AuroraRuntime/Source/IO/FS/Async.NT.hpp

/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: Async.NT.hpp
    Date: 2021-9-13
    Author: Reece
***/
#pragma once

namespace Aurora::IO::FS
{
    struct FileHandle
    {
        ~FileHandle();

        bool Init(const AuString &path, EFileOpenMode openMode, bool directIO, EFileAdvisoryLockLevel lock);
        void Init(HANDLE h);

        HANDLE handle {INVALID_HANDLE_VALUE};
        AuString path;
        bool readOnly;
        bool directIO;
    };

    struct NtAsyncFileStream : IAsyncFileStream
    {
        AuSPtr<IAsyncTransaction> NewTransaction() override;

        bool BlockingTruncate(AuUInt64 length) override;
        bool BlockingRead(AuUInt64 offset, const Memory::MemoryViewStreamWrite &parameters) override;
        bool BlockingWrite(AuUInt64 offset, const Memory::MemoryViewStreamRead &parameters) override;

        void Init(const AuSPtr<FileHandle> &handle);

        AuSPtr<FileHandle> GetHandle();

    private:
        AuSPtr<FileHandle> handle_;
    };

    struct NtAsyncFileTransaction : IAsyncTransaction, AuEnableSharedFromThis<NtAsyncFileTransaction>
    {
        ~NtAsyncFileTransaction();

        bool Init(const AuSPtr<FileHandle> &handle);

        bool StartRead(AuUInt64 offset, const AuSPtr<AuMemoryViewWrite> &memoryView) override;
        bool StartWrite(AuUInt64 offset, const AuSPtr<AuMemoryViewRead> &memoryView) override;

        bool Complete() override;
        AuUInt32 GetLastPacketLength() override;

        void SetCallback(const AuSPtr<IAsyncFinishedSubscriber> &sub) override;

        bool Wait(AuUInt32 timeout) override;
        AuSPtr<Loop::ILoopSource> NewLoopSource() override;

        void DispatchCb(AuUInt32 len);
        HANDLE GetHandle();
        AuSPtr<FileHandle> GetFileHandle();

        // Required for a very evil hack
        OVERLAPPED overlap_ {};
        HANDLE event_ = INVALID_HANDLE_VALUE;
        AuSPtr<NtAsyncFileTransaction> pin_;
        AuUInt32 lastAbstractStat_ {}, lastAbstractOffset_ {};
    private:
        AuSPtr<void> memoryHold_;
        AuSPtr<FileHandle> handle_;
        bool latch_ {};
        AuSPtr<IAsyncFinishedSubscriber> sub_;
    };
}