Bitcoin Core  22.99.0
P2P Digital Currency
generic_common_impl.h
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1 /**********************************************************************
2  * Copyright (c) 2018 Pieter Wuille, Greg Maxwell, Gleb Naumenko *
3  * Distributed under the MIT software license, see the accompanying *
4  * file LICENSE or http://www.opensource.org/licenses/mit-license.php.*
5  **********************************************************************/
6 
7 #ifndef _MINISKETCH_FIELDS_GENERIC_COMMON_IMPL_H_
8 #define _MINISKETCH_FIELDS_GENERIC_COMMON_IMPL_H_ 1
9 
10 #include <stdint.h>
11 
12 #include "../int_utils.h"
13 #include "../lintrans.h"
14 
15 namespace {
16 
18 template<typename I, int B, uint32_t MOD, typename F, typename T, const F* SQR, const F* QRT> class Field
19 {
20  typedef BitsInt<I, B> O;
21  typedef LFSR<O, MOD> L;
22 
23 public:
24  typedef I Elem;
25  constexpr int Bits() const { return B; }
26 
27  constexpr inline Elem Mul2(Elem val) const { return L::Call(val); }
28 
29  class Multiplier
30  {
31  T table;
32  public:
33  explicit Multiplier(const Field&, Elem a) { table.template Build<L::Call>(a); }
34  constexpr inline Elem operator()(Elem a) const { return table.template Map<O>(a); }
35  };
36 
37  Elem Mul(Elem a, Elem b) const { return GFMul<I, B, L, O>(a, b); }
38 
40  inline constexpr Elem Sqr(Elem a) const { return SQR->template Map<O>(a); }
41 
43  inline constexpr Elem Qrt(Elem a) const { return QRT->template Map<O>(a); }
44 
46  Elem Inv(Elem a) const { return InvExtGCD<I, O, B, MOD>(a); }
47 
49  Elem FromSeed(uint64_t seed) const {
50  uint64_t k0 = 0x496e744669656c64ull; // "IntField"
51  uint64_t k1 = seed;
52  uint64_t count = ((uint64_t)B) << 32;
53  Elem ret;
54  do {
55  ret = O::Mask(I(SipHash(k0, k1, count++)));
56  } while(ret == 0);
57  return ret;
58  }
59 
60  Elem Deserialize(BitReader& in) const { return in.template Read<B, I>(); }
61 
62  void Serialize(BitWriter& out, Elem val) const { out.template Write<B, I>(val); }
63 
64  constexpr Elem FromUint64(uint64_t x) const { return O::Mask(I(x)); }
65  constexpr uint64_t ToUint64(Elem val) const { return uint64_t(val); }
66 };
67 
68 }
69 
70 #endif
BitReader
Definition: int_utils.h:89
BitsInt::Mask
static constexpr I Mask(I val)
Definition: int_utils.h:178
count
static int count
Definition: tests.c:41
SipHash
uint64_t SipHash(uint64_t k0, uint64_t k1, uint64_t data)
Definition: int_utils.h:32
BitWriter
Definition: int_utils.h:52
LFSR
Class which implements a stateless LFSR for generic moduli.
Definition: int_utils.h:210
Sqr
void Sqr(std::vector< typename F::Elem > &poly, const F &field)
Square a polynomial.
Definition: sketch_impl.h:92
LFSR::Call
static constexpr I Call(const I &a)
Shift a value a up once, treating it as an N-bit LFSR, with pattern MOD.
Definition: int_utils.h:213
B
#define B
Definition: util_tests.cpp:1397
ByteUnit::T
@ T
k1
static const unsigned char k1[32]
Definition: chacha_poly_aead.cpp:19
Serialize
void Serialize(Stream &s, char a)
Definition: serialize.h:199
BitsInt
Definition: int_utils.h:160