source: trunk/ab5.0/ablib/src/Classes/System/IO/TextReader.ab @ 668

Namespace System
Namespace IO

Class TextReader
    Implements System.IDisposable
Public
    Virtual Sub ~TextReader()
        Dispose(False)
    End Sub

'   Static Null = StreamReader.Null As TextReader

Public
    Sub Close()
        Dispose(True)
    End Sub

    Sub Dispose()
        Dispose(True)
    End Sub

    Virtual Function Peek() As Long
        If pos >= buf.Length Then
            If Not Underflow() Then
                Peek = -1
                Exit Function
            End If
        End If
        Peek = buf[pos]
    End Function

    Virtual Function Read() As Long
        Read = Peek()
        pos++
    End Function
    /*
    @date 2008/02/26
    @auther Egtra
    */
    Virtual Function Read(buffer As *Char, index As Long, count As Long) As Long
        If buffer = 0 Then
            Throw New ArgumentNullException("buffer")
        ElseIf index < 0 Then
            Throw New ArgumentOutOfRangeException("index")
        ElseIf count < 0 Then
            Throw New ArgumentOutOfRangeException("count")
        End If
        Read = ReadImpl(VarPtr(buffer[index]), count)
    End Function

    Static Function Synchronized(reader As TextReader) As TextReader
        Synchronized = New Detail.SynchronizedTextReader(reader)
    End Function

    /*
    @date 2008/02/26
    @auther Egtra
    @retval Nothing EOFに達しているとき
    @retval 有効なStringインスタンス 読み取った1行
    */
    Virtual Function ReadLine() As String
        If Peek() = -1 Then
            Exit Function
        End If
        Dim sb = New Text.StringBuilder
        Dim isLead = FALSE
        Do
            Dim ch = Read()
            If ch = -1 Then Exit Do
            If isLead = FALSE Then
                If ch = &h0D Then
                    If Peek() = &h0A Then
                        Read() 'CR LFの場合
                    End If
                    Exit Do
                End If
                Select Case ch
                    Case -1 'EOF
                        Exit Do
                    Case &h0A 'LF
                        Exit Do
                    Case &h0B 'VT
                        Exit Do
                    Case &h0C 'FF
                        Exit Do
                    Case &h0D 'CR
                        Exit Do
#ifdef UNICODE
                    Case &h85 'NEL
                        Exit Do
                    Case &h2028 'LS
                        Exit Do
                    Case &h2029 'PS
                        Exit Do
#endif
                End Select
            End If
            sb.Append(ch As Char)
#ifndef UNICODE
            isLead = IsDBCSLeadByte(ch As Byte)
#endif
        Loop
        ReadLine = sb.ToString()
    End Function

    /*!
    @brief 現在位置からストリームの終わりまで読み込む。
    @date 2008/02/26
    @auther Egtra
    */
    Virtual Function ReadToEnd() As String
        buf.Remove(0, pos)
        While Underflow()
        Wend
        ReadToEnd = buf.ToString()
    End Function

Protected
    Sub TextReader()
        buf = New Text.StringBuilder
        pos = 0
    End Sub

    Virtual Sub Dispose(disposing As Boolean)
    End Sub

    /*!
    @brief バッファが足りなくなったときに呼ばれる。
    @date 2008/12/27
    @auther Egtra
    @retval True まだEOFに達していない場合
    @retval False EOFに達した場合
    */
    Virtual Function Underflow() As Boolean
        Underflow = False
    End Function

    /*!
    @brief 内部バッファを返す
    @date 2008/12/27
    @auther Egtra
    @return 内部バッファ
    */
    Function Buffer() As Text.StringBuilder
        Buffer = buf
    End Function

    /*!
    @date 2008/02/26
    @auther Egtra
    */
    Function ReadImpl(buffer As *Char, count As Long) As Long
        Dim p = StrPtr(buf)
        While buf.Length - pos < count
            If Underflow() = False Then Exit While
        Wend
        ReadImpl = Math.Min(buf.Length - pos, count)
        ActiveBasic.Strings.ChrCopy(buffer, VarPtr(p[pos]), ReadImpl As SIZE_T)
        pos += ReadImpl
    End Function

Private
    buf As Text.StringBuilder
    pos As Long
End Class

Namespace Detail

Class SynchronizedTextReader
    Inherits TextReader
Public
    Sub SynchronizedTextReader(reader As TextReader)
        cs = New ActiveBasic.Windows.CriticalSection
        base = reader
    End Sub

    Override Function Peek() As Long
'       Using lock = cs.Lock()
            Peek = base.Peek()
'       End Using
    End Function

    Override Function Read() As Long
'       Using lock = cs.Lock()
            Read = base.Read()
'       End Using
    End Function

    Override Function Read(buffer As *Char, index As Long, count As Long) As Long
'       Using lock = cs.Lock()
            Read = base.Read(buffer, index, count)
'       End Using
    End Function

    Override Function ReadToEnd() As String
'       Using lock = cs.Lock
            ReadToEnd = base.ReadToEnd
'       End Using
    End Function

Protected
    Override Sub Dispose(disposing As Boolean)
        Dim s = Nothing As Stream
        SetPointer(VarPtr(s) As *VoidPtr, InterlockedExchangePointer(ByVal VarPtr(base) As *VoidPtr, 0))
        If disposing Then
            If Not ActiveBasic.IsNothing(s) Then
                s.Dispose()
            End If
            cs.Dispose()
        End If
    End Sub

Private
    cs As ActiveBasic.Windows.CriticalSection
    base As TextReader
End Class

End Namespace

End Namespace
End Namespace