Rename CFX_CountRef to CFX_SharedCopyOnWrite

core/fxcrt/cfx_count_ref.h

-// Copyright 2016 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#ifndef CORE_FXCRT_CFX_COUNT_REF_H_
-#define CORE_FXCRT_CFX_COUNT_REF_H_
-
-#include "core/fxcrt/cfx_retain_ptr.h"
-#include "core/fxcrt/fx_system.h"
-
-// A shared object with Copy on Write semantics that makes it appear as
-// if each one were independent.
-template <class ObjClass>
-class CFX_CountRef {
- public:
-  CFX_CountRef() {}
-  CFX_CountRef(const CFX_CountRef& other) : m_pObject(other.m_pObject) {}
-  ~CFX_CountRef() {}
-
-  template <typename... Args>
-  ObjClass* Emplace(Args... params) {
-    m_pObject.Reset(new CountedObj(params...));
-    return m_pObject.Get();
-  }
-
-  CFX_CountRef& operator=(const CFX_CountRef& that) {
-    if (*this != that)
-      m_pObject = that.m_pObject;
-    return *this;
-  }
-
-  void SetNull() { m_pObject.Reset(); }
-  const ObjClass* GetObject() const { return m_pObject.Get(); }
-
-  template <typename... Args>
-  ObjClass* GetPrivateCopy(Args... params) {
-    if (!m_pObject)
-      return Emplace(params...);
-    if (!m_pObject->HasOneRef())
-      m_pObject.Reset(new CountedObj(*m_pObject));
-    return m_pObject.Get();
-  }
-
-  bool operator==(const CFX_CountRef& that) const {
-    return m_pObject == that.m_pObject;
-  }
-  bool operator!=(const CFX_CountRef& that) const { return !(*this == that); }
-  explicit operator bool() const { return !!m_pObject; }
-
- private:
-  class CountedObj : public ObjClass {
-   public:
-    template <typename... Args>
-    CountedObj(Args... params) : ObjClass(params...), m_RefCount(0) {}
-
-    CountedObj(const CountedObj& src) : ObjClass(src), m_RefCount(0) {}
-    ~CountedObj() { m_RefCount = 0; }
-
-    bool HasOneRef() const { return m_RefCount == 1; }
-    void Retain() { m_RefCount++; }
-    void Release() {
-      ASSERT(m_RefCount);
-      if (--m_RefCount == 0)
-        delete this;
-    }
-
-   private:
-    // To ensure ref counts do not overflow, consider the worst possible case:
-    // the entire address space contains nothing but pointers to this object.
-    // Since the count increments with each new pointer, the largest value is
-    // the number of pointers that can fit into the address space. The size of
-    // the address space itself is a good upper bound on it.
-    intptr_t m_RefCount;
-  };
-
-  CFX_RetainPtr<CountedObj> m_pObject;
-};
-
-#endif  // CORE_FXCRT_CFX_COUNT_REF_H_