serialize.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin developers
// Copyright (c) 2015-2021 The PIVX Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef PIVX_SERIALIZE_H
#define PIVX_SERIALIZE_H
 
#include <algorithm>
#include <array>
#include <assert.h>
#include <cstring>
#include <cstdint>
#include <ios>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <set>
#include <string.h>
#include <string>
#include <utility>
#include <vector>
 
#include "compat/endian.h"
#include "libzerocoin/Denominations.h"
#include "libzerocoin/SpendType.h"
#include "optional.h"
#include "prevector.h"
#include "span.h"
#include "sporkid.h"
 
class CScript;
 
static constexpr uint64_t MAX_SIZE = 0x02000000;
 
static const unsigned int MAX_VECTOR_ALLOCATE = 5000000;
 
struct deserialize_type {};
constexpr deserialize_type deserialize {};
 
template <typename T>
inline T& REF(const T& val)
{
    return const_cast<T&>(val);
}
 
inline char* CharCast(char* c) { return c; }
inline char* CharCast(unsigned char* c) { return (char*)c; }
inline const char* CharCast(const char* c) { return c; }
inline const char* CharCast(const unsigned char* c) { return (const char*)c; }
 
/*
 * Lowest-level serialization and conversion.
 * @note Sizes of these types are verified in the tests
 */
template<typename Stream> inline void ser_writedata8(Stream &s, uint8_t obj)
{
    s.write((char*)&obj, 1);
}
template<typename Stream> inline void ser_writedata16(Stream &s, uint16_t obj)
{
    obj = htole16(obj);
    s.write((char*)&obj, 2);
}
template<typename Stream> inline void ser_writedata16be(Stream &s, uint16_t obj)
{
    obj = htobe16(obj);
    s.write((char*)&obj, 2);
}
template<typename Stream> inline void ser_writedata32(Stream &s, uint32_t obj)
{
    obj = htole32(obj);
    s.write((char*)&obj, 4);
}
template<typename Stream> inline void ser_writedata64(Stream &s, uint64_t obj)
{
    obj = htole64(obj);
    s.write((char*)&obj, 8);
}
template<typename Stream> inline uint8_t ser_readdata8(Stream &s)
{
    uint8_t obj;
    s.read((char*)&obj, 1);
    return obj;
}
template<typename Stream> inline uint16_t ser_readdata16(Stream &s)
{
    uint16_t obj;
    s.read((char*)&obj, 2);
    return le16toh(obj);
}
template<typename Stream> inline uint16_t ser_readdata16be(Stream &s)
{
    uint16_t obj;
    s.read((char*)&obj, 2);
    return be16toh(obj);
}
template<typename Stream> inline uint32_t ser_readdata32(Stream &s)
{
    uint32_t obj;
    s.read((char*)&obj, 4);
    return le32toh(obj);
}
template<typename Stream> inline uint64_t ser_readdata64(Stream &s)
{
    uint64_t obj;
    s.read((char*)&obj, 8);
    return le64toh(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(char*, size_t) and .write(char*, size_t)
//
 
class CSizeComputer;
 
enum {
    // primary actions
    SER_NETWORK = (1 << 0),
    SER_DISK = (1 << 1),
    SER_GETHASH = (1 << 2),
};
 
template<typename X> X& ReadWriteAsHelper(X& x) { return x; }
template<typename X> const X& ReadWriteAsHelper(const X& x) { return x; }
 
#define READWRITE(...) (::SerReadWriteMany(s, ser_action, __VA_ARGS__))
#define READWRITEAS(type, obj) (::SerReadWriteMany(s, ser_action, ReadWriteAsHelper<type>(obj)))
#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, CSerActionSerialize()); } \
    template<typename Stream> \
    static void Unser(Stream& s, cls& obj) { SerializationOps(obj, s, CSerActionUnserialize()); } \
    template<typename Stream, typename Type, typename Operation> \
    static inline void SerializationOps(Type& obj, Stream& s, Operation ser_action) \
 
#define SERIALIZE_METHODS(cls, obj)                                                 \
    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);                                                            \
    }                                                                               \
    FORMATTER_METHODS(cls, obj)
 
/*
 * Basic Types
 */
template<typename Stream> inline void Serialize(Stream& s, char a    ) { ser_writedata8(s, a); } // TODO Get rid of bare char
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, int N> inline void Serialize(Stream& s, const char (&a)[N]) { s.write(a, N); }
template<typename Stream, int N> inline void Serialize(Stream& s, const unsigned char (&a)[N]) { s.write(CharCast(a), N); }
template<typename Stream> inline void Serialize(Stream& s, const Span<const unsigned char>& span) { s.write(CharCast(span.data()), span.size()); }
template<typename Stream> inline void Serialize(Stream& s, const Span<unsigned char>& span) { s.write(CharCast(span.data()), span.size()); }
 
template<typename Stream> inline void Unserialize(Stream& s, char& a    ) { a = ser_readdata8(s); } // TODO Get rid of bare char
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, int N> inline void Unserialize(Stream& s, char (&a)[N]) { s.read(a, N); }
template<typename Stream, int N> inline void Unserialize(Stream& s, unsigned char (&a)[N]) { s.read(CharCast(a), N); }
template<typename Stream> inline void Unserialize(Stream& s, Span<unsigned char>& span) { s.read(CharCast(span.data()), span.size()); }
 
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; }
 
// Serializatin for libzerocoin::CoinDenomination
template <typename Stream>
inline void Serialize(Stream& s, libzerocoin::CoinDenomination a)
{
    int f = libzerocoin::ZerocoinDenominationToInt(a);
    ser_writedata32(s, f);
}
 
template <typename Stream>
inline void Unserialize(Stream& s, libzerocoin::CoinDenomination& a)
{
    int f = ser_readdata32(s);
    a = libzerocoin::IntToZerocoinDenomination(f);
}
 
// Serialization for libzerocoin::SpendType
template <typename Stream>
inline void Serialize(Stream& s, libzerocoin::SpendType a)
{
    uint8_t f = static_cast<uint8_t>(a);
    ser_writedata8(s, f);
}
 
template <typename Stream>
inline void Unserialize(Stream& s, libzerocoin::SpendType & a)
{
    uint8_t f = ser_readdata8(s);
    a = static_cast<libzerocoin::SpendType>(f);
}
 
// Serialization for SporkId
template <typename Stream>
inline void Serialize(Stream& s, SporkId sporkID)
{
    int32_t f = static_cast<int32_t>(sporkID);
    ser_writedata32(s, f);
}
 
template <typename Stream>
inline void Unserialize(Stream& s, SporkId& sporkID)
{
    int32_t f = ser_readdata32(s);
    sporkID = (SporkId) f;
}
 
 
inline unsigned int GetSizeOfCompactSize(uint64_t nSize)
{
    if (nSize < 253)             return sizeof(unsigned char);
    else if (nSize <= std::numeric_limits<uint16_t>::max()) return sizeof(unsigned char) + sizeof(uint16_t);
    else if (nSize <= std::numeric_limits<unsigned int>::max())  return sizeof(unsigned char) + sizeof(unsigned int);
    else                         return sizeof(unsigned char) + 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<unsigned int>::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)
            break;
        n = (n >> 7) - 1;
    }
    return nRet;
}
 
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>();
    unsigned char 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) {
        unsigned char 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) {
            if (n == std::numeric_limits<I>::max()) {
                throw std::ios_base::failure("ReadVarInt(): size too large");
            }
            n++;
        } else {
            return 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);
    }
};
 
#define FIXEDBITSET(obj, size) Using<BitSetFormatter<size>>(obj)
#define DYNBITSET(obj) Using<BitSetFormatter<0>>(obj)
#define FIXEDVARINTSBITSET(obj, size) REF(CFixedVarIntsBitSet(REF(obj), (size)))
#define AUTOBITSET(obj, size) REF(CAutoBitSet(REF(obj), (size)))
 
/* Formatter for fixed (size N), or dynamic (size 0) bitsets */
 
template<size_t N>
struct BitSetFormatter
{
    template<typename Stream>
    void Ser(Stream& s, const std::vector<bool>& vec)
    {
        size_t size = (N == 0 ? vec.size() : N);
        if (N == 0) {
            WriteCompactSize(s, size);
        }
        std::vector<unsigned char> vBytes((size + 7) / 8);
        size_t ms = std::min(size, vec.size());
        for (size_t p = 0; p < ms; p++)
            vBytes[p / 8] |= vec[p] << (p % 8);
        s.write((char*)vBytes.data(), vBytes.size());
    }
 
    template<typename Stream>
    void Unser(Stream& s, std::vector<bool>& vec)
    {
        size_t size = (N == 0 ? ReadCompactSize(s) : N);
        vec.resize(size);
        std::vector<unsigned char> vBytes((size + 7) / 8);
        s.read((char*)vBytes.data(), vBytes.size());
        for (size_t p = 0; p < size; p++)
            vec[p] = (vBytes[p / 8] & (1 << (p % 8))) != 0;
        if (vBytes.size() * 8 != size) {
            size_t rem = vBytes.size() * 8 - size;
            uint8_t m = ~(uint8_t)(0xff >> rem);
            if (vBytes[vBytes.size() - 1] & m) {
                throw std::ios_base::failure("Out-of-range bits set");
            }
        }
    }
};
 
class CFixedVarIntsBitSet
{
protected:
    std::vector<bool>& vec;
    size_t size;
 
public:
    CFixedVarIntsBitSet(std::vector<bool>& vecIn, size_t sizeIn) : vec(vecIn), size(sizeIn) {}
 
    template <typename Stream>
    void Serialize(Stream& s) const
    {
        int32_t last = -1;
        for (int32_t i = 0; i < (int32_t)vec.size(); i++) {
            if (vec[i]) {
                WriteVarInt<Stream, VarIntMode::DEFAULT, uint32_t>(s, (uint32_t)(i - last));
                last = i;
            }
        }
        WriteVarInt<Stream, VarIntMode::DEFAULT, uint32_t>(s, 0); // stopper
    }
 
    template <typename Stream>
    void Unserialize(Stream& s)
    {
        vec.assign(size, false);
 
        int32_t last = -1;
        while (true) {
            uint32_t offset = ReadVarInt<Stream, VarIntMode::DEFAULT, uint32_t>(s);
            if (offset == 0) {
                break;
            }
            int32_t idx = last + offset;
            if (idx >= size) {
                throw std::ios_base::failure("out of bounds index");
            }
            if (last != -1 && idx <= last) {
                throw std::ios_base::failure("offset overflow");
            }
            vec[idx] = true;
            last = idx;
        }
    }
};
 
class CAutoBitSet
{
protected:
    std::vector<bool>& vec;
    size_t size;
 
public:
    explicit CAutoBitSet(std::vector<bool>& vecIn, size_t sizeIn) : vec(vecIn), size(sizeIn) {}
 
    template <typename Stream>
    void Serialize(Stream& s) const
    {
        assert(vec.size() == size);
 
        ser_writedata8(s, 0);
        s << FIXEDVARINTSBITSET(vec, vec.size());
    }
 
    template <typename Stream>
    void Unserialize(Stream& s)
    {
        uint8_t isVarInts = ser_readdata8(s);
        if (isVarInts != 0) {
            throw std::ios_base::failure("invalid value for isVarInts byte");
        }
        s >> FIXEDVARINTSBITSET(vec, size);
    }
};
 
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(v);
            s.write(((const char*)&raw) + 8 - Bytes, Bytes);
        } else {
            uint64_t raw = htole64(v);
            s.write((const char*)&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(((char*)&raw) + 8 - Bytes, Bytes);
            v = static_cast<I>(be64toh(raw));
        } else {
            s.read((char*)&raw, Bytes);
            v = static_cast<I>(le64toh(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<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((char*)v.data(), size);
    }
 
    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());
            }
        }
    };
};
 
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> void Serialize_impl(Stream& os, const prevector<N, T>& v, const unsigned char&);
template<typename Stream, unsigned int N, typename T, typename V> void Serialize_impl(Stream& os, const prevector<N, T>& v, const V&);
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> void Unserialize_impl(Stream& is, prevector<N, T>& v, const unsigned char&);
template<typename Stream, unsigned int N, typename T, typename V> void Unserialize_impl(Stream& is, prevector<N, T>& v, const 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> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const unsigned char&);
template<typename Stream, typename T, typename A> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const bool&);
template<typename Stream, typename T, typename A, typename V> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const 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> void Unserialize_impl(Stream& is, std::vector<T, A>& v, const unsigned char&);
template<typename Stream, typename T, typename A, typename V> void Unserialize_impl(Stream& is, std::vector<T, A>& v, const V&);
template<typename Stream, typename T, typename A> inline void Unserialize(Stream& is, std::vector<T, A>& v);
 
template<typename T, std::size_t N> unsigned int GetSerializeSize(const std::array<T, N> &item);
template<typename Stream, typename T, std::size_t N> void Serialize(Stream& os, const std::array<T, N>& item);
template<typename Stream, typename T, std::size_t N> void Unserialize(Stream& is, std::array<T, N>& item);
 
template<typename T> unsigned int GetSerializeSize(const Optional<T> &item);
template<typename Stream, typename T> void Serialize(Stream& os, const Optional<T>& item);
template<typename Stream, typename T> void Unserialize(Stream& is, Optional<T>& item);
 
template<typename T, std::size_t N>
unsigned int GetSerializeSize(const std::array<T, N> &item)
{
    unsigned int size = 0;
    for (size_t i = 0; i < N; i++) {
        size += GetSerializeSize(item[0]);
    }
    return size;
}
 
template<typename Stream, typename T>
void Serialize(Stream& os, const Optional<T>& item)
{
    // If the value is there, put 0x01 and then serialize the value.
    // If it's not, put 0x00.
    if (item) {
        unsigned char discriminant = 0x01;
        Serialize(os, discriminant);
        Serialize(os, *item);
    } else {
        unsigned char discriminant = 0x00;
        Serialize(os, discriminant);
    }
}
 
template<typename Stream, typename T>
void Unserialize(Stream& is, Optional<T>& item)
{
    unsigned char discriminant = 0x00;
    Unserialize(is, discriminant);
 
    if (discriminant == 0x00) {
        item = boost::none;
    } else {
        T object;
        Unserialize(is, object);
        item = object;
    }
}
 
 
template<typename Stream, typename T, std::size_t N>
void Serialize(Stream& os, const std::array<T, N>& item)
{
    for (size_t i = 0; i < N; i++) {
        Serialize(os, item[i]);
    }
}
 
template<typename Stream, typename T, std::size_t N>
void Unserialize(Stream& is, std::array<T, N>& item)
{
    for (size_t i = 0; i < N; i++) {
        Unserialize(is, item[i]);
    }
}
 
 
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... Elements> void Serialize(Stream& os, const std::tuple<Elements...>& item);
template<typename Stream, typename... Elements> void Unserialize(Stream& is, std::tuple<Elements...>& 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::shared_ptr<T>& p);
template<typename Stream, typename T> void Unserialize(Stream& os, std::shared_ptr<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>
inline void Serialize(Stream& os, const T& a)
{
    a.Serialize(os);
}
 
template<typename Stream, typename T>
inline 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((char*)str.data(), str.size() * sizeof(C));
}
 
template <typename Stream, typename C>
void Unserialize(Stream& is, std::basic_string<C>& str)
{
    unsigned int nSize = ReadCompactSize(is);
    str.resize(nSize);
    if (nSize != 0)
        is.read((char*)str.data(), nSize * sizeof(C));
}
 
template<typename T, typename A> unsigned int GetSerializeSize(const std::list<T, A>& m);
template<typename Stream, typename T, typename A> void Serialize(Stream& os, const std::list<T, A>& m);
template<typename Stream, typename T, typename A> void Unserialize(Stream& is, std::list<T, A>& m);
 
template<typename T, typename A>
unsigned int GetSerializeSize(const std::list<T, A>& l)
{
    unsigned int nSize = GetSizeOfCompactSize(l.size());
    for (typename std::list<T, A>::const_iterator it = l.begin(); it != l.end(); ++it)
        nSize += GetSerializeSize((*it));
    return nSize;
}
 
template<typename Stream, typename T, typename A>
void Serialize(Stream& os, const std::list<T, A>& l)
{
    WriteCompactSize(os, l.size());
    for (typename std::list<T, A>::const_iterator it = l.begin(); it != l.end(); ++it)
        Serialize(os, (*it));
}
 
template<typename Stream, typename T, typename A>
void Unserialize(Stream& is, std::list<T, A>& l)
{
    l.clear();
    unsigned int nSize = ReadCompactSize(is);
    for (unsigned int i = 0; i < nSize; i++)
    {
        T item;
        Unserialize(is, item);
        l.push_back(item);
    }
}
 
 
template<typename Stream, unsigned int N, typename T>
void Serialize_impl(Stream& os, const prevector<N, T>& v, const unsigned char&)
{
    WriteCompactSize(os, v.size());
    if (!v.empty())
        os.write((char*)v.data(), v.size() * sizeof(T));
}
 
template<typename Stream, unsigned int N, typename T, typename V>
void Serialize_impl(Stream& os, const prevector<N, T>& v, const V&)
{
    Serialize(os, Using<VectorFormatter<DefaultFormatter>>(v));
}
 
template<typename Stream, unsigned int N, typename T>
inline void Serialize(Stream& os, const prevector<N, T>& v)
{
    Serialize_impl(os, v, T());
}
 
 
template<typename Stream, unsigned int N, typename T>
void Unserialize_impl(Stream& is, prevector<N, T>& v, const unsigned char&)
{
    // Limit size per read so bogus size value won't cause out of memory
    v.clear();
    unsigned int nSize = ReadCompactSize(is);
    unsigned int i = 0;
    while (i < nSize)
    {
        unsigned int blk = std::min(nSize - i, (unsigned int)(1 + 4999999 / sizeof(T)));
        v.resize_uninitialized(i + blk);
        is.read((char*)&v[i], blk * sizeof(T));
        i += blk;
    }
}
 
template<typename Stream, unsigned int N, typename T, typename V>
void Unserialize_impl(Stream& is, prevector<N, T>& v, const V&)
{
    Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v));
}
 
template<typename Stream, unsigned int N, typename T>
inline void Unserialize(Stream& is, prevector<N, T>& v)
{
    Unserialize_impl(is, v, T());
}
 
 
 
template <typename Stream, typename T, typename A>
void Serialize_impl(Stream& os, const std::vector<T, A>& v, const unsigned char&)
{
    WriteCompactSize(os, v.size());
    if (!v.empty())
        os.write((char*)v.data(), v.size() * sizeof(T));
}
 
template <typename Stream, typename T, typename A>
void Serialize_impl(Stream& os, const std::vector<T, A>& v, const 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);
    }
}
 
template <typename Stream, typename T, typename A, typename V>
void Serialize_impl(Stream& os, const std::vector<T, A>& v, const V&)
{
    Serialize(os, Using<VectorFormatter<DefaultFormatter>>(v));
}
 
template <typename Stream, typename T, typename A>
inline void Serialize(Stream& os, const std::vector<T, A>& v)
{
    Serialize_impl(os, v, T());
}
 
 
template <typename Stream, typename T, typename A>
void Unserialize_impl(Stream& is, std::vector<T, A>& v, const unsigned char&)
{
    // Limit size per read so bogus size value won't cause out of memory
    v.clear();
    unsigned int nSize = ReadCompactSize(is);
    unsigned int i = 0;
    while (i < nSize) {
        unsigned int blk = std::min(nSize - i, (unsigned int)(1 + 4999999 / sizeof(T)));
        v.resize(i + blk);
        is.read((char*)&v[i], blk * sizeof(T));
        i += blk;
    }
}
 
template <typename Stream, typename T, typename A, typename V>
void Unserialize_impl(Stream& is, std::vector<T, A>& v, const V&)
{
    Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v));
}
 
template <typename Stream, typename T, typename A>
inline void Unserialize(Stream& is, std::vector<T, A>& v)
{
    Unserialize_impl(is, v, T());
}
 
 
 
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, int index, typename... Ts>
struct SerializeTuple {
    void operator() (Stream&s, std::tuple<Ts...>& t) {
        SerializeTuple<Stream, index - 1, Ts...>{}(s, t);
        s << std::get<index>(t);
    }
};
 
template<typename Stream, typename... Ts>
struct SerializeTuple<Stream, 0, Ts...> {
    void operator() (Stream&s, std::tuple<Ts...>& t) {
        s << std::get<0>(t);
    }
};
 
template<typename Stream, int index, typename... Ts>
struct DeserializeTuple {
    void operator() (Stream&s, std::tuple<Ts...>& t) {
        DeserializeTuple<Stream, index - 1, Ts...>{}(s, t);
        s >> std::get<index>(t);
    }
};
 
template<typename Stream, typename... Ts>
struct DeserializeTuple<Stream, 0, Ts...> {
    void operator() (Stream&s, std::tuple<Ts...>& t) {
        s >> std::get<0>(t);
    }
};
 
 
template<typename Stream, typename... Elements>
void Serialize(Stream& os, const std::tuple<Elements...>& item)
{
    const auto size = std::tuple_size<std::tuple<Elements...>>::value;
    SerializeTuple<Stream, size - 1, Elements...>{}(os, const_cast<std::tuple<Elements...>&>(item));
}
 
template<typename Stream, typename... Elements>
void Unserialize(Stream& is, std::tuple<Elements...>& item)
{
    const auto size = std::tuple_size<std::tuple<Elements...>>::value;
    DeserializeTuple<Stream, size - 1, Elements...>{}(is, item);
}
 
 
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();
    unsigned int nSize = ReadCompactSize(is);
    typename std::map<K, T, Pred, A>::iterator mi = m.begin();
    for (unsigned int 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 (typename std::set<K, Pred, A>::const_iterator it = m.begin(); it != m.end(); ++it)
        Serialize(os, (*it));
}
 
template <typename Stream, typename K, typename Pred, typename A>
void Unserialize(Stream& is, std::set<K, Pred, A>& m)
{
    m.clear();
    unsigned int nSize = ReadCompactSize(is);
    typename std::set<K, Pred, A>::iterator it = m.begin();
    for (unsigned int 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 std::shared_ptr<T>& p)
{
    Serialize(os, *p);
}
 
template<typename Stream, typename T>
void Unserialize(Stream& is, std::shared_ptr<T>& p)
{
    p = std::make_shared<T>(deserialize, is);
}
 
struct CSerActionSerialize {
    constexpr bool ForRead() const { return false; }
};
struct CSerActionUnserialize {
    constexpr bool ForRead() const { return true; }
};
 
 
/* ::GetSerializeSize implementations
 *
 * Computing the serialized size of objects is done through a special stream
 * object of type CSizeComputer, which only records the number of bytes written
 * to it.
 *
 * If your Serialize or SerializationOp method has non-trivial overhead for
 * serialization, it may be worthwhile to implement a specialized version for
 * CSizeComputer, which uses the s.seek() method to record bytes that would
 * be written instead.
 */
class CSizeComputer
{
protected:
    size_t nSize;
 
    const int nVersion;
 
public:
    explicit CSizeComputer(int nVersionIn) : nSize(0), nVersion(nVersionIn) {}
 
    void write(const char* psz, size_t _nSize)
    {
        this->nSize += _nSize;
    }
 
    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, CSerActionSerialize ser_action, const Args&... args)
{
    ::SerializeMany(s, args...);
}
 
template<typename Stream, typename... Args>
inline void SerReadWriteMany(Stream& s, CSerActionUnserialize ser_action, Args&&... args)
{
    ::UnserializeMany(s, args...);
}
 
template<typename Stream, typename Type, typename Fn>
inline void SerRead(Stream& s, CSerActionSerialize ser_action, Type&&, Fn&&)
{
}
 
template<typename Stream, typename Type, typename Fn>
inline void SerRead(Stream& s, CSerActionUnserialize ser_action, Type&& obj, Fn&& fn)
{
    fn(s, std::forward<Type>(obj));
}
 
template<typename Stream, typename Type, typename Fn>
inline void SerWrite(Stream& s, CSerActionSerialize ser_action, Type&& obj, Fn&& fn)
{
    fn(s, std::forward<Type>(obj));
}
 
template<typename Stream, typename Type, typename Fn>
inline void SerWrite(Stream& s, CSerActionUnserialize 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 T>
unsigned int GetSerializeSize(const Optional<T> &item)
{
    if (item) {
        return 1 + GetSerializeSize(*item);
    } else {
        return 1;
    }
}
 
#endif // PIVX_SERIALIZE_H