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Merge bitcoin#18112: Convert blockencodings.h to new serialization fr…
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…amework

bitcoin@353f376

Partial bitcoin#18112: Add CustomUintFormatter

bitcoin@e574fff

Partial bitcoin#18112: Add DifferenceFormatter

bitcoin@1063339

Partial bitcoin#18112: Make VectorFormatter support stateful formatters

bitcoin@56dd9f0

Partial bitcoin#18112: Convert CCompactSize to proper formatter

bitcoin@3ca574c
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@kwvg
kwvg committed May 20, 2021
1 parent 5472f8d commit c6a1395
Showing 3 changed files with 86 additions and 129 deletions.
140 changes: 34 additions & 106 deletions src/blockencodings.h
View file
Original file line number Diff line number Diff line change
@@ -11,18 +11,29 @@

class CTxMemPool;

// Dumb helper to handle CTransaction compression at serialize-time
struct TransactionCompressor {
private:
CTransactionRef& tx;
public:
explicit TransactionCompressor(CTransactionRef& txIn) : tx(txIn) {}
// Transaction compression schemes for compact block relay can be introduced by writing
// an actual formatter here.
using TransactionCompression = DefaultFormatter;

ADD_SERIALIZE_METHODS;
class DifferenceFormatter
{
uint64_t m_shift = 0;

template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(tx); //TODO: Compress tx encoding
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++);
}
};

@@ -32,39 +43,9 @@ class BlockTransactionsRequest {
uint256 blockhash;
std::vector<uint16_t> indexes;

ADD_SERIALIZE_METHODS;

template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(blockhash);
uint64_t indexes_size = (uint64_t)indexes.size();
READWRITE(COMPACTSIZE(indexes_size));
if (ser_action.ForRead()) {
size_t i = 0;
while (indexes.size() < indexes_size) {
indexes.resize(std::min((uint64_t)(1000 + indexes.size()), indexes_size));
for (; i < indexes.size(); i++) {
uint64_t index = 0;
READWRITE(COMPACTSIZE(index));
if (index > std::numeric_limits<uint16_t>::max())
throw std::ios_base::failure("index overflowed 16 bits");
indexes[i] = index;
}
}

int32_t offset = 0;
for (size_t j = 0; j < indexes.size(); j++) {
if (int32_t(indexes[j]) + offset > std::numeric_limits<uint16_t>::max())
throw std::ios_base::failure("indexes overflowed 16 bits");
indexes[j] = indexes[j] + offset;
offset = int32_t(indexes[j]) + 1;
}
} else {
for (size_t i = 0; i < indexes.size(); i++) {
uint64_t index = indexes[i] - (i == 0 ? 0 : (indexes[i - 1] + 1));
READWRITE(COMPACTSIZE(index));
}
}
SERIALIZE_METHODS(BlockTransactionsRequest, obj)
{
READWRITE(obj.blockhash, Using<VectorFormatter<DifferenceFormatter>>(obj.indexes));
}
};

@@ -78,24 +59,9 @@ class BlockTransactions {
explicit BlockTransactions(const BlockTransactionsRequest& req) :
blockhash(req.blockhash), txn(req.indexes.size()) {}

ADD_SERIALIZE_METHODS;

template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(blockhash);
uint64_t txn_size = (uint64_t)txn.size();
READWRITE(COMPACTSIZE(txn_size));
if (ser_action.ForRead()) {
size_t i = 0;
while (txn.size() < txn_size) {
txn.resize(std::min((uint64_t)(1000 + txn.size()), txn_size));
for (; i < txn.size(); i++)
READWRITE(TransactionCompressor(txn[i]));
}
} else {
for (size_t i = 0; i < txn.size(); i++)
READWRITE(TransactionCompressor(txn[i]));
}
SERIALIZE_METHODS(BlockTransactions, obj)
{
READWRITE(obj.blockhash, Using<VectorFormatter<TransactionCompression>>(obj.txn));
}
};

@@ -106,17 +72,7 @@ struct PrefilledTransaction {
uint16_t index;
CTransactionRef tx;

ADD_SERIALIZE_METHODS;

template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
uint64_t idx = index;
READWRITE(COMPACTSIZE(idx));
if (idx > std::numeric_limits<uint16_t>::max())
throw std::ios_base::failure("index overflowed 16-bits");
index = idx;
READWRITE(TransactionCompressor(tx));
}
SERIALIZE_METHODS(PrefilledTransaction, obj) { READWRITE(COMPACTSIZE(obj.index), Using<TransactionCompression>(obj.tx)); }
};

typedef enum ReadStatus_t
@@ -154,43 +110,15 @@ class CBlockHeaderAndShortTxIDs {

size_t BlockTxCount() const { return shorttxids.size() + prefilledtxn.size(); }

ADD_SERIALIZE_METHODS;

template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(header);
READWRITE(nonce);

uint64_t shorttxids_size = (uint64_t)shorttxids.size();
READWRITE(COMPACTSIZE(shorttxids_size));
SERIALIZE_METHODS(CBlockHeaderAndShortTxIDs, obj)
{
READWRITE(obj.header, obj.nonce, Using<VectorFormatter<CustomUintFormatter<SHORTTXIDS_LENGTH>>>(obj.shorttxids), obj.prefilledtxn);
if (ser_action.ForRead()) {
size_t i = 0;
while (shorttxids.size() < shorttxids_size) {
shorttxids.resize(std::min((uint64_t)(1000 + shorttxids.size()), shorttxids_size));
for (; i < shorttxids.size(); i++) {
uint32_t lsb = 0; uint16_t msb = 0;
READWRITE(lsb);
READWRITE(msb);
shorttxids[i] = (uint64_t(msb) << 32) | uint64_t(lsb);
static_assert(SHORTTXIDS_LENGTH == 6, "shorttxids serialization assumes 6-byte shorttxids");
}
}
} else {
for (size_t i = 0; i < shorttxids.size(); i++) {
uint32_t lsb = shorttxids[i] & 0xffffffff;
uint16_t msb = (shorttxids[i] >> 32) & 0xffff;
READWRITE(lsb);
READWRITE(msb);
if (obj.BlockTxCount() > std::numeric_limits<uint16_t>::max()) {
throw std::ios_base::failure("indexes overflowed 16 bits");
}
obj.FillShortTxIDSelector();
}

READWRITE(prefilledtxn);

if (BlockTxCount() > std::numeric_limits<uint16_t>::max())
throw std::ios_base::failure("indexes overflowed 16 bits");

if (ser_action.ForRead())
FillShortTxIDSelector();
}
};

9 changes: 7 additions & 2 deletions src/prevector.h
View file
Original file line number Diff line number Diff line change
@@ -452,15 +452,20 @@ class prevector {
return first;
}

void push_back(const T& value) {
template<typename... Args>
void emplace_back(Args&&... args) {
size_type new_size = size() + 1;
if (capacity() < new_size) {
change_capacity(new_size + (new_size >> 1));
}
new(item_ptr(size())) T(value);
new(item_ptr(size())) T(std::forward<Args>(args)...);
_size++;
}

void push_back(const T& value) {
emplace_back(value);
}

void pop_back() {
erase(end() - 1, end());
}
66 changes: 45 additions & 21 deletions src/serialize.h
View file
Original file line number Diff line number Diff line change
@@ -504,7 +504,7 @@ static inline Wrapper<Formatter, T&> Using(T&& t) { return Wrapper<Formatter, T&
#define FIXEDVARINTSBITSET(obj, size) CFixedVarIntsBitSet(REF(obj), (size))
#define AUTOBITSET(obj, size) CAutoBitSet(REF(obj), (size))
#define VARINT(obj, ...) Using<VarIntFormatter<__VA_ARGS__>>(obj)
#define COMPACTSIZE(obj) CCompactSize(REF(obj))
#define COMPACTSIZE(obj) Using<CompactSizeFormatter>(obj)
#define LIMITED_STRING(obj,n) LimitedString< n >(REF(obj))

class CFixedBitSet
@@ -678,6 +678,28 @@ struct VarIntFormatter
}
};

template<int Bytes>
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");
uint64_t raw = htole64(v);
s.write((const char*)&raw, Bytes);
}

template <typename Stream, typename I> void Unser(Stream& s, I& v)
{
static_assert(std::numeric_limits<I>::max() >= MAX && std::numeric_limits<I>::min() <= 0, "CustomUintFormatter type too small");
uint64_t raw = 0;
s.read((char*)&raw, Bytes);
v = le64toh(raw);
}
};

/** Serialization wrapper class for big-endian integers.
*
* Use this wrapper around integer types that are stored in memory in native
@@ -712,25 +734,26 @@ class BigEndian
}
};

class CCompactSize
/** Formatter for integers in CompactSize format. */
struct CompactSizeFormatter
{
protected:
uint64_t &n;
public:
explicit CCompactSize(uint64_t& nIn) : n(nIn) { }

unsigned int GetSerializeSize() const {
return GetSizeOfCompactSize(n);
template<typename Stream, typename I>
void Unser(Stream& s, I& v)
{
uint64_t n = ReadCompactSize<Stream>(s);
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>
void Serialize(Stream &s) const {
WriteCompactSize<Stream>(s, 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");

template<typename Stream>
void Unserialize(Stream& s) {
n = ReadCompactSize<Stream>(s);
WriteCompactSize<Stream>(s, v);
}
};

@@ -777,23 +800,25 @@ BigEndian<I> WrapBigEndian(I& n) { return BigEndian<I>(n); }
* 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, push_back, and const iterators.
* 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) {
s << Using<Formatter>(elem);
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;
@@ -805,9 +830,8 @@ struct VectorFormatter
allocated = std::min(size, allocated + MAX_VECTOR_ALLOCATE / sizeof(typename V::value_type));
v.reserve(allocated);
while (v.size() < allocated) {
typename V::value_type val;
s >> Using<Formatter>(val);
v.push_back(std::move(val));
v.emplace_back();
formatter.Unser(s, v.back());
}
}
};

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