userlibandfileserver/fileserver/sfile/sf_cache.cpp
changeset 0 a41df078684a
child 89 1df514389a47
child 102 ef2a444a7410
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/userlibandfileserver/fileserver/sfile/sf_cache.cpp	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,959 @@
+// Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of the License "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:
+// f32\sfile\sf_cache.cpp
+// 
+//
+
+#include <e32std.h>
+#include <e32std_private.h>
+#include "sf_std.h"
+#include <e32uid.h>
+#include <e32wins.h>
+#include <f32file.h>
+#include "sf_cache.h"
+
+const TInt KMaxCachedDirectories=6;
+
+TInt RefreshDriveInfo();
+void DestroyCachedDirectories(TPathListRecord* aPathRec);
+void DestroyCachedDirectory(TDriveNumber aDrive, TDirectoryCacheHeader* aDirCache);
+void DestroyCachedDirectory(TDriveNumber aDrive, TPathListRecord* aPathRec);
+
+const TInt KCacheHeapGranularity=0x0800; // Allocate heap in 2K chunks
+
+
+TBool gInitCacheCheckDrivesAndAddNotifications = EFalse;
+TBool gCacheCheckDrives = ETrue;
+
+
+// Cache per drive
+TDriveCacheHeader* gDriveFileNamesCache[KMaxDrives];
+
+TPathListRecord* TPathListRecord::First;
+TPathListRecord* TPathListRecord::LastStatic;
+
+
+#if defined(_DEBUG) || defined(_DEBUG_RELEASE)
+void dumpCache()
+	{
+	TDriveNumber drive;
+	for (drive=EDriveA; drive<=EDriveZ; ((TInt&)drive)++)
+		{
+		TDriveCacheHeader* pDH = gDriveFileNamesCache[drive];
+		RDebug::Printf("Dumping Drive %d", drive);
+		if (!pDH)
+			{
+			RDebug::Printf("Drive %d not cached",drive);
+			continue;
+			}
+		TDirectoryCacheHeader* p = pDH->iDirectoryList;
+		for (; p; p=p->iNext)
+			{
+			RDebug::Printf("    Dumping directory %S", p->iPath->PathName());
+			TFileCacheRecord** pIndexes = p->iCache;
+			TInt j;
+			for(j=0; j<p->iRecordCount; j++)
+				{
+				TFileCacheRecord& f = *pIndexes[j];
+				TBuf8<20> en = _S8("Entry ");
+				en.AppendNum(j);
+				f.Dump((const char*)en.Ptr());
+				}
+			}
+		}
+	}
+#endif
+
+CCacheNotifyDirChange::CCacheNotifyDirChange(TDriveNumber aDrive, TDirectoryCacheHeader& aDirHead)
+	: CActive(EPriorityHigh), iDrive(aDrive), iDirHead(&aDirHead)
+	{}
+
+CCacheNotifyDirChange::~CCacheNotifyDirChange()
+	{
+	__IF_DEBUG(Printf("~CCacheNotifyDirChange"));
+	Cancel();
+	}
+
+void CCacheNotifyDirChange::DoCancel()
+	{
+	__IF_DEBUG(Printf("DoCancel"));
+	gTheLoaderFs.NotifyChangeCancel(iStatus);
+	}
+	
+void CCacheNotifyDirChange::RunL()
+	{
+	__IF_DEBUG(Printf("Pop!! for drive %d path %S (%d)", iDrive, iDirHead->iPath->PathName(), iStatus.Int()));
+
+	// unlink directory & delete it
+	DestroyCachedDirectory(iDrive, iDirHead);
+	gCacheCheckDrives = ETrue;
+	}
+
+TInt CCacheNotifyDirChange::RegisterNotification(TPathListRecord* aPathRec, TNotifyType aType)
+//
+// Notification that a card has been mounted/removed
+//
+	{
+	TDriveUnit drive(iDrive);
+	TFileName pathName(drive.Name());
+	pathName.Append('\\');
+	TInt dl = pathName.Length();
+	const TText* ppp = pathName.Ptr() + dl;
+	const TDesC8& p8 = *aPathRec->PathName();
+	TInt p8l = p8.Length();
+	pathName.SetLength(dl + p8l);
+	TPtr pp((TText*)ppp, 0, KMaxFileName - dl);
+	pp.Copy(p8);
+	if (pathName[dl + p8l -1] != '\\')
+		pathName.Append('\\');
+
+	__IF_DEBUG(Printf("RegisterNotification for drive %d path %S", iDrive, &p8));
+	__IF_DEBUG(Print(_L("register notification for %S"), &pathName));
+	gTheLoaderFs.NotifyChange(aType, iStatus, pathName);
+	SetActive();
+	__LDRTRACE({	\
+		if (iStatus != KRequestPending)	\
+			RDebug::Printf("Notifier Immediate Complete %d", iStatus.Int()); \
+		});
+	return KErrNone;
+	}	
+
+TInt SetupNotify(TDriveNumber aDrive, TDirectoryCacheHeader& aDirHead)
+	{
+	if (aDirHead.iNotify != NULL)
+		{
+		__IF_DEBUG(Printf("SetupNotify!! notification already registered on drive %d path %S", aDrive, aDirHead.iPath->PathName()));
+		return KErrNone;
+		}
+
+	__IF_DEBUG(Printf("SetupNotify!! on drive %d path %S", aDrive, aDirHead.iPath->PathName()));
+	CCacheNotifyDirChange* pNotifier = new CCacheNotifyDirChange(aDrive, aDirHead);
+	if (!pNotifier)
+		return KErrNoMemory;
+	aDirHead.iNotify = pNotifier;
+	CActiveSchedulerLoader::Add(pNotifier);
+	return pNotifier->RegisterNotification(aDirHead.iPath, ENotifyFile);
+	}
+
+TInt AddNotifications()
+	{
+	TDriveNumber drive;
+	for (drive=EDriveA; drive<EDriveZ; ((TInt&)drive)++)	// Z always read-only so no notifiers required
+		{
+		TDriveCacheHeader* pDH = gDriveFileNamesCache[drive];
+		if (!pDH)
+			continue;
+
+		__IF_DEBUG(Printf("AddNotifications on drive %d att=0x%08x", drive, pDH->iDriveAtt));
+
+		TDirectoryCacheHeader* p = pDH->iDirectoryList;
+		for (; p; p=p->iNext)
+			{
+			TInt r = SetupNotify(drive, *p);
+			if (r != KErrNone)
+				{
+				DestroyCachedDirectory(drive, p);
+				return r;
+				}
+			}
+		}
+	gCacheCheckDrives = EFalse;
+	return KErrNone;
+	}
+
+//=============================== TFileCacheRecord ==================================
+//
+TInt TFileCacheRecord::Order(const TFileCacheRecord& aL, const TFileCacheRecord& aR)
+	{
+	return aL.Name().CompareF(aR.Name());
+	}
+
+//=============================== TPathListRecord ==================================
+//
+#if defined(_DEBUG) || defined(_DEBUG_RELEASE)
+void dumpPathList()
+	{
+	RDebug::Printf("Dumping Pathlist");
+	TPathListRecord* p = TPathListRecord::First;
+	TInt count=0;
+	for (; p; p=p->iNext, ++count)
+		RDebug::Printf("Pathlist pos %d %S",count,p->PathName());
+	}
+#endif
+
+_LIT8(KDirSystemPrograms, "System\\Programs");
+_LIT8(KDirSystemLibs, "System\\Libs");
+_LIT8(KDirSystemBin, "System\\Bin");
+_LIT8(KDirSysBin, "Sys\\Bin");
+
+TInt TPathListRecord::Init()
+	{
+	if (!AddToPathList(KDirSysBin, ETrue))
+		return KErrNoMemory;
+	if(!PlatSec::ConfigSetting(PlatSec::EPlatSecEnforceSysBin))
+		{
+		if (!AddToPathList(KDirSystemPrograms, ETrue))
+			return KErrNoMemory;
+		if (!AddToPathList(KDirSystemLibs, ETrue))
+			return KErrNoMemory;
+		if (!AddToPathList(KDirSystemBin, ETrue))
+			return KErrNoMemory;
+		}
+	return KErrNone;
+	}
+
+void TPathListRecord::MoveToHead()
+	{
+	if (iKeep || this == LastStatic->iNext)
+		return;
+	TPathListRecord* p = First;
+	// the record is always in the list
+	for (; p && p->iNext!=this; p=p->iNext) {}
+    __ASSERT_DEBUG(p, User::Invariant());
+	p->iNext = iNext;
+	iNext = LastStatic->iNext;
+	LastStatic->iNext = this;
+	}
+
+TPathListRecord* TPathListRecord::FindPathNameInList(const TDesC8& aPath)
+	{
+	__IF_DEBUG(Printf("TPathListRecord::FindPathNameInList %S",&aPath));
+	TPathListRecord* p = DoFindPathNameInList(aPath);
+	if (!p)
+		p = AddToPathList(aPath, EFalse);
+	return p;
+	}
+
+TPathListRecord* TPathListRecord::DoFindPathNameInList(const TDesC8& aPath)
+	{
+	// Accesses pathname list to retrieve pathname record
+	TPathListRecord* p = First;
+	for (; p; p=p->iNext)
+		{
+		if (p->PathName()->CompareF(aPath) == 0)
+			{
+			p->MoveToHead();
+			return p;
+			}
+		}
+	return NULL;
+	}
+
+TPathListRecord* TPathListRecord::AddToPathList(const TDesC8& aPath, TBool aKeep)
+	{
+	__LDRTRACE(dumpPathList());
+	__IF_DEBUG(Printf("Pathlist adding path %S keep %d",&aPath,aKeep));
+
+	TPathListRecord* n = TPathListRecord::New(aPath, aKeep);
+	if (!n)
+		return NULL;
+	TPathListRecord* p = First;
+	TPathListRecord* q = NULL;
+	TInt count = 0;
+	for (; p && ++count<KMaxCachedDirectories; q=p, p=p->iNext) {}
+	if (p)
+		{
+		// need to kill off entry pointed to by p
+		__IF_DEBUG(Printf("In AddToPathList killing %S", p->PathName()));
+		__ASSERT_ALWAYS(!aKeep, User::Invariant());
+		q->iNext = NULL;
+		DestroyCachedDirectories(p);
+		delete p;
+		}
+
+	if (aKeep)
+		{
+		// add to front of list
+		n->iNext = First;
+		First = n;
+		if (!LastStatic)
+			LastStatic = n;
+		}
+	else
+		{
+		// add new entry to front of dynamic list
+		n->iNext = LastStatic->iNext;
+		LastStatic->iNext = n;
+		}
+
+	// Refresh cache now we've added a new path
+	gCacheCheckDrives = ETrue;
+
+	__LDRTRACE(dumpPathList());
+	return n;
+	}
+
+TPathListRecord* TPathListRecord::New(const TDesC8& aPath, TBool aKeep)
+	{
+	TInt l = aPath.Length();
+	TInt size = sizeof(TPathListRecord) + Align4(l) + sizeof(TDesC8);
+	TPathListRecord* p = (TPathListRecord*)User::Alloc(size);
+	if (p)
+		{
+		p->iNext = NULL;
+		p->iKeep = aKeep;
+		TInt* pb = (TInt*)(p+1);
+		*pb = l;
+		memcpy(pb+1, aPath.Ptr(), l);
+		}
+	return p;
+	}
+
+void DestroyCachedDirectory(TDriveNumber aDrive, TPathListRecord* aPathRec)
+	{
+	__IF_DEBUG(Printf("DestroyCachedDirectory drive=%d path=%S",aDrive,aPathRec->PathName()));
+	TDriveCacheHeader* pDH = gDriveFileNamesCache[aDrive];
+	TDirectoryCacheHeader* p = pDH->iDirectoryList;
+	TDirectoryCacheHeader* q = 0;
+	for (; p && p->iPath!=aPathRec; q=p, p=p->iNext) {}
+	if (p)
+		{
+		__IF_DEBUG(Printf("    unlinking directory %S",p->iPath->PathName()));
+		if (q)
+			q->iNext = p->iNext;
+		else
+			pDH->iDirectoryList = p->iNext;
+		__IF_DEBUG(Printf("    deleting directory %S",p->iPath->PathName()));
+		delete p;
+		}
+	}
+
+void DestroyCachedDirectory(TDriveNumber aDrive, TDirectoryCacheHeader* aDirCache)
+	{
+	// First see if it contained in our list
+	__IF_DEBUG(Printf("DestroyCachedDirectory drive=%d path=%S", aDrive, aDirCache->iPath->PathName()));
+
+	TDriveCacheHeader* pDH = gDriveFileNamesCache[aDrive];
+	TDirectoryCacheHeader* p = pDH->iDirectoryList;
+	TDirectoryCacheHeader* q = 0;
+	for (; p && p!=aDirCache; q=p, p=p->iNext) {}
+	if (p)
+		{
+		__IF_DEBUG(Printf("    unlinking directory %S",p->iPath->PathName()));
+		if (q)
+			q->iNext = p->iNext;
+		else
+			pDH->iDirectoryList = p->iNext;
+		}
+	__IF_DEBUG(Printf("    deleting directory %S", aDirCache->iPath->PathName()));
+	delete aDirCache;
+	}
+
+void DestroyCachedDirectories(TPathListRecord* aPathRec)
+	{
+	__IF_DEBUG(Printf("DestroyCachedDirectories %S",aPathRec->PathName()));
+	TDriveNumber drive;
+	for (drive=EDriveA; drive<=EDriveZ; ((TInt&)drive)++)
+		{
+		TDriveCacheHeader* pDH = gDriveFileNamesCache[drive];
+		if (pDH)
+			{
+			__IF_DEBUG(Printf("DestroyCachedDirectories drive=%d driveatt=0x%08x",drive,pDH->iDriveAtt));
+			DestroyCachedDirectory(drive, aPathRec);
+			}
+		}
+	}
+
+//=============================== TCacheHeapList ==================================
+//
+TCacheHeapList::TCacheHeapList(TInt aSize)
+	:	iAllocated(Align4(sizeof(TCacheHeapList))),
+		iSize(aSize)
+	{}
+
+TAny* TCacheHeapList::Allocate(TInt aBytes)
+	{
+	__IF_DEBUG(Printf("TCacheHeapList::Allocate used=%d request=%d",iAllocated,aBytes));
+	TInt req = Align4(aBytes);
+	if (iAllocated+req > iSize)
+		return NULL;
+	TAny* p = PtrAdd(this, iAllocated);
+	iAllocated+=req;
+	return p;
+	}
+
+
+//=============================== TDriveCacheHeader==================================
+//
+TDriveCacheHeader::TDriveCacheHeader()
+	: iDirectoryList(NULL)
+	{}
+
+TDriveCacheHeader::~TDriveCacheHeader()
+	{
+	__IF_DEBUG(Printf("~TDriveCacheHeader"));
+	while (iDirectoryList)
+		{
+		TDirectoryCacheHeader* p = iDirectoryList;
+		iDirectoryList = p->iNext;
+		__IF_DEBUG(Printf("    deleting directory %S",p->iPath->PathName()));
+		delete p;
+		}
+	}
+
+TDirectoryCacheHeader* TDriveCacheHeader::FindDirCache(TPathListRecord* aPath)
+	{
+	TDirectoryCacheHeader* p = iDirectoryList;
+	for (; p && p->iPath!=aPath; p=p->iNext) {}
+	return p;
+	}
+
+TInt TDriveCacheHeader::GetDirCache(TDirectoryCacheHeader*& aCache, TPathListRecord* aPath, const TDesC8& aDriveAndPath)
+	{
+	__IF_DEBUG(Printf(">GetDirCache %S", &aDriveAndPath));
+	aCache = FindDirCache(aPath);
+	if (aCache)
+		{
+		__IF_DEBUG(Printf("<GetDirCache already exists %08x", aCache));
+		return KErrNone;
+		}
+	TDirectoryCacheHeader* p = new TDirectoryCacheHeader(aPath);
+	if (!p)
+		return KErrNoMemory;
+	TInt r = p->PopulateFromDrive(aDriveAndPath);
+	__IF_DEBUG(Printf("PopulateFromDrive ret %d", r));
+	if (r != KErrNoMemory && r != KErrLocked && iDriveNumber != EDriveZ)
+		r = SetupNotify((TDriveNumber)iDriveNumber, *p);
+	if (r == KErrNoMemory || r == KErrLocked)
+		{
+		delete p;
+		return r;
+		}
+	// Ignore other errors and keep created entry anyway, so for things like 'path not found'
+	// we have an empty directory cache which will get updated (via notification) if it get created.
+	// This empty entry also allows for a quicker check the second time around.
+
+	p->iNext = iDirectoryList;
+	iDirectoryList = p;
+	__IF_DEBUG(Printf("<GetDirCache new %08x", p));
+	aCache = p;
+	return KErrNone;
+	}
+
+//============================= TDirectoryCacheHeader================================
+//
+TDirectoryCacheHeader::TDirectoryCacheHeader(TPathListRecord* aPath)
+	:	iFirstHeapBlock(NULL), iPath(aPath), iRecordCount(0), iCache(NULL),
+		iNotPresent(ETrue), iNotify(NULL)
+	{}
+
+TDirectoryCacheHeader::~TDirectoryCacheHeader()
+	{
+	__IF_DEBUG(Printf("~TDirectoryCacheHeader %S",iPath->PathName()));
+	User::Free(iCache);
+	delete iNotify;
+
+	while (iFirstHeapBlock)
+		{
+		TCacheHeapList* p = iFirstHeapBlock;
+		iFirstHeapBlock = p->iNext;
+		User::Free(p);
+		}
+	}
+
+TInt TDirectoryCacheHeader::GetMoreHeap()
+	{
+	TAny* mem = User::Alloc(KCacheHeapGranularity);
+	if (!mem)
+		return KErrNoMemory;
+	TCacheHeapList* n = new (mem) TCacheHeapList(KCacheHeapGranularity);
+	n->iNext = iFirstHeapBlock;
+	iFirstHeapBlock = n;
+	return KErrNone;
+	}
+
+TAny* TDirectoryCacheHeader::Allocate(const TInt aBytes)
+	{
+	TAny* p = iFirstHeapBlock ? iFirstHeapBlock->Allocate(aBytes) : NULL;
+	if (!p)
+		{
+		if (GetMoreHeap()!=KErrNone)
+			return NULL;
+		p = iFirstHeapBlock->Allocate(aBytes);
+		}
+	return p;
+	}
+
+TFileCacheRecord* TDirectoryCacheHeader::NewRecord(const TDesC8& aName, TUint32 aAttr, TUint32 aVer, const TEntry& aEntry)
+	{
+	TInt l = aName.Length();
+	TInt minsize = l + sizeof(TFileCacheRecord);
+	TInt extra = aEntry.iSize >> 12;		// allow for 8 exports per 4K of file
+	if(extra>128)
+		extra = 128;
+	TInt size = (minsize + extra + 15) &~ 15;
+
+	TFileCacheRecord* p = (TFileCacheRecord*)Allocate(size);
+	if (p)
+		{
+		memclr(p, sizeof(TFileCacheRecord));
+		p->iAttr = aAttr;
+		p->iModuleVersion = aVer;
+		p->iExportDirCount = size - minsize;
+		p->iNameLength = l;
+		p->iExportDescType = (aEntry.iAtt & KEntryAttXIP) ? KImageHdr_ExpD_Xip : KImageHdr_ExpD_NoHoles;	// for now
+		p->iCacheStatus = 0;
+		memcpy(p+1, aName.Ptr(), l);
+		}
+	return p;
+	}
+
+TFileCacheRecord* TDirectoryCacheHeader::NewRecord(const TFileCacheRecord& aRecord, TInt aEDS)
+	{
+	TInt l = aRecord.Name().Length();
+	TInt minsize = l + sizeof(TFileCacheRecord);
+	TInt extra = aEDS + 2;
+	TInt size = (minsize + extra + 15) &~ 15;
+
+	TFileCacheRecord* p = (TFileCacheRecord*)Allocate(size);
+	if (p)
+		{
+		memcpy(p, &aRecord, minsize);
+		memclr((TUint8*)p + minsize, size - minsize);
+		}
+	return p;
+	}
+
+TInt TDirectoryCacheHeader::PopulateFromDrive(const TDesC8& aPathName)
+	{
+	// Wildcard searches through a named directory on a drive.
+	// Creates and fills records to newly populate the drive cache..
+
+	// only want gen-u-ine files
+	RDir d;
+	TFileName dp;
+	dp.Copy(aPathName);
+	__IF_DEBUG(Print(_L("Opening Directory %S"), &dp));
+
+	iNotPresent=ETrue;
+	TInt r=d.Open(gTheLoaderFs, dp, KEntryAttMatchExclude|KEntryAttDir|KEntryAttVolume);
+	__IF_DEBUG(Printf("Returns %d", r));
+	if (r != KErrNone)
+		{
+		return r;
+		}
+	
+	TEntryArray array;
+	TInt sizeofIndexArray=0;
+	TFileCacheRecord** pIndexes=NULL;
+	TInt currentIndex=0;
+	do	{
+		r=d.Read(array);
+		if (r==KErrNone || r==KErrEof)
+			{
+			TInt count=array.Count();
+			if (count==0)
+				break;
+			TInt newSize=currentIndex+count;
+			// Round alloc granularity up to the size of the cache cells, to avoid heap fragmentation when
+			// indexing large dirs (z:\sys\bin) - interference effect is minimised by allocating in larger blocks and by
+			// ensuring the freed memory can be reused for cache cells. See INC065949 for original defect.
+			const TInt arrayGranularity = KCacheHeapGranularity + RHeap::EAllocCellSize;
+			sizeofIndexArray = (sizeof(TFileCacheRecord*)*newSize + arrayGranularity - 1) / arrayGranularity * arrayGranularity;
+			TFileCacheRecord** p=(TFileCacheRecord**)User::ReAlloc(pIndexes,sizeofIndexArray);
+			if (!p)
+				{
+				r=KErrNoMemory;
+				break;
+				}
+			pIndexes=p;
+			TInt i=0;
+			while (i<count)
+				{
+				const TEntry& e = array[i++];
+				TInt nl = e.iName.Length();
+				if (nl > KMaxKernelName)
+					{
+					__IF_DEBUG(Printf("Name length %d - too long", nl));
+					continue;
+					}
+				TBuf8<KMaxKernelName> n8;
+				r = CheckedCollapse(n8, e.iName);
+				if (r != KErrNone)
+					{
+					__IF_DEBUG(Printf("Non-ASCII name"));
+					continue;
+					}
+				TFileNameInfo fni;
+				r = fni.Set(n8, 0);
+				if (r != KErrNone)
+					{
+					__IF_DEBUG(Printf("Bad name"));
+					continue;
+					}
+				TBuf8<KMaxKernelName> rootname;
+				fni.GetName(rootname, TFileNameInfo::EIncludeBaseExt);
+				TUint32 attr = fni.VerLen() ? ECodeSegAttExpVer : 0;
+				TFileCacheRecord* pR = NewRecord(rootname, attr, fni.Version(), e);
+				if (!pR)
+					{
+					r=KErrNoMemory;
+					break;
+					}
+				pIndexes[currentIndex] = pR;
+				currentIndex++;
+				}
+			}
+		} while (r==KErrNone);
+	d.Close();
+	if(r==KErrNoMemory)
+		return r;
+
+	iNotPresent = EFalse;
+	iCache = (TFileCacheRecord**)User::ReAlloc(pIndexes,sizeof(TFileCacheRecord*)*currentIndex);
+	iRecordCount = currentIndex;
+	if (currentIndex>1)
+		{
+		// don't sort an empty list, or a list with only 1 element
+		RPointerArray<TFileCacheRecord> rarray(iCache, iRecordCount);
+		rarray.Sort(&TFileCacheRecord::Order);
+		}
+
+	__LDRTRACE(	{	\
+	RDebug::Printf("RArray sorted");		\
+	TInt i;									\
+	for (i=0; i<iRecordCount; i++)			\
+		{									\
+		TFileCacheRecord* f = iCache[i];	\
+		const TDesC8& name = f->Name();		\
+		RDebug::Printf("%d: Entry=%S att %08x ver %08x", i, &name, f->iAttr, f->iModuleVersion);	\
+		}									\
+		});
+	return KErrNone;
+	}
+
+TInt RefreshDriveInfo()
+	{
+	// Find out what drives are present
+	__IF_DEBUG(Printf(">RefreshDriveInfo"));
+	TDriveList list;
+	TInt r = gTheLoaderFs.DriveList(list);
+	if (r!=KErrNone)
+		{
+		return r;
+		}
+	TDriveInfo d;
+	TDriveNumber drive;
+	for (drive=EDriveA; drive<=EDriveZ; ((TInt&)drive)++)
+		{
+		TInt att = list[drive];
+		if (att)
+			{
+			r = gTheLoaderFs.Drive(d,drive);
+			if (r != KErrNone)
+				continue;
+			if ((d.iDriveAtt & KDriveAttRemote) || (d.iDriveAtt & KDriveAttSubsted))
+	            continue; //Don't cache remote or substituted drives
+			if (gDriveFileNamesCache[drive] == NULL)
+				{
+				__IF_DEBUG(Printf("In RefreshDriveInfo adding drive %d, drive= 0x%08x media=0x%08x", drive, d.iDriveAtt, d.iMediaAtt));
+				TDriveCacheHeader* pDH = new TDriveCacheHeader;
+				if (!pDH)
+					return KErrNoMemory;
+				gDriveFileNamesCache[drive] = pDH;
+				pDH->iDriveAtt = d.iDriveAtt;
+				pDH->iDriveNumber = drive;
+				}
+			continue;
+			}
+		TDriveCacheHeader* pDH = gDriveFileNamesCache[drive];
+		delete pDH;
+		gDriveFileNamesCache[drive] = NULL;
+		}
+	__IF_DEBUG(Printf("<RefreshDriveInfo"));
+	return KErrNone;
+	}
+
+//
+void InitializeFileNameCache()
+	{
+	__IF_DEBUG(Printf("InitializeFileNameCache"));
+	gInitCacheCheckDrivesAndAddNotifications = EFalse;
+	gCacheCheckDrives = ETrue;
+	__ASSERT_ALWAYS(TPathListRecord::Init()==KErrNone, User::Invariant());
+	}
+
+TInt CheckLoaderCacheInit()
+	{
+	TInt r=KErrNone;
+	if(RefreshZDriveCache)
+		{
+		// force z: drive cache to be refreshed
+		__IF_DEBUG(Print(_L("Deleting z: drive cache\r\n")));
+		TDriveCacheHeader* pDH=gDriveFileNamesCache[EDriveZ];
+		delete pDH;
+		gDriveFileNamesCache[EDriveZ]=NULL;
+		gCacheCheckDrives=ETrue;
+		RefreshZDriveCache=EFalse;
+		}
+	if (gCacheCheckDrives)
+		{
+		__IF_DEBUG(Printf("Refreshing cache"));
+		r = RefreshDriveInfo();						// refreshing is a 'once-only' operation after setting
+		gCacheCheckDrives = EFalse;					// gCacheCheckDrives so as to prevent excessive refreshing
+		}
+	if (!gInitCacheCheckDrivesAndAddNotifications && StartupInitCompleted)
+		{
+		__IF_DEBUG(Printf("Refreshing cache and adding notifications after FS initialisation"));
+		r = RefreshDriveInfo();						// this is to provide an extra refresh to explicitly find
+		r = AddNotifications();						// all drives set up during FS initialisation
+		gInitCacheCheckDrivesAndAddNotifications = ETrue;	
+		}
+	return r;
+	}
+
+TFileCacheRecordSearch::TFileCacheRecordSearch(const TDesC8& aSearchName)
+	{
+	iNameLength = aSearchName.Length();
+	if(iNameLength>sizeof(iSearchName))
+		User::Invariant();
+	memcpy(iSearchName, aSearchName.Ptr(), iNameLength);
+	}
+
+TInt RImageFinder::SearchSingleDir()
+	{
+	__IF_DEBUG(Printf("SearchSingleDir %S drive %d", &iCurrentPath, iCurrentDrive));
+
+	TDriveCacheHeader* pDH = gDriveFileNamesCache[iCurrentDrive];
+	if (!pDH)
+		{
+		__IF_DEBUG(Printf("No such drive"));
+		return KErrNone;
+		}
+
+	TInt pl = iCurrentPath.Length();
+	TInt start = 0;
+	TInt len = pl;
+	if (pl)
+		{
+		if (iCurrentPath[0] == '\\')
+			start = 1, --len;
+		if (len>0 && iCurrentPath[start + len - 1] == '\\')
+			--len;
+		}
+	TPtrC8 path(iCurrentPath.Mid(start, len));
+	__IF_DEBUG(Printf("Normalised path %S", &path));
+	TChar c;
+	RFs::DriveToChar(iCurrentDrive, c);
+	TBuf8<KMaxFileName> drive_and_path = _S8("?:\\");
+	drive_and_path[0] = (TText8)c;
+	drive_and_path.Append(path);
+	if (drive_and_path[drive_and_path.Length()-1] != '\\')
+		drive_and_path.Append('\\');
+
+	TPathListRecord* prec = TPathListRecord::FindPathNameInList(path);
+	if (!prec)
+		return KErrNoMemory;
+	TDirectoryCacheHeader* dch = NULL;
+	TInt r = pDH->GetDirCache(dch, prec, drive_and_path);
+	if (r != KErrNone || dch->iNotPresent || dch->iRecordCount==0)
+		{
+		return r;
+		}
+
+	// set up to search for root name
+	__IF_DEBUG(Printf("Search directory for %S", &iRootName));
+	TFileCacheRecordSearch search(iRootName);
+	__LDRTRACE({const TDesC8& sr = search.Name(); RDebug::Printf("Search record %S", &sr);});
+	RPointerArray<TFileCacheRecord> rarray(dch->iCache, dch->iRecordCount);
+	TInt first = rarray.SpecificFindInOrder(&search, &TFileCacheRecord::Order, EArrayFindMode_First);
+	TInt last = rarray.SpecificFindInOrder(&search, &TFileCacheRecord::Order, EArrayFindMode_Last);
+	__IF_DEBUG(Printf("First %d Last %d", first, last));
+	TInt ix;
+	for (ix = first; ix < last; ++ix)
+		{
+		TFileCacheRecord* f = dch->iCache[ix];
+		RImageInfo img_info;
+		r = KErrNone;
+		if (!f->ExtrasValid())
+			{
+			r = f->GetImageInfo(img_info, drive_and_path, dch, ix);
+			if (r == KErrNoMemory)
+				return r;
+			f = dch->iCache[ix];	// may have been moved
+			}
+		if (r==KErrNone)
+			{
+			img_info = *f;
+			r = Try(img_info, f->Name(), drive_and_path);
+			if (r == KErrNoMemory)
+				{
+				img_info.Close();
+				return r;
+				}
+			f->iCacheStatus = img_info.iCacheStatus;
+			}
+		else
+			RecordCorruptFile();
+		img_info.Close();
+		if (r==KErrCompletion)
+			break;
+		}
+	return KErrNone;
+	}
+
+// Populate the 'extras' in the cache record by reading the file header
+// aPathName must be of the form ?:\dir\...\dir\ so that a fully qualified file name is obtained by
+// appending the file name.
+TInt TFileCacheRecord::GetImageInfo(RImageInfo& aInfo, const TDesC8& aPathName, TDirectoryCacheHeader* aDirHead, TInt aIndex)
+	{
+	const TDesC8& rootname = Name();
+	TBuf8<KMaxFileName> fn = aPathName;
+	TFileNameInfo fni;
+	fni.Set(rootname, 0);
+	fni.iVersion = iModuleVersion;
+	TUint flags = (iAttr & ECodeSegAttExpVer) ? TFileNameInfo::EForceVer : 0;
+	fni.GetName(fn, TFileNameInfo::EIncludeBaseExt | flags);
+	__IF_DEBUG(Printf("Opening file %S", &fn));
+	TInt r = OpenFile8(aInfo.iFile, fn);
+	__IF_DEBUG(Printf("Open file returns %d", r));
+	if (r != KErrNone)
+		return r;
+	TInt address = 0;
+	r = aInfo.iFile.Seek(ESeekAddress, address);
+	if (r!=KErrNotSupported)
+		{
+		__IF_DEBUG(Printf("ROM file at %08x", address));
+		TUint att;
+		r = aInfo.iFile.Att(att);
+		if (r!=KErrNone)
+			{
+			aInfo.Close();
+			return r;
+			}
+		if (att & KEntryAttXIP)
+			{
+			const TRomImageHeader& rih = *(const TRomImageHeader*)address;
+			__IF_DEBUG(Printf("XIP file"));
+			SetXIP(&rih);
+			if ((iAttr & ECodeSegAttExpVer) && iModuleVersion != rih.iModuleVersion)
+				{
+				// version in file name does not match version in header
+				aInfo.Close();
+				return KErrBadName;
+				}
+			iModuleVersion = rih.iModuleVersion;
+			iS = rih.iS;
+			iExportDirCount = (TUint16)rih.iExportDirCount;
+			iExportDescType = (TUint8)KImageHdr_ExpD_Xip;
+			iAttr |= rih.iFlags & (KRomImageFlagFixedAddressExe|KRomImageABIMask);
+			__LDRTRACE(Dump("Cached Info XIP"));
+			return KErrNone;
+			}
+		}
+	TFileCacheRecord* t = this;
+	r = E32ImageHeader::New(aInfo.iHeader, aInfo.iFile);
+	if (r != KErrNone)
+		{
+		aInfo.Close();
+		__IF_DEBUG(Printf("E32ImageHeader::New returns %d", r));
+		return r;
+		}
+	E32ImageHeader* h = aInfo.iHeader;
+	if ((iAttr & ECodeSegAttExpVer) && iModuleVersion != h->iModuleVersion)
+		{
+		// version in file name does not match version in header
+		aInfo.Close();
+		return KErrBadName;
+		}
+	wordmove(iUid, &h->iUid1, sizeof(iUid));
+	iModuleVersion = h->ModuleVersion();
+	h->GetSecurityInfo(iS);
+	iAttr |= (h->iFlags & ECodeSegAttFixed) | h->ABI();
+	if(h->iFlags&KImageNmdExpData)
+		iAttr |= ECodeSegAttNmdExpData;
+	TUint avail = iExportDirCount;
+	iExportDirCount = (TUint16)h->iExportDirCount;
+	iExportDescType = KImageHdr_ExpD_NoHoles;
+
+	// get export description...
+	E32ImageHeaderV* v = (E32ImageHeaderV*)h;
+	iExportDescType = v->iExportDescType;
+	TUint eds = v->iExportDescSize;
+	if (eds + 2 > avail)
+		{
+		// must reallocate this entry
+		t = aDirHead->NewRecord(*this, eds);
+		if (!t)
+			{
+			aInfo.Close();
+			return KErrNoMemory;
+			}
+		aDirHead->iCache[aIndex] = t;
+		}
+	TUint8* xd = (TUint8*)t->ExportDescription();
+	xd[0] = (TUint8)eds;
+	xd[1] = (TUint8)(eds>>8);
+	memcpy(xd+2, v->iExportDesc, eds);
+
+	__LDRTRACE(t->Dump("Cached Info"));
+	return KErrNone;
+	}
+
+RImageInfo& RImageInfo::operator=(const TFileCacheRecord& aRecord)
+	{
+	wordmove(this, &aRecord, sizeof(TImageInfo));
+	if (aRecord.ExtrasValid())
+		{
+		if (aRecord.IsXIP())
+			{
+			iRomImageHeader = aRecord.RomImageHeader();
+			wordmove(iUid, &iRomImageHeader->iUid1, sizeof(iUid));
+			}
+		else if (iExportDescType != KImageHdr_ExpD_NoHoles)
+			{
+			const TUint8* xd = (TUint8*)aRecord.ExportDescription();
+			iExportDescSize = (TUint16)(xd[0] | (xd[1]<<8));
+			iExportDesc = xd + 2;
+			}
+		}
+	return *this;
+	}
+
+
+#if defined(_DEBUG) || defined(_DEBUG_RELEASE)
+extern void memory_dump(const TAny* a, TUint l);
+
+void TFileCacheRecord::Dump(const char* aTitle)
+	{
+	RDebug::Printf(aTitle);
+	TUint32 uid1 = iUid[0];
+	TBool xip = (uid1 != (TUint32)KExecutableImageUidValue && uid1 != (TUint32)KDynamicLibraryUidValue);
+	const TDesC8& name = Name();
+	if (xip)
+		{
+		const TRomImageHeader* rih = RomImageHeader();
+		RDebug::Printf("Name: %S Ver %08x Attr %08x", &name, rih->iModuleVersion, iAttr);
+		RDebug::Printf("UIDS %08x %08x %08x SID %08x CAP %08x %08x", rih->iUid1, rih->iUid2, rih->iUid3,
+										rih->iS.iSecureId, rih->iS.iCaps[1], rih->iS.iCaps[0]);
+		RDebug::Printf("ExportDirCount %d ExportDescType %02x", rih->iExportDirCount, iExportDescType);
+		}
+	else
+		{
+		RDebug::Printf("Name: %S Ver %08x Attr %08x", &name, iModuleVersion, iAttr);
+		RDebug::Printf("UIDS %08x %08x %08x SID %08x CAP %08x %08x", iUid[0], iUid[1], iUid[2],
+										iS.iSecureId, iS.iCaps[1], iS.iCaps[0]);
+		RDebug::Printf("ExportDirCount %d ExportDescType %02x", iExportDirCount, iExportDescType);
+		if (iExportDescType != KImageHdr_ExpD_NoHoles)
+			{
+			const TUint8* xd = ExportDescription();
+			TUint eds = (xd[1]<<8) | xd[0];
+			RDebug::Printf("ExportDescSize %04x", eds);
+			memory_dump(xd+2, eds);
+			}
+		}
+	}
+#endif
+
+