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

#include "debug.hpp"
#include <ntoskrnl.hpp>


BOOL
NTAPI
IsGoToNextMap(IN PSHARED_CACHE_MAP SharedMap, IN ULONG TargetPages)
{
    BOOLEAN Skip = FALSE;

    if (SharedMap->Flags & (0x20 | 0x800))
        return TRUE;

    if ((SharedMap->OpenCount || SharedMap->DirtyPages) && SharedMap->FileSize.QuadPart)
    {
        Skip = TRUE;
    }

    if (!SharedMap->DirtyPages && Skip)
        return TRUE;

    if (SharedMap->Flags & SHARE_FL_WAITING_TEARDOWN)
        return FALSE;

    if (!TargetPages && Skip)
        return TRUE;

    SharedMap->LazyWritePassCount++;

    if ((SharedMap->LazyWritePassCount & 0xF) && (SharedMap->Flags & SHARE_FL_MODIFIED_NO_WRITE) &&
        CcCapturedSystemSize != MmSmallSystem && SharedMap->DirtyPages < 0x40 && Skip)
    {
        return TRUE;
    }

    if ((SharedMap->FileObject->Flags & 0x8000) && SharedMap->OpenCount &&
        CcCanIWrite(SharedMap->FileObject, 0x40000, 0, 0xFF) && Skip)
    {
        return TRUE;
    }

    return FALSE;
}

/* Later Move it to XDK */
class SpinLockSharedGuard {
public:
    SpinLockSharedGuard(PEX_SPIN_LOCK SpinLock) : m_SpinLock(SpinLock) {
        m_OldIrql = ExAcquireSpinLockShared(m_SpinLock);
    }

    ~SpinLockSharedGuard() {
        ExReleaseSpinLockShared(m_SpinLock, m_OldIrql);
    }

    SpinLockSharedGuard(const SpinLockSharedGuard&) = delete;
    SpinLockSharedGuard& operator=(const SpinLockSharedGuard&) = delete;

private:
    PEX_SPIN_LOCK m_SpinLock;
    KIRQL m_OldIrql;
};