Bitcoin ABC  0.22.13
P2P Digital Currency
blockfilter.h
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1 // Copyright (c) 2018 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_BLOCKFILTER_H
6 #define BITCOIN_BLOCKFILTER_H
7 
8 #include <primitives/block.h>
9 #include <primitives/blockhash.h>
10 #include <serialize.h>
11 #include <uint256.h>
12 #include <undo.h>
13 #include <util/bytevectorhash.h>
14 
15 #include <cstdint>
16 #include <set>
17 #include <string>
18 #include <unordered_set>
19 #include <vector>
20 
25 class GCSFilter {
26 public:
27  typedef std::vector<uint8_t> Element;
28  typedef std::unordered_set<Element, ByteVectorHash> ElementSet;
29 
30  struct Params {
31  uint64_t m_siphash_k0;
32  uint64_t m_siphash_k1;
33  uint8_t m_P;
34  uint32_t m_M;
35 
36  Params(uint64_t siphash_k0 = 0, uint64_t siphash_k1 = 0, uint8_t P = 0,
37  uint32_t M = 1)
38  : m_siphash_k0(siphash_k0), m_siphash_k1(siphash_k1), m_P(P),
39  m_M(M) {}
40  };
41 
42 private:
44  uint32_t m_N;
45  uint64_t m_F;
46  std::vector<uint8_t> m_encoded;
47 
49  uint64_t HashToRange(const Element &element) const;
50 
51  std::vector<uint64_t> BuildHashedSet(const ElementSet &elements) const;
52 
54  bool MatchInternal(const uint64_t *sorted_element_hashes,
55  size_t size) const;
56 
57 public:
59  explicit GCSFilter(const Params &params = Params());
60 
62  GCSFilter(const Params &params, std::vector<uint8_t> encoded_filter);
63 
65  GCSFilter(const Params &params, const ElementSet &elements);
66 
67  uint32_t GetN() const { return m_N; }
68  const Params &GetParams() const { return m_params; }
69  const std::vector<uint8_t> &GetEncoded() const { return m_encoded; }
70 
75  bool Match(const Element &element) const;
76 
82  bool MatchAny(const ElementSet &elements) const;
83 };
84 
85 constexpr uint8_t BASIC_FILTER_P = 19;
86 constexpr uint32_t BASIC_FILTER_M = 784931;
87 
88 enum class BlockFilterType : uint8_t {
89  BASIC = 0,
90  INVALID = 255,
91 };
92 
95 const std::string &BlockFilterTypeName(BlockFilterType filter_type);
96 
98 bool BlockFilterTypeByName(const std::string &name,
99  BlockFilterType &filter_type);
100 
102 const std::set<BlockFilterType> &AllBlockFilterTypes();
103 
105 const std::string &ListBlockFilterTypes();
106 
111 class BlockFilter {
112 private:
116 
117  bool BuildParams(GCSFilter::Params &params) const;
118 
119 public:
120  BlockFilter() = default;
121 
123  BlockFilter(BlockFilterType filter_type, const BlockHash &block_hash,
124  std::vector<uint8_t> filter);
125 
127  BlockFilter(BlockFilterType filter_type, const CBlock &block,
128  const CBlockUndo &block_undo);
129 
130  BlockFilterType GetFilterType() const { return m_filter_type; }
131  const BlockHash &GetBlockHash() const { return m_block_hash; }
132  const GCSFilter &GetFilter() const { return m_filter; }
133 
134  const std::vector<uint8_t> &GetEncodedFilter() const {
135  return m_filter.GetEncoded();
136  }
137 
139  uint256 GetHash() const;
140 
142  uint256 ComputeHeader(const uint256 &prev_header) const;
143 
144  template <typename Stream> void Serialize(Stream &s) const {
145  s << static_cast<uint8_t>(m_filter_type) << m_block_hash
146  << m_filter.GetEncoded();
147  }
148 
149  template <typename Stream> void Unserialize(Stream &s) {
150  std::vector<uint8_t> encoded_filter;
151  uint8_t filter_type;
152 
153  s >> filter_type >> m_block_hash >> encoded_filter;
154 
155  m_filter_type = static_cast<BlockFilterType>(filter_type);
156 
157  GCSFilter::Params params;
158  if (!BuildParams(params)) {
159  throw std::ios_base::failure("unknown filter_type");
160  }
161  m_filter = GCSFilter(params, std::move(encoded_filter));
162  }
163 };
164 
165 #endif // BITCOIN_BLOCKFILTER_H
const std::set< BlockFilterType > & AllBlockFilterTypes()
Get a list of known filter types.
constexpr uint32_t BASIC_FILTER_M
Definition: blockfilter.h:86
const std::string & BlockFilterTypeName(BlockFilterType filter_type)
Get the human-readable name for a filter type.
Definition: block.h:62
constexpr uint8_t BASIC_FILTER_P
Definition: blockfilter.h:85
const GCSFilter & GetFilter() const
Definition: blockfilter.h:132
bool MatchAny(const ElementSet &elements) const
Checks if any of the given elements may be in the set.
const BlockHash & GetBlockHash() const
Definition: blockfilter.h:131
const std::vector< uint8_t > & GetEncoded() const
Definition: blockfilter.h:69
bool BlockFilterTypeByName(const std::string &name, BlockFilterType &filter_type)
Find a filter type by its human-readable name.
std::vector< uint64_t > BuildHashedSet(const ElementSet &elements) const
Definition: blockfilter.cpp:68
GCSFilter m_filter
Definition: blockfilter.h:115
bool Match(const Element &element) const
Checks if the element may be in the set.
GCSFilter(const Params &params=Params())
Constructs an empty filter.
Definition: blockfilter.cpp:78
const std::vector< uint8_t > & GetEncodedFilter() const
Definition: blockfilter.h:134
void Serialize(Stream &s) const
Definition: blockfilter.h:144
bool MatchInternal(const uint64_t *sorted_element_hashes, size_t size) const
Helper method used to implement Match and MatchAny.
BlockFilterType
Definition: blockfilter.h:88
const char * name
Definition: rest.cpp:43
Complete block filter struct as defined in BIP 157.
Definition: blockfilter.h:111
std::vector< uint8_t > m_encoded
Definition: blockfilter.h:46
static unsigned char elements[DATACOUNT][DATALEN]
Definition: tests_impl.h:36
uint64_t HashToRange(const Element &element) const
Hash a data element to an integer in the range [0, N * M).
Definition: blockfilter.cpp:60
const std::string & ListBlockFilterTypes()
Get a comma-separated list of known filter type names.
This implements a Golomb-coded set as defined in BIP 158.
Definition: blockfilter.h:25
std::unordered_set< Element, ByteVectorHash > ElementSet
Definition: blockfilter.h:28
uint32_t m_M
Inverse false positive rate.
Definition: blockfilter.h:34
uint64_t m_siphash_k0
Definition: blockfilter.h:31
std::vector< uint8_t > Element
Definition: blockfilter.h:27
uint8_t m_P
Golomb-Rice coding parameter.
Definition: blockfilter.h:33
256-bit opaque blob.
Definition: uint256.h:120
Params(uint64_t siphash_k0=0, uint64_t siphash_k1=0, uint8_t P=0, uint32_t M=1)
Definition: blockfilter.h:36
A BlockHash is a unqiue identifier for a block.
Definition: blockhash.h:13
Undo information for a CBlock.
Definition: undo.h:73
uint32_t GetN() const
Definition: blockfilter.h:67
Params m_params
Definition: blockfilter.h:43
uint64_t m_siphash_k1
Definition: blockfilter.h:32
uint32_t m_N
Number of elements in the filter.
Definition: blockfilter.h:44
const Params & GetParams() const
Definition: blockfilter.h:68
BlockFilterType GetFilterType() const
Definition: blockfilter.h:130
uint64_t m_F
Range of element hashes, F = N * M.
Definition: blockfilter.h:45
BlockHash m_block_hash
Definition: blockfilter.h:114
void Unserialize(Stream &s)
Definition: blockfilter.h:149