source: trunk/ab5.0/ablib/src/Classes/System/IO/FileStream.ab@ 605

'Classes/System/IO/FileStream.ab

Namespace System
Namespace IO

/*
(handle As IntPtr, access As FileAccess)
(handle As IntPtr, access As FileAccess, ownsHandle As Boolean)
(handle As IntPtr, access As FileAccess, ownsHandle As Boolean)
(handle As IntPtr, access As FileAccess, ownsHandle As Boolean, isAsync As Boolean)
(path As String, mode As FileMode)
(path As String, mode As FileMode, access As FileAccess)
(path As String, mode As FileMode, access As FileAccess, share As FileShare, useAsync As Boolean)
(path As String, mode As FileMode, access As FileAccess, share As FileShare, options As FileOptions)
(path As String, mode As FileMode, rights As FileSystemRights, share As FileShare, options As FileOptions)
*/

Class FileStream
    Inherits Stream
Protected
    Sub initialize(ac As DWord, owns As Boolean, isAsync As Boolean)
        Imports ActiveBasic
        ownsHandle = owns
        If (ac And GENERIC_READ) = 0 Then
            readFn = New Detail.Unreadable
        End If
        If (ac And GENERIC_WRITE) = 0 Then
            writeFn = New Detail.Unwritable
        End If
        If GetFileType(handle) <> FILE_TYPE_DISK Then
            seekFn = New Detail.Unseekable
        End If
        If isAsync Then
            If IsNothing(seekFn) Then
                seekFn = New Detail.OverlappedSeekable
            End If
            If IsNothing(readFn) Then
                readFn = New Detail.OverlappedReadable
            End If
            If IsNothing(writeFn) Then
                writeFn = New Detail.OverlappedWritable
            End If
        Else
            If IsNothing(seekFn) Then
                seekFn = New Detail.Seekable
            End If
            If IsNothing(readFn) Then
                readFn = New Detail.Readable
            End If
            If IsNothing(writeFn) Then
                writeFn = New Detail.Writable
            End If
        End If
    End Sub

    Sub openFile(path As String, mode As FileMode, rights As DWord, share As FileShare, ByRef options As FileOptions)
        Imports ActiveBasic
        If IsNothing(path) Then
            Throw New ArgumentNullException("path")
        ElseIf path.Length = 0 Then
            Throw New ArgumentException("path.Length = 0")
        End If
        Dim sh = share As DWord
        Dim mo = mode As DWord
        Dim op = options As DWord

        If mode = FileMode.Append Then
            mo = OPEN_ALWAYS
            seekFn = New Detail.Unseekable
        End If

        Dim os = Environment.OSVersion
        Dim platform = os.Platform As DWord
        If platform = PlatformID.Win32Windows As DWord Or platform = PlatformID.Win32S As DWord Then
            options = (op As DWord And Not FILE_FLAG_OVERLAPPED) As FileOptions
        End If

        handle = CreateFile(ToTCStr(path), rights, sh, ByVal NULL, mo, op, 0)
        If handle = INVALID_HANDLE_VALUE Then
        'エラー処理
        'Throw ArgumentException
        'Throw IOException
        'Throw System.IO.FileNotFoundException
            handle = 0
            Detail.ThrowWinLastErrorIOException("Failed to open/create file.")
        End If
    
        filePath = path

        If mode = FileMode.Append Then
            Seek(0, SeekOrigin.End)
        End If
    End Sub

    Sub initWithOpen(path As String, mode As FileMode, access As FileAccess, share As FileShare, options As FileOptions)
        openFile(path, mode, access As DWord, share, options)
        initialize(access, True, UseOverlappled(options))
    End Sub

    Sub initWithOpen2(path As String, mode As FileMode, rights As DWord, share As FileShare, options As FileOptions)
        openFile(path, mode, rights, share, options)
        Dim ac = 0 As DWord
        If (rights And GENERIC_READ) Or (rights And FILE_READ_DATA) Then
            ac = (ac As DWord Or GENERIC_READ) As FileAccess
        End If
        If (rights And GENERIC_WRITE) Or (rights And FILE_WRITE_DATA) Then
            ac = (ac As DWord Or GENERIC_WRITE) As FileAccess
        End If
        initialize(ac, True, UseOverlappled(options))
    End Sub

    Static Function UseOverlappled(options As FileOptions) As Boolean
        Dim op = options As DWord
        If op And FILE_FLAG_OVERLAPPED Then
            UseOverlappled = True
        Else
            UseOverlappled = False
        End If
    End Function

    Sub FileStream()
    End Sub
Public
    /*!
    @brief ファイルを開く。
    @param[in] path ファイルパス
    @param[in] mode 開き方
    @param[in] rights 使用するアクセス権の指定
    @param[in] share 共有方法
    @param[in] option オプション
    @date 2008/08/21
    @auther Egtra
    */
    Sub FileStream(path As String, mode As FileMode, rights As Security.AccessControl.FileSystemRights, share As FileShare, options As FileOptions)
        initWithOpen2(path, mode, rights As DWord, share, options)
    End Sub
    /*!
    @brief ファイルを開く。
    @param[in] path ファイルパス
    @param[in] mode 開き方
    @param[in] access ファイルアクセスの指定
    @param[in] share 共有方法
    @param[in] option オプション
    */
    Sub FileStream(path As String, mode As FileMode, access As FileAccess, share As FileShare, options As FileOptions)
        initWithOpen(path, mode, access, share, options)
    End Sub
    /*!
    @brief ファイルを開く。
    @param[in] path ファイルパス
    @param[in] mode 開き方
    @param[in] access ファイルアクセスの指定
    @param[in] share 共有方法
    @param[in] useAsync 非同期にするならTrue
    @date 2008/08/21
    @auther Egtra
    */
    Sub FileStream(path As String, mode As FileMode, access As FileAccess, share As FileShare, useAsync As Boolean)
        Dim options = FileOptions.None
        If useAsync Then
            options = FileOptions.Asynchronous
        End If
        initWithOpen(path, mode, access, share, options)
    End Sub
    /*!
    @brief ファイルを開く。
    @param[in] path ファイルパス
    @param[in] mode 開き方
    @param[in] access ファイルアクセスの指定
    @param[in] share 共有方法
    */
    Sub FileStream(path As String, mode As FileMode, access As FileAccess, share As FileShare)
        initWithOpen(path,mode,access,share,FileOptions.None)
    End Sub
    /*!
    @brief ファイルを開く。
    @param[in] path ファイルパス
    @param[in] mode 開き方
    @param[in] access ファイルアクセスの指定
    */
    Sub FileStream(path As String, mode As FileMode, access As FileAccess)
        initWithOpen(path,mode,access,FileShare.None,FileOptions.None)
    End Sub
    /*!
    @brief ファイルを開く。
    @param[in] path ファイルパス
    @param[in] mode 開き方
    */
    Sub FileStream(path As String, mode As FileMode)
        Dim access As FileAccess
        Select Case mode
            Case FileMode.Append
                access=FileAccess.Write
            Case FileMode.Create
                access=FileAccess.ReadWrite
            Case FileMode.CreateNew
                access=FileAccess.ReadWrite
            Case FileMode.Open
                access=FileAccess.ReadWrite
            Case FileMode.OpenOrCreate
                access=FileAccess.ReadWrite
            Case FileMode.Truncate
                access=FileAccess.Write
        End Select
        initWithOpen(path,mode,access,FileShare.None,FileOptions.None)
    End Sub
    /*!
    @brief 既存ハンドルを基にストリームを作る。
    @param[in] h ハンドル
    @param[in] access ファイルアクセスの指定
    @param[in] owns 所有権を保持するかどうか（TrueならDispose時に基のハンドルも閉じる）
    @param[in] isAsync 重複IOを使用するかどうか
    @date 2008/02/26
    @auther Egtra
    @todo SafeFileHandle版に置き換えること
    */
    Sub FileStream(h As HANDLE, access As FileAccess, owns = True As Boolean, isAsync = False As Boolean)
        handle = h
        initialize(access, owns, isAsync)
    End Sub
Public
    /*!
    @brief  ファイルが読み込みに対応しているかを返す
    */
    Override Function CanRead() As Boolean
        Return readFn.CanRead
    End Function

    /*!
    @brief  ファイルがシークに対応しているかを返す
    */
    Override Function CanSeek() As Boolean
        Return seekFn.CanSeek
    End Function

    /*!
    @brief  ファイルが書き込みに対応しているかを返す
    */
    Override Function CanWrite() As Boolean
        Return writeFn.CanWrite
    End Function

    /*!
    @brief  保持しているハンドルを返す
    */
    Function Handle() As HANDLE
        Return handle
    End Function

    Override Function Length() As QWord
        disposedCheck()
        Length = seekFn.Length(This)
    End Function

    Function Name() As String
        Return This.filePath
    End Function

    Override Sub Position(value As QWord)
        disposedCheck()
        seekFn.Position(This, value)
    End Sub
    Override Function Position() As QWord
        disposedCheck()
        Position = seekFn.Position(This)
    End Function

Public
    /* Safe～Handle系の実装は要相談！！ */
/*  Function SafeFileHandle() As SafeFileHandle
    End Function*/

Public
    Override Function BeginRead(buffer As *Byte, offset As Long, count As Long, callback As AsyncCallback, state As Object) As System.IAsyncResult
        disposedCheck()
        If buffer = 0 Then
            Throw New ArgumentNullException("FileStream.BeginRead", "buffer")
        End If
        BeginRead = readFn.BeginRead(This, buffer, offset, count, callback, state)
    End Function

    Override Function BeginWrite(buffer As *Byte, offset As Long, count As Long, callback As AsyncCallback, state As Object) As System.IAsyncResult
        disposedCheck()
        If buffer = 0 Then
            Throw New ArgumentNullException("FileStream.BeginWrite", "buffer")
        End If
        BeginWrite = writeFn.BeginWrite(This, buffer, offset, count, callback, state)
    End Function

    Override Function EndRead(asyncResult As System.IAsyncResult) As Long
        disposedCheck()
        EndRead = readFn.EndRead(This, asyncResult)
    End Function

    Override Sub EndWrite(asyncResult As System.IAsyncResult)
        disposedCheck()
        writeFn.EndWrite(This, asyncResult)
    End Sub

    Override Sub Flush()
        disposedCheck()
        Dim ret = FlushFileBuffers(This.handle)
        If ret = FALSE Then
            Detail.ThrowWinLastErrorIOException("FileStream.Flush: Failed to flush.")
        End If
    End Sub

/*  Function GetAccessControl() As FileSecurity
    FileSecurityの実装がまだできてない。
    End Function*/

    Sub Lock(position As QWord, length As QWord)
        disposedCheck()
        If position < 0 Then
            Throw New ArgumentOutOfRangeException("FileStream.Lock: An argument is negative value.", New System.UInt64(position), "position")
        ElseIf length < 0 Then
            Throw New ArgumentOutOfRangeException("FileStream.Lock: An argument is negative value.", New System.UInt64(length), "length")
        End If
        If LockFile(handle, LODWORD(position), HIDWORD(position), LODWORD(length), HIDWORD(length)) = FALSE Then
            Detail.ThrowWinLastErrorIOException("FileStream.Lock: Failed to lock.")
        End If
    End Sub

    Override Function Read(buffer As *Byte, offset As Long, count As Long) As Long
        disposedCheck()
        If buffer = 0 Then
            Throw New ArgumentNullException("FileStream.Read", "buffer")
        End If
        Read = readFn.Read(This, buffer, offset, count)
    End Function

    /*!
    @brief  ストリームの現在位置を移動させる。
    @param[in] offset   originからの移動量
    @param[in] origin   移動の基準位置
    @return 移動後の新しい現在位置
    @exception DisposedException    既にストリームが閉じられている場合
    @exception ArgumentException    移動後の位置が負の位置（ファイル先頭より手前）になる場合
    @exception IOException  その他エラーが発生した場合
    */
    Override Function Seek(offset As Int64, origin As SeekOrigin) As Int64
        disposedCheck()
        Seek = seekFn.Seek(This, offset, origin)
    End Function

/*  Sub SetAccessControl(fileSecurity As FileSecurity)
    FileSecurityの実装がまだできてない。
    End Sub*/

    Override Sub SetLength(value As QWord)
        disposedCheck()
        seekFn.SetLength(This, value)
    End Sub

    Override Function ToString() As String
        Return This.Name()
    End Function

    Sub Unlock(position As QWord, length As QWord)
        disposedCheck()
        Dim ret = UnlockFile(handle, LODWORD(position), HIDWORD(position), LODWORD(length), HIDWORD(length))
        If ret = FALSE Then
            Detail.ThrowWinLastErrorIOException("FileStream.Unlock failed")
        End If
    End Sub

    Override Sub Write(buffer As *Byte, offset As Long, count As Long)
        disposedCheck()
        If buffer = 0 Then
            Throw New ArgumentNullException("FileStream.Write", "buffer")
        End If
        writeFn.Write(This, buffer, offset, count)
    End Sub

Protected
    Override Sub Dispose(disposing As Boolean)
        If handle <> 0 Then
            CloseHandle(InterlockedExchangePointer(ByVal VarPtr(handle), NULL))
        End If
    End Sub

    Sub disposedCheck()
        If handle = 0 Then
            Throw New ObjectDisposedException("FileStream: This stream has already closed.")
        End If
    End Sub

Private
    handle As HANDLE
    seekFn As Detail.SeekFunctions
    readFn As Detail.ReadFunctions
    writeFn As Detail.WriteFunctions
    filePath As String
    ownsHandle As Boolean
End Class

End Namespace
End Namespace