compressionlibs/ziplib/test/oldezlib/zip/ZipFile.cpp
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compressionlibs/ziplib/test/oldezlib/zip/ZipFile.cpp	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,909 @@
+// Copyright (c) 2003-2009 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:
+// $Revision: 1.1 $
+// 
+//
+
+
+
+#include <caf/content.h>
+#include <caf/data.h>
+#include "oldzipfile.h"
+
+using namespace TOLDEZIP;
+// ====================================================================
+// CZipFile public exported interface
+// ====================================================================
+
+/**
+Creates a new CZipFile object using the supplied file server session and 
+a valid file handle. The caller must have sufficient sufficient rights to 
+access the content of the zipfile, if encrypted/protected.
+
+@param aFs File server session used for opening the zipfile
+@param aFile File handle to be used for accessing the zipfile
+@return CZipFile object associated with the zipfile if it succeeded
+@leave KZipArchiveError If file cannot be accessed(invalid handle, corrupt file header, etc.)
+@leave KZipFileIOError If file cannot be read
+@leave KCentralDirectoryTrailerNotFound If zip file header doesn't contain information about files inside the archive
+@leave KCentralDirectoryTrailerInvalid If the information about files inside the archive is corrupt
+@leave KMultiDiskArchivesNotSupported If zipfile is a multi disk archive
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C CZipFile* CZipFile::NewL(RFs& aFs, RFile& aFile)
+	{
+	TFileName file;
+	aFile.Name(file);
+	CZipFile* zipFile = new(ELeave) CZipFile(aFs, file);
+	CleanupStack::PushL(zipFile);
+	zipFile->ConstructL(aFile);
+	CleanupStack::Pop(zipFile);
+	return zipFile;
+	}
+	
+/**
+Creates a new CZipFile object using the supplied file server session and 
+file name. The caller must have sufficient capabilities to access the directory. 
+The caller must also have sufficient rights to access the content of the 
+zipfile, if encrypted/protected.
+
+@param aFs File server session used for opening the zipfile
+@param aFileName Name of the zipfile 
+@return CZipFile object associated with the zipfile if it succeeded
+@leave KZipArchiveError If file cannot be accessed(invalid handle, corrupt file header, etc.)
+@leave KZipFileIOError If file cannot be read
+@leave KCentralDirectoryTrailerNotFound If zip file header doesn't contain information about files inside the archive
+@leave KCentralDirectoryTrailerInvalid If the information about files inside the archive is corrupt
+@leave KMultiDiskArchivesNotSupported If zipfile is a multi disk archive. 
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C CZipFile* CZipFile::NewL(RFs& aFs, const TDesC& aFileName)
+	{
+	CZipFile* zipFile = new(ELeave) CZipFile(aFs, aFileName);
+	CleanupStack::PushL(zipFile);
+	zipFile->ConstructL(aFileName);
+	CleanupStack::Pop(zipFile);
+	return zipFile;
+	}
+
+/**
+Destructor
+*/
+EXPORT_C CZipFile::~CZipFile()
+	{
+	DeleteMemberPointers();
+	}
+
+/** 
+@deprecated in 7.0 
+*/
+EXPORT_C CZipFile::CZipFile(RFs& aFs, const TDesC& aFileName)
+	: iFileName(aFileName), iFs(aFs)
+	{
+	}
+ 
+/** 
+@deprecated in 7.0 
+*/	
+EXPORT_C TInt CZipFile::OpenL(void)
+	{
+	if (!iMemberPointers)
+		{
+		ConstructL(iFileName);
+		}
+	return KErrNone;
+	}
+	
+/** 
+@deprecated in 7.0 
+*/
+EXPORT_C void CZipFile::Close(void)
+	{
+	DeleteMemberPointers();
+	}
+
+/**
+Second phase of construction. Used by Rfile using NewL overload.
+
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C void CZipFile::ConstructL(RFile& aFile)
+	{
+	// Use the full name derived from the session path
+	ContentAccess::CContent* content = 
+		ContentAccess::CContent::NewL(aFile);
+	CleanupStack::PushL(content);
+	iData = content->OpenContentL(ContentAccess::EPeek);
+
+	// Parent content object no longer needed because we only need data
+	CleanupStack::PopAndDestroy(content);
+
+	// Seek to the end
+	TInt length = 0;
+	User::LeaveIfError(iData->Seek(ESeekEnd, length));
+	iFileLength = length;
+
+	TInt status;
+	TUint32 offset;
+
+	if ((status = FindCentralDirectoryTrailer(offset)) != KErrNone) 
+		{
+		DeleteMemberPointers();
+		User::Leave(status);
+		}
+
+	if ((status = ReadCentralDirectoryTrailer(offset, iTrailer)) != KErrNone) 
+		{
+		DeleteMemberPointers();
+		User::Leave(status);
+		}
+
+	if (iTrailer.iStartDiskNumber != iTrailer.iDiskNumber) 
+		{
+		DeleteMemberPointers();
+		User::Leave(KMultiDiskArchivesNotSupported);
+		}
+
+	if ((iTrailer.iOffset + iTrailer.iSize) > iFileLength)
+		{
+		DeleteMemberPointers();
+	    User::Leave(KCentralDirectoryTrailerInvalid);
+		}
+
+	if (LoadMemberPointersL() != KErrNone)
+		{
+		User::Leave(KZipFileIOError);
+		}	
+	}
+
+/**
+Second phase of construction. Used by filename using NewL overload
+
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C void CZipFile::ConstructL(const TDesC& aFileName)
+	{
+	TInt status;
+	TUint32 offset;
+	
+	TRAP(status, OpenFileL(aFileName));
+	if (status)
+		{
+		User::Leave(KZipArchiveError);
+		}
+	else
+	if ((status = FindCentralDirectoryTrailer(offset)) != KErrNone) 
+		{
+		DeleteMemberPointers();
+		User::Leave(status);
+		}
+	else 
+	if ((status = ReadCentralDirectoryTrailer(offset, iTrailer)) != KErrNone) 
+		{
+		DeleteMemberPointers();
+		User::Leave(status);
+		}
+	else 
+	if (iTrailer.iStartDiskNumber != iTrailer.iDiskNumber) 
+		{
+		DeleteMemberPointers();
+		User::Leave(KMultiDiskArchivesNotSupported);
+		}
+	else
+	if ((iTrailer.iOffset > iFileLength) ||
+	    ((iTrailer.iOffset + iTrailer.iSize) > iFileLength)) 
+		{
+		DeleteMemberPointers();
+	    User::Leave(KCentralDirectoryTrailerInvalid);
+		}
+	else
+	if (LoadMemberPointersL() != KErrNone)
+		{
+		User::Leave(KZipFileIOError);
+		}	
+	}
+
+/**
+Gets the size of the compressed data contained in the zip file in bytes
+Each CZipFile object has a compressed and uncompressed size. This method will 
+return the compressed size of a zip file.
+
+@param aSize On return, the size of the compressed data in bytes
+@return KErrNotReady If object hasn't been properly constructed
+@return KErrCASizeNotDetermined	If size could not be determined 
+@return ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C TInt CZipFile::Size(TInt& aSize) const
+{
+	TInt err = KErrNotReady;
+	if (iData)
+		{
+		TRAP(err, iData->DataSizeL(aSize));
+		}
+	return err;
+}
+
+/**
+Constructs and returns a CZipFileMember object which is used to access 
+information about a compressed file contained in the CZipFile archive. 
+The name of the file to be searched for in the zipfile is case-sensitive. 
+
+@param aName The name of the file to be searched in the zipfile 
+@return the pointer to CZipFileMember object
+@return NULL if the file doesn't exist in the zipfile
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C CZipFileMember* CZipFile::MemberL(const TDesC& aName)
+	{
+	TLocalHeader		  header;
+	const TMemberPointer* memberPointer;
+	HBufC* localName = aName.AllocL();
+	TInt loop = 0;
+	while (loop < localName->Length())
+		{
+		if ((*localName)[loop] == '\\')
+			{
+			(localName->Des())[loop] = '/';
+			}
+		loop++;
+		}
+	
+	memberPointer = FindMemberPointer(*localName, EFalse);
+	if (memberPointer == NULL)
+		{
+		delete localName;
+		return NULL;
+		}
+	else
+	if (ReadLocalHeader(memberPointer->iLocalHeaderOffset, header) != KErrNone)
+		{
+		delete localName;
+		return NULL;
+		}
+	else
+		{
+		CleanupStack::PushL(localName);
+		CZipFileMember* thisMember = MakeMemberL(*memberPointer, header);
+		CleanupStack::PopAndDestroy();		// localName
+		return thisMember;
+		}
+	}
+
+/**
+Constructs and returns a CZipFileMember object which is used to access 
+information about a compressed file contained in the CZipFile archive. 
+The name of the file to be searched for in the zipfile is case-insensitive.
+
+@param aName The name of the file to be searched in the zipfile 
+@return A pointer to a member object of zip file
+@return NULL If the file doesn't exist in the zipfile
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C CZipFileMember* CZipFile::CaseInsensitiveMemberL(const TDesC& aName)
+{
+	TLocalHeader		  header;
+	const TMemberPointer* memberPointer;
+	HBufC* localName = aName.AllocL();
+	TInt loop=0;
+	while (loop < localName->Length())
+		{
+		if ((*localName)[loop] == '\\')
+			{
+			(localName->Des())[loop] = '/';
+			}
+		loop++;
+		}
+	
+	memberPointer = FindMemberPointer(*localName, ETrue);
+	if (memberPointer == NULL)
+		{
+		delete localName;
+		return NULL;
+		}
+	else
+	if (ReadLocalHeader(memberPointer->iLocalHeaderOffset, header) != KErrNone)
+		{
+		delete localName;
+		return NULL;
+		}
+	else
+		{
+		CleanupStack::PushL(localName);
+		CZipFileMember* thisMember = MakeMemberL(*memberPointer, header);
+		CleanupStack::PopAndDestroy();
+		return thisMember;
+		}
+
+	}
+
+/**
+Constructs and returns a CZipFileMember object which is used to access 
+information about a compressed file contained in the CZipFile archive. 
+An exact match for the filename is searched for first. If a match is not found, 
+a case-insensitive search is performed. If both filenames exist in the archive, 
+the case-sensitive match will be returned.
+ 
+@param aName The name of the file to be searched in the zipfile 
+@return A pointer to a member object of zip file
+@return NULL If the file doesn't exist in the zipfile
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C CZipFileMember* CZipFile::CaseSensitiveOrCaseInsensitiveMemberL(const TDesC& aName)
+{
+	CZipFileMember* member;
+	member = MemberL(aName);
+	if (member)
+		{
+		return member;
+		}
+	else
+		{
+		return CaseInsensitiveMemberL(aName);
+		}
+}
+
+/**
+Creates and returns the input stream for a file in the archive. Only files 
+compressed with Stored or Deflated compression methods are supported.
+
+@param aMember The compressed file in the archive
+@param aStream On return, the stream to be used for reading the contents of the compressed file.  The caller owns this object and is responsible for deleting it.
+@return KErrNone if successful
+@return KCompressionMethodNotSupported if compression format unsupported 
+@return ... Any one of the system-wide error codes for other errors.
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C TInt CZipFile::GetInputStreamL(const CZipFileMember* aMember, RZipFileMemberReaderStream*& aStream)
+	{
+	TUint32 compressionMethod;
+	
+	compressionMethod = aMember->iCompressionMethod;
+	if ((compressionMethod != EStored) && (compressionMethod != EDeflated)) 
+	    {
+	    return KCompressionMethodNotSupported;
+	    }
+	aStream = RZipFileMemberReaderStream::NewL(
+								*this,
+							   aMember->iDataOffset,
+							   aMember->iCompressedSize,
+							   aMember->iUncompressedSize,
+							   compressionMethod);
+	return KErrNone;
+	}
+	
+
+
+/**
+Gets the iterator used for iterating through the files contained in the ZIP 
+file. It is the caller's responsibility to release the iterator when finsihed.
+ 
+@return Pointer to a newly allocated CZipFileMemberIterator object
+@leave ... Any one of the system-wide error codes for other errors.
+*/
+EXPORT_C CZipFileMemberIterator* CZipFile::GetMembersL()
+	{
+	return new (ELeave) CZipFileMemberIterator(this);
+	}
+	
+
+
+// Implementation
+
+/*
+ * Find the 'end of central directory record'. This is at the 'end' of
+ * the file, but since it is not a fixed length structure, we have to
+ * hunt for it.
+ *
+ * We try assuming that the variable length section of the record is
+ * empty, which usually appears to be the case.
+ *
+ * If this does not work we resort to 'walking backwards' through the
+ * file looking for the signature bytes.
+ *
+ */
+ 
+TInt CZipFile::FindCentralDirectoryTrailer(TUint32& offset)
+{
+	TBuf8<KSignatureLength> signature;
+		
+    if (iFileLength <= KCentralDirectoryTrailerFixedLength) 
+		{
+    	return KZipArchiveError;
+		}
+    // Try the obvious place first.Assuming that the comment (variable 
+    // length section) is empty,try to find the signature at the offset.
+    offset = iFileLength - KCentralDirectoryTrailerFixedLength;
+	if (Seek(offset) != KErrNone) 
+		{
+    	return KZipFileIOError;
+		}
+	TInt err = iData->Read(signature);
+
+	if ( err != KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+
+	if ((signature[0] == 0x50) && 
+		(signature[1] == 0x4b) &&
+		(signature[2] == 0x05) &&
+		(signature[3] == 0x06)) 
+		{
+		return KErrNone;
+		}
+	else 
+		{
+		// There must be some comments, hence the central directory 
+		// record > 22 bytes.
+		// This is a slow but fairly obvious way of searching 
+		// backwards through the file starting from the offset.
+		TUint EndOfTrailerSearch = 0; //Upto beginning of File
+
+		if(iFileLength > KMaxTrailerSearchLength+KCentralDirectoryTrailerFixedLength)
+			EndOfTrailerSearch = offset - KMaxTrailerSearchLength; //Upto Last 64K+22 bytes
+
+		while (offset >= EndOfTrailerSearch) 
+			{
+			if (Seek(offset) != KErrNone)
+				{
+				return KZipFileIOError;
+				}
+			if (iData->Read(signature) != KErrNone)
+				{
+				return KZipFileIOError;
+				}
+			if ((signature[0] == 0x50) && 
+				(signature[1] == 0x4b) &&
+				(signature[2] == 0x05) &&
+				(signature[3] == 0x06)) 
+				{			
+				return KErrNone;
+				}
+			--offset;
+			}
+		return KCentralDirectoryTrailerNotFound;
+		}	
+	}
+	
+TInt CZipFile::ReadCentralDirectoryTrailer(TUint32 offset, struct TCentralDirectoryTrailer& r )
+{
+    // Skip the signature		    
+    if (Seek(offset + KSignatureLength) != KErrNone) 
+    	{
+    	return KZipFileIOError;
+    	} 
+	else
+	if (Read(r.iDiskNumber) != KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+	else
+	if (Read(r.iStartDiskNumber)!= KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+	else
+	if (Read(r.iLocalEntryCount) != KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+	else
+	if (Read(r.iTotalEntryCount) != KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+	else
+	if (Read(r.iSize) != KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+	else
+	if (Read(r.iOffset) != KErrNone) 
+		{
+		return KZipFileIOError;
+		}
+	else
+		{
+		return KErrNone;
+		}
+}
+
+TInt CZipFile::LoadMemberPointersL(void)
+	{
+	TCentralDirectoryHeader	header;
+	TUint32					i;
+	TUint32					memberPointerCount;
+		
+	if (Seek(iTrailer.iOffset) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+	memberPointerCount = iTrailer.iTotalEntryCount;
+	iMemberPointers = new (ELeave) TMemberPointer[memberPointerCount];
+	for (i = 0; i < memberPointerCount; i++)
+		{
+		iMemberPointers[i].iName = NULL;
+		}
+	CCnvCharacterSetConverter* converter = CCnvCharacterSetConverter::NewL();
+	CleanupStack::PushL(converter);
+	TInt converterState = CCnvCharacterSetConverter::KStateDefault;
+	for (i = 0; i < memberPointerCount; i++)
+		{
+		if (ReadCentralDirectoryHeaderL(header, iMemberPointers[i], converter, converterState) != KErrNone)
+			{
+			return KZipFileError;
+			}
+		}
+	CleanupStack::PopAndDestroy(converter);
+	return KErrNone;
+	}
+	
+LOCAL_C void ConvertFileNameToUnicodeL(
+						TDes16& aUnicode,
+						const TDesC8& aForeign,
+						const TUint16& aMadeBy,
+						CCnvCharacterSetConverter* aConverter,
+						TInt aConverterState,
+						RFs aFs)
+// Have to decide whether filename encoding is CP850 or CP1252. According to tec support
+// at WinZip, if 'madeby' is set to DOS(0) then the encoding is CP850 and if it's set to
+// NTFS (11) then it's CP1252.  However, if the MS Compressed Folders program was used
+// to zip, then madeby is always set to NTFS and the encoding is always CP850 - the exact
+// opposite. Because of this confusion, I have written a very basic decision algorithm
+// based on the premise that filenames are likely to use alphabet-style extended
+// characters (rather than box edges or punctuation etc.)
+	{
+	TInt len = aForeign.Length();
+	TInt ANSIpoints = 0;
+	TInt OEMpoints = 0;
+	for (TInt i=0; i<len; i++)
+		{
+		if (aForeign[i] >= 128 && aForeign[i] <= 165)
+			OEMpoints ++;
+		if (aForeign[i] >= 192 && aForeign[i] <= 255)
+			ANSIpoints ++;
+		}
+	if (ANSIpoints == OEMpoints)
+		{
+		if (aMadeBy>>8) //only interested in the upper byte
+			ANSIpoints ++;
+		else
+			OEMpoints ++;
+		}
+	TInt unconvertibleChars = 0;
+
+	CCnvCharacterSetConverter::TAvailability availabilty = CCnvCharacterSetConverter::EAvailable;
+	if (ANSIpoints > OEMpoints)
+		{
+		// It's probably ANSI (CP1252)
+		availabilty = aConverter->PrepareToConvertToOrFromL(KCharacterSetIdentifierCodePage1252,aFs);
+		aConverter->ConvertToUnicode(aUnicode, aForeign, aConverterState, unconvertibleChars);
+		
+		}
+	if (OEMpoints > ANSIpoints || unconvertibleChars)
+		{
+		// It's definitely OEM (CP850)
+ 		availabilty = aConverter->PrepareToConvertToOrFromL(KCharacterSetIdentifierCP850,aFs);
+		if(availabilty != CCnvCharacterSetConverter::EAvailable )
+			{
+			//if cp850 plugin is not available, use cp1252
+			aConverter->PrepareToConvertToOrFromL(KCharacterSetIdentifierCodePage1252, aFs);
+			}
+		
+		aConverter->ConvertToUnicode(aUnicode, aForeign, aConverterState);
+		
+		}
+	}
+
+TInt CZipFile::ReadCentralDirectoryHeaderL(
+		 		   TCentralDirectoryHeader& aHeader, 
+		 		   TMemberPointer&          aMemberPointer,
+				   CCnvCharacterSetConverter* aConverter,
+				   TInt aConverterState)
+/*
+As this function might be called many times and the request will 
+eventually be translated to calls to server to read the data, 
+so performance is the major issue. Try to minimize calls to server.
+Read data in a chunk rather than member-by-member.
+*/
+	{
+	TByte tmpHeader[KCentralDirectoryHeaderFixedLength];
+ 
+	if (Read(tmpHeader,KCentralDirectoryHeaderFixedLength) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+
+	Mem::Copy(&aHeader.iSignature, &tmpHeader[0], 4);
+
+	if (aHeader.iSignature != KCentralDirectoryHeaderSignature)
+		{
+		return KZipFileIOError;
+		}
+
+	Mem::Copy(&aHeader.iMadeBy, &tmpHeader[4], 2);
+	Mem::Copy(&aHeader.iRequired, &tmpHeader[6], 2);
+	Mem::Copy(&aHeader.iFlags, &tmpHeader[8], 2);
+	Mem::Copy(&aHeader.iCompressionMethod, &tmpHeader[10], 2);
+	Mem::Copy(&aHeader.iLastModifiedFileTime, &tmpHeader[12], 2);
+	Mem::Copy(&aHeader.iLastModifiedFileDate, &tmpHeader[14], 2);
+	Mem::Copy(&aHeader.iCRC32, &tmpHeader[16], 4);
+	Mem::Copy(&aHeader.iCompressedSize, &tmpHeader[20], 4);
+	Mem::Copy(&aHeader.iUncompressedSize, &tmpHeader[24], 4);
+	Mem::Copy(&aHeader.iFileNameLength, &tmpHeader[28], 2);
+	Mem::Copy(&aHeader.iExtraFieldLength, &tmpHeader[30], 2);
+	Mem::Copy(&aHeader.iFileCommentLength, &tmpHeader[32], 2);
+	Mem::Copy(&aHeader.iDiskNumberStart, &tmpHeader[34], 2);
+	Mem::Copy(&aHeader.iInternalFileAttributes, &tmpHeader[36], 2);
+	Mem::Copy(&aHeader.iExternalFileAttributes, &tmpHeader[38], 4);
+	Mem::Copy(&aHeader.iLocalHeaderOffset, &tmpHeader[42], 4);
+
+	aMemberPointer.iCRC32             = aHeader.iCRC32;
+	aMemberPointer.iCompressedSize    = aHeader.iCompressedSize;
+	aMemberPointer.iUncompressedSize  = aHeader.iUncompressedSize;
+	aMemberPointer.iLocalHeaderOffset = aHeader.iLocalHeaderOffset;
+    aMemberPointer.iName = new(ELeave) TFileName;
+	
+	TBuf8<KMaxFileName> input;
+	if (iData->Read(input, aHeader.iFileNameLength) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+	ConvertFileNameToUnicodeL(*aMemberPointer.iName, input, aHeader.iMadeBy, aConverter, aConverterState, iFs);
+	
+    // Ignore the remaining fields
+	TInt pos;
+
+	pos = aHeader.iExtraFieldLength;	
+	if (pos != 0)
+		{
+		// Don't pass aHeader.iExtraFieldLength in place of pos
+		// as the below function will update the content of that variable.
+		// In this case, the function is used to ignore the data
+		// by just moving the current file pointer location.
+		if (iData->Seek(ESeekCurrent, pos) != KErrNone) 
+			{
+			return KZipFileIOError;
+			}
+		}
+
+	pos = aHeader.iFileCommentLength;
+	if (pos != 0)
+		{
+		// Don't pass aHeader.iFileCommentLength in place of pos
+		// as the below function will update the content of that variable.
+		// In this case, the function is used to ignore the data
+		// by just moving the current file pointer location.
+		if (iData->Seek(ESeekCurrent, pos) != KErrNone) 
+			{
+			return KZipFileIOError;
+			}
+		}
+
+  	return  KErrNone;
+}
+
+TInt CZipFile::ReadLocalHeader(TUint32 aOffset, TLocalHeader& aHeader)
+/*
+As this function might be called many times and the request will 
+eventually be translated to calls to server to read the data, 
+so performance is the major issue. Try to minimize calls to server.
+Read data in a chunk rather than member-by-member.
+*/
+	{
+	TByte tmpHeader[KLocalHeaderFixedLength];
+
+	if (Seek(aOffset) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+	if (Read(tmpHeader,KLocalHeaderFixedLength) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+	Mem::Copy(&aHeader.iSignature, &tmpHeader[0], 4);
+
+	if (aHeader.iSignature != KLocalHeaderSignature)
+		{
+		return KLocalHeaderSignatureInvalid;
+		}
+
+	Mem::Copy(&aHeader.iVersionNeeded, &tmpHeader[4], 2);
+	Mem::Copy(&aHeader.iFlags, &tmpHeader[6], 2);
+	Mem::Copy(&aHeader.iCompressionMethod, &tmpHeader[8], 2);
+	Mem::Copy(&aHeader.iLastModifiedFileTime, &tmpHeader[10], 2);
+	Mem::Copy(&aHeader.iLastModifiedFileDate, &tmpHeader[12], 2);
+	Mem::Copy(&aHeader.iCRC32, &tmpHeader[14], 4);
+	Mem::Copy(&aHeader.iCompressedSize, &tmpHeader[18], 4);
+	Mem::Copy(&aHeader.iUncompressedSize, &tmpHeader[22], 4);
+	Mem::Copy(&aHeader.iFileNameLength, &tmpHeader[26], 2);
+	Mem::Copy(&aHeader.iExtraFieldLength, &tmpHeader[28], 2);
+
+	return  KErrNone;
+	}
+	
+const CZipFile::TMemberPointer* CZipFile::FindMemberPointer(const TDesC& aName, TBool aCaseInsensitive)
+	{
+	for (TUint32 i = 0; i < iTrailer.iTotalEntryCount; i++)
+		{
+		if (aCaseInsensitive && (!aName.CompareF(*iMemberPointers[i].iName)))
+			{
+			return iMemberPointers + i;
+			}
+		else if (aName == *iMemberPointers[i].iName)
+			{
+			return iMemberPointers + i;
+			}
+		}
+	return NULL;
+	}
+
+RZipFileMemberReaderStream* CZipFile::MakeInputStreamL(
+							TUint32 aDataOffset, 
+							TUint32 aCompressedSize, 
+							TUint32 aUncompressedSize, 
+							TUint32 aCompressionMethod)
+	{
+	return RZipFileMemberReaderStream::NewL(
+						    *this,
+							aDataOffset,
+							aCompressedSize,
+							aUncompressedSize, 
+							aCompressionMethod);
+	}
+
+CZipFileMember* CZipFile::MakeMemberL(TInt aMemberIndex)
+	{
+	TLocalHeader    header;
+	TMemberPointer*	memberPointer;
+	
+	if (aMemberIndex >= iTrailer.iTotalEntryCount)
+		{
+		return NULL;
+		}
+	memberPointer = iMemberPointers + aMemberIndex;
+	if (ReadLocalHeader(memberPointer->iLocalHeaderOffset, header) != KErrNone)
+		{
+		return NULL;
+		}
+	else
+		{
+		return MakeMemberL(*memberPointer, header);
+		}
+	}
+	
+CZipFileMember* CZipFile::MakeMemberL(
+                              const TMemberPointer& aMemberPointer, 
+			                  const TLocalHeader&   aHeader)
+	{
+	CZipFileMember* member;
+	
+	member = new (ELeave) CZipFileMember;
+	CleanupStack::PushL(member);
+	member->iCRC32 = aMemberPointer.iCRC32;
+	member->iCompressedSize = aMemberPointer.iCompressedSize;
+	member->iCompressionMethod = aHeader.iCompressionMethod;
+	member->iName = new (ELeave) TFileName(*aMemberPointer.iName);
+	TInt loop=0;
+	while (loop < member->iName->Length())
+		{
+		if ((*member->iName)[loop] == '/')
+			{
+			(*member->iName)[loop] = '\\';
+			}
+		loop++;
+		}
+	member->iUncompressedSize = aMemberPointer.iUncompressedSize;
+	member->iDataOffset = aMemberPointer.iLocalHeaderOffset + 
+		                  KLocalHeaderFixedLength + 
+						  aHeader.iFileNameLength + 
+						  aHeader.iExtraFieldLength;
+	CleanupStack::Pop();
+	return member;
+	}
+
+void CZipFile::DeleteMemberPointers()
+	{
+	if (iMemberPointers)
+		{
+		for (TUint32 i = 0; i < iTrailer.iTotalEntryCount; i++)
+			{
+			delete iMemberPointers[i].iName;
+			}
+		delete[] iMemberPointers;
+		iMemberPointers = 0;
+		}
+
+	delete iData;
+	iData = NULL;
+	return;
+	}
+
+void CZipFile::OpenFileL(const TDesC& aFileName)
+	{
+	// We need to look at the session path of the filesystem passed
+	// in to derive the fullpath of the file to open
+	HBufC* sessionPath = HBufC::NewLC(KMaxFileName);
+	TPtr ptr(sessionPath->Des());
+	User::LeaveIfError(iFs.SessionPath(ptr));
+	TParse parse;
+	User::LeaveIfError(parse.Set(aFileName, sessionPath, NULL));
+	
+	// Use the full name derived from the session path
+	ContentAccess::CContent* content = 
+		ContentAccess::CContent::NewL(parse.FullName());
+	CleanupStack::PushL(content);
+	iData = content->OpenContentL(ContentAccess::EPeek);
+
+	// Parent content object no longer needed because we only need data
+	CleanupStack::PopAndDestroy(content);
+
+	// Seek to the end
+	TInt length = 0;
+	User::LeaveIfError(iData->Seek(ESeekEnd, length));
+	iFileLength = length;
+	CleanupStack::PopAndDestroy(sessionPath);
+	}
+
+TInt CZipFile::Read(TUint16& aUs)
+	{
+	TPckgBuf<TUint16> temp(aUs);
+	
+	if (iData->Read(temp) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+	
+	aUs=temp();
+	return KErrNone;
+	}
+	
+TInt CZipFile::Read(TUint32& aUl)
+	{
+	TPckgBuf<TUint32> temp;
+	
+	if (iData->Read(temp) != KErrNone)
+		{
+		return KZipFileIOError;
+		}
+	aUl=temp();
+	return KErrNone;
+	}
+
+TInt CZipFile::Read(TByte* aBytes, TUint32 aLength)
+
+	{
+	TPtr8 ptr(aBytes, aLength);
+	if(iData->Read(ptr, aLength))
+		{
+		return KZipFileIOError;
+		}
+	else
+		{
+		return KErrNone;
+		}
+	}
+	
+TInt CZipFile::Seek(TInt aOffset)
+	{
+	if (iData->Seek(ESeekStart, aOffset) < 0) 
+		{
+		return KZipFileIOError;
+		}
+	else
+		{
+		return KErrNone;
+		}
+	}
+