shared.h

konqueror3 embedded版本, KDE环境下的当家浏览器的嵌入式版本源码包.

#ifndef SHARED_H
#define SHARED_H

namespace khtml {

template<class type> class Shared
{
public:
    Shared() { _ref=0; /*counter++;*/ }
    ~Shared() { /*counter--;*/ }

    void ref() { _ref++;  }
    void deref() {
	if(_ref) _ref--;
	if(!_ref)
	    delete static_cast<type *>(this);
    }
    bool hasOneRef() { //kdDebug(300) << "ref=" << _ref << endl;
    	return _ref==1; }

    int refCount() const { return _ref; }
//    static int counter;
protected:
    unsigned int _ref;
};

template<class type> class TreeShared
{
public:
    TreeShared() { _ref = 0; m_parent = 0; /*counter++;*/ }
    TreeShared( type *parent ) { _ref=0; m_parent = parent; /*counter++;*/ }
    ~TreeShared() { /*counter--;*/ }

    void ref() { _ref++;  }
    void deref() {
	if(_ref) _ref--;
	if(!_ref && !m_parent) {
	    delete static_cast<type *>(this);
	}
    }
    bool hasOneRef() { //kdDebug(300) << "ref=" << _ref << endl;
    	return _ref==1; }

    int refCount() const { return _ref; }
//    static int counter;

    void setParent(type *parent) { m_parent = parent; }
    type *parent() const { return m_parent; }
private:
    unsigned int _ref;
protected:
    type *m_parent;
};

template <class T> class SharedPtr;

template <class T> bool operator==(const SharedPtr<T> &a, const SharedPtr<T> &b);
template <class T> bool operator==(const SharedPtr<T> &a, const T *b);
template <class T> bool operator==(const T *a, const SharedPtr<T> &b);

template <class T> class SharedPtr
{
public:
    SharedPtr() : m_ptr(0) {}
    explicit SharedPtr(T *ptr) : m_ptr(ptr) { if (m_ptr) m_ptr->ref(); }
    SharedPtr(const SharedPtr &o) : m_ptr(o.m_ptr) { if (m_ptr) m_ptr->ref(); }
    ~SharedPtr() { if (m_ptr) m_ptr->deref(); }

    bool isNull() const { return m_ptr == 0; }
    bool notNull() const { return m_ptr != 0; }

    void reset() { if (m_ptr) m_ptr->deref(); m_ptr = 0; }
    void reset(T *o) { if (o) o->ref(); if (m_ptr) m_ptr->deref(); m_ptr = o; }

    T * get() const { return m_ptr; }
    T &operator*() const { return *m_ptr; }
    T *operator->() const { return m_ptr; }

    bool operator!() const { return m_ptr == 0; }

    inline friend bool operator==(const SharedPtr &a, const SharedPtr &b) { return a.m_ptr == b.m_ptr; }
    inline friend bool operator==(const SharedPtr &a, const T *b) { return a.m_ptr == b; }
    inline friend bool operator==(const T *a, const SharedPtr &b) { return a == b.m_ptr; }

    SharedPtr &operator=(const SharedPtr &);

private:
    T* m_ptr;
};

template <class T> SharedPtr<T> &SharedPtr<T>::operator=(const SharedPtr<T> &o)
{
    if (o.m_ptr)
        o.m_ptr->ref();
    if (m_ptr)
        m_ptr->deref();
    m_ptr = o.m_ptr;
    return *this;
}

template <class T> inline bool operator!=(const SharedPtr<T> &a, const SharedPtr<T> &b) { return !(a==b); }
template <class T> inline bool operator!=(const SharedPtr<T> &a, const T *b) { return !(a == b); }
template <class T> inline bool operator!=(const T *a, const SharedPtr<T> &b) { return !(a == b); }

template <class T, class U> inline SharedPtr<T> static_pointer_cast(const SharedPtr<U> &p) { return SharedPtr<T>(static_cast<T *>(p.get())); }
template <class T, class U> inline SharedPtr<T> const_pointer_cast(const SharedPtr<U> &p) { return SharedPtr<T>(const_cast<T *>(p.get())); }

} // namespace

#endif