boxtec
/
bitcoin
mirror of https://github.com/bitcoin/bitcoin
4
1
Fork 0
Code Issues Projects Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from 'master'
${ noResults }
bitcoin/src/serialize.h

1188 lines
40 KiB
Raw Permalink Blame History

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 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> // IWYU pragma: keep
#include <compat/endian.h>
#include <prevector.h>
#include <span.h>
#include <algorithm>
#include <concepts>
#include <cstdint>
#include <cstring>
#include <ios>
#include <limits>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include <vector>
/**
* The maximum size of a serialized object in bytes or number of elements
* (for eg vectors) when the size is encoded as CompactSize.
*/
static constexpr uint64_t MAX_SIZE = 0x02000000;
/** Maximum amount of memory (in bytes) to allocate at once when deserializing vectors. */
static const unsigned int MAX_VECTOR_ALLOCATE = 5000000;
/**
* Dummy data type to identify deserializing constructors.
*
* By convention, a constructor of a type T with signature
*
* template <typename Stream> T::T(deserialize_type, Stream& s)
*
* is a deserializing constructor, which builds the type by
* deserializing it from s. If T contains const fields, this
* is likely the only way to do so.
*/
struct deserialize_type {};
constexpr deserialize_type deserialize {};
/*
* Lowest-level serialization and conversion.
*/
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);
}
class SizeComputer;
/**
* Convert any argument to a reference to X, maintaining constness.
*
* This can be used in serialization code to invoke a base class's
* serialization routines.
*
* Example use:
* class Base { ... };
* class Child : public Base {
* int m_data;
* public:
* SERIALIZE_METHODS(Child, obj) {
* READWRITE(AsBase<Base>(obj), obj.m_data);
* }
* };
*
* static_cast cannot easily be used here, as the type of Obj will be const Child&
* during serialization and Child& during deserialization. AsBase will convert to
* const Base& and Base& appropriately.
*/
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(...) (ser_action.SerReadWriteMany(s, __VA_ARGS__))
#define SER_READ(obj, code) ser_action.SerRead(s, obj, [&](Stream& s, typename std::remove_const<Type>::type& obj) { code; })
#define SER_WRITE(obj, code) ser_action.SerWrite(s, obj, [&](Stream& s, const Type& obj) { code; })
/**
* Implement the Ser and Unser methods needed for implementing a formatter (see Using below).
*
* Both Ser and Unser are delegated to a single static method SerializationOps, which is polymorphic
* in the serialized/deserialized type (allowing it to be const when serializing, and non-const when
* deserializing).
*
* Example use:
* struct FooFormatter {
* FORMATTER_METHODS(Class, obj) { READWRITE(obj.val1, VARINT(obj.val2)); }
* }
* would define a class FooFormatter that defines a serialization of Class objects consisting
* of serializing its val1 member using the default serialization, and its val2 member using
* VARINT serialization. That FooFormatter can then be used in statements like
* READWRITE(Using<FooFormatter>(obj.bla)).
*/
#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)
/**
* Variant of FORMATTER_METHODS that supports a declared parameter type.
*
* If a formatter has a declared parameter type, it must be invoked directly or
* indirectly with a parameter of that type. This permits making serialization
* depend on run-time context in a type-safe way.
*
* Example use:
* struct BarParameter { bool fancy; ... };
* struct Bar { ... };
* struct FooFormatter {
* FORMATTER_METHODS(Bar, obj, BarParameter, param) {
* if (param.fancy) {
* READWRITE(VARINT(obj.value));
* } else {
* READWRITE(obj.value);
* }
* }
* };
* which would then be invoked as
* READWRITE(BarParameter{...}(Using<FooFormatter>(obj.foo)))
*
* parameter(obj) can be invoked anywhere in the call stack; it is
* passed down recursively into all serialization code, until another
* serialization parameter overrides it.
*
* Parameters will be implicitly converted where appropriate. This means that
* "parent" serialization code can use a parameter that derives from, or is
* convertible to, a "child" formatter's parameter type.
*
* Compilation will fail in any context where serialization is invoked but
* no parameter of a type convertible to BarParameter is provided.
*/
#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); \
}
/**
* Implement the Serialize and Unserialize methods by delegating to a single templated
* static method that takes the to-be-(de)serialized object as a parameter. This approach
* has the advantage that the constness of the object becomes a template parameter, and
* thus allows a single implementation that sees the object as const for serializing
* and non-const for deserializing, without casts.
*/
#define SERIALIZE_METHODS(cls, obj) \
BASE_SERIALIZE_METHODS(cls) \
FORMATTER_METHODS(cls, obj)
/**
* Variant of SERIALIZE_METHODS that supports a declared parameter type.
*
* See FORMATTER_METHODS_PARAMS for more information on parameters.
*/
#define SERIALIZE_METHODS_PARAMS(cls, obj, paramcls, paramobj) \
BASE_SERIALIZE_METHODS(cls) \
FORMATTER_METHODS_PARAMS(cls, obj, paramcls, paramobj)
// 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>)
//
// clang-format off
// 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>;
template <typename Stream, CharNotInt8 V> void Serialize(Stream&, V) = delete; // char serialization forbidden. Use uint8_t or int8_t
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, BasicByte B, int N> void Serialize(Stream& s, const B (&a)[N]) { 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)); }
template <typename Stream, CharNotInt8 V> void Unserialize(Stream&, V) = delete; // char serialization forbidden. Use uint8_t or int8_t
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, BasicByte B, int N> void Unserialize(Stream& s, B (&a)[N]) { s.read(MakeWritableByteSpan(a)); }
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)); }
template <typename Stream> inline void Serialize(Stream& s, bool a) { uint8_t f = a; ser_writedata8(s, f); }
template <typename Stream> inline void Unserialize(Stream& s, bool& a) { uint8_t f = ser_readdata8(s); a = f; }
// clang-format on
/**
* Compact Size
* size < 253 -- 1 byte
* size <= USHRT_MAX -- 3 bytes (253 + 2 bytes)
* size <= UINT_MAX -- 5 bytes (254 + 4 bytes)
* size > UINT_MAX -- 9 bytes (255 + 8 bytes)
*/
constexpr 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(SizeComputer& 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;
}
/**
* Decode a CompactSize-encoded variable-length integer.
*
* As these are primarily used to encode the size of vector-like serializations, by default a range
* check is performed. When used as a generic number encoding, range_check should be set to false.
*/
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;
}
/**
* Variable-length integers: bytes are a MSB base-128 encoding of the number.
* The high bit in each byte signifies whether another digit follows. To make
* sure the encoding is one-to-one, one is subtracted from all but the last digit.
* Thus, the byte sequence a[] with length len, where all but the last byte
* has bit 128 set, encodes the number:
*
* (a[len-1] & 0x7F) + sum(i=1..len-1, 128^i*((a[len-i-1] & 0x7F)+1))
*
* Properties:
* * Very small (0-127: 1 byte, 128-16511: 2 bytes, 16512-2113663: 3 bytes)
* * Every integer has exactly one encoding
* * Encoding does not depend on size of original integer type
* * No redundancy: every (infinite) byte sequence corresponds to a list
* of encoded integers.
*
* 0: [0x00] 256: [0x81 0x00]
* 1: [0x01] 16383: [0xFE 0x7F]
* 127: [0x7F] 16384: [0xFF 0x00]
* 128: [0x80 0x00] 16511: [0xFF 0x7F]
* 255: [0x80 0x7F] 65535: [0x82 0xFE 0x7F]
* 2^32: [0x8E 0xFE 0xFE 0xFF 0x00]
*/
/**
* Mode for encoding VarInts.
*
* Currently there is no support for signed encodings. The default mode will not
* compile with signed values, and the legacy "nonnegative signed" mode will
* accept signed values, but improperly encode and decode them if they are
* negative. In the future, the DEFAULT mode could be extended to support
* negative numbers in a backwards compatible way, and additional modes could be
* added to support different varint formats (e.g. zigzag encoding).
*/
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(SizeComputer& 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;
}
}
}
/** Simple wrapper class to serialize objects using a formatter; used by Using(). */
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); }
};
/** Cause serialization/deserialization of an object to be done using a specified formatter class.
*
* To use this, you need a class Formatter that has public functions Ser(stream, const object&) for
* serialization, and Unser(stream, object&) for deserialization. Serialization routines (inside
* READWRITE, or directly with << and >> operators), can then use Using<Formatter>(object).
*
* This works by constructing a Wrapper<Formatter, T>-wrapped version of object, where T is
* const during serialization, and non-const during deserialization, which maintains const
* correctness.
*/
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)
/** Serialization wrapper class for integers in VarInt format. */
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);
}
};
/** Serialization wrapper class for custom integers and enums.
*
* It permits specifying the serialized size (1 to 8 bytes) and endianness.
*
* Use the big endian mode for values that are stored in memory in native
* byte order, but serialized in big endian notation. This is only intended
* to implement serializers that are compatible with existing formats, and
* its use is not recommended for new data structures.
*/
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(AsBytes(Span{&raw, 1}).last(Bytes));
} else {
uint64_t raw = htole64_internal(v);
s.write(AsBytes(Span{&raw, 1}).first(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(AsWritableBytes(Span{&raw, 1}).last(Bytes));
v = static_cast<I>(be64toh_internal(raw));
} else {
s.read(AsWritableBytes(Span{&raw, 1}).first(Bytes));
v = static_cast<I>(le64toh_internal(raw));
}
}
};
template<int Bytes> using BigEndianFormatter = CustomUintFormatter<Bytes, true>;
/** Formatter for integers in CompactSize format. */
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>;
class CompactSizeWriter
{
protected:
uint64_t n;
public:
explicit CompactSizeWriter(uint64_t n_in) : n(n_in) { }
template<typename Stream>
void Serialize(Stream &s) const {
WriteCompactSize<Stream>(s, n);
}
};
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;
}
};
/** Formatter to serialize/deserialize vector elements using another formatter
*
* Example:
* struct X {
* std::vector<uint64_t> v;
* SERIALIZE_METHODS(X, obj) { READWRITE(Using<VectorFormatter<VarInt>>(obj.v)); }
* };
* will define a struct that contains a vector of uint64_t, which is serialized
* as a vector of VarInt-encoded integers.
*
* V is not required to be an std::vector type. It works for any class that
* exposes a value_type, size, reserve, emplace_back, back, and const iterators.
*/
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());
}
}
};
};
/**
* Forward declarations
*/
/**
* string
*/
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);
/**
* prevector
*/
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);
/**
* vector
*/
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);
/**
* pair
*/
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);
/**
* map
*/
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);
/**
* set
*/
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);
/**
* shared_ptr
*/
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);
/**
* unique_ptr
*/
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);
/**
* If none of the specialized versions above matched, default to calling member function.
*/
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);
}
/** Default formatter. Serializes objects as themselves.
*
* The vector/prevector serialization code passes this to VectorFormatter
* to enable reusing that logic. It shouldn't be needed elsewhere.
*/
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); }
};
/**
* string
*/
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)
{
unsigned int nSize = ReadCompactSize(is);
str.resize(nSize);
if (nSize != 0)
is.read(MakeWritableByteSpan(str));
}
/**
* prevector
*/
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();
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(AsWritableBytes(Span{&v[i], blk}));
i += blk;
}
} else {
Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v));
}
}
/**
* vector
*/
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();
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(AsWritableBytes(Span{&v[i], blk}));
i += blk;
}
} else {
Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v));
}
}
/**
* pair
*/
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);
}
/**
* map
*/
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);
}
}
/**
* set
*/
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);
}
}
/**
* unique_ptr
*/
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));
}
/**
* shared_ptr
*/
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);
}
/**
* Support for (un)serializing many things at once
*/
template <typename Stream, typename... Args>
void SerializeMany(Stream& s, const Args&... args)
{
(::Serialize(s, args), ...);
}
template <typename Stream, typename... Args>
inline void UnserializeMany(Stream& s, Args&&... args)
{
(::Unserialize(s, args), ...);
}
/**
* Support for all macros providing or using the ser_action parameter of the SerializationOps method.
*/
struct ActionSerialize {
static constexpr bool ForRead() { return false; }
template<typename Stream, typename... Args>
static void SerReadWriteMany(Stream& s, const Args&... args)
{
::SerializeMany(s, args...);
}
template<typename Stream, typename Type, typename Fn>
static void SerRead(Stream& s, Type&&, Fn&&)
{
}
template<typename Stream, typename Type, typename Fn>
static void SerWrite(Stream& s, Type&& obj, Fn&& fn)
{
fn(s, std::forward<Type>(obj));
}
};
struct ActionUnserialize {
static constexpr bool ForRead() { return true; }
template<typename Stream, typename... Args>
static void SerReadWriteMany(Stream& s, Args&&... args)
{
::UnserializeMany(s, args...);
}
template<typename Stream, typename Type, typename Fn>
static void SerRead(Stream& s, Type&& obj, Fn&& fn)
{
fn(s, std::forward<Type>(obj));
}
template<typename Stream, typename Type, typename Fn>
static void SerWrite(Stream& s, Type&&, Fn&&)
{
}
};
/* ::GetSerializeSize implementations
*
* Computing the serialized size of objects is done through a special stream
* object of type SizeComputer, 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
* SizeComputer, which uses the s.seek() method to record bytes that would
* be written instead.
*/
class SizeComputer
{
protected:
size_t nSize{0};
public:
SizeComputer() {}
void write(Span<const std::byte> src)
{
this->nSize += src.size();
}
/** Pretend _nSize bytes are written, without specifying them. */
void seek(size_t _nSize)
{
this->nSize += _nSize;
}
template<typename T>
SizeComputer& operator<<(const T& obj)
{
::Serialize(*this, obj);
return (*this);
}
size_t size() const {
return nSize;
}
};
template<typename I>
inline void WriteVarInt(SizeComputer &s, I n)
{
s.seek(GetSizeOfVarInt<I>(n));
}
inline void WriteCompactSize(SizeComputer &s, uint64_t nSize)
{
s.seek(GetSizeOfCompactSize(nSize));
}
template <typename T>
size_t GetSerializeSize(const T& t)
{
return (SizeComputer() << t).size();
}
/** Wrapper that overrides the GetParams() function of a stream (and hides GetVersion/GetType). */
template <typename Params, typename SubStream>
class ParamsStream
{
const Params& m_params;
SubStream& m_substream; // private to avoid leaking version/type into serialization code that shouldn't see it
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; }
int GetVersion() = delete; // Deprecated with Params usage
int GetType() = delete; // Deprecated with Params usage
};
/** Wrapper that serializes objects with the specified parameters. */
template <typename Params, typename T>
class ParamsWrapper
{
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);
}
};
/**
* Helper macro for SerParams structs
*
* Allows you define SerParams instances and then apply them directly
* to an object via function call syntax, eg:
*
* constexpr SerParams FOO{....};
* ss << FOO(obj);
*/
#define SER_PARAMS_OPFUNC \
/** \
* Return a wrapper around t that (de)serializes it with specified parameter params. \
* \
* See FORMATTER_METHODS_PARAMS for more information on serialization parameters. \
*/ \
template <typename T> \
auto operator()(T&& t) const \
{ \
return ParamsWrapper{*this, t}; \
}
#endif // BITCOIN_SERIALIZE_H
Reference in new issue View Git Blame Copy Permalink