/*
* Decoder.cs - Implementation of the "System.Text.Decoder" class.
*
* Copyright (c) 2001 Southern Storm Software, Pty Ltd
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
namespace System.Text{
using System;
using System.Runtime.InteropServices;
[Serializable]
[ComVisible (true)]
public abstract class Decoder
{
// Constructor.
protected Decoder () {}
DecoderFallback fallback = new DecoderReplacementFallback ();
DecoderFallbackBuffer fallback_buffer;
[ComVisible (false)]
public DecoderFallback Fallback {
get { return fallback; }
set {
if (value == null)
throw new ArgumentNullException ();
fallback = value;
fallback_buffer = null;
}
}
[ComVisible (false)]
public DecoderFallbackBuffer FallbackBuffer {
get {
if (fallback_buffer == null)
fallback_buffer = fallback.CreateFallbackBuffer ();
return fallback_buffer;
}
}
// Get the number of characters needed to decode a buffer.
public abstract int GetCharCount (byte[] bytes, int index, int count);
// Get the characters that result from decoding a buffer.
public abstract int GetChars (byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex);
[ComVisible (false)]
public virtual int GetCharCount (byte [] bytes, int index, int count, bool flush)
{
if (flush)
Reset ();
return GetCharCount (bytes, index, count);
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe virtual int GetCharCount (byte* bytes, int count, bool flush)
{
if (bytes == null)
throw new ArgumentNullException ("bytes");
if (count < 0)
throw new ArgumentOutOfRangeException ("count");
byte [] barr = new byte [count];
Marshal.Copy ((IntPtr) bytes, barr, 0, count);
return GetCharCount (barr, 0, count, flush);
}
public virtual int GetChars (
byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex, bool flush)
{
CheckArguments (bytes, byteIndex, byteCount);
CheckArguments (chars, charIndex);
if (flush)
Reset ();
return GetChars (bytes, byteIndex, byteCount, chars, charIndex);
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe virtual int GetChars (byte* bytes, int byteCount,
char* chars, int charCount, bool flush)
{
CheckArguments (chars, charCount, bytes, byteCount);
char [] carr = new char [charCount];
Marshal.Copy ((IntPtr) chars, carr, 0, charCount);
byte [] barr = new byte [byteCount];
Marshal.Copy ((IntPtr) bytes, barr, 0, byteCount);
return GetChars (barr, 0, byteCount, carr, 0, flush);
}
[ComVisible (false)]
public virtual void Reset ()
{
if (fallback_buffer != null)
fallback_buffer.Reset ();
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe virtual void Convert (
byte* bytes, int byteCount,
char* chars, int charCount, bool flush,
out int bytesUsed, out int charsUsed, out bool completed)
{
CheckArguments (chars, charCount, bytes, byteCount);
bytesUsed = byteCount;
while (true) {
charsUsed = GetCharCount (bytes, bytesUsed, flush);
if (charsUsed <= charCount)
break;
flush = false;
bytesUsed >>= 1;
}
completed = bytesUsed == byteCount;
charsUsed = GetChars (bytes, bytesUsed, chars, charCount, flush);
}
[ComVisible (false)]
public virtual void Convert (
byte [] bytes, int byteIndex, int byteCount,
char [] chars, int charIndex, int charCount, bool flush,
out int bytesUsed, out int charsUsed, out bool completed)
{
CheckArguments (bytes, byteIndex, byteCount);
CheckArguments (chars, charIndex);
if (charCount < 0 || chars.Length < charIndex + charCount)
throw new ArgumentOutOfRangeException ("charCount");
bytesUsed = byteCount;
while (true) {
charsUsed = GetCharCount (bytes, byteIndex, bytesUsed, flush);
if (charsUsed <= charCount)
break;
flush = false;
bytesUsed >>= 1;
}
completed = bytesUsed == byteCount;
charsUsed = GetChars (bytes, byteIndex, bytesUsed, chars, charIndex, flush);
}
void CheckArguments (char [] chars, int charIndex)
{
if (chars == null)
throw new ArgumentNullException ("chars");
if (charIndex < 0 || chars.Length <= charIndex)
throw new ArgumentOutOfRangeException ("charIndex");
}
void CheckArguments (byte [] bytes, int byteIndex, int byteCount)
{
if (bytes == null)
throw new ArgumentNullException ("bytes");
if (byteIndex < 0 || bytes.Length <= byteIndex)
throw new ArgumentOutOfRangeException ("byteIndex");
if (byteCount < 0 || bytes.Length < byteIndex + byteCount)
throw new ArgumentOutOfRangeException ("byteCount");
}
unsafe void CheckArguments (char* chars, int charCount, byte* bytes, int byteCount)
{
if (chars == null)
throw new ArgumentNullException ("chars");
if (bytes == null)
throw new ArgumentNullException ("bytes");
if (charCount < 0)
throw new ArgumentOutOfRangeException ("charCount");
if (byteCount < 0)
throw new ArgumentOutOfRangeException ("byteCount");
}
}; // class Decoder
}; // namespace System.Text
|