// Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "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:

//

#if !defined(__APSRECCACHE_H__)

#define __APSRECCACHE_H__

#include <e32base.h>

#include <apmrec.h>

#include "APSRECUTIL.H"

const TUint KFileHashMapEntries = 40;

/**

An entry for a recognized file in the recognition cache.

The entries is organized as single-linked list.

The recognition result itself is reference-counted.

@internalComponent

*/

class CRecognitionResultHashMapEntry : public CBase

	{

public:

	static CRecognitionResultHashMapEntry* NewL(const TDesC& aFileName, TTime aLastModified, const TDataRecognitionResult& aResult, CRecognitionResultHashMapEntry* aNext);

	~CRecognitionResultHashMapEntry();

	inline const CRecognitionResultHashMapEntry* Next() const { return iNext; }

	inline CRecognitionResultHashMapEntry* Next() { return iNext; }

	inline TTime LastModified() const { return iLastModified; }

	inline const TDesC& FileName() const { return iResult->FileName(); }

	inline CRecognitionResult* Result() const { iResult->Open(); return iResult; }

	void UpdateL(TTime aLastModified, const TDataRecognitionResult& aResult);

private:

	CRecognitionResultHashMapEntry(TTime aLastModified, CRecognitionResult* aResult, CRecognitionResultHashMapEntry* aNext);

private:

	TTime iLastModified;

	CRecognitionResult* iResult;

	CRecognitionResultHashMapEntry* iNext;

	};

/**

A hash map for finding and adding recognition results.

@internalComponent

*/

class CRecognitionResultHashMap : public CBase

	{

public:

	CRecognitionResultHashMap();

	~CRecognitionResultHashMap();

	CRecognitionResult* Get(const TDesC& aKey, TTime& aLastModified) const;

	TBool AddL(const TDesC& aKey, TTime aLastModified, const TDataRecognitionResult& aResult);

	inline TUint NumberOfEntries() const { return iNumberOfEntries; }

protected:

	TUint GetIndex(const TDesC& aKey) const;

private:

	inline CRecognitionResultHashMapEntry* Entry(TUint aIndex);

	inline const CRecognitionResultHashMapEntry* Entry(TUint aIndex) const;

	inline void SetEntry(TUint aIndex, CRecognitionResultHashMapEntry* aEntry);

private:

	TUint iNumberOfEntries;

	CRecognitionResultHashMapEntry* iEntries[KFileHashMapEntries];

	};

/**

A directory entry in the cache.

Such an entry doesn't necessarily hold all files of a directory, but

only the ones that have been recognized so far.

@internalComponent

*/

class CCacheDirectoryEntry : public CBase

	{

public:

	static CCacheDirectoryEntry* NewL(const TDesC& aDirectory);

	~CCacheDirectoryEntry();

	inline const TDesC& Directory() const { return *iDirectory; }

	inline CRecognitionResultHashMap& Files() { return iFiles; } //lint !e1536 Suppress exposing low access member

	inline TUint NumberOfEntries() const { return iFiles.NumberOfEntries(); }

private:

	CCacheDirectoryEntry();

public:

	static const TInt iOffset;

private:

	HBufC* iDirectory; // own copy!

	CRecognitionResultHashMap iFiles;

	TDblQueLink iDlink;

	friend class CApsRecognitionCache;

	};

/**

A recognition result cache.

The cache holds a list of directories (stored as an RPointerArray). Recently

used directories are stored on top of the list, rarely used directories are

stored at the bottom. 

This strategy improves performance: 

search for files is started at the top (principle of locality) 

and cleanup is done from the bottom.

The files themselves are stored in a hash map (within directories).

@internalComponent

*/

class CApsRecognitionCache : public CBase

	{

public:

	CApsRecognitionCache(RFs& aFs);

	~CApsRecognitionCache();

	void AddL(const TDesC& aDirectory, const TDesC& aFileName, const TDataRecognitionResult& aRecognitionResult);

	void AddL(const RFile& aFile, const TDesC& aDirectory, const TDesC& aFileName, const TDataRecognitionResult& aRecognitionResult);

	TBool Get(const TDesC& aDirectory, const TDesC& aFileName, TDataRecognitionResult& aRecognitionResult);

	CRecognitionResult* Get(const RFile& aFile, const TDesC& aDirectory, const TDesC& aFileName);

	void Flush();

private:

	void DoAddL(const TDesC& aDirectory, const TDesC& aFileName, const TTime& aLastModified, const TDataRecognitionResult& aRecognitionResult);

	CRecognitionResult* DoGet(const TDesC& aDirectory, const TDesC& aFileName, const TTime& aLastModified);

	TBool CompareDirectories(const TDesC& aDir1, const TDesC& aDir2) const;

	void Cleanup();

private: // data

	RFs& iFs;

	TDblQue<CCacheDirectoryEntry> iDirectoryHeader;

	TDblQueIter<CCacheDirectoryEntry> iIter;

	TUint iNumberOfEntries;

	};

//inlines

inline CRecognitionResultHashMapEntry* CRecognitionResultHashMap::Entry(TUint aIndex)

	{

	ASSERT(aIndex < KFileHashMapEntries);

	return iEntries[aIndex];

	}  //lint !e1762 Suppress member function could be made const

inline const CRecognitionResultHashMapEntry* CRecognitionResultHashMap::Entry(TUint aIndex) const

	{

	ASSERT(aIndex < KFileHashMapEntries);

	return iEntries[aIndex];

	}

inline void CRecognitionResultHashMap::SetEntry(TUint aIndex, CRecognitionResultHashMapEntry* aEntry)

	{

	ASSERT(Entry(aIndex) == aEntry->Next());

	iEntries[aIndex] = aEntry;

	}

#endif // __APSRECCACHE_H__