source: trunk/Include/Classes/System/IO/StreamReader.ab@ 426

Namespace System
Namespace IO

Class StreamReader
    Inherits TextReader
Public
    Sub StreamReader(path As String)
        init(New FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
    End Sub

    Sub StreamReader(stream As Stream)
        init(stream)
    End Sub

    Override Sub Dispose(disposing As Boolean)
        s.Dispose(disposing)
        size = 0
        cur = 0
        last = 0
    End Sub

    Override Function Peek() As Long
        If cur = last Then
            last = s.Read(buf, 0, size)
            cur = 0
            If last = 0 Then
                Peek = -1
                Exit Function
            End If
        End If
        Peek = buf[cur]
    End Function

    Override Function Read() As Long
        Read = Peek()
        cur++
    End Function

    Override Function Read(buffer As *StrChar, index As Long, count As Long) As Long
        If buffer = 0 Then
        ElseIf index < 0 Then
        ElseIf count < 0 Then
        End If

        Dim n = last - cur
        If count <= n Then
            Read = ReadFromBuffer(buffer, index, count)
            Exit Function
        End If
        Dim p = VarPtr(buffer[index])
        Read = ReadFromBuffer(p, 0, n)
        If Read = count Then 'バッファの中身で足りた場合
            Exit Function
        End If
        p = VarPtr(p[n])
        count -= n
        If count > size Then
            n = (count \ size) * size 'sizeの倍数分だけは直接bufferへ読み込ませる
            Dim read = s.Read(p, 0, n)
            If read = 0 Then 'EOF
                Exit Function
            End If
            p = VarPtr(p[n])
            Read += n
            count -= n
        End If
        last = s.Read(buffer, 0, size)
        cur = 0
        If last = 0 Then 'EOF
            Exit Function
        End If
        Read += ReadFromBuffer(p, 0, Math.Min(last, count))
    End Function

    Override Function ReadLine() As String
        Dim sb = New Text.StringBuilder(256)
        Do
            Dim ch = Read()
            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
'               Case &h85 'NEL
'                   Exit Do
'               Case &h2028 'LS
'                   Exit Do
'               Case &h2029 'PS
'                   Exit Do
            End Select
            sb.Append(ch As StrChar) 'ToDo キャスト不要にすべきというチケットを書くこと
        Loop
        ReadLine = sb.ToString
    End Function

    Override Function ReadToEnd() As String
    End Function

Private
    Sub init(str As Stream)
        s = str
        size = 4096
        last = 0
        cur = 0
        buf = GC_malloc(size)
    End Sub

    /**
    @brief バッファの中身から読み取る。
    文字数が足りなくても、元のストリームまで読みには行かない。
    */
    Function ReadFromBuffer(p As *StrChar, index As Long, count As Long) As Long
        memcpy(VarPtr(p[index]), VarPtr(buf[cur]), count * SizeOf (StrChar))
        cur += count
        ReadFromBuffer = count
    End Function

    s As Stream
    size As Long
    cur As Long
    last As Long '中身の終わり
    buf As *Byte '暫定
End Class

End Namespace
End Namespace