#if !FEATURE_ENCODING_ASCII
using System;
using System.Text;
namespace Renci.SshNet.Common
{
///
/// Implementation of ASCII Encoding
///
public class ASCIIEncoding : Encoding
{
private readonly char _fallbackChar;
private static readonly char[] ByteToChar;
static ASCIIEncoding()
{
if (ByteToChar == null)
{
ByteToChar = new char[128];
var ch = '\0';
for (byte i = 0; i < 128; i++)
{
ByteToChar[i] = ch++;
}
}
}
///
/// Initializes a new instance of the class.
///
public ASCIIEncoding()
{
_fallbackChar = '?';
}
///
/// Calculates the number of bytes produced by encoding a set of characters from the specified character array.
///
/// The character array containing the set of characters to encode.
/// The index of the first character to encode.
/// The number of characters to encode.
///
/// The number of bytes produced by encoding the specified characters.
///
/// is null.
/// or is less than zero.-or- and do not denote a valid range in .
public override int GetByteCount(char[] chars, int index, int count)
{
return count;
}
///
/// Encodes a set of characters from the specified character array into the specified byte array.
///
/// The character array containing the set of characters to encode.
/// The index of the first character to encode.
/// The number of characters to encode.
/// The byte array to contain the resulting sequence of bytes.
/// The index at which to start writing the resulting sequence of bytes.
///
/// The actual number of bytes written into .
///
/// is null.-or- is null.
/// or or is less than zero.-or- and do not denote a valid range in .-or- is not a valid index in .
/// does not have enough capacity from to the end of the array to accommodate the resulting bytes.
public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex)
{
for (var i = 0; i < charCount && i < chars.Length; i++)
{
var b = (byte)chars[i + charIndex];
if (b > 127)
b = (byte) _fallbackChar;
bytes[i + byteIndex] = b;
}
return charCount;
}
///
/// Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.
///
/// The byte array containing the sequence of bytes to decode.
/// The index of the first byte to decode.
/// The number of bytes to decode.
///
/// The number of characters produced by decoding the specified sequence of bytes.
///
/// is null.
/// or is less than zero.-or- and do not denote a valid range in .
public override int GetCharCount(byte[] bytes, int index, int count)
{
return count;
}
///
/// Decodes a sequence of bytes from the specified byte array into the specified character array.
///
/// The byte array containing the sequence of bytes to decode.
/// The index of the first byte to decode.
/// The number of bytes to decode.
/// The character array to contain the resulting set of characters.
/// The index at which to start writing the resulting set of characters.
///
/// The actual number of characters written into .
///
/// is null.-or- is null.
/// or or is less than zero.-or- and do not denote a valid range in .-or- is not a valid index in .
/// does not have enough capacity from to the end of the array to accommodate the resulting characters.
public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
{
for (var i = 0; i < byteCount; i++)
{
var b = bytes[i + byteIndex];
char ch;
if (b > 127)
{
ch = _fallbackChar;
}
else
{
ch = ByteToChar[b];
}
chars[i + charIndex] = ch;
}
return byteCount;
}
///
/// Calculates the maximum number of bytes produced by encoding the specified number of characters.
///
/// The number of characters to encode.
///
/// The maximum number of bytes produced by encoding the specified number of characters.
///
/// is less than zero.
public override int GetMaxByteCount(int charCount)
{
if (charCount < 0)
throw new ArgumentOutOfRangeException("charCount", "Non-negative number required.");
return charCount + 1;
}
///
/// Calculates the maximum number of characters produced by decoding the specified number of bytes.
///
/// The number of bytes to decode.
///
/// The maximum number of characters produced by decoding the specified number of bytes.
///
/// is less than zero.
public override int GetMaxCharCount(int byteCount)
{
if (byteCount < 0)
throw new ArgumentOutOfRangeException("byteCount", "Non-negative number required.");
return byteCount;
}
}
}
#endif // !FEATURE_ENCODING_ASCII