouldn't see it
    SubStream &m_substream;
 
public:
    ParamsStream(const Params &params LIFETIMEBOUND,
                 SubStream &substream LIFETIMEBOUND)
        : m_params{params}, m_substream{substream} {}
    template <typename U> ParamsStream &operator<<(const U &obj) {
        ::Serialize(*this, obj);
        return *this;
    }
    template <typename U> ParamsStream &operator>>(U &&obj) {
        ::Unserialize(*this, obj);
        return *this;
    }
    void write(Span<const std::byte> src) { m_substream.write(src); }
    void read(Span<std::byte> dst) { m_substream.read(dst); }
    void ignore(size_t num) { m_substream.ignore(num); }
    bool eof() const { return m_substream.eof(); }
    size_t size() const { return m_substream.size(); }
    const Params &GetParams() const { return m_params; }
    // Deprecated with Params usage
    int GetVersion() = delete;
    // Deprecated with Params usage
    int GetType() = delete;
};
 
template <typename Params, typename T> class ParamsWrapper {
    static_assert(std::is_lvalue_reference<T>::value,
                  "ParamsWrapper needs an lvalue reference type T");
    const Params &m_params;
    T m_object;
 
public:
    explicit ParamsWrapper(const Params &params, T obj)
        : m_params{params}, m_object{obj} {}
 
    template <typename Stream> void Serialize(Stream &s) const {
        ParamsStream ss{m_params, s};
        ::Serialize(ss, m_object);
    }
    template <typename Stream> void Unserialize(Stream &s) {
        ParamsStream ss{m_params, s};
        ::Unserialize(ss, m_object);
    }
};
 
template <typename Params, typename T>
static auto WithParams(const Params &params, T &&t) {
    return ParamsWrapper<Params, T &>{params, t};
}
 
#endif // BITCOIN_SERIALIZE_H