Introduce GCSFilter::QuerySet a cached hash query set for GCSFilter::MatchAny

pstratem · pstratem · commit 9035eb95b286 · 2023-01-26T00:30:09.000-05:00
Caching the hashed and sorted elements allows for a substantially faster
GCSFilter::MatchAny. We will use this later for faster wallet rescans.
diff --git a/src/blockfilter.cpp b/src/blockfilter.cpp
@@ -24,6 +24,32 @@ static const std::map<BlockFilterType, std::string> g_filter_types = {
     {BlockFilterType::BASIC, "basic"},
 };
 
+GCSFilter::QuerySet::QuerySet(const Params& params, const ElementSet& elements)
+    : m_params(params)
+{
+    for (const Element& element : elements)
+        insert(element, false);
+    std::sort(m_hashed_elements.begin(), m_hashed_elements.end());
+}
+
+void GCSFilter::QuerySet::insert(const Element& element, bool sort)
+{
+    uint64_t hashed_element = HashElement(element, m_params.m_siphash_k0, m_params.m_siphash_k1);
+    m_hashed_elements.push_back(hashed_element);
+    if (sort)
+        std::sort(m_hashed_elements.begin(), m_hashed_elements.end());
+}
+
+std::vector<uint64_t> GCSFilter::QuerySet::sorted_and_ranged(const uint64_t& F) const
+{
+    std::vector<uint64_t> ranged_elements;
+    ranged_elements.reserve(m_hashed_elements.size());
+    for (const uint64_t& hashed_element : m_hashed_elements) {
+        ranged_elements.push_back(RangeHashedElement(hashed_element, F));
+    }
+    return ranged_elements;
+}
+
 uint64_t GCSFilter::HashElement(const Element& element) const
 {
     return HashElement(element, m_params.m_siphash_k0, m_params.m_siphash_k1);
diff --git a/src/blockfilter.h b/src/blockfilter.h
@@ -40,6 +40,18 @@ class GCSFilter
         {}
     };
 
+    class QuerySet
+    {
+    private:
+        std::vector<uint64_t> m_hashed_elements;
+    public:
+        Params m_params;
+        QuerySet(const Params& params) : m_params(params) {};
+        QuerySet(const Params& params, const ElementSet& elements);
+        void insert(const Element& element, bool sort = true);
+        std::vector<uint64_t> sorted_and_ranged(const uint64_t& F) const;
+    };
+
 private:
     Params m_params;
     uint32_t m_N;  //!< Number of elements in the filter
