/*
 * PROJECT: Alcyone System Kernel
 * LICENSE: BSD Clause 3
 * PURPOSE: Cache Controller:: Lazy Writer
 * NT KERNEL: 5.11.9360
 * COPYRIGHT:  2023-2029 Dibymartanda Samanta <>
 */ 

#include <ntoskrnl.h>
#define NTDEBUG
#include <debug.h>
#include "ccinternal.hpp"


extern "C"


/*Internal Function*/

BOOLEAN
NTAPI
CcPinFileData(
    _In_ PFILE_OBJECT FileObject,
    _In_ PLARGE_INTEGER FileOffset,
    _In_ ULONG Length,
    _In_ BOOLEAN IsNoWrite,
    _In_ BOOLEAN Flags,
    _In_ ULONG PinFlags,
    _Out_ PCC_BCB* Bcb,
    _Out_ PVOID* Buffer,
    _Out_ LARGE_INTEGER* BeyondLastByte)
{
     // Unimplemented
}

BOOLEAN 
NTAPI
CcMapDataCommon(
    _In_ PFILE_OBJECT FileObject,
    _In_ PLARGE_INTEGER FileOffset,
    _In_ ULONG Length,
    _In_ ULONG Flags,
    _Out_ PVOID *Bcb,
    _Out_ PVOID *Buffer
)
  {
  if (Flags & FILE_PIN_SEQUENTIAL_READ)
        InterlockedIncrement(&CcSequentialReadCount);
    else
        InterlockedIncrement(&CcRandomReadCount);

    KeGetCurrentThread()->WaitIrql = PASSIVE_LEVEL;

    if (Flags & FILE_PIN_SEQUENTIAL_READ)
    {
        *Buffer = CcGetVirtualAddress(SharedMap, *FileOffset, (PVACB *)&Bcb, &ReceivedLength);
        return TRUE;
    }
    else
    {
        LARGE_INTEGER BeyondLastByte;
        if (CcPinFileData(FileObject, FileOffset, Length, TRUE, 0, Flags, Bcb, Buffer, &BeyondLastByte))
        {
            return TRUE;
        }
        else
        {
            InterlockedIncrement(&CCFailedPinReadCount);
            return FALSE;
        }
    }

   }
}

VOID
NTAPI
CcUnpinFileDataEx(
    _In_ PCC_BCB Bcb,
    _In_ BOOLEAN& WriteStatus,
    _In_ ULONG& UnPinType)
{
	PSHARED_CACHE_MAP SharedCacheMap = nullptr;
    KIRQL OldIrql = {0};
    ULONG NumberOfPages = {0};
	BOOLEAN ReadOnly = false;


    /* If it is not BCB Ptr,it must be VACB Pointer, free it*/
    if (Bcb->NodeTypeCode != BCB_NODE_TYPE_CODE)
    {   
        PVACB Vacb = reinterpret_cast<PVACB>(Bcb);
       
        CcFreeVirtualAddress(Vacb);

        return;
    }

    SharedCacheMap = Bcb->SharedCacheMap;
    /* Is it only Unpinning if so is their no write performed by Cache Controller */
    if (!(SharedCacheMap->Flags & SHARED_CACHE_MAP_MODIFIED_NO_WRITE) || UnPinType == UnPin)
        ReadOnly = TRUE;

    OldIrql = KeAcquireSpinLockRaiseToDpc(&SharedCacheMap->BcbSpinLock);
    /* Just reduce pin count if BCB is not set to be cleaned else perform cleaning of BCB*/
    if (UnPinType < CLEAN_BCB_PIN)
    {
        ASSERT(Bcb->PinCount > 0);
        Bcb->PinCount--;
    }
    else
    {
        if (UnPinType != CLEAN_BCB_PIN)
            KeBugCheckEx(UNEXPECTED_VALUE, UnPinType, (ULONG_PTR)Bcb, 0, 0);

        if (Bcb->IsBCBDirty)
        {
            NumberOfPages = (Bcb->Length / PAGE_SIZE);

            Bcb->IsBCBDirty = FALSE;
            Bcb->NewestDirtiedPage = 0;
            Bcb->NewestLsn.QuadPart = 0;

            CcDeductIsBCBDirtyPages(SharedCacheMap, NumberOfPages);
            /*Adjust page count */
            if (CcPagesYetToWrite <= NumberOfPages)
                CcPagesYetToWrite = 0;
            else
                CcPagesYetToWrite -= NumberOfPages;

            if (!SharedCacheMap->IsBCBDirtyPages && SharedCacheMap->OpenCount)
                CcInsertIntoCleanSharedCacheMapList(SharedCacheMap);
        }
    }

    if (Bcb->PinCount)
    {   /* If not read only BCB, release resources,their no point being pinned at that case */
        if (!ReadOnly)
            ExReleaseResourceLite(&Bcb->BcbResource);

        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
    }
	/*if BCB is dirty, free the virtual adress*/
    else if (Bcb->IsBCBDirty)
    {
        if (Bcb->BaseAddress)
        {
            CcFreeVirtualAddress(Bcb->Vacb);

            Bcb->BaseAddress = NULL;
            Bcb->Vacb = NULL;
        }

        if (!ReadOnly)
            ExReleaseResourceLite(&Bcb->BcbResource);

        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
    }
    else
    {
        KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->VacbSpinLock);

        RemoveEntryList(&Bcb->Link);

        if (SharedCacheMap->SectionSize.QuadPart > CACHE_OVERALL_SIZE &&
            (SharedCacheMap->Flags & SHARED_CACHE_MAP_MODIFIED_NO_WRITE))
        {
            CcAdjustVacbLevelLockCount(SharedCacheMap, &Bcb->FileOffset.QuadPart, -1); 
        }

        KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->VacbSpinLock);

        if (Bcb->BaseAddress)
            CcFreeVirtualAddress(Bcb->Vacb); 

        if (!ReadOnly)
            ExReleaseResourceLite(&Bcb->BcbResource);

        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);

        CcDeallocateBcb(Bcb);
    }
    
}

BOOLEAN
VECTORCALL
CcPinFileData(
    IN PFILE_OBJECT FileObject,
    IN PLARGE_INTEGER FileOffset,
    IN ULONG Length,
    IN BOOLEAN IsReadOnly,
    IN BOOLEAN IsWriteOnly,
    IN ULONG Flags,
    OUT PCC_BCB *Bcb,
    OUT PVOID *BaseAddress,
    OUT PLARGE_INTEGER BeyondLastByte)
{
    // Unimplemented
}


BOOLEAN
NTAPI
CcMapData(
    IN PFILE_OBJECT FileObject,
    IN PLARGE_INTEGER FileOffset,
    IN ULONG Length,
    IN ULONG Flags,
    OUT PVOID *Bcb,
    OUT PVOID *Buffer)
{
    //Unimplemented
}

BOOLEAN
FASTCALL
CcMapDataCommon(
    IN PFILE_OBJECT FileObject,
    IN PLARGE_INTEGER FileOffset,
    IN ULONG Length,
    IN ULONG Flags,
    OUT PVOID *Bcb,
    OUT PVOID *Buffer)
{
    //Unimplemented
}

BOOLEAN
NTAPI
CcPinMappedData(
    IN PFILE_OBJECT FileObject,
    IN PLARGE_INTEGER FileOffset,
    IN ULONG Length,
    IN ULONG Flags,
    IN OUT PCC_BCB Bcb)
{
    //Unimplemented
}

BOOLEAN
NTAPI
CcPinRead(
    IN PFILE_OBJECT FileObject,
    IN PLARGE_INTEGER FileOffset,
    IN ULONG Length,
    IN ULONG Flags,
    OUT PVOID *Bcb,
    OUT PVOID *Buffer)
{
    //Unimplemented
}

BOOLEAN
NTAPI
CcPreparePinWrite(
    IN PFILE_OBJECT FileObject,
    IN PLARGE_INTEGER FileOffset,
    IN ULONG Length,
    IN BOOLEAN Zero,
    IN ULONG Flags,
    OUT PVOID *Bcb,
    OUT PVOID *Buffer)
{
    //Unimplemented
}

VOID
NTAPI
CcSetBcbOwnerPointer(
    IN PMBCB Bcb,
    IN PVOID OwnerPointer)
{
     if (Bcb->NodeTypeCode == 762)
    {
        /* Iterate through all bitmap ranges */
         for (auto it = ListEntryIterator::begin(&Bcb->BitmapRanges); it != ListEntryIterator::end(&Bcb->BitmapRanges); ++it)
        {   auto* Bcb = CONTAINING_RECORD(it->Blink,MBCB,BitmapRanges);
            ExSetResourceOwnerPointer(&Bcb->DirtyPages,OwnerPointer);
        }
    }
    else
    {
        /* Single bitmap range */
        ExSetResourceOwnerPointer(&Bcb->BitmapRange1.FirstDirtyPage,OwnerPointer);
    }
}


VOID
NTAPI
CcUnpinData(
    _In_ PVOID BcbPtr)
{
	PCC_BCB Bcb = reinterpret_cast<PCC_BCB>(BcbPtr);
    BOOLEAN WRITE_FLAG = NULL;
		
if (reinterpret_cast<ULONG_PTR>((Bcb & 1))
{
    WRITE_FLAG = TRUE;
    Bcb = reinterpret_cast<PCC_BCB>(reinterpret_cast<ULONG_PTR>(Bcb) & ~(1));

    CcUnpinFileDataEx(Bcb, WRITE_FLAG, UNPIN_BCB);

    return;
}

 if (Bcb->NodeTypeCode != 762)
{
        WRITE_FLAG = FALSE;
        CcUnpinFileDataEx(Bcb, WRITE_FLAG, UNPIN_BCB);
        return;
}
 for (auto it = ListEntryIterator::begin(&Bcb->BcbLinks); it != ListEntryIterator::end(&Bcb->BcbLinks); ++it)
{
        auto* BCB_CURRENT = CONTAINING_RECORD(it->Blink, CC_BCB, BcbLinks);
        
		CcUnpinData(BCB_CURRENT);
		
}
ExFreePoolWithTag(Bcb,NULL);
}

VOID
NTAPI
CcUnpinDataForThread(IN PVOID BcbPtr,
                     IN ERESOURCE_THREAD ResourceThreadId)
{
    PCC_BCB Bcb = BcbPtr;
    BOOLEAN WRITE_FLAG = NULL;

if (reinterpret_cast<ULONG_PTR>((Bcb & 1))
{
    WRITE_FLAG = TRUE;
    Bcb = reinterpret_cast<PCC_BCB>(reinterpret_cast<ULONG_PTR>(Bcb) & ~(1));

    CcUnpinFileDataEx(Bcb, WRITE_FLAG, );

    return;
}

if (Bcb->NodeTypeCode != 762)
{
        WRITE_FLAG = FALSE;
		ExReleaseResourceForThreadLite(&Bcb->Resource, ResourceThreadId);
        CcUnpinFileDataEx(Bcb, WRITE_FLAG, UNPIN_BCB);
        return;
}
 for (auto it = ListEntryIterator::begin(&Bcb->BcbLinks); it != ListEntryIterator::end(&Bcb->BcbLinks); ++it)
{
        auto* BCB_CURRENT = CONTAINING_RECORD(it->Blink, CC_BCB, BcbLinks);
        
		CcUnpinData(BCB_CURRENT);
		
}
ExFreePoolWithTag(Bcb,NULL);
    
}