diff options
-rw-r--r-- | src/blockfilter.cpp | 44 | ||||
-rw-r--r-- | src/blockfilter.h | 3 |
2 files changed, 47 insertions, 0 deletions
diff --git a/src/blockfilter.cpp b/src/blockfilter.cpp index e4c95ccfbd..52d8f8c296 100644 --- a/src/blockfilter.cpp +++ b/src/blockfilter.cpp @@ -149,3 +149,47 @@ GCSFilter::GCSFilter(uint64_t siphash_k0, uint64_t siphash_k1, uint8_t P, uint32 bitwriter.Flush(); } + +bool GCSFilter::MatchInternal(const uint64_t* element_hashes, size_t size) const +{ + VectorReader stream(GCS_SER_TYPE, GCS_SER_VERSION, m_encoded, 0); + + // Seek forward by size of N + uint64_t N = ReadCompactSize(stream); + assert(N == m_N); + + BitStreamReader<VectorReader> bitreader(stream); + + uint64_t value = 0; + size_t hashes_index = 0; + for (uint32_t i = 0; i < m_N; ++i) { + uint64_t delta = GolombRiceDecode(bitreader, m_P); + value += delta; + + while (true) { + if (hashes_index == size) { + return false; + } else if (element_hashes[hashes_index] == value) { + return true; + } else if (element_hashes[hashes_index] > value) { + break; + } + + hashes_index++; + } + } + + return false; +} + +bool GCSFilter::Match(const Element& element) const +{ + uint64_t query = HashToRange(element); + return MatchInternal(&query, 1); +} + +bool GCSFilter::MatchAny(const ElementSet& elements) const +{ + const std::vector<uint64_t> queries = BuildHashedSet(elements); + return MatchInternal(queries.data(), queries.size()); +} diff --git a/src/blockfilter.h b/src/blockfilter.h index 7809e6875a..d45d31046f 100644 --- a/src/blockfilter.h +++ b/src/blockfilter.h @@ -36,6 +36,9 @@ private: std::vector<uint64_t> BuildHashedSet(const ElementSet& elements) const; + /** Helper method used to implement Match and MatchAny */ + bool MatchInternal(const uint64_t* sorted_element_hashes, size_t size) const; + public: /** Constructs an empty filter. */ |