examples/ForumNokia/Symbian_OS_End-to-End_Sockets_API_Example/SocketTaskManager/engine/Response.cpp

/*
 * Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.
 *    
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *    
 *  * Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  * Neither the name of Nokia Corporation nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *    
 *    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 *    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 *    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *    
 *    Description:  
 */


// INCLUDE FILES
#include "Response.h"
#include "TaskManager.pan"

// CONSTANTS
_LIT(KError, "#Error:");
_LIT(KOkMessage, "#OK");
_LIT(KTab, "\t");
_LIT(KSeparator, "#");

// ================= MEMBER FUNCTIONS =======================

// constructor
CResponse::CResponse()
: iMessageBuffer( NULL ), iExpectedPackageSize( 0 ), iState( ENotComplete )
        {
        }
        
// destructor   
CResponse::~CResponse()
        {
        iIds.Close();
        delete iDescriptions;
        delete iMessageBuffer;
        }

// ----------------------------------------------------
// CResponse::NewL()
// Two-phased constructor.
// ----------------------------------------------------
//      
CResponse* CResponse::NewL()
        {
        CResponse* self = CResponse::NewLC();
        CleanupStack::Pop(self);
        return self;
        }

// ----------------------------------------------------
// CResponse::NewLC()
// Two-phased constructor.
// ----------------------------------------------------
//      
CResponse* CResponse::NewLC()
        {
        CResponse* self = new (ELeave) CResponse;
        CleanupStack::PushL(self);
        self->ConstructL();
        return self;
        }

// ----------------------------------------------------
// CResponse::ConstructL()
// Symbian OS default constructor can leave.
// ----------------------------------------------------
//      
void CResponse::ConstructL()
        {
        iDescriptions = new (ELeave) CDesCArrayFlat(1);
    iMessageBuffer = HBufC::NewL(0);
        }

// ----------------------------------------------------
// CResponse::InputDataL()
// This functions constructs a response object from the 
// data received from the server. E.g. if aData contains 
// tasks, tasks are parsed to arrays, where they can be 
// easily fetched. 
// ----------------------------------------------------
//      
void CResponse::ParseDataL( TDesC& aData )
        {
        // error occurred in the server side (i.e. the aData begins #Error: ).
        if (KError() == aData.Left(7))
                {
                iState = EError;
                // remove the #-character.
                iError = aData.Mid(1);
                return;
                }
        
        // response for completing task.
        if (aData.Find(KOkMessage) != KErrNotFound)
                {
                iResponseType = ETaskComplete;
                return;
                }
                
        TLex lex(aData);
        TTaskReadStatus status = EStart;
        
        // Tasks are in form: #id#description#id#description#
        while (!lex.Eos())
                {
                if (lex.Peek() == TChar(KSeparator()[0]))
                        {
                        switch (status)
                                {
                                // first #-character found
                                case EStart:
                                        {
                                        status = EReadId;
                                        break;
                                        }
                                // read the id of the tasks.
                                case EReadId:
                                        {
                                        status = EReadTask;
                                        TInt id;
                                        TLex tmp(lex.MarkedToken());
                                        User::LeaveIfError(tmp.Val(id));
                                        User::LeaveIfError(iIds.Append(id));
                                        break;
                                        }
                                // read the description of the task.
                                case EReadTask:
                                        {
                                        status = EReadId;
                                        TPtrC task = lex.MarkedToken();
                                        iDescriptions->AppendL(task);
                                        break;
                                        }
                                }
                        lex.Inc();
                        lex.Mark();
                        }
                else
                        {
                        lex.Inc();      
                        }
                }       
        }

// ----------------------------------------------------
// CResponse::HasError()
// Returns whether errors occurred in the server side 
// or not.
// ----------------------------------------------------
//      
TBool CResponse::HasError() const
        {
        TBool retval = EFalse;
        if (iError.Length() > 0)
                {
                retval = ETrue;
                }
        return retval;
        }

// ----------------------------------------------------
// CResponse::Error()
// Returns the error description. 
// ----------------------------------------------------
//      
TBuf<KMaxError> CResponse::Error() const
        {
        return iError;
        }

// ----------------------------------------------------
// CResponse::TaskCount()
// Returns the amount of tasks received from the server. 
// ----------------------------------------------------
//      
TInt CResponse::TaskCount() const
        {
        return iIds.Count();
        }

// ----------------------------------------------------
// CResponse::TaskDescription()
// Returns a task description. 
// ----------------------------------------------------
//      
TBuf<KMaxTaskLength> CResponse::TaskDescription(const TInt& aIndex) const
        {
        if (aIndex >= iDescriptions->Count() || 0 > aIndex)
                {
                Panic(ETaskManagerInvalidTaskIndex);
                }
                
        return (*iDescriptions)[aIndex];
        }

// ----------------------------------------------------
// CResponse::TaskId()
// Returns a task id. 
// ----------------------------------------------------
//      
TInt CResponse::TaskId(const TInt& aIndex) const
        {
        if (aIndex >= iDescriptions->Count() || 0 > aIndex)
                {
                Panic(ETaskManagerInvalidTaskIndex);
                }

        return iIds[aIndex];
        }

// ----------------------------------------------------
// CResponse::ResponseType()
// Returns the type of this response. 
// ----------------------------------------------------
//      
CResponse::TResponseType CResponse::ResponseType() const
        {
        return iResponseType;
        }

// ----------------------------------------------------
// CResponse::InputDataL()
// Makes it possible to store a part of the data into the
// CResponse class.
// ----------------------------------------------------
//      
void CResponse::InputDataL( const TDesC8& aData )
    {
    iMessageBuffer = iMessageBuffer->ReAllocL(iMessageBuffer->Length() + aData.Length());
    HBufC* newData = HBufC::NewLC(aData.Length());
    newData->Des().Copy(aData);
    iMessageBuffer->Des() += newData->Des();
    CleanupStack::PopAndDestroy(newData);
    
    DoCheck();
    }

// ----------------------------------------------------
// CResponse::DoCheck()
// Does a check on the received package and sets the state
// that determines what the engine should do next.
// ----------------------------------------------------
//      
void CResponse::DoCheck()
    {
        if( iExpectedPackageSize == 0 )
                {
                // We try to extract the size of the package, which should be found in the beginning
                // of the package, before the first separator character
                TInt separatorIndex = iMessageBuffer->Find( KSeparator );

                if( separatorIndex == KErrNotFound )
                        { // The size of the package can't be read before the first separator sign is found
            iState = ENotComplete;
            return;
                        }

        // Extracted size is converted into TInt
                TPtrC sizePtr = iMessageBuffer->Left( separatorIndex );

                TLex converter( sizePtr );
                if( converter.Val( iExpectedPackageSize ) != KErrNone )
                        { // conversion failed
            iState = EError;
            return;
                        }
                }

    TBuf<6> asciiSize;
    asciiSize.Num( iExpectedPackageSize );

    if( iMessageBuffer->Length() - asciiSize.Length() < iExpectedPackageSize )
        { // The entire package hasn't been received
        iState = ENotComplete;
        return;
        }

    iExpectedPackageSize = 0;

    // The size component is cut from the message
    TPtrC data = iMessageBuffer->Right( iMessageBuffer->Length() -
                                        iMessageBuffer->Find( KSeparator ) );
    
        TRAPD(error, ParseDataL( data );)
        PanicIfError(error);
        
        iState = EComplete;
    }

// ----------------------------------------------------
// CResponse::GetState()
// Returns the state to the engine.
// ----------------------------------------------------
//      
CResponse::TResponseState CResponse::GetState() const
    {
    return iState;
    }

// End of file

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