source: trunk/Include/Classes/System/IO/MemoryStream.ab@ 472

NameSpace System
NameSpace IO

Class MemoryStream
    Inherits Stream

Public
    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを初期化します。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream()
        This.writable = True
        This.resizable = True
        This.visible = False
        This.create()
        This.pointer = This.allocate(0)
        This.streamLength = 0
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを初期容量を指定して初期化します。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream(capacity As Long)
        This.writable = True
        This.resizable = True
        This.visible = False
        This.create()
        This.pointer = This.allocate(capacity)
        This.streamLength = capacity
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを指定したバッファに基づいて初期化します。容量を変更することはできません。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream(buffer As *Byte, length As Long)
        This.writable = True
        This.resizable = False
        This.visible = False
        This.create()
        This.pointer = This.allocate(length)
        MoveMemory(This.pointer,buffer,length)
        This.streamLength = length
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを指定したバッファに基づいて初期化します。容量を変更することはできません。また、書き込みをサポートするかどうかも指定できます。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream(buffer As *Byte, length As Long, writable As Boolean)
        This.writable = writable
        This.resizable = False
        This.visible = False
        This.create()
        This.pointer = This.allocate(length)
        MoveMemory(This.pointer,buffer,length)
        This.streamLength = length
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを指定したバッファの指定された領域に基づいて初期化します。容量を変更することはできません。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream(buffer As *Byte, index As Long, count As Long)
        This.writable = True
        This.resizable = False
        This.visible = False
        This.create()
        This.pointer = This.allocate(count)
        MoveMemory(This.pointer,VarPtr(buffer[index]),count)
        This.streamLength = count
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを指定したバッファの指定された領域に基づいて初期化します。容量を変更することはできません。また、書き込みをサポートするかどうかを指定できます。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream(buffer As *Byte, index As Long, count As Long, writable As Boolean)
        This.writable = writable
        This.resizable = False
        This.visible = False
        This.create()
        This.pointer = This.allocate(count)
        MoveMemory(This.pointer,VarPtr(buffer[index]),count)
        This.streamLength = count
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスの新しいインスタンスを指定したバッファの指定された領域に基づいて初期化します。容量を変更することはできません。また、書き込みをサポートするかどうかを指定できます。GetBufferメソッドをサポートするかどうかを指定できます。
    @author NoWest
    @date   2008/3/12
    */
    Sub MemoryStream(buffer As *Byte, index As Long, count As Long, writable As Boolean, visible As Boolean)
        This.writable = writable
        This.resizable = False
        This.visible = visible
        This.create()
        This.pointer = This.allocate(count)
        MoveMemory(This.pointer,VarPtr(buffer[index]),count)
        This.streamLength = count
        This.currentPosition = 0
    End Sub

    /*!
    @brief  MemoryStreamクラスのデストラクタです。
    @author NoWest
    @date   2008/3/12
    */
    Sub ~MemoryStream()
        This.Close()
    End Sub

Public
    /*!
    @brief  ストリームが読み取りをサポートしているかどうかを示す値を取得します。
    @author NoWest
    @date   2008/3/12
    */
    Override Function CanRead() As Boolean
        If This.pointer Then
            Return True
        Else
            Return False
        End If
    End Function

    /*!
    @brief  ストリームがシークをサポートしているかどうかを示す値を取得します。
    @author NoWest
    @date   2008/3/12
    */
    Override Function CanSeek() As Boolean
        If This.pointer Then
            Return True
        Else
            Return False
        End If
    End Function

    /*!
    @brief  ストリームが書き込みをサポートしているかどうかを示す値を取得します。
    @author NoWest
    @date   2008/3/12
    */
    Override Function CanWrite() As Boolean
        If This.pointer Then
            Return This.writable
        Else
            Return False
        End If
    End Function

    /*!
    @brief  ストリームに割り当てるメモリ容量をバイト単位で設定します。
    @author NoWest
    @date   2008/3/12
    */
    Virtual Sub Capacity(value As Long)
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If value < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Capacity: A capacity is set to negative value.", New System.Int64(value),"Capacity")
        If value < This.streamLength Then Throw New ArgumentOutOfRangeException("MemoryStream.Capacity: A capacity is less than the current length of the stream.",New System.Int64(value),"Capacity")
        This.pointer = This.reallocate(This.pointer,value)
    End Sub

    /*!
    @brief  ストリームに割り当てられたメモリ容量をバイト単位で取得します。
    @author NoWest
    @date   2008/3/12
    */
    Virtual Function Capacity() As Long
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        Return This.size(This.pointer)
    End Function

    /*!
    @brief  ストリームの長さをバイト単位で取得します。Capacityプロパティの値より小さい場合があります。
    @author NoWest
    @date   2008/3/12
    */
    Override Function Length() As Int64
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        Return This.streamLength
    End Function

    /*!
    @brief  ストリームの現在位置を設定します。
    @author NoWest
    @date   2008/3/12
    */
    Override Sub Position(value As Int64)
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If value < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Position: The position is set to a negative value.", New System.Int64(value), "Position")
        If value > Int32.MaxValue() Then Throw New ArgumentOutOfRangeException("MemoryStream.Position: The position is a value greater than MaxValue.", New System.Int64(value), "Position")
        This.currentPosition = value As Long
    End Sub

    /*!
    @brief  ストリームの現在位置を取得します。
    @author NoWest
    @date   2008/3/12
    */
    Override Function Position() As Int64
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        Return This.currentPosition As Int64
    End Function

    Override Sub Flush()
    End Sub

/*  Virtual Function GetBuffer() As Array<Byte>
        If visible = False Then Return NULL
        Return p
    End Function*/

    /*!
    @brief  ストリームから指定されたバイト数を読み取り、bufferに書き込みます。
    @author NoWest
    @date   2008/3/12
    */
    Override Function Read(buffer As *Byte, offset As Long, count As Long) As Long
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If buffer = 0 Then Throw New ArgumentNullException("FileStream.Read: An argument is a null value.", "buffer")
        If offset < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Read: An argument is a negative value.", New System.Int64(offset), "offset")
        If count < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Read: An argument is a negative value.", New System.Int64(count), "count")
        If (This.streamLength - (This.currentPosition + count)) < 0 Then
            count + = (This.streamLength - (This.currentPosition + count))
        ElseIf count < 1 Then
            Return 0
        End If
        MoveMemory(VarPtr(buffer[offset]),VarPtr(This.pointer[This.currentPosition]),count)
        This.currentPosition + = count
        Return count
    End Function

    /*!
    @brief  ストリームから指定された1バイト読み取ります。
    @author NoWest
    @date   2008/3/12
    */
    Override Function ReadByte() As Long
        Dim b As Byte
        Dim ret = Read(VarPtr(b), 0, 1)
        If ret <> 0 Then
            Return b
        Else
            Return -1
        End If
    End Function

    /*!
    @brief  ストリーム内の位置を指定した値に設定します。
    @author NoWest
    @date   2008/3/12
    */
    Override Function Seek(offset As Int64, origin As SeekOrigin) As Int64
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If offset > Int32.MaxValue() Then Throw New ArgumentOutOfRangeException("MemoryStream.Seek: The offset is a value greater than MaxValue.", New System.Int64(offset), "offset")
        Select Case origin
            Case SeekOrigin.Begin
                If offset < 0 Then Throw New IOException("MemoryStream.Seek: Seeking is attempted before the beginning of the stream.")
                This.currentPosition = offset As Long
            Case SeekOrigin.Current
                Beep(440,10)
                If (This.currentPosition + offset) < 0 Then Throw New IOException("MemoryStream.Seek: Seeking is attempted before the beginning of the stream.")
                This.currentPosition += offset As Long
            Case SeekOrigin.End
                If (This.streamLength + offset) < 0 Then Throw New IOException("MemoryStream.Seek: Seeking is attempted before the beginning of the stream.")
                This.currentPosition = (This.streamLength + offset) As Long
            Case Else
                Throw New ArgumentException("MemoryStream.Seek: An argument is an invalid SeekOrigin","origin")
        End Select
        Return This.currentPosition As Int64
    End Function

    /*!
    @brief  ストリームの長さを設定します。メモリ容量を超えては設定できません。
    @author NoWest
    @date   2008/3/12
    */
    Override Sub SetLength(value As Int64)
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If This.writable = False Then Throw New NotSupportedException("MemoryStream: The current stream is not writable")
        If This.resizable = False Then Throw New NotSupportedException("MemoryStream: The current stream is not resizable")
        If value > This.Capacity() Then Throw New NotSupportedException("MemoryStream.SetLength: This stream length is larger than the current capacity.")
        If value < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Read: An argument is a negative value.", New System.Int64(value), "value")
        If value > Int32.MaxValue() Then Throw New ArgumentOutOfRangeException("MemoryStream.SetLength: The length is a value greater than MaxValue.", New System.Int64(value), "value")
        This.pointer = This.reallocate(This.pointer,value As Long)
        This.streamLength = value As Long
    End Sub

    /*!
    @brief  ストリームにbufferの内容を指定したバイト数書き込みます。
    @author NoWest
    @date   2008/3/12
    */
    Override Sub Write(buffer As *Byte, offset As Long, count As Long)
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If This.writable = False Then Throw New NotSupportedException("MemoryStream: The current stream is not writable")
        If buffer = 0 Then Throw New ArgumentNullException("MemoryStream.Write: An argument is a null value.", "buffer")
        If offset < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Write: An argument is a negative value.", New System.Int64(offset), "offset")
        If count < 0 Then Throw New ArgumentOutOfRangeException("MemoryStream.Write: An argument is a negative value.", New System.Int64(count), "count")
        If count > (This.streamLength - This.currentPosition) Then 
            If This.resizable = False Then Throw New NotSupportedException("MemoryStream: The current stream is not resizable")
            If (This.Capacity() - This.currentPosition) < count Then 
                This.pointer = This.reallocate(This.pointer,This.currentPosition+count)
            End If
            This.streamLength = This.currentPosition+count
        End If
        MoveMemory(VarPtr(This.pointer[This.currentPosition]),VarPtr(buffer[offset]),count)
        This.currentPosition + = count
    End Sub

    /*!
    @brief  ストリームに1バイト書き込みます。
    @author NoWest
    @date   2008/3/12
    */
    Override Sub WriteByte(b As Byte)
        Write(VarPtr(b), 0, 1)
    End Sub

/*  Virtual Function ToArray() As Array<Byte>
        TODO:
    End Function*/

    /*!
    @brief  ストリームの内容全体をまるごと別のストリームに書き込みます。
    @author NoWest
    @date   2008/3/12
    */
    Virtual Sub WriteTo(stream As Stream)
        If This.pointer = 0 Then Throw New ObjectDisposedException("MemoryStream: This stream has closed.")
        If ActiveBasic.IsNothing(stream) Then Throw New ArgumentNullException("MemoryStream.WriteTo: An argument is a null value.", "stream")
        stream.Write(This.pointer,0,This.Capacity())
    End Sub

Protected

    /*!
    @brief  Streamクラスから継承
    @author NoWest
    @date   2008/3/12
    */
    Override Sub Dispose(disposing As Boolean)
        This.destroy()
    End Sub

Private
    /* Heap memory address */
    pointer As *Byte
    /* MemoryStream status */
    writable As Boolean
    resizable As Boolean
    visible As Boolean
    streamLength As Long
    currentPosition As Long

    /*
    バッファ管理用のPrivate関数類
    一応初期設定ではGC_mallocでメモリを確保しています。
    */
    handle As HANDLE
    Sub create()
#ifdef NOT_USE_GC
        This.handle = HeapCreate(0,0,0)
#endif
    End Sub

    Sub destroy()
#ifdef NOT_USE_GC
        HeapFree(This.handle,0,InterlockedExchangePointer(ByVal VarPtr(This.pointer) As VoidPtr,NULL) As VoidPtr)
        HeapDestroy(InterlockedExchangePointer(ByVal VarPtr(This.handle) As VoidPtr,NULL) As HANDLE)
#endif
    End Sub

    Function allocate(length As SIZE_T) As VoidPtr
#ifdef NOT_USE_GC
        Return HeapAlloc(This.handle,HEAP_ZERO_MEMORY,length)
#else
        Return GC_malloc_atomic(length)
#endif
    End Function

    Function reallocate(p As VoidPtr, length As SIZE_T) As VoidPtr
#ifdef NOT_USE_GC
        Return HeapReAlloc(This.handle,HEAP_ZERO_MEMORY,p,This.currentPosition+count)
#else
        Return _System_pGC->__realloc(p,length)
#endif
    End Function

    Function size(p As VoidPtr) As Long
#ifdef NOT_USE_GC
        Return HeapSize(This.handle,0,p)
#else
        Dim pmemobj = _System_pGC->GetMemoryObjectPtr(p)
        Return pmemobj->size
#endif
    End Function
End Class

End NameSpace 'IO
End NameSpace 'System