stdirect.cpp

如题 就是 这东西 为什么非要我 说到 20个 字 呢 看看这回 够 不

// Stdirect.cpp
//
// Copyright (c) 1999-2007 Symbian Software Ltd.  All rights reserved.
//
// $Change: 937687 $

// Example to demonstrate writing out a network of objects
// to a direct file store and then loading them all back in.
//
// Demonstrates the persistence of a direct file store and the idea
// of the root stream. 
//
// The example:
//      constructs three different types of object,
//
//      puts data into the objects,
//
//      displays the content of the objects,
//
//      creates a direct file store (replacing any existing direct 
//      file store of the same name),
//
//      writes the objects to a single stream,
//
//      makes this stream the root stream,
//
//      closes the store and deletes the objects (from memory),
//
//      re-opens the store and restores the objects from the root stream,
//
//      displays the contents of the restored objects
//
//
// Notes:
//      The file name and extension of the direct file store is "stdirect.dat".
//      and will be created in c:\data\ 

// SYSTEM HEADERS
#include <s32file.h>

// PROJECT HEADERS
#include "ststd.h"

// Constructs objects of type CClassA, CClassB and CClassC,
// externalizes them to a direct file store and then destroys the
// CClassA, CClassB and CClassC objects. 
LOCAL_C void doMakeAndStoreL(const TDesC& aName);

// Constructs "empty" CClassA, ClassB and CCLassC objects and
// restores them from the direct file store.
LOCAL_C void doRestoreL(const TDesC& aName);

// Displays the contents of a CClassA object
class CClassA;
LOCAL_C void doShow(const TDesC& aHeading, const CClassA& anA);

// Displays the contents of a CClassB object
class CClassB;
LOCAL_C void doShow(const TDesC& aHeading, const CClassB& aB);

// Displays the contents of a CClassB object
class CClassC;
LOCAL_C void doShow(const TDesC& aHeading, const CClassC& aC);

// definition of CClassA
class CClassA : public CBase
    {
public :
    static CClassA* NewLC();
    ~CClassA();
    void SetTextL(const TDesC& aData);
    void ExternalizeL(RWriteStream& aStream) const;
    void InternalizeL(RReadStream& aStream);
public :
    HBufC*   iVarBuffer;
    TInt     iIntValue;
    TUint    iUintValue;
    };

// definition of CClassB
class CClassB : public CBase
    {
public :
    static CClassB* NewLC();
    void ExternalizeL(RWriteStream& aStream) const;
    void InternalizeL(RReadStream& aStream);
public :
    TBuf<32> iFixBuffer;
    TUint    iUintValue;
    TInt     iIntValue;
    TReal    iRealValue;
    };

// definition of CClassC
#define KStdirectClassCGranularity 4

class CClassC : public CBase
    {
public :
    static CClassC* NewLC();
    ~CClassC();
    void ConstructL();
    void AddNumberToArrayL(TInt aValue);
    void ExternalizeL(RWriteStream& aStream) const;
    void InternalizeL(RReadStream& aStream);
public :
    TBuf<32>                iFixBuffer;
    CArrayFixFlat<TInt>*    iArray;
    };

// The file name, extension and path for the file store
_LIT(KFullNameOfFileStore, "C:\\epoc32ex\\data\\stdirect.dat");

//  Do the example
LOCAL_C void doExampleL()
    {
    // make sure directory exists
    fsSession.MkDirAll(KFullNameOfFileStore);
    doMakeAndStoreL(KFullNameOfFileStore);
    doRestoreL(KFullNameOfFileStore);
    }

LOCAL_C void doMakeAndStoreL(const TDesC& aName)
    {
    // Construct an object of type CClassA and put some data into it
    _LIT(KTxtForClassA, "Text for CClassA");
    CClassA* theA = CClassA::NewLC();
    theA->SetTextL(KTxtForClassA);    
    theA->iIntValue  = -1;
    theA->iUintValue = 2;

    // Construct an object of type CClassB and put some data into it
    _LIT(KTxtForClassB, "Text for CClassB");
    CClassB* theB = CClassB::NewLC();
    theB->iFixBuffer = KTxtForClassB;
    theB->iIntValue  = -3;
    theB->iUintValue = 4; 
    theB->iRealValue = 5.6;

    // Construct an object of type CClassC and put some data into it
    _LIT(KTxtForClassC, "Text for CClassC");
    CClassC* theC = CClassC::NewLC();
    theC->iFixBuffer = KTxtForClassC;    
    theC->AddNumberToArrayL(21);
    theC->AddNumberToArrayL(42);
    theC->AddNumberToArrayL(101);

    // Show contents of the CClassA object
    _LIT(KTxtClassAContent, "CClassA content ...");
    doShow(KTxtClassAContent, *theA);

    // Show contents of the CClassB object
    _LIT(KTxtClassBContent, "CClassB content ...");
    doShow(KTxtClassBContent, *theB);                    

    // Show contents of the CClassC object
    _LIT(KTxtClassCContent, "CClassC content ...");
    doShow(KTxtClassCContent, *theC);                    
                
    TParse filestorename;
    fsSession.Parse(aName, filestorename);
    CFileStore* store = CDirectFileStore::ReplaceLC(fsSession, filestorename.FullName(), EFileWrite);
    store->SetTypeL(KDirectFileStoreLayoutUid);

    RStoreWriteStream outstream;
    TStreamId id = outstream.CreateLC(*store);
    outstream  << *theA << *theB << *theC; 

    // Equally we could have done:
    //        outstream << *theA;
    //        outstream << *theB;
    //        outstream << *theC;
    // to the same effect
    
    // The order in which the objects are written out is
    // arbitrary, but it is important to note that 
    // THE ORDER IN WHICH THEY ARE WRITTEN OUT IS THE SAME
    // AS THE ORDER IN WHICH THEY WILL BE READ IN LATER !
                
    outstream.CommitL();
    CleanupStack::PopAndDestroy();
    store->SetRootL(id);
    store->CommitL();

    // Destroy the direct file store object (closes the file),
    // Destroy the CClassC object,
    // Destroy the CClassB object,
    // Destroy the CClassA object.
    CleanupStack::PopAndDestroy(4, theA);
    }

LOCAL_C void doRestoreL(const TDesC& aName)
    {
    // Construct "empty" CClassA, CClassB and CClassC objects
    CClassA* theA = CClassA::NewLC();
    CClassB* theB = CClassB::NewLC();
    CClassC* theC = CClassC::NewLC();
                    
    TParse filestorename;
    fsSession.Parse(aName, filestorename);
    CFileStore* store = CDirectFileStore::OpenLC(fsSession, filestorename.FullName(), EFileRead);
    RStoreReadStream instream;
    instream.OpenLC(*store, store->Root());
    instream  >> *theA >> *theB >> *theC; 

    // Equally we could have done:
    //        instream >> *theA;
    //        instream >> *theB;
    //        instream >> *theC;
    // to the same effect

    CleanupStack::PopAndDestroy();

    // Show restored contents of the CClassA object
    _LIT(KTxtRestoredCClassA, "Restored CClassA content ...");
    doShow(KTxtRestoredCClassA, *theA);

    // Show restored contents of the CClassB object
    _LIT(KTxtRestoredCClassB, "Restored CClassB content ...");
    doShow(KTxtRestoredCClassB, *theB);                    

    // Show restored contents of the CClassC object
    _LIT(KTxtRestoredCClassC, "Restored CClassC content ...");
    doShow(KTxtRestoredCClassC, *theC);    
                
    CleanupStack::PopAndDestroy(4, theA);
    }
    
_LIT(KTxtNewLine,   "\n");
_LIT(KFormatType1,  "\n%S, ");
_LIT(KFormatType2,  "%d, ");
_LIT(KFormatType3,  "%u  ");
_LIT(KFormatType4,  "%u, ");
_LIT(KFormatType5,  "%f  ");                    
            
LOCAL_C void doShow(const TDesC& aHeading, const CClassA& anA)
    {
    console->Printf(KTxtNewLine);
    console->Printf(aHeading);
    console->Printf(KFormatType1, anA.iVarBuffer);
    console->Printf(KFormatType2, anA.iIntValue);
    console->Printf(KFormatType3, anA.iUintValue);
    console->Printf(KTxtNewLine);
    }

LOCAL_C void doShow(const TDesC& aHeading, const CClassB& aB)
    {
    console->Printf(KTxtNewLine);
    console->Printf(aHeading);
    console->Printf(KFormatType1, &aB.iFixBuffer);
    console->Printf(KFormatType2, aB.iIntValue);
    console->Printf(KFormatType4, aB.iUintValue);
    console->Printf(KFormatType5, aB.iRealValue);
    console->Printf(KTxtNewLine);
    }

_LIT(KTxtNoArrayItems,  "<No array items>");
_LIT(KTxtColonsep,      ": ");
_LIT(KTxtCommasep,      ", ");
_LIT(KFormatType6,      "%d array item(s)");
_LIT(KFormatType7,      "%S%d");

LOCAL_C void doShow(const TDesC& aHeading, const CClassC& aC)
    {
    console->Printf(KTxtNewLine);
    console->Printf(aHeading);
    console->Printf(KFormatType1, &aC.iFixBuffer);
    
    TInt count = aC.iArray->Count();
    if (!count)
        {
        console->Printf(KTxtNoArrayItems);
        }
    else
        {
        TPtrC ptr;
        ptr.Set(KTxtColonsep);
        console->Printf(KFormatType6, count);
        for (TInt index = 0; index < count; index++)
            {
            console->Printf(KFormatType7, &ptr, (*aC.iArray)[index]);
            ptr.Set(KTxtCommasep);        
            }
        }
    console->Printf(KTxtNewLine);
    }

/////////////////////////////////////////////////////////////////
CClassA* CClassA::NewLC()
    {
    CClassA* self = new(ELeave) CClassA;
    CleanupStack::PushL(self);
    return self;
    }
    
CClassA::~CClassA()
    {
    delete iVarBuffer;
    }

void CClassA::SetTextL(const TDesC& aData)
    {
    iVarBuffer = aData.AllocL();    
    }

void CClassA::ExternalizeL(RWriteStream& aStream) const
    {
    aStream.WriteInt32L(iVarBuffer->Des().MaxLength());
    aStream << *iVarBuffer;
    aStream.WriteInt32L(iIntValue);
    aStream.WriteUint32L(iUintValue);
    }  
 
void CClassA::InternalizeL(RReadStream& aStream)
    {
    TInt maxlen;
    maxlen     = aStream.ReadInt32L();
    iVarBuffer = HBufC::NewL(aStream,maxlen);
    iIntValue  = aStream.ReadInt32L();
    iUintValue = aStream.ReadUint32L();
    }  
         

/////////////////////////////////////////////////////////////////
CClassB* CClassB::NewLC()
    {
    CClassB* self = new(ELeave) CClassB;
    CleanupStack::PushL(self);
    return self;
    }

//TODO Implement the following function
void CClassB::ExternalizeL(RWriteStream& /* aStream */) const
    {
    }  
 
void CClassB::InternalizeL(RReadStream& aStream)
    {
    aStream >> iFixBuffer;
    iIntValue  = aStream.ReadInt32L();
    iUintValue = aStream.ReadUint32L();
    iRealValue = aStream.ReadReal64L();
    }  

/////////////////////////////////////////////////////////////////
CClassC* CClassC::NewLC()
    {
    CClassC* self = new(ELeave) CClassC;
    CleanupStack::PushL(self);
    self->ConstructL();
    return self;
    }
    
void CClassC::ConstructL()
    {
    iArray = new(ELeave) CArrayFixFlat<TInt>(KStdirectClassCGranularity);
    }

void CClassC::AddNumberToArrayL(TInt aValue)
    {
    iArray->AppendL(aValue);
    }

CClassC::~CClassC()
    {
    delete iArray;
    }

void CClassC::ExternalizeL(RWriteStream& aStream) const
    {
    aStream << iFixBuffer;

    TInt count;
    count = iArray->Count();
    aStream.WriteInt32L(count);
    for (TInt index = 0; index < count; index++)
        {
        aStream.WriteInt32L((*iArray)[index]);
        }
    }  

//TODO implement the following function 
void CClassC::InternalizeL(RReadStream& /* aStream */)
    {
    }