backupandrestore/backupengine/src/sbebufferhandler.cpp
changeset 0 d0791faffa3f
child 24 523717cdb0ad
child 29 3ae5cb0b4c02
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/backupandrestore/backupengine/src/sbebufferhandler.cpp	Tue Feb 02 01:11:40 2010 +0200
@@ -0,0 +1,1198 @@
+// Copyright (c) 2004-2009 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:
+// Implementation of CBufferFileWriter and CBufferReader
+// 
+//
+
+/**
+ @file
+*/
+
+
+#include "sbebufferhandler.h"
+#include "sblog.h"
+#include <connect/panic.h>
+
+namespace conn
+	{
+	template<class T>
+	TBool ReadFromBufferF(T& aT, TUint8*& appCurrent, const TUint8* apEnd)
+	/** Template class to read flat structures from the buffer
+	
+	@param aT on return the flat structure.
+	@param appCurrent The current point into the buffer.
+	@param apEnd The end of the buffer.
+	@return ETrue if read succesfully. EFalse if a retry is needed.
+	*/
+		{
+		static TBuf8<sizeof(T)> SBuffer; // Static buffer used for buffering!
+		TBool ret = EFalse;
+		
+		// Is there anything already in the buffer?
+		TUint8* ptr = NULL;
+		if (SBuffer.Size() > 0)
+			{
+			TInt size = SBuffer.Size();
+			SBuffer.Append(appCurrent, sizeof(T) - size);
+			ptr = const_cast<TUint8*>(SBuffer.Ptr());
+			
+			appCurrent += sizeof(T) - size;
+			
+			ret = ETrue;
+			} // if
+		else
+			{
+			// Is there enough room in current
+			if ((apEnd - appCurrent) < static_cast<TInt>(sizeof(T)))
+				{
+				// Need to buffer
+				SBuffer.Copy(appCurrent, apEnd - appCurrent);
+				} // if
+			else
+				{
+				ptr = appCurrent;
+				appCurrent += sizeof(T);
+				ret = ETrue;
+				} // else
+			} // else
+			
+		if (ret)
+			{
+			// Use a loop to copy to avoid alignment issues
+			TUint8* ptrOut = reinterpret_cast<TUint8*>(&aT);
+			for (TUint x = 0; x < sizeof(T); x++)
+				{
+				*ptrOut++ = *ptr++;
+				} // for
+			
+			SBuffer.SetLength(0);
+			}
+			
+		return ret;
+		}
+
+	template TBool ReadFromBufferF<TFileFixedHeader>(TFileFixedHeader&, TUint8*&, const TUint8*);
+	template TBool ReadFromBufferF<TSnapshot>(TSnapshot&, TUint8*&, const TUint8*);
+	
+	template<class T>
+	TBool WriteToBufferF(T& aT, TPtr8& aPtr)
+	/** Writes flat structures to the buffer.
+	
+	NOTE: This should _ONLY_ be used to write T classes to the buffer.
+	
+	@param aT The flat structure to write to the buffer.
+	@param ptr The buffer to write to.
+	@return ETrue on success. EFalse on failure.
+	*/
+		{
+		TBool ret = EFalse;
+		
+		if ((aPtr.MaxSize() - aPtr.Size()) >= static_cast<TInt>(sizeof(T)))
+			{
+			aPtr.Append(reinterpret_cast<TUint8*>(&aT), sizeof(T));
+			ret = ETrue;
+			} // if
+		
+		return ret;
+		}
+		
+	TBool ReadFromBufferV(TPtr8& aT, TInt aSize, TUint8*& appCurrent, const TUint8* apEnd)
+	/** Reads from the buffer.
+	
+	@param aT on return the data read.
+	@param aSize size of the data to read.
+	@param appCurrent Pointer to read from.
+	@param apEnd the end of the data.
+	@return ETrue on success. EFalse on failure.
+	*/
+		{
+		TBool ret = EFalse;
+		
+		// Does into already contain data?
+		if (aT.Size() > 0)
+			{
+			TInt tocopy = aSize - aT.Size();
+			aT.Append(appCurrent, tocopy);
+			appCurrent += tocopy;
+			ret = ETrue;
+			} // if
+		else
+			{
+			// Is there enough data?
+			if ((apEnd - appCurrent) < aSize)
+				{
+				aT.Copy(appCurrent, apEnd - appCurrent);
+				appCurrent = const_cast<TUint8*>(apEnd);
+				} // if
+			else
+				{
+				aT.Copy(appCurrent, aSize);
+				appCurrent += aSize;
+				ret = ETrue;
+				} // else
+			} // else
+		
+		return ret;
+		}
+		
+	TBool WriteToBufferV(const TPtr8& aPtr, TInt aSize, TPtr8& aBuffer)
+	/** Writes some vairable data to the buffer.
+	
+	NOTE: This should _ONLY_ be used to write T classes to the buffer.
+	
+	@param aPtr buffer to read from.
+	@param aSize size of the data to write.
+	@param aBuffer the buffer to write to.
+	@return ETrue on success. EFalse on failure.
+	*/
+		{
+		TBool ret = EFalse;
+		
+		if ((aBuffer.MaxSize() - aBuffer.Size()) >= aSize)
+			{
+			aBuffer.Append(aPtr.Ptr(), aSize);
+			ret = ETrue;
+			} // if
+		
+		
+		return ret;
+		}
+		
+	CBufferFileWriter* CBufferFileWriter::NewL(RFs& aFs, CDesCArray* aFileNames)
+	/** Symbain constructor
+	
+	@param aFs Handle to the Symbian Fs file server
+	@param aFileNames list of files to write ownership transfer
+	@return a CBufferFileWriter.
+	*/
+		{
+		CBufferFileWriter* self = new(ELeave) CBufferFileWriter(aFs, aFileNames);
+		CleanupStack::PushL(self);
+		self->ConstructL();
+		CleanupStack::Pop(self);
+		
+		return self;
+		} // NewL
+		
+	CBufferFileWriter::CBufferFileWriter(RFs& aFs, CDesCArray* aFileNames) :
+		iFs(aFs), iFileNames(aFileNames)
+	/** Standard C++ constructor
+	
+	@param aFs an RFS to use in this class.
+	*/
+		{
+		} // CBufferFileWriter
+		
+	CBufferFileWriter::~CBufferFileWriter()
+	/** Standard C++ destructor
+	*/
+		{
+		delete iFileNames;
+		iFileHandle.Close();
+		}
+		
+	void CBufferFileWriter::ConstructL()
+	/** Symbain second phase constructor
+	
+	@param aFileNames list of files to write
+	*/
+		{
+		#if defined(SBE_LOGGING_ENABLED)
+		if (iFileNames)
+			{
+			TUint count = iFileNames->Count();
+			while(count--)
+				{
+				const TDesC& fileName = (*iFileNames)[count];
+            	__LOG2("CBufferFileWriter::ConstructL() - file[%04d] is: %S", count, &fileName);
+				}
+			}
+		
+		#endif
+		}
+		
+	void CBufferFileWriter::StartL(TPtr8& aBuffer, TBool& aCompleted)
+	/** Start writing the files to the buffer
+	
+	@param aBuffer The buffer to write to.
+	@param aCompleted on return if we have finished.
+	*/
+		{
+        __LOG("CBufferFileWriter::StartL() - START");
+		WriteToBufferL(aBuffer, aCompleted);
+        __LOG("CBufferFileWriter::StartL() - END");
+		} // StartL
+		
+	void CBufferFileWriter::ContinueL(TPtr8& aBuffer, TBool& aCompleted)
+	/** Continue writing the files to the buffer
+	
+	@param aBuffer The buffer to write to.
+	@param aCompleted on return if we have finished.
+	*/
+		{
+        __LOG("CBufferFileWriter::ContinueL() - START");
+		WriteToBufferL(aBuffer, aCompleted);
+        __LOG("CBufferFileWriter::ContinueL() - END");
+		}
+
+	void CBufferFileWriter::WriteToBufferL(TPtr8& aBuffer, TBool& aCompleted)
+	/** Writes files to the buffer
+	
+	@param aBuffer The buffer to write to.
+	@param aCompleted on return if we have finished.
+	*/
+		{
+		aCompleted = EFalse;
+		
+		const TUint count = iFileNames->Count();
+		while (iCurrentFile < count)
+			{
+            const TDesC& name = (*iFileNames)[iCurrentFile];
+			
+			_LIT( KTrailingBackSlash, "\\" );
+            if (name.Right(1) == KTrailingBackSlash() )
+            	{
+             	// Directory entry
+ 	           	__LOG1("CBufferFileWriter::WriteToBufferL() - empty directory: %S ", &name);
+ 	           	if(!iHeaderWritten)
+ 	        	   {
+ 	        	   TFileFixedHeader header(name.Length(), 0, 0, 0);
+ 	        	   if (WriteToBufferF(header, aBuffer) == EFalse)
+ 	        		   {
+ 	        		   __LOG("CBufferFileReader::WriteToBufferL() - WriteToBufferF() returned False so breaking!");
+ 	        		   break;
+ 	        		   }
+ 	        	   iHeaderWritten = ETrue;
+ 	        	   } // if
+ 	           	
+				TPtr8 ptr(reinterpret_cast<TUint8*>(const_cast<TUint16*>(name.Ptr())), name.Size(), name.Size());
+				
+				if (WriteToBufferV(ptr, ptr.Size(), aBuffer) == EFalse)
+					{
+					__LOG("CBufferFileReader::WriteToBufferL() - WriteToBufferV() returned False so breaking!");
+					break;
+					}
+
+ 	           	iHeaderWritten = EFalse;
+ 	           	iFileNameWritten = EFalse;
+            	}
+            else
+            	{
+				if (!iFileOpen) // File needs to be opened
+					{
+	                __LOG1("CBufferFileWriter::WriteToBufferL() - trying to open: %S for reading", &name);
+					const TInt error = iFileHandle.Open(iFs, name, EFileRead | EFileShareReadersOnly);
+	                if  (error != KErrNone)
+	                    {
+	                    __LOG2("CBufferFileWriter::WriteToBufferL() - opening: %S for reading failed with error: %d", &name, error);
+	                    User::Leave(error);
+	                    }
+
+					iFileOpen = ETrue;
+					} // if
+					
+				if (iFileOpen && !iHeaderWritten)
+					{
+					// File size
+					TInt size;
+					TInt err = iFileHandle.Size(size);
+	                __LOG2("CBufferFileWriter::WriteToBufferL() - size of file is: %d (err: %d)", size, err);
+					TUint att;
+					err = iFileHandle.Att(att);
+					__LOG2("CBufferFileWriter::WriteToBufferL() - attributes: %d (err: %d)", size, err);
+					TTime modified;
+					err = iFileHandle.Modified(modified);
+					__LOG2("CBufferFileWriter::WriteToBufferL() - modified: %d (err: %d)", size, err);
+					TFileFixedHeader header((*iFileNames)[iCurrentFile].Length(), size, att, modified.Int64());
+					if (WriteToBufferF(header, aBuffer) == EFalse)
+						{
+						__LOG("CBufferFileReader::WriteToBufferL() - WriteToBufferF() returned False so breaking!");
+						break;
+						}
+						
+					iHeaderWritten = ETrue;
+					} // if
+					
+				// Write filename
+				if (!iFileNameWritten)
+					{
+					
+					TPtr8 ptr(reinterpret_cast<TUint8*>(const_cast<TUint16*>(name.Ptr())), name.Size(), name.Size());
+					
+					if (WriteToBufferV(ptr, ptr.Size(), aBuffer) == EFalse)
+						{
+						__LOG("CBufferFileReader::WriteToBufferV() - WriteToBufferF() returned False so breaking!");
+						break;
+						}
+					iFileNameWritten = ETrue;
+					}
+
+	            __LOG1("CBufferFileWriter::WriteToBufferL() - buffer is of length: %d", aBuffer.Length());
+					
+				TInt bufferLeft = aBuffer.MaxSize() - aBuffer.Size();
+				TPtr8 ptr(const_cast<TUint8*>(aBuffer.Ptr()) + aBuffer.Size(), bufferLeft);
+				TInt fileSize = 0;
+				iFileHandle.Size(fileSize);
+				TInt fileLeft = fileSize - iOffset;
+				if (bufferLeft < fileLeft)
+					{
+	                __LOG("CBufferFileWriter::WriteToBufferL() - buffer space available is less than file size!");
+
+	                // Write buffer size
+					User::LeaveIfError(iFileHandle.Read(iOffset, ptr, bufferLeft)); // TODO: Is this correct?
+					aBuffer.SetLength(aBuffer.Length() + bufferLeft);
+					iOffset += bufferLeft;
+					break;
+					} // if
+				else
+					{
+	                __LOG("CBufferFileWriter::WriteToBufferL() - enough space in buffer for whole file...");
+
+	                // Write file size
+					User::LeaveIfError(iFileHandle.Read(ptr, fileLeft)); // TODO: Is this correct?
+					aBuffer.SetLength(aBuffer.Length() + fileLeft);
+					} // else
+
+	            __LOG1("CBufferFileWriter::WriteToBufferL() - After read from file, buffer is now of length: %d", aBuffer.Length());
+	            
+				iFileHandle.Close();
+				iFileOpen = EFalse;
+				iHeaderWritten = EFalse;
+				iFileNameWritten = EFalse;
+				iOffset = 0;
+            	} //else
+			++iCurrentFile;
+			} // while
+			
+		if (iCurrentFile >= count)
+			{
+			aCompleted = ETrue;
+			} // if
+		} // WriteToBufferL
+		
+	CBufferFileReader* CBufferFileReader::NewL(RFs& aFs, RSnapshots* apSnapshots, MValidationHandler* aValidationHandler)
+	/** Symbian OS constructor
+	
+	@param aFs File server to use.
+	@param apSnapshots list of snapshots.
+	*/
+		{
+        __LOG("CBufferFileReader::NewL() - START");
+		CBufferFileReader* self = new(ELeave) CBufferFileReader(aFs, apSnapshots, aValidationHandler);
+		
+		CleanupStack::PushL( self );
+		
+	#ifdef SBE_LOGGING_ENABLED
+        if  (apSnapshots)
+            {
+		    const TInt count = apSnapshots->Count();
+            __LOG1("CBufferFileReader::NewL() - Got %d snapshots to compare against during restore...", count);
+
+		    for(TInt x = 0; x < count; ++x)
+			    {
+                const TDesC& snapshot = (*apSnapshots)[x]->FileName();
+                __LOG3("CBufferFileReader::NewL() -    snapshot[%4d/%4d] is: %S", x+1, count, &snapshot);
+			    } // for x
+
+		    }
+	#endif
+        
+        __LOG("CBufferFileReader::NewL() - END");
+        
+        CleanupStack::Pop( self );
+		return self;
+		} // NewL
+		
+	CBufferFileReader::CBufferFileReader(RFs& aFs, RSnapshots* apSnapshots, MValidationHandler* aValidationHandler) :
+		iFs(aFs), iSnapshots(apSnapshots), iValidationHandler(aValidationHandler)
+	/** C++ constructor
+	
+	@param aFs File server to use.
+	@param apSnapshots list of snapshots.
+	*/
+		{
+		} // CBufferFileReader
+		
+	void CBufferFileReader::StartL(const TDesC8& aBuffer, TBool aLastSection)
+	/** Start reading from the buffer.
+	
+	@param aBuffer The buffer to read from.
+	@param aLastSection Is this the last section?
+	*/
+		{
+        __LOG("CBufferFileReader::StartL() - START");
+        if (iSnapshots)
+        	{
+        	iSnapshots->Sort(CSnapshot::Compare);
+        	}
+		ReadFromBufferL(aBuffer, aLastSection);
+        __LOG("CBufferFileReader::StartL() - END");
+		} // StartL
+	
+	void CBufferFileReader::ContinueL(const TDesC8& aBuffer, TBool aLastSection)
+	/** Continue reading from the buffer.
+	
+	@param aBuffer The buffer to read from.
+	@param aLastSection Is this the last section?
+	*/
+		{
+        __LOG("CBufferFileReader::ContinueL() - START");
+		ReadFromBufferL(aBuffer, aLastSection);
+        __LOG("CBufferFileReader::ContinueL() - END");
+		} // ContinueL
+	
+	void CBufferFileReader::CheckFileInSnapshotL()
+	/**
+	Checks to see if a given file is in a snapshot.
+	*/
+		{
+        __LOG2("CBufferFileReader::CheckFileInSnapshot() - START - ipSnapshots: 0x%08x, iSnapshotChecked: %d", iSnapshots, iSnapshotChecked);
+
+		iRestore = ETrue;
+		
+		if (iSnapshots)
+			{
+			CSnapshot* snapshot = CSnapshot::NewLC(TTime().Int64(), iFileName);
+			TInt res = iSnapshots->Find(snapshot, CSnapshot::Match);
+			if (res == KErrNotFound)
+				{
+				iRestore = EFalse;
+				}
+			CleanupStack::PopAndDestroy(snapshot);		
+			} // if
+		
+		iSnapshotChecked = ETrue;
+
+        __LOG2("CBufferFileReader::CheckFileInSnapshot() - END - iSnapshotChecked: %d, iRestore: %d", iSnapshotChecked, iRestore);
+		}
+		
+	void CBufferFileReader::RecreateDirL()
+	/**
+	Recreates a directory path on disk.
+	*/
+		{
+        __LOG1("CBufferFileReader::RecreateDirL() - START - iFileName: %S", &iFileName);
+		// Create the path
+		TInt err = iFs.MkDirAll(iFileName);
+		if ((err != KErrNone) && (err != KErrAlreadyExists))
+			{
+            __LOG1("CBufferFileReader::WriteToFile() - making directory resulted in fatal error: %d", err);
+			User::Leave(err);
+			} // if
+        
+        __LOG("CBufferFileReader::RecreateDirL() - END");
+		}
+		
+	
+	void CBufferFileReader::RecreateFileL()
+	/**
+	Recreates a file on disk. Deletes the original if it still exists.
+	*/
+		{
+        __LOG1("CBufferFileReader::RecreateFileL() - START - iFileName: %S", &iFileName);
+		// Create the path
+		TInt err = iFs.MkDirAll(iFileName);
+		if ((err != KErrNone) && (err != KErrAlreadyExists))
+			{
+            __LOG1("CBufferFileReader::WriteToFile() - making directory resulted in fatal error: %d", err);
+			User::Leave(err);
+			} // if
+
+        
+        err = iFileHandle.Replace(iFs, iFileName, EFileWrite);
+        __LOG1("CBufferFileReader::WriteToFile() - replacing file returned err: %d", err);
+        User::LeaveIfError( err );
+			
+		iFileOpen = ETrue;
+        __LOG("CBufferFileReader::RecreateFileL() - END");
+		}
+	
+		
+	TBool CBufferFileReader::WriteToFileL(TUint8*& aCurrent, const TUint8* aEnd)
+	/**
+	Writes data to a file.
+	
+	@param aCurrent start point of data to write.
+	@param aEnd end point of data to write.
+	@return ETrue if write finished. EFalse if there is more data to write.
+	*/
+		{
+        __LOG2("CBufferFileReader::WriteToFile() - START - iFileHandle: 0x%08x, iFixedHeader.iFileSize: %d", iFileHandle.SubSessionHandle(), iFixedHeader.iFileSize);
+		TBool retVal = ETrue;
+		TInt filesize;
+		const TInt err1 = iFileHandle.Size(filesize);
+        __LOG2("CBufferFileReader::WriteToFile() - fileSize: %d (err: %d)", filesize, err1);
+		User::LeaveIfError(err1);
+		if ((aEnd - aCurrent) >= (iFixedHeader.iFileSize - filesize))
+			{
+			TPtr8 ptr(aCurrent, iFixedHeader.iFileSize -filesize, iFixedHeader.iFileSize - filesize);
+			const TInt err2 = iFileHandle.Write(ptr);
+            __LOG2("CBufferFileReader::WriteToFile() - writing %d bytes returned error: %d", ptr.Length(), err2);
+			User::LeaveIfError(err2);
+
+			// Write the attributes & modified time
+			const TInt err3 = iFileHandle.Set(iFixedHeader.iModified, 
+					iFixedHeader.iAttributes, KEntryAttNormal);
+
+            __LOG1("CBufferFileReader::WriteToFile() - setting attribs returned error: %d", err3);
+			User::LeaveIfError(err3);
+			
+			// Move current along
+			aCurrent += iFixedHeader.iFileSize - filesize;
+
+			// Finished reset state
+			Reset();
+			} // if
+		else
+			{
+			TInt size = aEnd - aCurrent;
+			TPtr8 ptr(aCurrent, size, size);
+			const TInt err2 = iFileHandle.Write(ptr);
+            __LOG2("CBufferFileReader::WriteToFile() - writing %d bytes returned error: %d", ptr.Length(), err2);
+
+			retVal = EFalse;
+			} // else
+			
+        __LOG1("CBufferFileReader::WriteToFile() - END - finished: %d", retVal);
+		return retVal;
+		}
+
+	void CBufferFileReader::ReadFromBufferL(const TDesC8& aBuffer, TBool aLastSection)
+	/** Reads from the buffer and writes files to disk.
+	
+	@param aBuffer The buffer to read from.
+	@param aLastSection Is this the last section?
+	@leave KErrUnderflow More data is needed.
+	*/	
+        {
+        __LOG5("CBufferFileReader::ReadFromBufferL() - START - iFileNameRead: %d, iSnapshotChecked: %d, iRestore: %d, iFileOpen: %d, iFileName: %S", iFileNameRead, iSnapshotChecked, iRestore, iFileOpen, &iFileName);
+
+        TUint8* current = const_cast<TUint8*>(aBuffer.Ptr());
+		const TUint8* end = current + aBuffer.Size();
+		
+		// Workaround for "dual fixed header in backup" error. Tries to detect the special error case where iFixedHeaderRead=true but filename wasn't read
+		if(iFixedHeaderRead && !iFileNameRead && !iBytesRead && (end-current) >= 12)
+			{
+			// Check the first 12 bytes of the header we already got (the iModified is different between the problematic second header)
+			const TUint8* tempbuf = (TUint8*)&iFixedHeader;
+			TBool workAroundNeeded = ETrue;
+			for(TInt i = 0; i < 12; i++)
+				{
+				if(current[i] != tempbuf[i])
+					{
+					workAroundNeeded = EFalse;
+					break;
+					}
+				}
+
+			if(workAroundNeeded)
+				{
+				__LOG("CBufferFileReader::ReadFromBufferL() - Dual header was detected, workaround!!!");
+				iFixedHeaderRead = EFalse; // Mark that the processing loop reads the fixed header again
+				}
+			}
+		
+		while (current < end)
+			{
+            __LOG2("CBufferFileReader::ReadFromBufferL() - iFixedHeaderRead: %d, iLeftToSkip: %d", iFixedHeaderRead, iLeftToSkip);
+
+			// Do we have the fixed header?
+			if (!iFixedHeaderRead)
+				{
+				if (ReadFromBufferF(iFixedHeader, current, end) == EFalse)
+					{
+					__LOG("CBufferFileReader::ReadFromBufferL() - ReadFromBufferF() returned False so breaking!");
+					break;
+					} // if
+				
+                __LOG1("CBufferFileReader::ReadFromBufferL() - fixed header - iFileNameLength:  %d", iFixedHeader.iFileNameLength);
+                __LOG1("CBufferFileReader::ReadFromBufferL() - fixed header - iFileSize:        %d", iFixedHeader.iFileSize);
+                __LOG1("CBufferFileReader::ReadFromBufferL() - fixed header - iAttributes:      %d", iFixedHeader.iAttributes);
+                
+                if ((iFixedHeader.iFileNameLength > KMaxFileName) || (!iFixedHeader.iFileNameLength))
+					{
+					__LOG1("CBufferFileReader::ReadFromBufferL() - Leaving - iFileNameLength: %d more then MaxLength", iFixedHeader.iFileNameLength);
+					User::Leave(KErrOverflow);
+					}
+                
+				iFixedHeaderRead = ETrue;
+				} // if
+
+				
+            __LOG1("CBufferFileReader::ReadFromBufferL() - iFileNameRead: %d", iFileNameRead);
+			if (!iFileNameRead)
+				{
+				TPtr8 ptr(reinterpret_cast<TUint8*>(const_cast<TUint16*>(iFileName.Ptr())), iBytesRead, iFixedHeader.iFileNameLength * KCharWidthInBytes);
+				
+				if (ReadFromBufferV(ptr, iFixedHeader.iFileNameLength * KCharWidthInBytes, current, end) == EFalse)
+					{
+					iBytesRead = ptr.Size();
+					__LOG1("CBufferFileReader::ReadFromBufferL() - ReadFromBufferV() returned False - Filename bytes read: %d", iBytesRead);
+					break;
+					} // if
+				
+				iFileName.SetLength(iFixedHeader.iFileNameLength);
+				iFileNameRead = ETrue;
+                __LOG1("CBufferFileReader::ReadFromBufferL() - Got filename: %S", &iFileName);
+				}
+			
+			// Is the file in the snapshot, if not it was deleted in an increment and does not need restoring
+            __LOG1("CBufferFileReader::ReadFromBufferL() - iSnapshotChecked: %d", iSnapshotChecked);
+			if (!iSnapshotChecked)
+				{
+				CheckFileInSnapshotL();
+				} // if
+			
+            __LOG2("CBufferFileReader::ReadFromBufferL() - iValidationHandler: 0x%08x, iRestore: %d", iValidationHandler, iRestore);
+			if (iValidationHandler != NULL)
+				{
+				if (iRestore)
+					{
+					iRestore = iValidationHandler->ValidFileL(iFileName);
+                    __LOG1("CBufferFileReader::ReadFromBufferL() - validation handler result: %d", iRestore);
+					}
+				}
+			
+			if (!iRestore && !iLeftToSkip)
+				{
+                __LOG1("CBufferFileReader::ReadFromBufferL() - restore not permitted, skipping file data (%d bytes)", iFixedHeader.iFileSize);
+				iLeftToSkip = iFixedHeader.iFileSize; // So we can skip the bytes
+				}
+			
+            __LOG1("CBufferFileReader::ReadFromBufferL() - iFileOpen: %d", iFileOpen);
+			if (iRestore)
+				{
+				// Check if it is a directory or file
+				_LIT( KTrailingBackSlash, "\\" );
+				if (iFileName.Right(1) == KTrailingBackSlash())
+					{
+					__LOG("CBufferFileReader::ReadFromBufferL() - Attempting to recreate directory path...");
+					RecreateDirL();
+					Reset();
+					}
+				else 
+					{
+					// Have we opened the file?
+					if (!iFileOpen)
+						{
+						__LOG("CBufferFileReader::ReadFromBufferL() - Attempting to recreate file...");
+						RecreateFileL();		
+						}
+					
+					// Write to the file
+	                __LOG("CBufferFileReader::ReadFromBufferL() - Attempting to write to file...");
+					if (!WriteToFileL(current, end))
+						{
+						__LOG("CBufferFileReader::ReadFromBufferL() - WriteToFileL() returned False so breaking!");
+						break;
+						}	
+					}//if
+				} // if
+			else
+				{
+				// We need to skip the bytes in the data
+                __LOG2("CBufferFileReader::ReadFromBufferL() - We\'re in skip mode. EndPos: %8d, CurrentPos: %8d", end, current);
+				if ((end - current) >= iLeftToSkip)
+					{
+					current += iLeftToSkip;
+
+					// Finished reset state
+                    __LOG("CBufferFileReader::ReadFromBufferL() - Finished skipping");
+					Reset();
+					} // if
+				else
+					{
+                    __LOG1("CBufferFileReader::ReadFromBufferL() - Still more data to skip...: %d bytes", iLeftToSkip);
+					iLeftToSkip = iLeftToSkip - (end - current);
+					break;
+					} // else
+				} // else
+			} // while
+			
+            __LOG3("CBufferFileReader::ReadFromBufferL() - aLastSection: %d, iFileOpen: %d, iLeftToSkip: %d", aLastSection, iFileOpen, iLeftToSkip);
+
+			if ((aLastSection && iFileOpen) ||
+			    (aLastSection && (iLeftToSkip > 0)))
+				{
+                __LOG("CBufferFileReader::ReadFromBufferL() - Leaving with KErrUnderflow because not all skipped data was consumed!");
+				User::Leave(KErrUnderflow);
+			} // if
+
+        __LOG("CBufferFileReader::ReadFromBufferL() - END");
+		} // ReadFromBufferL
+		
+	void CBufferFileReader::RedirectMIDletRestorePathL(const TDesC& aOriginal, CDesCArray& aRedirected)
+	/** Redirects the midlet restore path
+	
+	@param aOriginal the original path
+	@param aRedirected the redirected path
+	*/
+		{
+		TFileName redirectedFilename(KMIDletTempRestorePath);
+		// Backslash used to isolate the filename from aOriginal's absolute path
+		const TChar KTCharBackslash('\\');
+		
+		// Isolate the filename from aOriginal and Append it to our temp path
+		redirectedFilename.Append(aOriginal.Mid(aOriginal.LocateReverseF(KTCharBackslash) + 1));
+		aRedirected.AppendL(redirectedFilename);
+		}
+
+	void CBufferFileReader::ReadMIDletsFromBufferL(const TDesC8& aBuffer, TBool aLastSection, 
+		CDesCArray& aUnpackedFileNames)
+	/** Reads from the buffer and writes files to disk.
+	
+	@param aBuffer The buffer to read from.
+	@param aLastSection Is this the last section?
+	@leave KErrUnderflow More data is needed.
+	*/	
+		{
+		TUint8* current = const_cast<TUint8*>(aBuffer.Ptr());
+		const TUint8* end = current + aBuffer.Size();
+		TInt fileIndex = 0;
+		while (current < end)
+			{
+			// Do we have the fixed header?
+			if (!iFixedHeaderRead)
+				{
+				if (ReadFromBufferF(iFixedHeader, current, end) == EFalse)
+					{
+					__LOG("CBufferFileReader::ReadMIDletsFromBufferL() - ReadFromBufferF() returned False so breaking!");
+					break;
+					} // if
+				__LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - fixed header - iFileNameLength:  %d", iFixedHeader.iFileNameLength);
+                __LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - fixed header - iFileSize:        %d", iFixedHeader.iFileSize);
+                __LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - fixed header - iAttributes:      %d", iFixedHeader.iAttributes);	
+					
+				if ((iFixedHeader.iFileNameLength > KMaxFileName) || (!iFixedHeader.iAttributes) || (!iFixedHeader.iFileNameLength))
+					{
+					__LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - Leaving - iFileNameLength: %d more then MaxLength", iFixedHeader.iFileNameLength);
+					User::Leave(KErrOverflow);
+					}
+				
+				iFixedHeaderRead = ETrue;
+				} // if
+				
+			if (!iFileNameRead)
+				{
+				TPtr8 ptr(reinterpret_cast<TUint8*>(const_cast<TUint16*>(iFileName.Ptr())), iBytesRead, iFixedHeader.iFileNameLength * KCharWidthInBytes);
+				
+				if (ReadFromBufferV(ptr, iFixedHeader.iFileNameLength * KCharWidthInBytes, current, end) == EFalse)
+					{
+					iBytesRead = ptr.Size();
+					__LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - ReadFromBufferV() returned False - Filename bytes read: %d", iBytesRead);
+					break;
+					} // if
+				
+					
+				iFileName.SetLength(iFixedHeader.iFileNameLength);
+				
+				// Throw away the unpacked filename, as we're now
+				RedirectMIDletRestorePathL(iFileName, aUnpackedFileNames);
+				
+				// We don't need the original filename any more, we're using the one returne by Redirect...
+				iFileName = aUnpackedFileNames[fileIndex];
+				
+				iFileNameRead = ETrue;
+				
+				// set the index to the next file in the list
+				fileIndex++;
+				}
+				
+			// Is the file in the snapshot, if not it was deleted in an increment and does not need restoring
+			if (!iSnapshotChecked)
+				{
+				CheckFileInSnapshotL();
+				} // if
+			
+			if (!iRestore && !iLeftToSkip)
+				{
+                __LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - restore not permitted, skipping file data (%d bytes)", iFixedHeader.iFileSize);
+				iLeftToSkip = iFixedHeader.iFileSize; // So we can skip the bytes
+				}
+
+			if (iRestore)
+				{
+				// Have we opened the file?
+				if (!iFileOpen)
+					{
+					RecreateFileL();
+					}
+					
+				// Write to the file
+				if (!WriteToFileL(current, end))
+					{
+					__LOG("CBufferFileReader::ReadMIDletsFromBufferL() - WriteToFileL() returned False so breaking!");
+					break;
+					}
+				} // if
+			else
+				{
+				// We need to skip the bytes in the data
+				if ((end - current) >= iLeftToSkip)
+					{
+					current += iLeftToSkip;
+
+					// Finished reset state
+					Reset();
+					} // if
+				else
+					{
+					__LOG1("CBufferFileReader::ReadMIDletsFromBufferL() - Still more data to skip...: %d bytes", iLeftToSkip);
+					iLeftToSkip = iLeftToSkip - (end - current);
+					break;
+					} // else
+				} // else
+			} // while
+			
+			if ((aLastSection && iFileOpen) ||
+			    (aLastSection && (iLeftToSkip > 0)))
+				{
+				User::Leave(KErrUnderflow);
+				} // if
+		} // ReadMIDletsFromBufferL
+		
+	void CBufferFileReader::Reset()
+	/** Resets the state of the object.
+	*/
+		{
+		iFileHandle.Close();
+		iFileOpen = EFalse;
+		iFileNameRead = EFalse;
+		iLeftToSkip = 0;
+		iSnapshotChecked = EFalse;
+		iFileName.SetLength(0);
+		iFixedHeaderRead = EFalse;
+		iBytesRead = 0;
+		}
+		
+	CBufferFileReader::~CBufferFileReader()
+	/** destructor
+	*/
+		{
+		iFileHandle.Close();
+		}
+		
+	
+	
+	CBufferSnapshotWriter* CBufferSnapshotWriter::NewL(RSnapshots* aSnapshots)
+	/** Symbian OS constructor
+	
+	@param aFiles File information to write to the buffer.ownernship transfer
+	*/
+		{
+		CBufferSnapshotWriter* self = new(ELeave) CBufferSnapshotWriter(aSnapshots);
+		CleanupStack::PushL(self);
+		self->ConstructL();
+		CleanupStack::Pop(self);
+		
+		return self;
+		} // NewL
+		
+	CBufferSnapshotWriter::CBufferSnapshotWriter(RSnapshots* aSnapshots) : iSnapshots(aSnapshots)
+	/** Standard C++ constructor
+	*/
+		{
+		}
+		
+	void CBufferSnapshotWriter::ConstructL()
+	/** Symbian second phase constructor
+
+	@param aFiles File information to write to the buffer.
+	*/
+		{
+		__ASSERT_DEBUG(iSnapshots, Panic(KErrArgument));
+		#ifdef SBE_LOGGING_ENABLED
+        const TInt count = iSnapshots->Count();
+        __LOG1("CBufferFileReader::NewL() - Got %d snapshots to compare against during restore...", count);
+
+	    for(TInt x = 0; x < count; ++x)
+		    {
+            const TDesC& snapshot = (*iSnapshots)[x]->FileName();
+            __LOG3("CBufferFileReader::NewL() -    snapshot[%4d/%4d] is: %S", x+1, count, &snapshot);
+		    } // for x
+
+		#endif
+		} // ConstructL
+		
+	CBufferSnapshotWriter::~CBufferSnapshotWriter()
+	/** Standard C++ destructor
+	*/
+		{
+		if(iSnapshots)
+			{
+			iSnapshots->ResetAndDestroy();
+			delete iSnapshots;
+			}
+		} // ~CBufferSnapshotWriter
+		
+	void CBufferSnapshotWriter::StartL(TPtr8& aBuffer, TBool& aCompleted)
+	/** Starts writing to the buffer 
+	
+	@param aBuffer The buffer.
+	@param aCompleted On return if we have finished writing data.
+	*/
+		{
+        __LOG("CBufferSnapshotWriter::StartL() - START");
+		WriteToBufferL(aBuffer, aCompleted);
+        __LOG("CBufferSnapshotWriter::StartL() - END");
+		} // WriteToBufferL
+
+	void CBufferSnapshotWriter::ContinueL(TPtr8& aBuffer, TBool& aCompleted)
+	/** Continues writing to the buffer 
+	
+	@param aBuffer The buffer.
+	@param aCompleted On return if we have finished writing data.
+	*/
+		{
+        __LOG("CBufferSnapshotWriter::ContinueL() - START");
+		WriteToBufferL(aBuffer, aCompleted);
+        __LOG("CBufferSnapshotWriter::ContinueL() - END");
+		} // WriteToBufferL
+		
+	void CBufferSnapshotWriter::WriteToBufferL(TPtr8& aBuffer, TBool& aCompleted)
+	/** Writes to the buffer 
+
+	@param aBuffer The buffer.
+	@param aCompleted On return if we have finished writing data.
+	*/
+		{
+        __LOG1("CBufferSnapshotWriter::WriteToBufferL() - START - aBuffer length: %d", aBuffer.Length());
+		aCompleted = EFalse;
+		
+		const TUint count = iSnapshots->Count();
+		while (iCurrentSnapshot < count)
+			{
+            __LOG1("CBufferSnapshotWriter::WriteToBufferL() - iCurrentSnapshot: %d", iCurrentSnapshot);
+
+			// Check there is enough room
+			if (sizeof(TSnapshot) > static_cast<TUint>(aBuffer.MaxSize() - aBuffer.Size()))
+				{
+				__LOG("CBufferSnapshotWriter::WriteToBufferL() - Snapshot size is more than buffer available - break");
+				break;
+				} // if
+				
+			// Write modified
+			TSnapshot snapshot;
+			(*iSnapshots)[iCurrentSnapshot]->Snapshot(snapshot);
+            __LOG1("CBufferSnapshotWriter::WriteToBufferL() - writing snapshot for file: %S", &snapshot.iFileName);
+
+			WriteToBufferF(snapshot, aBuffer);
+			
+			++iCurrentSnapshot;			
+			} // while
+
+		if (iCurrentSnapshot >= count)
+			{
+			aCompleted = ETrue;
+			} // if
+
+        __LOG1("CBufferSnapshotWriter::WriteToBufferL() - END - aCompleted: %d", aCompleted);
+		} // WriteToBufferL
+	
+	CBufferSnapshotReader* CBufferSnapshotReader::NewL(RSnapshots& aSnapshots)
+	/** Symbian constructor
+	
+	@param aFiles Locaton to store files read from buffer.
+	*/
+		{
+		return new (ELeave) CBufferSnapshotReader(aSnapshots);
+		}
+		
+	CBufferSnapshotReader::CBufferSnapshotReader(RSnapshots& aSnapshots) :
+		iSnapshots(aSnapshots)
+	/** C++ constructor
+	
+	@param aSnapshots snapshots of files.
+	*/
+		{
+		}
+		
+	CBufferSnapshotReader::~CBufferSnapshotReader()
+	/**
+	C++ destructor
+	*/
+		{
+		}
+		
+	void CBufferSnapshotReader::StartL(const TDesC8& aBuffer, TBool aLastSection)
+	/** Starts reading data from the buffer
+	
+	@param aBuffer buffer to read from.
+	@param aLastSection is this the last section.
+	*/
+		{
+        __LOG2("CBufferSnapshotReader::StartL() - START - buffer len: %d, aLastSection: %d", aBuffer.Length(), aLastSection);
+
+		ReadFromBufferL(aBuffer, aLastSection);
+
+        __LOG("CBufferSnapshotReader::StartL() - END");
+		}
+		
+	void CBufferSnapshotReader::ContinueL(const TDesC8& aBuffer, TBool aLastSection)
+	/** Continues reading data from the buffer
+	
+	@param aBuffer buffer to read from.
+	@param aLastSection is this the last section.
+	*/
+		{
+        __LOG2("CBufferSnapshotReader::ContinueL() - START - buffer len: %d, aLastSection: %d", aBuffer.Length(), aLastSection);
+
+		ReadFromBufferL(aBuffer, aLastSection);
+
+        __LOG("CBufferSnapshotReader::ContinueL() - END");
+		}
+		
+	void CBufferSnapshotReader::ReadFromBufferL(const TDesC8& aBuffer, TBool /*aLastSection*/)
+	/** Reads data from the buffer
+	
+	@param aBuffer buffer to read from.
+	@param aLastSection is this the last section.
+	*/
+		{
+        __LOG("CBufferSnapshotReader::ReadFromBufferL() - START");
+
+		TUint8* current = const_cast<TUint8*>(aBuffer.Ptr());
+		const TUint8* end = current + aBuffer.Size();
+		while (current < end)
+			{
+			if (ReadFromBufferF(iSnapshot, current, end) == EFalse)
+				{
+				__LOG("CBufferSnapshotReader::ReadFromBufferL() - returned EFalse breaking!");
+				break;
+				}
+			
+            __LOG1("CBufferSnapshotReader::ReadFromBufferL() - read snapshot info for file: %S", &iSnapshot.iFileName);
+            CSnapshot* snapshot = CSnapshot::NewLC(iSnapshot);
+			iSnapshots.AppendL(snapshot);
+			CleanupStack::Pop(snapshot);
+			} // while
+
+        __LOG("CBufferSnapshotReader::ReadFromBufferL() - END");
+		} // ReadFromBufferL
+		
+	
+	// CSnapshot //
+	
+	/**
+	
+	Symbian 2nd phase construction creates a CSelection
+	
+	@param aType - Selection Type
+	@param aSelection - Selection Nmae
+	@return CSelection a pointer to a new object 
+	*/
+	CSnapshot* CSnapshot::NewLC(const TInt64& aModified, const TDesC& aFileName)
+		{
+		CSnapshot* self = new (ELeave) CSnapshot(aModified);
+		CleanupStack::PushL(self);
+		self->ConstructL(aFileName);
+		return self;
+		}
+	
+	/**
+	
+	Symbian 2nd phase construction creates a Selection
+	
+	@param aSnapshot - TSnapshot snapshot
+	@return CSelection a pointer to a new object 
+	*/
+	CSnapshot* CSnapshot::NewLC(const TSnapshot& aSnapshot)
+		{
+		return CSnapshot::NewLC(aSnapshot.iModified, aSnapshot.iFileName);
+		}
+	
+	/**
+	Standard C++ destructor
+	*/
+	CSnapshot::~CSnapshot()
+		{
+		delete iFileName;
+		}
+	
+	/**
+	Standard C++ constructor
+	*/
+	CSnapshot::CSnapshot(const TInt64& aModified) : iModified(aModified)
+		{
+		}
+		
+	/**
+	Symbian 2nd phase constructor
+	*/
+	void CSnapshot::ConstructL(const TDesC& aFileName)
+		{
+		iFileName = aFileName.AllocL();
+		}
+	
+	/**
+	Selection Type
+	
+	@return TSelectionType Type
+	*/
+	const TInt64& CSnapshot::Modified() const
+		{
+		return iModified;
+		}
+	
+	/**
+	Selection Name
+	
+	@return const TDesC& Name
+	*/
+	const TDesC& CSnapshot::FileName() const
+		{
+		return *iFileName;
+		}
+		
+	/**
+	Create snapshot of type TSnapshot
+	
+	@return TSnapshot snapshot
+	
+	*/
+	void CSnapshot::Snapshot(TSnapshot& aSnapshot)
+		{
+		aSnapshot.iFileName = *iFileName;
+		aSnapshot.iModified = iModified;
+		}
+		
+	/**
+	Method will be used for Sort on RPointerArray
+	
+	@param aFirst CSnapshot& snapshot to compare
+	@param aSecond CSnapshot& snapshot to compare
+	
+	@see RArray::Sort()
+	*/
+	TInt CSnapshot::Compare(const CSnapshot& aFirst, const CSnapshot& aSecond)
+		{
+		return aFirst.FileName().CompareF(aSecond.FileName());
+		}
+		
+	/**
+	Method will be used for Find on RPointerArray
+	
+	@param aFirst CSnapshot& snapshot to match
+	@param aSecond CSnapshot& snapshot to match
+	
+	@see RArray::Find()
+	*/
+	TBool CSnapshot::Match(const CSnapshot& aFirst, const CSnapshot& aSecond)
+		{
+		return (aFirst.FileName() == aSecond.FileName());
+		}
+
+
+	} // namespace conn
+