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examples/SysLibs/EzlibExample/ezlibexample.cpp

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// Copyright (c) 2007-2009 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:
// This example program demonstrates the use of the Ezlib API. 
// The code demonstrates how to 
// -# Open a ZIP file and get the properties of each file
// -# Extract a selected member of the ZIP file and save it to a new file. 
// -# Save all the members of a ZIP file to a file.
// -# Open a GZIP file and extract the contents to a file. 
// -# Compress a file into a GZIP file.
//



#include "ezlibexample.h"
#include <e32cons.h>
#include <ezgzip.h>

_LIT(KTitle, "Ezlib example");
_LIT(KTextPressAKey, "\n\nPress any key to step through the example\n");
_LIT(KExit,"\nPress any key to exit the application");
_LIT(KPressAKey,"\nPress any key to continue \n");
_LIT(KProperties,"Press any key to have a look at the properties of the zipped files \n");
_LIT(KDecompress,"Gzip file successfully decompressed\n");
_LIT(KCompress,"\nFile successfully compressed to gzip format and saved\n");
_LIT(KNoFilesFound,"No appropriate files located in this folder.\r\n");
_LIT(KLineSpace, "\r\n");
_LIT(KFileInfo,"\nCompressing file %S");
_LIT(KFileOpen,"\nOpening file: %S\r\n");
_LIT(KFileExtract,"\nExtracting the file %S\n");
_LIT(KFileZipExtract,"\nExtracting files from the zip file %S\n");

#if defined(__WINS__)
_LIT(KCInputZipFile, "\\private\\E80000B7\\zip\\input\\EzlibZipFolder.zip");
_LIT(KCInputGzipPath, "\\private\\E80000B7\\gzip\\error.wav");
_LIT(KCInputGzipFile, "\\private\\E80000B7\\gzip\\icon.bmp.gz");
#endif

#if defined(__EPOC32__)
_LIT(KZInputZipFile, "z:\\private\\E80000B7\\zip\\input\\EzlibZipFolder.zip");
_LIT(KZInputGzipPath, "z:\\private\\E80000B7\\gzip\\error.wav");
_LIT(KZInputGzipFile, "z:\\private\\E80000B7\\gzip\\icon.bmp.gz");
#endif

_LIT(KZipName,"\nName:                  %S      ");
_LIT(KZipCRC32,"\nCRC32:                        %X      ");
_LIT(KZipCSize,"\nCompressed Size:      %d");
_LIT(KZipUCSize,"\nUncompressed Size:   %d");
_LIT(KOpenedSuccessfully, "%S opened successfully.\n");

_LIT(KExtractZipPathMulti, "\\private\\E80000B7\\zip\\extracts\\");
_LIT(KExtractZipPathSingle, "\\private\\E80000B7\\zip\\extracts\\singlefile\\");
_LIT(KCompressGzipPath, "\\private\\E80000B7\\gzip\\extracts\\");
_LIT(KCompressZipFile, "icon.bmp");
_LIT(KExtractGzipFile, "error.wav");

CEzlibExample * CEzlibExample::NewLC()
        {
        CEzlibExample * rep = new(ELeave) CEzlibExample();
        CleanupStack::PushL(rep);
        rep->ConstructL();
        return rep;
        }
        
CEzlibExample::CEzlibExample()
        {
        }       

void CEzlibExample::ConstructL()
        {       
        iConsole = Console::NewL(KTitle,TSize(KConsFullScreen,KConsFullScreen));
        iConsole->Printf(KTextPressAKey);
        iConsole->Getch();
        }

CEzlibExample::~CEzlibExample()
        {
        iConsole->Printf(KExit);
        iConsole->Getch();
        
        delete iConsole;
        }
        
        
void CEzlibExample::GetPropertiesL(TFileName& aFileName, RFs& aFsSession)
        {
        CZipFile* zipFile = 0;
        CZipFileMember* member = 0;
        CZipFileMemberIterator* fileMembers;

        iConsole->Printf(KFileOpen, &aFileName);
        
        zipFile = CZipFile::NewL(aFsSession, aFileName);
        CleanupStack::PushL(zipFile);
        
        iConsole->Printf(KOpenedSuccessfully, &aFileName);
        
        // Search for a file in the zip archive.
        // The name of the file to be searched for 
        // in the zipfile is case-insensitive.
        _LIT(KSearchFile, "EzlibZipFolder\\icon.bmp");
        member = zipFile->CaseInsensitiveMemberL(KSearchFile);
        CleanupStack::PushL(member);
        if(member != NULL)
                {
                // Extract the file that was searched for and found.
                ExtractFilesL(member, zipFile, aFsSession, KExtractZipPathSingle);
                iConsole->Printf(KFileExtract, &KSearchFile);                   
                }
        else
                {
                iConsole->Printf(KNoFilesFound);
                }
        CleanupStack::PopAndDestroy(member);    
        // Gets the iterator used for iterating through the files 
        // contained in the ZIP file.   
        fileMembers = zipFile->GetMembersL();
        CleanupStack::PushL(fileMembers);
        // Moves the entry iterator onto the next 
        // zip file member contained in the ZIP file
        member = fileMembers->NextL();

        iConsole->Printf(KFileZipExtract, &aFileName);
        iConsole->Printf(KProperties);
        iConsole->Getch();
        
        // Get the properties of all the files
        while(member != NULL)
                {
                CleanupStack::PushL(member);
                
                // Retrieve CRC(Cyclic Redundancy Check) value in a compressed file 
                // contained in a CZipFile archive file.
                TUint32 redundencyCode = member->CRC32();
                
                // Retrieve the size of uncompressed file 
                // contained in a CZipFile archive file.
                TUint32 UnCompSize = member->UncompressedSize();
                
                // Retrieve the size of compressed file 
                // contained in a CZipFile archive file.
                TUint32 CompSize = member->CompressedSize();
                
                // Print the properties
                // Name of the zipped file
                TFileName fileName = *member->Name();
                iConsole->Printf(KZipName, &fileName);
                
                // CRC value which will be printed in hexadecimal
                iConsole->Printf(KZipCRC32, redundencyCode);
                
                // Size of the compressed file
                iConsole->Printf(KZipCSize, CompSize);
                
                // Original size of te file
                iConsole->Printf(KZipUCSize,UnCompSize);
                
                // Extract each member in the zip file
                ExtractFilesL(member, zipFile, aFsSession, KExtractZipPathMulti);
                
                CleanupStack::PopAndDestroy(member); 
                member = fileMembers->NextL();
                }
                
        CleanupStack::PopAndDestroy(fileMembers); 
        CleanupStack::PopAndDestroy(zipFile);
        }
        
void CEzlibExample::ExtractFilesL(const CZipFileMember* aMember, CZipFile* aZipFile, RFs& aFsSession, const TDesC& aOutputPath)
        {
        TInt loop = 0;
        // Allocate memory for the retrieved name of a 
        // compressed file contained in a CZipFile archive file.
        HBufC* name = aMember->Name()->AllocLC();
        while(loop < name->Length())
                {
                if((*name)[loop] == '/')
                        {
                        name->Des()[loop] = '\\';
                        }
                loop++;
                }
        
        // Create the directory to which the files need to be extracted.
        TFileName fn;
        fn.Append(aOutputPath);
        // Append the name of the file to the directory 
        // where the file would get extracted.
        fn.Append(*name);
        aFsSession.MkDirAll(fn);
        
        RFile extractedMember;
        extractedMember.Replace(aFsSession,fn, EFileShareAny|EFileWrite);
        CleanupClosePushL(extractedMember);
        
        RZipFileMemberReaderStream* fileStream;
        // Create and return the input stream for a file in the archive.
        TInt error = aZipFile->GetInputStreamL(aMember, fileStream);
        if(error != KErrNone)
                {
                _LIT(KCompressionNotSupported, "Error! Compression Method Not Supported");
                iConsole->Printf(KCompressionNotSupported);
                iConsole->Printf(KLineSpace);
                CleanupStack::PopAndDestroy(2,name); //expanded member, name
                aFsSession.Delete(fn);
                return;
                }
        CleanupStack::PushL(fileStream);

        // Retrieve the size of uncompressed file contained 
        // in a CZipFile archive file.
        TUint16 size = aMember->UncompressedSize();

        RBuf8 bytes;
        bytes.CreateL(size);
        bytes.CleanupClosePushL();

        // Read the specified number of bytes of binary data 
        // from the file at the current position.
        User::LeaveIfError(fileStream->Read(bytes,size));
        // Write to the file
        User::LeaveIfError(extractedMember.Write(bytes));
        
        CleanupStack::PopAndDestroy(4,name); // bytes, fileStream, expanded member and name
        
        }

void CEzlibExample::ExtractGzipFileL(RFs& aFsSession)
        {
        iConsole->Printf(KPressAKey);
        iConsole->Getch();
          
         #if defined(__WINS__)
        TFileName gzipInputFileName(KCInputGzipFile);   
        #endif
        
        #if defined(__EPOC32__)
        TFileName gzipInputFileName(KZInputGzipFile);
        #endif
                                                        
        //TFileName gzipInputFileName(KInputGzipFile);

        RFile input;
        RFile output;

        User::LeaveIfError(input.Open(aFsSession, gzipInputFileName, EFileStream | EFileRead | EFileShareAny));
        CleanupClosePushL(input);
        
        TFileName outputFile(KCompressGzipPath);
        // Append the path to the directory where you want to 
        // store the uncompressed file.
        aFsSession.MkDirAll(outputFile);
        outputFile.Append(KCompressZipFile);
        
        // Create and open icon.bmp on 
        // c:\private\E80000B7\gzip\extracts\ folder.
        output.Replace(aFsSession, outputFile, EFileStream | EFileWrite | EFileShareExclusive);
        CleanupClosePushL(output);
        
        // icon.bmp.gz file is the input file
        TPtrC inputFile = gzipInputFileName;
        
        RBuf uncompressedFile;
        uncompressedFile.CreateL(outputFile.Length());
        uncompressedFile.CleanupClosePushL();

        _LIT(KUfl,"%S");
        // Format and copy the filename into the descriptor
        uncompressedFile.Format(KUfl,&inputFile);

        _LIT(KInfo,"\nDecompressing file %S\n");
        iConsole->Printf(KInfo,&inputFile);
        
        CEZGZipToFile *def = CEZGZipToFile::NewLC(aFsSession,uncompressedFile,output);
        
        // Decompress the gzip file
        while(def->InflateL())
                {
                // InflateL decompresses the file in stages. 
                // It returns false when decompression is complete
                }
        iConsole->Printf(KDecompress);
        
        CleanupStack::PopAndDestroy(4); // input, output, uncompressedFile, def

        }
        
void CEzlibExample::CompressToGzipFileL(RFs& aFsSession)
        {
        iConsole->Printf(KPressAKey);
        iConsole->Getch();
        
        #if defined(__WINS__)
        TFileName inputFileToBeGzipped(KCInputGzipPath);        
        #endif
        
        #if defined(__EPOC32__)
        TFileName inputFileToBeGzipped(KZInputGzipPath);
        #endif
        //TFileName inputFileToBeGzipped(KInputGzipPath);

        RFile input;
        
        User::LeaveIfError(input.Open(aFsSession, inputFileToBeGzipped, EFileStream | EFileRead | EFileShareAny));
        CleanupClosePushL(input);
        
        // Set the output path to the directory where you 
        // want to store the compressed file.
        TFileName outputFile(KCompressGzipPath);
        aFsSession.MkDirAll(outputFile);
        outputFile.Append(KExtractGzipFile);
        
        iConsole->Printf(KFileInfo, &inputFileToBeGzipped);
        
        // Prevent the length of the descriptor to which data is written,
        // from exceeding its maximum length by appending additional length.
        const TInt extensionLength = 3;
        
        RBuf compressedFile;
        compressedFile.CreateL(outputFile.Length() + extensionLength);
        compressedFile.CleanupClosePushL();

        _LIT(KAppendExtension,"%S.gz");
        // Format and copy the filename into the descriptor
        compressedFile.Format(KAppendExtension,&outputFile);
        
        CEZFileToGZip *def = CEZFileToGZip::NewLC(aFsSession, compressedFile, input);
        // Compress the file to gzip format
        while(def->DeflateL())
                {
                // DeflateL compresses the file in stages. 
                // It returns false when compression is complete
                }
        
        iConsole->Printf(KCompress);

        CleanupStack::PopAndDestroy(3); // def, compressedFile, input

        }

                        
LOCAL_C void MainL()
        {
        // Create an Active Scheduler to handle asychronous calls
        CActiveScheduler* scheduler = new(ELeave) CActiveScheduler;
        CleanupStack::PushL(scheduler);
        CActiveScheduler::Install( scheduler );
        
        CEzlibExample * app = CEzlibExample::NewLC();

        RFs fsSession;  
        // Connect to file session
        User::LeaveIfError(fsSession.Connect());
        
        // Create the private directory on the writable drive
        // i.e. "\private\E80000B7\"
        // Note that the number E80000B7 is the process security id 
        // taken from the 2nd UID specified in the mmp file.

    fsSession.CreatePrivatePath(RFs::GetSystemDrive());
    // Set the session path to this private directory on the writable drive
    fsSession.SetSessionToPrivate(RFs::GetSystemDrive());
        
        // Get the properties of files in the zip file
        #if defined(__WINS__)
        TBuf<256> inputFileName(KCInputZipFile);        
        #endif
        
        #if defined(__EPOC32__)
        TBuf<256> inputFileName(KZInputZipFile);
        #endif
        
        app->GetPropertiesL(inputFileName, fsSession);
        
        // Compress a file to gzip format
        app->CompressToGzipFileL(fsSession);
        
        // Extract a gzip file
        app->ExtractGzipFileL(fsSession);
                
        CleanupStack::PopAndDestroy(2); //app, scheduler
        // Close the file session
        fsSession.Close();
        
        }

GLDEF_C TInt E32Main()
        {
    __UHEAP_MARK;
    CTrapCleanup* cleanup = CTrapCleanup::New();
    if(cleanup == NULL)
        {
        return KErrNoMemory;
        }
    TRAPD(err, MainL());
        if(err != KErrNone)
                {
                User::Panic(_L("Failed to complete"),err);
                }

    delete cleanup;
    __UHEAP_MARKEND;
    return KErrNone;
        }

        

---

Copyright ©2010 Nokia Corporation and/or its subsidiary(-ies).
All rights reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License v1.0.