Updated ClonedPtr

Author: hamishun

include/helib/CModulus.h

@@ -20,7 +20,7 @@
 #include <helib/NumbTh.h>
 #include <helib/PAlgebra.h>
 #include <helib/bluestein.h>
-#include <helib/clonedPtr.h>
+#include <helib/ClonedPtr.h>
 
 namespace helib {
 
@@ -61,17 +61,17 @@ class Cmodulus
   long rInv;
 
   // tables for forward FFT
-  copied_ptr<NTL::zz_pX> powers;
+  CopiedPtr<NTL::zz_pX> powers;
   NTL::Vec<NTL::mulmod_precon_t> powers_aux;
-  copied_ptr<NTL::fftRep> Rb;
+  CopiedPtr<NTL::fftRep> Rb;
 
   // tables for backward FFT
-  copied_ptr<NTL::zz_pX> ipowers;
+  CopiedPtr<NTL::zz_pX> ipowers;
   NTL::Vec<NTL::mulmod_precon_t> ipowers_aux;
-  copied_ptr<NTL::fftRep> iRb;
+  CopiedPtr<NTL::fftRep> iRb;
 
   // PhimX modulo q, for faster division w/ remainder
-  copied_ptr<zz_pXModulus1> phimx;
+  CopiedPtr<zz_pXModulus1> phimx;
 
   // Allocate memory and compute roots
   void privateInit(const PAlgebra&, long rt);

include/helib/ClonedPtr.h

@@ -0,0 +1,332 @@
+/* Copyright (C) 2012-2020 IBM Corp.
+ * This program is Licensed under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License. See accompanying LICENSE file.
+ */
+#ifndef HELIB_CLONEDPTR_H
+#define HELIB_CLONEDPTR_H
+
+#include <utility> // std::swap
+/**
+ * @file ClonedPtr.h
+ * @brief Implementation of smart pointer `ClonedPtr` with "cloning" semantics.
+ * The API should be familiar to those that use the standard library smart
+ * pointers (unique_ptr and shared_ptr).
+ *
+ * Two "cloning" policies are provided; one for "deep cloning" (default) and the
+ * other "shallow cloning". For an object to be managed by `ClonedPtr`, a class
+ * needs a "clone" method for deep cloning that creates a raw pointer to a copy
+ * of the object or a copy constructor for shallow cloning.  An alias
+ * `CopiedPtr` is provided for convenience which is a `ClonedPtr` with shallow
+ * clone policy.
+ **/
+
+namespace helib {
+
+/**
+ * @brief Clone any type of pointer.
+ * @param ptr Pointer to be cloned. That is the object that it points to is
+ *`cloned`.
+ * @return A new pointer object that points to a freshly cloned object.
+ * @note Requires that the object being cloned has a `clone` method.
+ **/
+template <typename PTR>
+PTR clonePtr(PTR& ptr)
+{
+  static_assert(std::is_pointer<decltype(ptr->clone())>::value,
+                "`clone` method must return raw pointer.");
+
+  return PTR(ptr->clone());
+}
+
+/**
+ * @struct DeepCopy
+ * @brief Deep copy an object by using its clone method.
+ * @tparam T The type of object to be cloned.
+ **/
+template <typename T>
+struct DeepCopy
+{
+  /**
+   * @brief Apply the cloning policy.
+   * @param ptr The pointer to apply clone policy.
+   * @return The pointer to apply clone policy.
+   **/
+  static T* apply(const T* ptr)
+  {
+    static_assert(std::is_pointer<decltype(ptr->clone())>::value,
+                  "`clone` method must return raw pointer.");
+
+    return ptr->clone();
+  }
+};
+
+/**
+ * @struct ShallowCopy
+ * @brief Shallow copy an object by using its copy constructor.
+ * @tparam T The type of object to be cloned.
+ **/
+template <typename T>
+struct ShallowCopy
+{
+  /**
+   * @brief Apply the cloning policy.
+   * @param ptr The pointer to apply clone policy.
+   * @return The pointer to apply clone policy.
+   **/
+  static T* apply(const T* ptr)
+  {
+    static_assert(std::is_copy_constructible<T>::value,
+                  "Must be copy constructable.");
+
+    return new T(*ptr);
+  }
+};
+
+/**
+ * @class ClonedPtr
+ * @brief A smart pointer that `clones` the object it holds when it is copied.
+ * @tparam T The type of object managed by the pointer.
+ * @tparam Cloner A policy of how to clone the object pointed to, either `deep`
+ * or `shallow`. The default is `deep`.
+ **/
+template <typename T, typename Cloner = DeepCopy<T>>
+class ClonedPtr
+{
+public:
+  /**
+   * @brief The type of the managed object.
+   **/
+  using value_type = T;
+
+  /**
+   * @brief Explicit constructor to create new `ClonedPtr` object.
+   * @param p The raw pointer to the object that `ClonedPtr` will manage.
+   **/
+  explicit ClonedPtr(T* p = nullptr) : ptr(p) {}
+
+  /**
+   * @brief Special constructor to create new `ClonedPtr` object promoting a
+   * nullptr.
+   **/
+  ClonedPtr(std::nullptr_t) : ptr(nullptr) {}
+
+  /**
+   * @brief The destructor deletes the managed object.
+   **/
+  ~ClonedPtr()
+  {
+    if (ptr != nullptr)
+      delete ptr;
+  }
+
+  /**
+   * @brief Copy construct by cloning the managed object based on the
+   * cloning policy.
+   * @param other The `ClonedPtr` object to be cloned.
+   **/
+  ClonedPtr(const ClonedPtr& other) : ptr(copy(other.ptr)) {}
+
+  /**
+   * @brief Move construct by taking ownership of the managed object by the
+   * `ClonedPtr` object being `moved` and setting its pointer to `nullptr`.
+   * @param other The `ClonedPtr` object to be moved.
+   **/
+  ClonedPtr(ClonedPtr&& other) noexcept : ptr{std::exchange(other.ptr, nullptr)}
+  {}
+
+  /**
+   * @brief Copy assign by cloning the managed object based on the
+   * cloning policy.
+   * @param other The `ClonedPtr` object to be cloned.
+   * @return Reference to `*this`.
+   **/
+  ClonedPtr& operator=(const ClonedPtr& other)
+  {
+    if (this != &other) {
+      delete ptr;
+      ptr = copy(other.ptr);
+    }
+    return *this;
+  }
+
+  /**
+   * @brief Move construct by taking ownership of the managed object by the
+   * `ClonedPtr` object being `moved` and setting its pointer to `nullptr`.
+   * @param other The `ClonedPtr` object to be moved.
+   * @return Reference to `*this`.
+   **/
+  ClonedPtr& operator=(ClonedPtr&& other) noexcept
+  {
+    if (this != &other) {
+      delete ptr;
+      ptr = std::exchange(other.ptr, nullptr);
+    }
+    return *this;
+  }
+
+  /**
+   * @brief Reset method deletes the object that it currently managed and
+   * manages the object given by a raw pointer.
+   * @param p The raw pointer to replace the raw pointer currently managed by
+   * the `ClonedPtr` object. The default is `nullptr`.
+   **/
+  void reset(T* p = nullptr)
+  {
+    if (ptr != p) {
+      if (ptr != nullptr)
+        delete ptr;
+      ptr = p;
+    }
+  }
+
+  /**
+   * @brief Release the ownership of the currently managed object by
+   * returning the pointer and setting the held pointer to nullptr.
+   * @return the pointer currently held by the `ClonedPtr` object.
+   **/
+  T* release() noexcept
+  {
+    T* ptr_to_release = ptr;
+    ptr = nullptr;
+    return ptr_to_release;
+  }
+
+  /**
+   * @brief convert `ClonedPtr` to `bool`, `false` if there is a managed object
+   * is else converts to `true`.
+   **/
+  explicit operator bool() const noexcept { return ptr != nullptr; }
+
+  /**
+   * @brief Dereference the smart pointer.
+   * @return `const` reference to manged object.
+   **/
+  const T& operator*() const { return *ptr; }
+
+  /**
+   * @brief Dereference the smart pointer.
+   * @return Reference to managed object.
+   **/
+  T& operator*() { return *ptr; }
+
+  /**
+   * @brief Struct dereference to access members of the managed object.
+   * @return The `const` raw pointer to the managed object.
+   **/
+  const T* operator->() const { return ptr; }
+
+  /**
+   * @brief Struct dereference to access members of the managed object.
+   * @return The raw pointer to the managed object.
+   **/
+  T* operator->() { return ptr; }
+
+  /**
+   * @brief Get the pointer managed by `ClonedPtr` object.
+   * @return The `const` raw pointer to the managed object.
+   **/
+  const T* get() const { return ptr; }
+
+  /**
+   * @brief Get the pointer managed by `ClonedPtr` object.
+   * @return The raw pointer to the managed object.
+   **/
+  T* get() { return ptr; }
+
+  /**
+   * @brief Equal to another `ClonedPtr` object.
+   * @param other `ClonedPtr` object to compare to.
+   * @return `true` if this `ClonedPtr` manages the same object as `other`
+   * else `false`.
+   **/
+  bool operator==(const ClonedPtr& other) const { return ptr == other.ptr; }
+
+  /**
+   * @brief Not equal to another `ClonedPtr` object.
+   * @param other `ClonedPtr` object to compare to.
+   * @return `true` if this `ClonedPtr` does not manage the same object as
+   * `other` else `false`.
+   **/
+  bool operator!=(const ClonedPtr& other) const { return ptr != other.ptr; }
+
+  /**
+   * @brief Less than another `ClonedPtr` object.
+   * @param other `ClonedPtr` object to compare to.
+   * @return `true` if the address of the managed object is less than that of
+   * the object managed by `other` else `false`.
+   **/
+  bool operator<(const ClonedPtr& other) const { return ptr < other.ptr; }
+
+  /**
+   * @brief Greater than another `ClonedPtr` object.
+   * @param other `ClonedPtr` object to compare to.
+   * @return `true` if the address of the managed object is greater than that of
+   * the object managed by `other` else `false`.
+   **/
+  bool operator>(const ClonedPtr& other) const { return ptr > other.ptr; }
+
+  /**
+   * @brief Less than or equal to another `ClonedPtr` object.
+   * @param other `ClonedPtr` object to compare to.
+   * @return `true` if the address of the managed object is less than or equal
+   * to that of the object managed by `other` else `false`.
+   **/
+  bool operator<=(const ClonedPtr& other) const { return ptr <= other.ptr; }
+
+  /**
+   * @brief Greater than or equal to another `ClonedPtr` object.
+   * @param other `ClonedPtr` object to compare to.
+   * @return `true` if the address of the managed object is greater than or
+   *equal to that of the object managed by `other` else `false`.
+   **/
+  bool operator>=(const ClonedPtr& other) const { return ptr >= other.ptr; }
+
+  /**
+   * @brief Swap the managed objects of the this `ClonedPtr` object and
+   * another.
+   * @param other `ClonedPtr` object to swap managed object with.
+   **/
+  void swap(ClonedPtr& other) { std::swap(ptr, other.ptr); }
+
+private:
+  // Copy function applies cloning policy.
+  T* copy(T* p) { return (p ? Cloner::apply(p) : nullptr); }
+
+  // The raw pointer to the managed object.
+  T* ptr = nullptr;
+};
+
+/**
+ * @brief `CopiedPtr` is an alias to `ClonedPtr` but with the cloning policy
+ * set to `shallow` copy.
+ * @tparam T Type of the object pointed to by `CopiedPtr`.
+ **/
+template <typename T>
+using CopiedPtr = ClonedPtr<T, ShallowCopy<T>>;
+
+/**
+ * @brief Construct an object of type `T` based on arguments passed and point
+ * to it with a `ClonedPtr` object.
+ * @param args The arguments to be forwarded to create an object that will be
+ * pointed to by `ClonedPtr`.
+ * @tparam T The type of object that will be constructed and pointed to by the
+ * `ClonedPtr` object.
+ * @tparam Args Packed type for arguments to construct a `ClonedPtr`.
+ * @return A `ClonedPtr` object pointing to the newly constructed object.
+ **/
+template <typename T, typename... Args>
+ClonedPtr<T> makeClonedPtr(Args&&... args)
+{
+  return ClonedPtr<T>(new T(std::forward<Args>(args)...));
+}
+
+} // namespace helib
+
+#endif // HELIB_CLONEDPTR_H