/*

* Copyright (c) 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:  Enumerator objects

*

*/

#ifndef CMEDIAMTPDATAPROVIDERENUMERATOR_H

#define CMEDIAMTPDATAPROVIDERENUMERATOR_H

#include <e32base.h>

#include <d32dbms.h>

#include "mmmtpenumerationcallback.h"

#include "cmmmtpdpperflog.h"

// Forward declarations

class MMTPDataProviderFramework;

class MMTPObjectMgr;

class CMTPObjectMetaData;

class CMediaMtpDataProvider;

/**

* Defines file enumerator.  Enumerates all files/directories under a

* specified path or storage

*/

class CMediaMtpDataProviderEnumerator: public CActive

    {

public:

    /**

    * Two phase constructor

    * @param aFramework Reference to MMTPDataProviderFramework

    * @param aDataProvider Reference to CMediaMtpDataProvider

    * @return A pointer to a new instance of the object

    */

    static CMediaMtpDataProviderEnumerator* NewL( MMTPDataProviderFramework& aFramework,

        CMediaMtpDataProvider& aDataProvider );

    /**

    * destructor

    */

    ~CMediaMtpDataProviderEnumerator();

    /**

    * Kick off the enumeration on the specified storage

    * @param aStorageId storage to be enumerated

    */

    void StartL( TUint32 aStorageId );

    // introduce to cleanup db at close session

    void SessionClosedL();

protected:

    // from CActive

    /**

    * Cancel the enumeration process

    */

    void DoCancel();

    void RunL();

    /**

    * Ignore the error, continue with the next one

    */

    TInt RunError( TInt aError );

private:

    /**

    * Standard C++ Constructor

    * @param aFramework Reference to MMTPDataProviderFramework

    * @param aDataProvider Reference to CMediaMtpDataProvider

    */

    CMediaMtpDataProviderEnumerator( MMTPDataProviderFramework& aFramework,

        CMediaMtpDataProvider& aDataProvider );

    void ConstructL();

    /**

    * Called when the enumeration is completed

    */

    void SignalCompleteL( MMTPEnumerationCallback& aCallback,

        TInt aError = KErrNone );

    void ScanStorageL( TUint32 aStorageId );

    /**

    * Scan next storage

    */

    void ScanNextStorageL();

    /**

    * Scans directory at aPath recursing into subdirectories on a depth

    * first basis.

    *

    * Directory entries are kept in iDirStack - which is a LIFO stack.

    * The current path, needed since TEntries don't keep track of it,

    * is kept in iPath.

    *

    * The algorithm works as follows:

    *

    * 1. Read directory entries.

    * 2. ProcessEntriesL is called if no error occurs and >= 1 entries are

    *    read.

    * 3. ProcessEntriesL adds entries to database, if entry is directory

    *    add to iDirStack.

    * 4. When all entries are processed pop entry off the dirstack,

    *    if entry is empty TEntry remove one directory from iPath.

    * 5. Append entry name onto iPath - to update path with new depth

    *    (parent/subdir).

    * 6. Push an empty TEntry onto iDirStack - this tells us we have

    *    recursed one, think of it as pushing the '\' separator onto

    *    iDirStack.

    * 7. Repeat 1-7 until iDirStack is empty.

    */

    void ScanDirL();

    /**

    * Recurse into the next directory on the stack

    * and scan it for entries.

    */

    void ScanNextDirL();

    /**

    * Scan next sub dir

    */

    void ScanNextSubdirL();

    /**

    * Iterates iEntries adding entries as needed to object manager and

    *  iDirStack.

    */

    void ProcessEntriesL();

    /**

    * Add a file entry to the object store

    * @param aFullFileName current scanned file path

    */

    void AddEntryL( const TDesC& aFullFileName );

    /**

    * Returns a TMTPFormatCode for the requested object

    */

    TMTPFormatCode GetObjectFormatCode( const TDesC& aFullFileName );

    /**

    * @param aFullFileName the object file name

    * @return the file if needed to be enumeratored?

    */

    TBool IsFileAccepted( const TDesC& aFullFileName );

    /**

    * start count system tick

    */

    void StartEnumerationCount();

    /**

    * check if the system tick more than predefined value

    * @retuan if more than the predefined value, return true

    *         else return false

    */

    TBool IsOverThreshold();

    /**

    * Get modified content and report to Symbian MTP Framework

    */

    void GetModifiedContentL( const TDesC& aStorageRoot );

private:

    // Owned

    /** MMTPDataProviderFramework used to access MTP components*/

    MMTPDataProviderFramework& iFramework;

    /** MTP Object Manager */

    MMTPObjectMgr& iObjectMgr;

    /** MTP Data Provider ID */

    TUint iDataProviderId;

    CMediaMtpDataProvider& iDataProvider;

    TParse iPath;

    RDir iDir;

    TEntryArray iEntries;

    TInt iFirstUnprocessed;

    RPointerArray<TEntry> iDirStack;

    RArray<TUint> iStorages;

    TUint32 iStorageId;

    TUint32 iParentHandle;

    TMTPFormatCode iFormatCode;

    TBool iScanningDir;

    // record the system tick

    TUint iTickCountBegin;

    TInt iTickPeriod;

#if defined(_DEBUG) || defined(MMMTPDP_PERFLOG)

    CMmMtpDpPerfLog* iPerfLog;

#endif

    };

#endif // CMEDIAMTPDATAPROVIDERENUMERATOR_H