CWE-ou-minkata/Sources/Plasma/NucleusLib/pnKeyedObject/plKey.h

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*==LICENSE==*/
#ifndef plKey_h_inc
#define plKey_h_inc

#include "HeadSpin.h"
#include "plRefFlags.h"
#include "plString.h"

class hsKeyedObject;
class plRefMsg;
class plUoid;
class hsBitVector;

//// plKey ///////////////////////////////////////////////////////////////////
//  Pointer to a plKeyData struct, which is a handle to a keyedObject

class plKeyData;
class plKeyImp;

class plKey 
{
public:
    // Constructors and destructors and copy stuff
    plKey() : fKeyData(nullptr) { }
    plKey(std::nullptr_t) : fKeyData(nullptr) { }
    plKey(const plKey& rhs);
    ~plKey();
    plKey& operator=(const plKey& rhs);

    bool operator==(const plKey& rhs) const { return fKeyData == rhs.fKeyData; }
    bool operator==(const plKeyData* rhs) const { return fKeyData == rhs; }
    bool operator!=(const plKey& rhs) const { return !(*this == rhs); }
    bool operator!=(const plKeyData* rhs) const { return !(*this == rhs); }

    plKeyData* operator->() const;
    plKeyData& operator*() const;

    operator plKeyImp*() const { return (plKeyImp*)fKeyData; }

    static plKey Make(plKeyData* data) { return plKey(data); }

protected:
    // Pointer to our real key
    plKeyData* fKeyData;
    void IIncRef();
    void IDecRef();

    // Internal constructor, extra param is to distinguish it from the void* constructor
    plKey(plKeyData* data);
};

//// plKeyData ///////////////////////////////////////////////////////////////
//  Base virtual class that provides the essential functionality you would
//  want from a plKey-ish thing.

class plKeyData
{
public:
    virtual const plUoid&   GetUoid() const=0;
    virtual const plString& GetName() const=0;

    virtual hsKeyedObject*  GetObjectPtr()=0;
    virtual hsKeyedObject*  ObjectIsLoaded() const=0;
    virtual hsKeyedObject*  VerifyLoaded() = 0;

    //----------------------
    // Allow a keyed object to behave as if it has an active ref when in fact the object
    // should only be active ref'ed by a non-keyed parent.  Essentially just bumps/decs
    // the active ref count to facilitate normal object creation/destruction
    //----------------------
    virtual hsKeyedObject*  RefObject(plRefFlags::Type flags = plRefFlags::kActiveRef)=0;
    virtual void            UnRefObject(plRefFlags::Type flags = plRefFlags::kActiveRef)=0;

    //----------------------
    // Release has two behaviors, depending on whether the ref is active or passive:
    // Active - Release decs the ActiveRefCnt. When it gets to zero, the object will be deleted.
    // Passive - Unregisters my interest in when the object is created or destroyed.
    //----------------------
    virtual void Release(plKey targetKey)=0;

    virtual uint16_t      GetActiveRefs() const = 0;

    virtual uint16_t      GetNumNotifyCreated() const = 0;
    virtual plRefMsg*   GetNotifyCreated(int i) const = 0;
    virtual const hsBitVector& GetActiveBits() const = 0;

protected:
    // Protected so only the registry can create it
    plKeyData();
    virtual ~plKeyData();

#ifdef HS_DEBUGGING
    // Debugging info fields
    plString    fIDName;
    const char* fClassType;
#endif

    //// RefCount Stuff //////////////////////////////////////////////////////////
    //  The refcounts on plKeyData/plKeyImps are zero-based. When you first create
    //  a new plKeyImp (which should ONLY ever be done inside the resMgr), it gets
    //  a refcount of zero. Assigning a new plKey to represent it bumps it to 1,
    //  and when that key goes away, the refcount drops to zero and the ResManager
    //  is notified of the fact and may delete the keyImp.
    //  So the only refcounts on keys outside of the resMgr should be one or more;
    //  only inside the resMgr should there EVER exist keys with a refcount of 0.
    //
    //  Using our own refCount system instead of hsRefCnt allows us to make it all
    //  protected, so that only plKey can actually ref/unref, which is as it should
    //  be.

    // Only one class should ever touch this...
    friend class plKey;

    // Refcount--the number of plKeys that have pointers to us.
    uint16_t fRefCount;
};

#endif // plKey_h_inc