Changeset 426 for trunk/Include/Classes/System/IO/StreamReader.ab

Timestamp:

Feb 26, 2008, 3:33:49 AM (17 years ago)

Author:

イグトランス (egtra)

Message:

StreamReaderの実装開始。
Stringの+演算子で右辺がNullのときに起こるアクセス違反を回避。

File:

• trunk/Include/Classes/System/IO/StreamReader.ab (modified) (1 diff)

trunk/Include/Classes/System/IO/StreamReader.ab

@@ -2 +2 @@
 Namespace IO
 
+Class StreamReader
+    Inherits TextReader
+Public
+    Sub StreamReader(path As String)
+        init(New FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
+    End Sub
 
-Class StreamReader
-    Inherits System.IO.TextReader
-    ' TODO: 実装
+    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