#344 Implement user traits mechanisms

examples/checkpoint_example_user_traits.cc

@@ -0,0 +1,18 @@
+#include "checkpoint/checkpoint.h"
+
+#include "checkpoint_example_user_traits.hpp"
+
+int main(int, char**){
+  test::TestObj obj;
+
+  //Each invocation will be handled based on the traits attached
+  auto s_info_a = checkpoint::serialize(obj);
+  auto s_info_b = checkpoint::serialize<checkpoint_trait>(obj);
+  auto s_info_c = checkpoint::serialize<checkpoint_trait, checkpoint_trait>(obj);
+  auto s_info_d = checkpoint::serialize<test::random_trait, checkpoint_trait>(obj);
+  auto s_info_e = checkpoint::serialize<checkpoint_trait, test::random_trait>(obj);
+  auto s_info_f = checkpoint::serialize<test::random_trait, test::random_trait>(obj);
+  auto s_info_g = checkpoint::serialize<shallow_trait>(obj);
+  auto s_info_h = checkpoint::serialize<misc::namespace_trait>(obj);
+  auto s_info_i = checkpoint::serialize<misc::hook_all_trait>(obj);
+}

examples/checkpoint_example_user_traits.hpp

@@ -0,0 +1,66 @@
+#include "checkpoint/checkpoint.h"
+
+struct checkpoint_trait {} CheckpointTrait;
+struct shallow_trait {} ShallowTrait;
+
+namespace test {
+  struct random_trait {} RandomTrait;
+
+  struct TestObj {
+    int a = 1;
+
+    TestObj() {}
+
+    template<typename SerT, typename std::enable_if_t<SerT::template has_not_traits<shallow_trait>::value>* = nullptr>
+    void serialize(SerT& s){
+      if constexpr(SerT::template has_traits<checkpoint_trait>::value){
+        if(s.isSizing()) printf("Customizing serialization for checkpoint\n");
+        s | a;
+      } else {
+        if(s.isSizing()) printf("Default serializing testObj\n");
+      }
+
+      static_assert(SerT::template has_not_traits<shallow_trait>::value, "ShallowTrait should have been removed!\n");
+    }
+  };
+}
+
+namespace test {
+  template<typename SerT, typename std::enable_if_t<SerT::template has_traits<random_trait>::value>* = nullptr>
+  void serialize(SerT& s, TestObj& myObj){
+    if(s.isSizing()) printf("Inserting random extra object serialization step! ");
+    myObj.serialize(s);
+  }
+
+  template<typename SerT, typename std::enable_if_t<SerT::template has_traits<shallow_trait>::value>* = nullptr>
+  void serialize(SerT& s, TestObj& myObj){
+    if(s.isSizing()) printf("Removing shallow trait before passing along!\n");
+    auto newS = s.template withoutTraits<shallow_trait>();
+    myObj.serialize(newS);
+  }
+}
+
+namespace misc {
+  template<typename SerT, typename std::enable_if_t<SerT::template has_traits<test::random_trait>::value>* = nullptr>
+  void serialize(SerT& s, test::TestObj& myObj){
+    if(s.isSizing()) printf("Serializers in other namespaces don't usually get found ");
+    myObj.serialize(s);
+  }
+
+
+  const struct namespace_trait {} NamespaceTrait;
+  template<typename SerT, typename std::enable_if_t<SerT::template has_traits<namespace_trait>::value>* = nullptr>
+  void serialize(SerT& s, test::TestObj& myObj){
+    if(s.isSizing()) printf("A misc:: trait means we can serialize from misc:: too: ");
+    myObj.serialize(s);
+  }
+
+
+  const struct hook_all_trait {} HookAllTrait;
+  template<typename SerT, typename T, typename std::enable_if_t<SerT::template has_traits<hook_all_trait>::value>* = nullptr>
+  void serialize(SerT& s, T& myObj){
+    if(s.isSizing()) printf("We can even add on a generic pre-serialize hook: ");
+    auto newS = s.template withoutTraits<hook_all_trait>();
+    myObj.serialize(newS);
+  }
+}

src/checkpoint/checkpoint_api.h

@@ -78,7 +78,7 @@ using SerializedReturnType = std::unique_ptr<SerializedInfo>;
  * \return a \c std::unique_ptr to a \c SerializedInfo containing the buffer
  * with serialized data and the size of the buffer
  */
-template <typename T>
+template <typename... UserTraits, typename T>
 SerializedReturnType serialize(T& target, BufferCallbackType fn = nullptr);
 
 /**
@@ -101,7 +101,7 @@ SerializedReturnType serialize(T& target, BufferCallbackType fn = nullptr);
  *
  * \return a pointer to the newly reified \c T based on bytes in \c buf
  */
-template <typename T>
+template <typename T, typename... UserTraits>
 T* deserialize(char* buf, char* object_buf);
 
 /**
@@ -118,7 +118,7 @@ T* deserialize(char* buf, char* object_buf);
  *
  * \return a unique pointer to the newly reified \c T based on bytes in \c buf
  */
-template <typename T>
+template <typename T, typename... UserTraits>
 std::unique_ptr<T> deserialize(char* buf);
 
 /**
@@ -132,7 +132,7 @@ std::unique_ptr<T> deserialize(char* buf);
  * \param[in] t a valid pointer to a \c T that has been user-allocated and
  * constructed
  */
-template <typename T>
+template <typename... UserTraits, typename T>
 void deserializeInPlace(char* buf, T* t);
 
 /**
@@ -143,7 +143,7 @@ void deserializeInPlace(char* buf, T* t);
  *
  * \return a unique pointer to \c T that must be deallocated
  */
-template <typename T>
+template <typename T, typename... UserTraits>
 std::unique_ptr<T> deserialize(SerializedReturnType&& in);
 
 /**
@@ -153,7 +153,7 @@ std::unique_ptr<T> deserialize(SerializedReturnType&& in);
  *
  * \return number of bytes for the \c target
  */
-template <typename T>
+template <typename... UserTraits, typename T>
 std::size_t getSize(T& target);
 
 /**
@@ -170,7 +170,7 @@ std::size_t getSize(T& target);
  *
  * \return memory footprint of the \c target
  */
-template <typename T>
+template <typename... UserTraits, typename T>
 std::size_t getMemoryFootprint(T& target, std::size_t size_offset = 0);
 
 /**
@@ -184,7 +184,7 @@ std::size_t getMemoryFootprint(T& target, std::size_t size_offset = 0);
  * \param[in] target the \c T to serialize
  * \param[in] file name of the file to create
  */
-template <typename T>
+template <typename... UserTraits, typename T>
 void serializeToFile(T& target, std::string const& file);
 
 /**
@@ -200,7 +200,7 @@ void serializeToFile(T& target, std::string const& file);
  *
  * \return unique pointer to the new object \c T
  */
-template <typename T>
+template <typename T, typename... UserTraits>
 std::unique_ptr<T> deserializeFromFile(std::string const& file);
 
 /**
@@ -214,7 +214,7 @@ std::unique_ptr<T> deserializeFromFile(std::string const& file);
  * \param[in] file the filename to read with bytes for \c T
  * \param[in] t a valid, constructed \c T to deserialize into
  */
-template <typename T>
+template <typename... UserTraits, typename T>
 void deserializeInPlaceFromFile(std::string const& file, T* buf);
 
 /**
@@ -227,7 +227,7 @@ void deserializeInPlaceFromFile(std::string const& file, T* buf);
  * \param[in] target the \c T to serialize
  * \param[in] stream to serialize into, with tellp and write functions.
  */
-template <typename T, typename StreamT>
+template <typename... Traits, typename T, typename StreamT>
 void serializeToStream(T& target, StreamT& stream);
 
 /**
@@ -243,7 +243,7 @@ void serializeToStream(T& target, StreamT& stream);
  *
  * \return unique pointer to the new object \c T
  */
-template <typename T, typename StreamT>
+template <typename T, typename... Traits, typename StreamT>
 std::unique_ptr<T> deserializeFromStream(StreamT& stream);
 
 /**
@@ -257,7 +257,7 @@ std::unique_ptr<T> deserializeFromStream(StreamT& stream);
  * \param[in] stream the stream to read with bytes for \c T, with tellg and read functions
  * \param[in] t a valid, constructed \c T to deserialize into
  */
-template <typename T, typename StreamT>
+template <typename... Traits, typename T, typename StreamT>
 void deserializeInPlaceFromStream(StreamT& stream, T* buf);
 
 

src/checkpoint/checkpoint_api.impl.h

@@ -53,97 +53,97 @@
 
 namespace checkpoint {
 
-template <typename T>
+template <typename... Traits, typename T>
 SerializedReturnType serialize(T& target, BufferCallbackType fn) {
-  auto ret = dispatch::serializeType<T>(target, fn);
+  auto ret = dispatch::serializeType<T, Traits...>(target, fn);
   auto& buf = std::get<0>(ret);
   std::unique_ptr<SerializedInfo> base_ptr(
     static_cast<SerializedInfo*>(buf.release())
   );
   return base_ptr;
 }
 
-template <typename T>
+template <typename T, typename... Traits>
 T* deserialize(char* buf, char* object_buf) {
-  return dispatch::deserializeType<T>(buf, object_buf);
+  return dispatch::deserializeType<T, Traits...>(buf, object_buf);
 }
 
-template <typename T>
+template <typename T, typename... Traits>
 std::unique_ptr<T> deserialize(char* buf) {
-  auto t = dispatch::deserializeType<T>(buf);
+  auto t = dispatch::deserializeType<T, Traits...>(buf);
   return std::unique_ptr<T>(t);
 }
 
-template <typename T>
+template <typename T, typename... Traits>
 std::unique_ptr<T> deserialize(SerializedReturnType&& in) {
-  auto t = dispatch::deserializeType<T>(in->getBuffer());
+  auto t = dispatch::deserializeType<T, Traits...>(in->getBuffer());
   return std::unique_ptr<T>(t);
 }
 
-template <typename T>
+template <typename... Traits, typename T>
 void deserializeInPlace(char* buf, T* t) {
-  return dispatch::deserializeType<T>(dispatch::InPlaceTag{}, buf, t);
+  return dispatch::deserializeType<T, Traits...>(dispatch::InPlaceTag{}, buf, t);
 }
 
-template <typename T>
+template <typename... Traits, typename T>
 std::size_t getSize(T& target) {
-  return dispatch::Standard::size<T, Sizer>(target);
+  return dispatch::Standard::size<T, SerializerRef<Sizer, Traits...>>(target);
 }
 
-template <typename T>
+template <typename... Traits, typename T>
 std::size_t getMemoryFootprint(T& target, std::size_t size_offset) {
   return size_offset + std::max(
-    dispatch::Standard::footprint<T, Footprinter>(target),
+    dispatch::Standard::footprint<T, SerializerRef<Footprinter, Traits...>>(target),
     sizeof(target)
   );
 }
 
-template <typename T>
+template <typename... Traits, typename T>
 void serializeToFile(T& target, std::string const& file) {
-  auto len = getSize<T>(target);
-  dispatch::Standard::pack<T, PackerBuffer<buffer::IOBuffer>>(
+  auto len = getSize<Traits...>(target);
+  dispatch::Standard::pack<T, SerializerRef<PackerBuffer<buffer::IOBuffer>, Traits...>>(
     target, len, buffer::IOBuffer::WriteToFileTag{}, len, file
   );
 }
 
-template <typename T>
+template <typename T, typename... Traits>
 std::unique_ptr<T> deserializeFromFile(std::string const& file) {
   auto mem = dispatch::Standard::allocate<T>();
   T* t_buf = dispatch::Standard::construct<T>(mem);
-  auto t = dispatch::Standard::unpack<T, UnpackerBuffer<buffer::IOBuffer>>(
+  auto t = dispatch::Standard::unpack<T, SerializerRef<UnpackerBuffer<buffer::IOBuffer>, Traits...>>(
     t_buf, buffer::IOBuffer::ReadFromFileTag{}, file
   );
   return std::unique_ptr<T>(t);
 }
 
-template <typename T>
+template <typename... Traits, typename T>
 void deserializeInPlaceFromFile(std::string const& file, T* t) {
-  dispatch::Standard::unpack<T, UnpackerBuffer<buffer::IOBuffer>>(
+  dispatch::Standard::unpack<T, SerializerRef<UnpackerBuffer<buffer::IOBuffer>, Traits...>>(
     t, buffer::IOBuffer::ReadFromFileTag{}, file
   );
 }
 
-template <typename T, typename StreamT>
+template <typename... Traits, typename T, typename StreamT>
 void serializeToStream(T& target, StreamT& stream) {
   auto len = getSize<T>(target);
-  dispatch::Standard::pack<T, StreamPacker<StreamT>>(
+  dispatch::Standard::pack<T, SerializerRef<StreamPacker<StreamT>, Traits...>>(
     target, len, stream
   );
 }
 
-template <typename T, typename StreamT>
+template <typename T, typename... Traits, typename StreamT>
 std::unique_ptr<T> deserializeFromStream(StreamT& stream) {
   auto mem = dispatch::Standard::allocate<T>();
   T* t_buf = dispatch::Standard::construct<T>(mem);
-  auto t = dispatch::Standard::unpack<T, StreamUnpacker<StreamT>>(
+  auto t = dispatch::Standard::unpack<T, SerializerRef<StreamUnpacker<StreamT>, Traits...>>(
     t_buf, stream
   );
   return std::unique_ptr<T>(t);
 }
 
-template <typename T, typename StreamT>
+template <typename... Traits, typename T, typename StreamT>
 void deserializeInPlaceFromStream(StreamT& stream, T* t) {
-  dispatch::Standard::unpack<T, StreamUnpacker<StreamT>>(
+  dispatch::Standard::unpack<T, SerializerRef<StreamUnpacker<StreamT>, Traits...>>(
     t, stream
   );
 }

src/checkpoint/dispatch/dispatch.h

@@ -188,21 +188,21 @@ struct Standard {
   static SerialByteType* allocate();
 };
 
-template <typename T>
+template <typename T, typename... UserTraits>
 buffer::ImplReturnType packBuffer(
   T& target, SerialSizeType size, BufferObtainFnType fn
 );
 
 template <typename Serializer, typename T>
 inline void serializeArray(Serializer& s, T* array, SerialSizeType const len);
 
-template <typename T>
+template <typename T, typename... UserTraits>
 buffer::ImplReturnType serializeType(T& target, BufferObtainFnType fn = nullptr);
 
-template <typename T>
+template <typename T, typename... UserTraits>
 T* deserializeType(SerialByteType* data, SerialByteType* allocBuf = nullptr);
 
-template <typename T>
+template <typename T, typename... UserTraits>
 void deserializeType(InPlaceTag, SerialByteType* data, T* t);
 
 template <typename T>