// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// f32\sfat32\inc\sl_leafdir_cache.h

// 

//

/**

 @file

 @internalTechnology

*/

#ifndef SL_LEAFDIR_CACHE_H

#define SL_LEAFDIR_CACHE_H

//---------------------------------------------------------------------------------------------------------------------------------

class CLeafDirTree;

/*

A data structure to define the location of a direcotry 

*/

class TLeafDirData

	{

public:

	TLeafDirData();

	TLeafDirData(TUint aClusterNum);

	TLeafDirData(TUint aClusterNum, const TEntryPos& aMRUPos);

	inline TBool operator==(const TLeafDirData &aDirPos) const;

	inline TBool operator!=(const TLeafDirData &aDirPos) const;

public:

	TUint 		iClusterNum;

	TEntryPos	iMRUPos;

	};

/*

Class definition for the nodes of the leaf dir cache

All cached direcotries are stored as nodes in a tree structure

*/

class CLeafDirTreeNode : public CBase

	{

public:

	// Types of the nodes

    enum  TLeafDirTreeNodeType

        {

        ERoot,				// Represents the root node, i.e. the root path

        ELeaf,				// Represents a pure 'leaf' nodes, no child

        ELeafIntermediary,	// Represents a 'leaf' node, but has at least one child

        EPureIntermediary,	// Represents a pure 'intermediary' node, which only exists to share the common path of other nodes

        };

    static CLeafDirTreeNode* NewL(CLeafDirTree* aOwnerTree, const TDesC& aPathName, const TLeafDirData& aDirPos, TLeafDirTreeNodeType aType);

	~CLeafDirTreeNode();

	inline CLeafDirTreeNode* Parent();

	inline void SetParent(CLeafDirTreeNode* aNode);

	inline RPointerArray<CLeafDirTreeNode>& Children();

	void MakeItChildL(CLeafDirTreeNode* aNode);

	TInt RemoveChild(CLeafDirTreeNode* aNode);

	inline const TLeafDirData& LeafDirData() const;

	inline TUint32 StartClusterNum() const;

	inline void SetLeafDirData(const TLeafDirData& aLeafDirData);

	inline const TDesC& Path() const;

	void SetPathL(const TDesC& aPathData);

	void SetType(const CLeafDirTreeNode::TLeafDirTreeNodeType aType);

	inline TBool IsRoot() const;

	inline TBool IsLeaf();

	inline TBool IsLeafIntermediary();

	inline TBool IsPureIntermediary();

private:

	void ConstructL(CLeafDirTree* aOwnerTree, const TDesC& aPathName);

	CLeafDirTreeNode(const TLeafDirData& aDirPos , TLeafDirTreeNodeType aType);

	CLeafDirTreeNode(const CLeafDirTreeNode& aLeafDirTreeNode);

	CLeafDirTreeNode* operator=(CLeafDirTreeNode& aLeafDirTreeNode);

private:

	CLeafDirTree* iOwnerTree;					// A pointer to the owner of this node.

	CLeafDirTreeNode* iParent;					// The parent of this node 

	RPointerArray<CLeafDirTreeNode> iChildren;	// The children of this node

	RBuf iPath;									// The path of the direcotry this node represents

	TLeafDirData iLeafDirData;				    // The position of the direcotry this node represents

	TLeafDirTreeNodeType iNodeType;				// The type of the node

	};

/*

Class definition for the tree structure of the leaf dir cache

All cached direcotries are stored as nodes in a tree structure

*/

class CLeafDirTree : public CBase

	{

public:

	static CLeafDirTree* NewL(TUint32 aSize);

	~CLeafDirTree();

public:

	TInt Search(const TDesC& aPath, CLeafDirTreeNode*& aNodeFound, TLeafDirData& aDirPos); 

	TInt DoSearch(const TDesC& aPath, CLeafDirTreeNode* aNodeToStart, CLeafDirTreeNode*& aNodeFound, TLeafDirData& aDirPos);

	void InsertL(const TDesC& aPath, const TLeafDirData& aDirPos, CLeafDirTreeNode*& aNodeInserted);

	void DoInsertL(CLeafDirTreeNode* aNodeToStart, const TDesC& aPath, const TLeafDirData& aDirPos, CLeafDirTreeNode*& aNodeInserted);

	void RemoveDirL(const TLeafDirData& aDirPos);

	void UpdateMRUPos(const TLeafDirData& aLeafDirData);

	void RemoveFromCacheL(CLeafDirTreeNode* aNodeToDelete);

	CLeafDirTreeNode* FindLeftestLeafNode(CLeafDirTreeNode* aNodeToStart) const;

	void DeleteSubTreeL(CLeafDirTreeNode* aNodeToStart);

	void Reset();

	CLeafDirTreeNode* LruNode();

	void AddOntoLruL(CLeafDirTreeNode* aNodeToAdd);

	TInt RemoveFromLru(CLeafDirTreeNode* aNodeToRemove);

	TInt MakeMostRecentlyUsed(CLeafDirTreeNode* aNodeUsed);

	inline TInt LruCount() const;

	void CheckLimitL();

	// For debugging & testing only

	#ifdef _DEBUG

		TInt ObjectCount() const {return iContainer.Count();};

		void AddToObjectContainerL(CLeafDirTreeNode* aNode);

		void RemoveFromObjectContainerL(CLeafDirTreeNode* aNode);

		void DumpTreeContentL() const;

	#endif	//_DEBUG

private:

	void ConstructL();

	CLeafDirTree(TUint32 aSize);

private:

	CLeafDirTreeNode* iRoot;					// The root node

	RPointerArray<CLeafDirTreeNode> iLruList;	// The list containing all the LRU cached nodes

	TUint32 iSize;								// The maximum number of items allowed to cache 

	// For debugging & testing only

	#ifdef _DEBUG

		RPointerArray<CLeafDirTreeNode> iContainer;	// The container containing all nodes

	#endif	//_DEBUG

	};

/*

Class definition for leaf directory cache.

Acting as an interface class for CFatMountCB to use.

*/

class CLeafDirCache : public CBase

	{

public:	

	static CLeafDirCache* NewL(TUint32 aLimit);

	~CLeafDirCache();

	void Reset();

	TInt FindInCache(const TDesC& aLeafDirName, TLeafDirData& aDirPos) const; 

	void AddToCacheL(const TDesC& aLeafDirName, const TLeafDirData& aDirPos);

	void RemoveDirL(const TLeafDirData& aDirPos); 

	void UpdateMRUPos(const TLeafDirData& aLeafDirData);

	TInt CacheCount() const;

	// For debugging & testing only

	#ifdef _DEBUG

		void DumpCacheContentL() const;

		TInt NodeCount() const;

	#endif	//_DEBUG

private:

	CLeafDirCache(TUint32 aLimit);

	void ConstructL();

private:

	TUint32 iSize;		    // The cache size

	CLeafDirTree* iTree;	// The cache content, represented as a tree structure

	};

//---------------------------------------------------------------------------------------------------------------------------------

#include"sl_leafdir_cache.inl"

#endif //SL_LEAFDIR_CACHE_H