Encode decode WIP

Author: geonove

ddsketch/include/ddsketch.hpp

@@ -25,6 +25,8 @@
 #include <variant>
 #include "store.hpp"
 #include "store_factory.hpp"
+#include "common_defs.hpp"
+#include "memory_operations.hpp"
 
 namespace datasketches {
 
@@ -61,6 +63,9 @@ class DDSketch {
   double get_min() const;
   double get_max() const;
 
+  void serialize(std::ostream& os) const;
+  static DDSketch deserialize(std::istream& is);
+
 protected:
   Store positive_store;
   Store negative_store;
@@ -70,6 +75,11 @@ class DDSketch {
   const double min_indexed_value;
   const double max_indexed_value;
 
+  // Serialization constants
+  static const uint8_t SERIAL_VERSION = 1;
+  static const uint8_t FAMILY = 18; // DDSketch family ID
+  static const size_t PREAMBLE_SIZE_BYTES = 8;
+
   void check_value_trackable(const double& value) const;
   template<store_concept OtherStore>
   void check_mergeability(const DDSketch<OtherStore, Mapping>& other) const;

ddsketch/include/ddsketch_impl.hpp

@@ -194,6 +194,23 @@ double DDSketch<Store, Mapping>::get_quantile(const double& rank, const double&
   }
   throw std::invalid_argument("no such element");
 }
+
+template<store_concept Store, class Mapping>
+void DDSketch<Store, Mapping>::serialize(std::ostream& os) const {
+  index_mapping.serialize(os);
+  if (zero_count > 0.0) {
+    write(os, zero_count);
+  }
+
+  positive_store.serialize(os);
+  negative_store.serialize(os);
+}
+
+template<store_concept Store, class Mapping>
+DDSketch<Store, Mapping> DDSketch<Store, Mapping>::deserialize(std::istream &is) {
+
+}
+
 }
 
 #endif

ddsketch/include/dense_store.hpp

@@ -50,6 +50,9 @@ class DenseStore {
 
   void merge(const SparseStore<Allocator>& other);
 
+  void serialize(std::ostream& is) const;
+  DenseStore<Derived, Allocator> deserialize(std::ostream& is);
+
   iterator begin() const;
   iterator end() const;
 

ddsketch/include/dense_store_impl.hpp

@@ -335,6 +335,15 @@ template<class Derived, typename Allocator>
 typename DenseStore<Derived, Allocator>::reverse_iterator::reference DenseStore<Derived, Allocator>::reverse_iterator::operator*() const {
   return Bin(this->index, this->bins[this->index - this->offset]);
 }
+
+template<class Derived, typename Allocator>
+void DenseStore<Derived, Allocator>::serialize(std::ostream& os) const {
+  if (is_empty()) {
+    return;
+  }
+
+
+}
 }
 
 #endif //DENSE_STORE_IMPL_HPP

ddsketch/include/index_mapping.hpp

@@ -44,7 +44,6 @@ class IndexMapping {
   double min_indexable_value() const;
   double max_indexable_value() const;
   void serialize(std::ostream& os) const;
-
   static Derived deserialize(std::istream& is);
 
   ~IndexMapping() = default;

ddsketch/test/DDSketchTest.cpp

@@ -527,7 +527,7 @@ TEST_CASE("quantile", "[ddsketch]") {
     ddsketch.update(val);
   }
 
-  std::cout << ddsketch.get_quantile(0.5) << std::endl;
-  std::cout << ddsketch.get_rank(4) << std::endl;
+  // std::cout << ddsketch.get_quantile(0.5) << std::endl;
+  // std::cout << ddsketch.get_rank(4) << std::endl;
 }
 } /* namespace datasketches */