// Copyright (c) 2006-2009 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:

//

/**

 @file

 @publishedPartner

 */

#include <mtp/cmtptypefile.h>

#include <mtp/mtpdatatypeconstants.h>

// File type constants.

const TInt KMTPFileChunkSizeForLargeFile(0x00080000); // 512K

//For file size less than 512K, we will use this smaller chunk size to reduce the heap usage.

const TInt KMTPFileChunkSizeForSmallFile(0x00010000); //64K

//For file size larger than it, we will split one setSize() to several smaller one, each with the following size.

const TInt64 KMTPFileSetSizeChunk(1<<30); //1G

const TUint KUSBHeaderLen = 12;

CMTPTypeFile::CFileWriter* CMTPTypeFile::CFileWriter::NewL(RFile&  aFile, RBuf8& aWriteBuf)

    {

    CFileWriter *self = new(ELeave)CFileWriter(aFile, aWriteBuf);

    CleanupStack::PushL(self);

    self->ConstructL();

    CleanupStack::Pop(self);

    return self;

    }

void CMTPTypeFile::CFileWriter::GetWriteBuf(TPtr8& aChunk)

    {

    WaitForWriteComplete();

    aChunk.Set(&iBuf[0], 0, iBuf.MaxLength());

    }

TInt CMTPTypeFile::CFileWriter::GetResult() const

    {

    return iWriteResult;

    }

void CMTPTypeFile::CFileWriter::Write(TInt aLength)

    {

    iFile.Write(iBuf, aLength, iStatus);

    SetActive();

    }

void CMTPTypeFile::CFileWriter::WaitForWriteComplete()

    {

    /*

     * We didn't want to cancel the file write here.

     * But we need to wait until the file write complete.

     * The Cancel() function of CActive will do the wait until the file write complete.

     * If the Write already complete and the RunL() invoked there's nothing happened in the Cancel().

     */

    Cancel(); 

    //Have to save the result.

    iWriteResult = iStatus.Int();

    }

void CMTPTypeFile::CFileWriter::RunL()

    {

    //Have to save the result.

    iWriteResult = iStatus.Int();

    }

CMTPTypeFile::CFileWriter::~CFileWriter()

    {

    WaitForWriteComplete(); //make sure all async request complete

    if(iWriteResult != KErrNone)

        {

        iFile.SetSize(0);

        }

    }

void CMTPTypeFile::CFileWriter::DoCancel()

    {

    //We didn't really want to cancel the file write, so we do nothing here

    }

CMTPTypeFile::CFileWriter::CFileWriter(RFile&  aFile, RBuf8& aBuf):CActive(EPriorityStandard), iWriteResult(KErrNone), iFile(aFile), iBuf(aBuf) 

    {

    }

void CMTPTypeFile::CFileWriter::ConstructL()

    {

    CActiveScheduler::Add(this);

    }

/**

 MTP file object data type factory method. 

 @param aFs The handle of an active file server session.

 @param aName The name of the file. Any path components (i.e. drive letter

 or directory), which are not specified, are taken from the session path. 

 @param aMode The mode in which the file is opened (@see TFileMode).

 @return A pointer to the MTP file object data type. Ownership IS transfered.

 @leave One of the system wide error codes, if a processing failure occurs.

 @see TFileMode

 */

EXPORT_C CMTPTypeFile* CMTPTypeFile::NewL(RFs& aFs, const TDesC& aName, TFileMode aMode)

    {

    CMTPTypeFile* self = NewLC(aFs, aName, aMode);

    CleanupStack::Pop(self);

    return self;

    }

/**

 MTP file object data type factory method. A pointer to the MTP file object data

 type is placed on the cleanup stack.

 @param aFs The handle of an active file server session.

 @param aName The name of the file. Any path components (i.e. drive letter

 or directory), which are not specified, are taken from the session path. 

 @param aMode The mode in which the file is opened (@see TFileMode).

 @return A pointer to the MTP file object data type. Ownership IS transfered.

 @leave One of the system wide error codes, if a processing failure occurs.

 @see TFileMode

 */

EXPORT_C CMTPTypeFile* CMTPTypeFile::NewLC(RFs& aFs, const TDesC& aName, TFileMode aMode)

    {

    CMTPTypeFile* self = new(ELeave) CMTPTypeFile;

    CleanupStack::PushL(self);

    self->ConstructL(aFs, aName, aMode);

    return self;

    }

EXPORT_C CMTPTypeFile* CMTPTypeFile::NewL(RFs& aFs, const TDesC& aName, TFileMode aMode, TInt64 aRequiredSize, TInt64 aOffSet)

    {

    CMTPTypeFile* self = NewLC(aFs, aName, aMode,aRequiredSize,aOffSet);

	CleanupStack::Pop(self);

    return self;

    }

EXPORT_C CMTPTypeFile* CMTPTypeFile::NewLC(RFs& aFs, const TDesC& aName, TFileMode aMode, TInt64 aRequiredSize, TInt64 aOffSet)

    {

    CMTPTypeFile* self = new(ELeave) CMTPTypeFile;

    CleanupStack::PushL(self);

    self->ConstructL(aFs, aName, aMode, aRequiredSize, aOffSet);

    return self;

    }

/**

 Destructor

 */

EXPORT_C CMTPTypeFile::~CMTPTypeFile()

    {

    delete iFileWriter1;

    delete iFileWriter2;

    iFile.Close();

    iBuffer1.Close();

    iBuffer2.Close();

    Cancel();

    }

/**

 Sets the size of the file, this function must be called in case of file writting/receiving. related resouce

 will be allocated in this function to prepare to receive the incoming data.

 @param aSize The new size of the file (in bytes).

 @leave One of the system wide error codes, if a processing failure occurs.

 */

EXPORT_C void CMTPTypeFile::SetSizeL(TUint64 aSize)

    {

    iTargetFileSize = (TInt64)aSize; //keep a record for the target file size

    iRemainingDataSize = (TInt64)aSize;//Current implemenation does not support file size with 2 x64 

    if(iRemainingDataSize> KMTPFileChunkSizeForLargeFile) //512K

        {

        iBuffer1.CreateMaxL(KMTPFileChunkSizeForLargeFile);

        iBuffer2.CreateMaxL(KMTPFileChunkSizeForLargeFile);

        }

    else

        {

        iBuffer1.CreateMaxL(KMTPFileChunkSizeForSmallFile);

        iBuffer2.CreateMaxL(KMTPFileChunkSizeForSmallFile);

        }

    if(iRemainingDataSize> KMTPFileSetSizeChunk)

        {

        //split the setSize to multiple calling of 512M

        User::LeaveIfError(iFile.SetSize(KMTPFileSetSizeChunk));

        iCurrentFileSetSize = KMTPFileSetSizeChunk;

        }

    else

        {

        User::LeaveIfError(iFile.SetSize(aSize));

        iCurrentFileSetSize = aSize;

        }

    iFileWriter1 = CFileWriter::NewL(iFile, iBuffer1);

    iFileWriter2 = CFileWriter::NewL(iFile, iBuffer2);

    }

/**

 Provides a reference to the native file object encapsulate by the MTP file 

 object data type.

 @return The native file object reference.

 */

#ifdef SYMBIAN_ENABLE_64_BIT_FILE_SERVER_API

EXPORT_C RFile64& CMTPTypeFile::File()

#else

EXPORT_C RFile& CMTPTypeFile::File()

#endif

    {

    return iFile;

    }

EXPORT_C TInt CMTPTypeFile::FirstReadChunk(TPtrC8& aChunk) const

    {

    aChunk.Set(NULL, 0);

    iReadSequenceState = EIdle;

    iBuffer1.Zero();

#ifdef SYMBIAN_ENABLE_64_BIT_FILE_SERVER_API

    TInt64 pos =iOffSet;

#else

    TInt pos = static_cast<TInt>(iOffSet);

#endif

    TInt err(iFile.Seek(ESeekStart, pos));

    if (err == KErrNone)

        {

        // The USB SIC header is 12 bytes long. If the first chunk is 128K - 12 bytes, 

        // the USB SIC transport will not buffer data, which will improve the transfer rate.

        err = iFile.Read(iBuffer1, iBuffer1.MaxLength() - KUSBHeaderLen);

        if (err == KErrNone)

            {

            //this chunk is going to be used by USB to read  data from it, only CMTPTypefile::RunL() can toggle this flag

            //When it finishe reading data into Buffer2.

            iBuffer1AvailForWrite = EFalse;

            aChunk.Set(iBuffer1.Ptr(), iBuffer1.Length());

            //Set the commit chunk to be filled in by CMTPTypeFile::RunL()

            iCurrentCommitChunk.Set(&iBuffer2[0], 0, iBuffer2.MaxLength());

            iRemainingDataSize -= aChunk.Length();

            if (aChunk.Length() == 0)

                {

                // Empty File.

                iReadSequenceState = EIdle;

                err = KMTPChunkSequenceCompletion;

                }

            else

                {

                if (iRemainingDataSize <= 0)

                    {

                    // EOF.

                    iReadSequenceState = EIdle;

                    aChunk.Set(aChunk.Ptr(), aChunk.Length() + iRemainingDataSize);  //for partial

                    err = KMTPChunkSequenceCompletion;

                    }

                else

                    {

                    iReadSequenceState = EInProgress;

                    //This is NOT the last chunk, issue more CMTPTypeFile::RunL()

                    if (!IsActive())

                        {

                        //Since the writting data into file sever will take a long time, will issue a dedicated Active Object to do that.

                        const_cast<CMTPTypeFile*>(this)->SetActive();

                        TRequestStatus* status = (TRequestStatus*)&iStatus;

                        User::RequestComplete(status, KErrNone);

                        }

                    else

                        {

                        //This is a very extreme cases, it only occurs when the following assumption is met

                        //1. USB already took buffer1 and already issue CMTPTypeFileRunL(), therefore, the ActiveObject has completed itself, 

                        //2. Somehow, this active object is not scheduled to be running even after the USB already use out the other buffer.

                        //3. USB's active object is scheduled to be running prior to the last File active object(this should not happen if ActiveScheduler follow the priority scheduler).

                        //4. USB call this function again to get the other data buffer.

                        //5. Then it find the previous active is not scheduled to run.

                        //in single-core platform, the code rely on the CActiveScheduler to guarantee the first active call which has higher priority to be running firstly before

                        //the 2nd USB active. but for multi-core platform, this should be re-evaluated .

                        iReadSequenceState = EIdle;

                        err = KMTPChunkSequenceCompletion;

                        }

                    }

                }

            }

        else

            {

            iReadSequenceState = EIdle;

            iFileRdWrError = ETrue;

            }

        }

    iByteSent += aChunk.Length();

    return err;

    }

EXPORT_C TInt CMTPTypeFile::NextReadChunk(TPtrC8& aChunk) const

    {

    TInt err(KErrNone);

    if((iReadSequenceState != EInProgress) || (iFileRdWrError))

        {

        aChunk.Set(NULL, 0);

        return KErrNotReady;

        }

    //This is called by USB's RunL(), here, the only possible scenarios is that the CMTPTypleFile::RunL() issued in FirReadChunk or last NextReadChunk must 

    //have already finished. Now take the buffer which is filled in by data in CMTPTypleFile::RunL().

    aChunk.Set(iCurrentCommitChunk.Ptr(), iCurrentCommitChunk.Length());

    if(iBuffer1AvailForWrite)

        {//We have already used buffer_1, now buffer2 contains data read into by CMTPTypeFile::RunL();

        //Set the commit chunk to be filled in by CMTPTypeFile::RunL()

        iCurrentCommitChunk.Set(&iBuffer1[0], 0, iBuffer1.MaxLength());

        }

    else

        {

        //Set the commit chunk to be filled in by CMTPTypeFile::RunL()

        iCurrentCommitChunk.Set(&iBuffer2[0], 0, iBuffer2.MaxLength());

        }

    iRemainingDataSize -= aChunk.Length();

    if(aChunk.Length() == 0)

        {

        iReadSequenceState = EIdle;

        err = KMTPChunkSequenceCompletion;

        }

    else if(iRemainingDataSize> 0)

        {

        //This is NOT the last chunk, issue more CMTPTypeFile::RunL()

        if (!IsActive())

            {

            //Since the writting data into file sever will take a long time, will issue a dedicated Active Object to do that.

            ((CMTPTypeFile*)this)->SetActive();

            TRequestStatus* status = (TRequestStatus*)&iStatus;

            User::RequestComplete(status, KErrNone);

            }

        else

            {

            //This is a very extreme cases, it only occurs when the following assumption is met

            //1. USB already took buffer1 and already issue CMTPTypeFileRunL(), therefore, the ActiveObject has completed itself, 

            //2. Somehow, this active object is not scheduled to be running even after the USB already use out the other buffer.

            //3. USB's active object is scheduled to be running prior to the last File active object(this should not happen if ActiveScheduler follow the priority scheduler).

            //4. USB call this function again to get the other data buffer.

            //5. Then it find the previous active is not scheduled to run.

            //in single-core platform, the code rely on the CActiveScheduler to guarantee the first active call which has higher priority to be running firstly before

            //the 2nd USB active. but for multi-core platform, this should be re-evaluated .

            iReadSequenceState = EIdle;

            err = KMTPChunkSequenceCompletion;

            }

        }

    else

        {//Last Chunk. Do not issue Active object. and indicate this completion of the chunk

        iReadSequenceState = EIdle;

        aChunk.Set(aChunk.Ptr(), aChunk.Length() + iRemainingDataSize); //for partial

        err = KMTPChunkSequenceCompletion;

        }

    iByteSent += aChunk.Length();

    return err;

    }

EXPORT_C TInt CMTPTypeFile::FirstWriteChunk(TPtr8& aChunk)

    {

    __ASSERT_DEBUG(iBuffer1AvailForWrite, User::Invariant());

    __ASSERT_DEBUG(!iFileRdWrError, User::Invariant());

    aChunk.Set(NULL, 0, 0);

    iWriteSequenceState = EIdle;

#ifdef SYMBIAN_ENABLE_64_BIT_FILE_SERVER_API

    TInt64 pos =0;

#else

    TInt pos =0;

#endif

    TInt err(iFile.Seek(ESeekStart, pos));

    if (err == KErrNone)

        {

        iFileWriter1->GetWriteBuf(aChunk);

        iWriteSequenceState = EInProgress;

        //this chunk is going to be used by Transport to write data into it, and when it is full, transport

        //will call back CommitChunkL(), at that time, the ETrue means it already contains data in it.

        //it is ready for reading data from it. 

        //This is a initial value for it to trigger the double-buffering mechanism.

        iBuffer1AvailForWrite = ETrue;

        }

    return err;

    }

EXPORT_C TInt CMTPTypeFile::NextWriteChunk(TPtr8& aChunk)

    {

    TInt err(KErrNone);

    aChunk.Set(NULL, 0, 0);

    if (iWriteSequenceState != EInProgress)

        {

        err = KErrNotReady;

        }

    else

        {//toggle between buffer 1 and buffer 2 here.

        if(iBuffer1AvailForWrite)

            {

            iFileWriter1->GetWriteBuf(aChunk);

            }

        else

            {

            iFileWriter2->GetWriteBuf(aChunk);

            }

        }

    return err;

    }

EXPORT_C TUint64 CMTPTypeFile::Size() const

    {

    //The USB transport layer uses USB Container Length to determine the total size of data to be

    //transfered. In USB protocol, the Container Length is 32 bits long which is up to 4G-1, so 

    //for synchronization of a large file >=4G-12 bytes (the USB header is 12 bytes long), the

    //Container Length can't be used to determine the total size of data any more. In this kind of

    //case, our USB transport layer implementation will call this function to get the actual data size.

    //The RFile::SetSize() method may take over 40 seconds if we create a file and set its size

    //to a very large value, and this will cause timeout in MTP protocol layer. To avoid this 

    //timeout, when creating a large file(over 512MB), instead of setting its size directly to

    //the target size by one singile RFile::SetSize() call, we'll call RFile::SetSize() multiple

    //times and set the file size step by step acumulately. For example, for a 2GB file, its

    //size will be set to 0.5G first, and then 1G, 1.5G and at last 2G.

    //So if a file is transfering to device, the size of the file that returned by RFile::Size() is

    //just a temporary value and means nothing. In this case, let's return the target file size instead.

    if(!iFileOpenForRead && iRemainingDataSize)

        {        

        return iTargetFileSize;

        }

    //If the initiator get partial of the file, return the requested partial size 

    if (iFileOpenForRead && iTargetFileSize)

        {

        return iTargetFileSize;

        }

#ifdef SYMBIAN_ENABLE_64_BIT_FILE_SERVER_API

    TInt64 size;

#else

    TInt size;

#endif

    iFile.Size(size);

    return size;

    }

EXPORT_C TUint CMTPTypeFile::Type() const

    {

    return EMTPTypeFile;