support serde instance

fi/include/frequent_items_sketch.hpp

@@ -46,7 +46,7 @@ template<
   typename W = uint64_t,
   typename H = std::hash<T>,
   typename E = std::equal_to<T>,
-  typename S = serde<T>,
+  typename S = serde<T>, // deprecated, to be removed in the next major version
   typename A = std::allocator<T>
 >
 class frequent_items_sketch {
@@ -232,39 +232,89 @@ class frequent_items_sketch {
   /**
    * This method serializes the sketch into a given stream in a binary form
    * @param os output stream
+   *
+   * Deprecated, to be removed in the next major version
    */
   void serialize(std::ostream& os) const;
 
+  /**
+   * This method serializes the sketch into a given stream in a binary form
+   * @param os output stream
+   * @param instance of a SerDe
+   */
+  template<typename SerDe = serde<T>>
+  void serialize(std::ostream& os, const SerDe& sd = SerDe()) const;
+
   // This is a convenience alias for users
   // The type returned by the following serialize method
   using vector_bytes = std::vector<uint8_t, typename std::allocator_traits<A>::template rebind_alloc<uint8_t>>;
 
-
   /**
    * This method serializes the sketch as a vector of bytes.
    * An optional header can be reserved in front of the sketch.
    * It is a blank space of a given size.
    * This header is used in Datasketches PostgreSQL extension.
    * @param header_size_bytes space to reserve in front of the sketch
    * @return serialized sketch as a vector of bytes
+   *
+   * Deprecated, to be removed in the next major version
    */
   vector_bytes serialize(unsigned header_size_bytes = 0) const;
 
+  /**
+   * This method serializes the sketch as a vector of bytes.
+   * An optional header can be reserved in front of the sketch.
+   * It is a blank space of a given size.
+   * This header is used in Datasketches PostgreSQL extension.
+   * @param header_size_bytes space to reserve in front of the sketch
+   * @param instance of a SerDe
+   * @return serialized sketch as a vector of bytes
+   */
+  template<typename SerDe = serde<T>>
+  vector_bytes serialize(unsigned header_size_bytes = 0, const SerDe& sd = SerDe()) const;
+
   /**
    * This method deserializes a sketch from a given stream.
    * @param is input stream
+   * @param instance of an Allocator
    * @return an instance of the sketch
+   *
+   * Deprecated, to be removed in the next major version
    */
   static frequent_items_sketch deserialize(std::istream& is, const A& allocator = A());
 
+  /**
+   * This method deserializes a sketch from a given stream.
+   * @param is input stream
+   * @param instance of a SerDe
+   * @param instance of an Allocator
+   * @return an instance of the sketch
+   */
+  template<typename SerDe = serde<T>>
+  static frequent_items_sketch deserialize(std::istream& is, const SerDe& sd = SerDe(), const A& allocator = A());
+
   /**
    * This method deserializes a sketch from a given array of bytes.
    * @param bytes pointer to the array of bytes
    * @param size the size of the array
+   * @param instance of an Allocator
    * @return an instance of the sketch
+   *
+   * Deprecated, to be removed in the next major version
    */
   static frequent_items_sketch deserialize(const void* bytes, size_t size, const A& allocator = A());
 
+  /**
+   * This method deserializes a sketch from a given array of bytes.
+   * @param bytes pointer to the array of bytes
+   * @param size the size of the array
+   * @param instance of a SerDe
+   * @param instance of an Allocator
+   * @return an instance of the sketch
+   */
+  template<typename SerDe = serde<T>>
+  static frequent_items_sketch deserialize(const void* bytes, size_t size, const SerDe& sd = SerDe(), const A& allocator = A());
+
   /**
    * Returns a human readable summary of this sketch
    * @param print_items if true include the list of items retained by the sketch

fi/include/frequent_items_sketch_impl.hpp

@@ -162,6 +162,12 @@ frequent_items_sketch<T, W, H, E, S, A>::get_frequent_items(frequent_items_error
 
 template<typename T, typename W, typename H, typename E, typename S, typename A>
 void frequent_items_sketch<T, W, H, E, S, A>::serialize(std::ostream& os) const {
+  serialize(os, S());
+}
+
+template<typename T, typename W, typename H, typename E, typename S, typename A>
+template<typename SerDe>
+void frequent_items_sketch<T, W, H, E, S, A>::serialize(std::ostream& os, const SerDe& sd) const {
   const uint8_t preamble_longs = is_empty() ? PREAMBLE_LONGS_EMPTY : PREAMBLE_LONGS_NONEMPTY;
   write(os, preamble_longs);
   const uint8_t serial_version = SERIAL_VERSION;
@@ -199,7 +205,7 @@ void frequent_items_sketch<T, W, H, E, S, A>::serialize(std::ostream& os) const
     }
     write(os, weights, sizeof(W) * num_items);
     aw.deallocate(weights, num_items);
-    S().serialize(os, items, num_items);
+    sd.serialize(os, items, num_items);
     for (i = 0; i < num_items; i++) items[i].~T();
     alloc.deallocate(items, num_items);
   }
@@ -215,6 +221,12 @@ size_t frequent_items_sketch<T, W, H, E, S, A>::get_serialized_size_bytes() cons
 
 template<typename T, typename W, typename H, typename E, typename S, typename A>
 auto frequent_items_sketch<T, W, H, E, S, A>::serialize(unsigned header_size_bytes) const -> vector_bytes {
+  return serialize(header_size_bytes, S());
+}
+
+template<typename T, typename W, typename H, typename E, typename S, typename A>
+template<typename SerDe>
+auto frequent_items_sketch<T, W, H, E, S, A>::serialize(unsigned header_size_bytes, const SerDe& sd) const -> vector_bytes {
   const size_t size = header_size_bytes + get_serialized_size_bytes();
   vector_bytes bytes(size, 0, map.get_allocator());
   uint8_t* ptr = bytes.data() + header_size_bytes;
@@ -256,7 +268,7 @@ auto frequent_items_sketch<T, W, H, E, S, A>::serialize(unsigned header_size_byt
     ptr += copy_to_mem(weights, ptr, sizeof(W) * num_items);
     aw.deallocate(weights, num_items);
     const size_t bytes_remaining = end_ptr - ptr;
-    ptr += S().serialize(ptr, bytes_remaining, items, num_items);
+    ptr += sd.serialize(ptr, bytes_remaining, items, num_items);
     for (i = 0; i < num_items; i++) items[i].~T();
     alloc.deallocate(items, num_items);
   }
@@ -285,6 +297,12 @@ class frequent_items_sketch<T, W, H, E, S, A>::items_deleter {
 
 template<typename T, typename W, typename H, typename E, typename S, typename A>
 frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>::deserialize(std::istream& is, const A& allocator) {
+  return deserialize(is, S(), allocator);
+}
+
+template<typename T, typename W, typename H, typename E, typename S, typename A>
+template<typename SerDe>
+frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>::deserialize(std::istream& is, const SerDe& sd, const A& allocator) {
   const auto preamble_longs = read<uint8_t>(is);
   const auto serial_version = read<uint8_t>(is);
   const auto family_id = read<uint8_t>(is);
@@ -313,7 +331,7 @@ frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>:
     read(is, weights.data(), sizeof(W) * num_items);
     A alloc(allocator);
     std::unique_ptr<T, items_deleter> items(alloc.allocate(num_items), items_deleter(num_items, false, alloc));
-    S().deserialize(is, items.get(), num_items);
+    sd.deserialize(is, items.get(), num_items);
     items.get_deleter().set_destroy(true); // serde did not throw, so the items must be constructed
     for (uint32_t i = 0; i < num_items; i++) {
       sketch.update(std::move(items.get()[i]), weights[i]);
@@ -328,6 +346,12 @@ frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>:
 
 template<typename T, typename W, typename H, typename E, typename S, typename A>
 frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>::deserialize(const void* bytes, size_t size, const A& allocator) {
+  return deserialize(bytes, size, S(), allocator);
+}
+
+template<typename T, typename W, typename H, typename E, typename S, typename A>
+template<typename SerDe>
+frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>::deserialize(const void* bytes, size_t size, const SerDe& sd, const A& allocator) {
   ensure_minimum_memory(size, 8);
   const char* ptr = static_cast<const char*>(bytes);
   const char* base = static_cast<const char*>(bytes);
@@ -371,7 +395,7 @@ frequent_items_sketch<T, W, H, E, S, A> frequent_items_sketch<T, W, H, E, S, A>:
     A alloc(allocator);
     std::unique_ptr<T, items_deleter> items(alloc.allocate(num_items), items_deleter(num_items, false, alloc));
     const size_t bytes_remaining = size - (ptr - base);
-    ptr += S().deserialize(ptr, bytes_remaining, items.get(), num_items);
+    ptr += sd.deserialize(ptr, bytes_remaining, items.get(), num_items);
     items.get_deleter().set_destroy(true); // serde did not throw, so the items must be constructed
     for (uint32_t i = 0; i < num_items; i++) {
       sketch.update(std::move(items.get()[i]), weights[i]);

fi/test/frequent_items_sketch_custom_type_test.cpp

@@ -60,7 +60,7 @@ TEST_CASE("frequent items: custom type", "[frequent_items_sketch]") {
   REQUIRE(sketch.get_maximum_error() == sketch2.get_maximum_error());
 
   auto bytes = sketch.serialize();
-  auto sketch3 = frequent_test_type_sketch::deserialize(bytes.data(), bytes.size(), 0);
+  auto sketch3 = frequent_test_type_sketch::deserialize(bytes.data(), bytes.size(), alloc(0));
   REQUIRE_FALSE(sketch3.is_empty());
   REQUIRE(sketch3.get_total_weight() == 17);
   REQUIRE(sketch3.get_estimate(1) == 10);