smartptr.h

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// smartptr.h - originally written and placed in the public domain by Wei Dai
 
 
#ifndef CRYPTOPP_SMARTPTR_H
#define CRYPTOPP_SMARTPTR_H
 
#include "config.h"
#include "stdcpp.h"
 
NAMESPACE_BEGIN(CryptoPP)
 
 
template <class T> class simple_ptr
{
public:
        simple_ptr(T *p = NULLPTR) : m_p(p) {}
        ~simple_ptr()
        {
                delete m_p;
                m_p = NULLPTR;
        }
 
        T *m_p;
};
 
template <class T> class member_ptr
{
public:
        explicit member_ptr(T *p = NULLPTR) : m_p(p) {}
 
        ~member_ptr();
 
        const T& operator*() const { return *m_p; }
        T& operator*() { return *m_p; }
 
        const T* operator->() const { return m_p; }
        T* operator->() { return m_p; }
 
        const T* get() const { return m_p; }
        T* get() { return m_p; }
 
        T* release()
        {
                T *old_p = m_p;
                m_p = NULLPTR;
                return old_p;
        }
 
        void reset(T *p = NULLPTR);
 
protected:
        member_ptr(const member_ptr<T>& rhs);           // copy not allowed
        void operator=(const member_ptr<T>& rhs);       // assignment not allowed
 
        T *m_p;
};
 
template <class T> member_ptr<T>::~member_ptr() {delete m_p;}
template <class T> void member_ptr<T>::reset(T *p) {delete m_p; m_p = p;}
 
// ********************************************************
 
template<class T> class value_ptr : public member_ptr<T>
{
public:
        value_ptr(const T &obj) : member_ptr<T>(new T(obj)) {}
        value_ptr(T *p = NULLPTR) : member_ptr<T>(p) {}
        value_ptr(const value_ptr<T>& rhs)
                : member_ptr<T>(rhs.m_p ? new T(*rhs.m_p) : NULLPTR) {}
 
        value_ptr<T>& operator=(const value_ptr<T>& rhs);
        bool operator==(const value_ptr<T>& rhs)
        {
                return (!this->m_p && !rhs.m_p) || (this->m_p && rhs.m_p && *this->m_p == *rhs.m_p);
        }
};
 
template <class T> value_ptr<T>& value_ptr<T>::operator=(const value_ptr<T>& rhs)
{
        T *old_p = this->m_p;
        this->m_p = rhs.m_p ? new T(*rhs.m_p) : NULLPTR;
        delete old_p;
        return *this;
}
 
// ********************************************************
 
template<class T> class clonable_ptr : public member_ptr<T>
{
public:
        clonable_ptr(const T &obj) : member_ptr<T>(obj.Clone()) {}
        clonable_ptr(T *p = NULLPTR) : member_ptr<T>(p) {}
        clonable_ptr(const clonable_ptr<T>& rhs)
                : member_ptr<T>(rhs.m_p ? rhs.m_p->Clone() : NULLPTR) {}
 
        clonable_ptr<T>& operator=(const clonable_ptr<T>& rhs);
};
 
template <class T> clonable_ptr<T>& clonable_ptr<T>::operator=(const clonable_ptr<T>& rhs)
{
        T *old_p = this->m_p;
        this->m_p = rhs.m_p ? rhs.m_p->Clone() : NULLPTR;
        delete old_p;
        return *this;
}
 
// ********************************************************
 
template<class T> class counted_ptr
{
public:
        explicit counted_ptr(T *p = NULLPTR);
        counted_ptr(const T &r) : m_p(0) {attach(r);}
        counted_ptr(const counted_ptr<T>& rhs);
 
        ~counted_ptr();
 
        const T& operator*() const { return *m_p; }
        T& operator*() { return *m_p; }
 
        const T* operator->() const { return m_p; }
        T* operator->() { return get(); }
 
        const T* get() const { return m_p; }
        T* get();
 
        void attach(const T &p);
 
        counted_ptr<T> & operator=(const counted_ptr<T>& rhs);
 
private:
        T *m_p;
};
 
template <class T> counted_ptr<T>::counted_ptr(T *p)
        : m_p(p)
{
        if (m_p)
                m_p->m_referenceCount = 1;
}
 
template <class T> counted_ptr<T>::counted_ptr(const counted_ptr<T>& rhs)
        : m_p(rhs.m_p)
{
        if (m_p)
                m_p->m_referenceCount++;
}
 
template <class T> counted_ptr<T>::~counted_ptr()
{
        if (m_p && --m_p->m_referenceCount == 0)
                delete m_p;
}
 
template <class T> void counted_ptr<T>::attach(const T &r)
{
        if (m_p && --m_p->m_referenceCount == 0)
                delete m_p;
        if (r.m_referenceCount == 0)
        {
                m_p = r.clone();
                m_p->m_referenceCount = 1;
        }
        else
        {
                m_p = const_cast<T *>(&r);
                m_p->m_referenceCount++;
        }
}
 
template <class T> T* counted_ptr<T>::get()
{
        if (m_p && m_p->m_referenceCount > 1)
        {
                T *temp = m_p->clone();
                m_p->m_referenceCount--;
                m_p = temp;
                m_p->m_referenceCount = 1;
        }
        return m_p;
}
 
template <class T> counted_ptr<T> & counted_ptr<T>::operator=(const counted_ptr<T>& rhs)
{
        if (m_p != rhs.m_p)
        {
                if (m_p && --m_p->m_referenceCount == 0)
                        delete m_p;
                m_p = rhs.m_p;
                if (m_p)
                        m_p->m_referenceCount++;
        }
        return *this;
}
 
// ********************************************************
 
template <class T> class vector_member_ptrs
{
public:
        vector_member_ptrs(size_t size=0)
                : m_size(size), m_ptr(new member_ptr<T>[size]) {}
        ~vector_member_ptrs()
                {delete [] this->m_ptr;}
 
        member_ptr<T>& operator[](size_t index)
                {CRYPTOPP_ASSERT(index<this->m_size); return this->m_ptr[index];}
        const member_ptr<T>& operator[](size_t index) const
                {CRYPTOPP_ASSERT(index<this->m_size); return this->m_ptr[index];}
 
        size_t size() const {return this->m_size;}
        void resize(size_t newSize)
        {
                member_ptr<T> *newPtr = new member_ptr<T>[newSize];
                for (size_t i=0; i<this->m_size && i<newSize; i++)
                        newPtr[i].reset(this->m_ptr[i].release());
                delete [] this->m_ptr;
                this->m_size = newSize;
                this->m_ptr = newPtr;
        }
 
private:
        vector_member_ptrs(const vector_member_ptrs<T> &c);     // copy not allowed
        void operator=(const vector_member_ptrs<T> &x);         // assignment not allowed
 
        size_t m_size;
        member_ptr<T> *m_ptr;
};
 
NAMESPACE_END
 
#endif