public void Write(string value, StringLengthPrefix lengthPrefix)
{
if (value == null)
{
if (lengthPrefix == StringLengthPrefix.Byte)
{
Write((byte)0);
}
else if (lengthPrefix == StringLengthPrefix.Int32)
{
Write(0);
}
}
else
{
if (lengthPrefix == StringLengthPrefix.Byte)
{
Write((byte)Encoding.UTF8.GetByteCount(value));
}
else if (lengthPrefix == StringLengthPrefix.Int32)
{
Write(Encoding.UTF8.GetByteCount(value));
}
var bytes = Encoding.UTF8.GetBytes(value);
Write(bytes, 0, bytes.Length);
}
}
private static byte[] CreateLengthPrefixedString(string value, StringLengthPrefix length, Encoding encoding)
{
var stringLength = value.Length;
byte[] lengthData = null;
switch (length)
{
case StringLengthPrefix.One: lengthData = new byte[] { (byte)stringLength }; break;
case StringLengthPrefix.Two: lengthData = BitConverter.GetBytes((short)stringLength); break;
case StringLengthPrefix.Four: lengthData = BitConverter.GetBytes(stringLength); break;
}
;
var stringData = encoding.GetBytes(value);
var data = new byte[stringData.Length + lengthData.Length];
Buffer.BlockCopy(lengthData, 0, data, 0, lengthData.Length);
Buffer.BlockCopy(stringData, 0, data, lengthData.Length, stringData.Length);
return(data);
}
/// <summary>
/// Reads a <see cref="string"/> from the current stream with one of the prefix reading methods.
/// </summary>
/// <param name="readPrefix">The method to read the prefix.</param>
/// <exception cref="EndOfStreamException"/>
/// <exception cref="ObjectDisposedException"/>
/// <exception cref="IOException"/>
/// <exception cref="ArgumentException"/>
/// <exception cref="ArgumentOutOfRangeException"/>
/// <returns>The string being read.</returns>
public string ReadString(StringLengthPrefix readPrefix)
{
int length;
if (readPrefix == StringLengthPrefix.Byte)
{
length = ReadByte();
}
else if (readPrefix == StringLengthPrefix.Int32)
{
length = ReadInt32();
}
else
{
throw new ArgumentException("Can't read string without knowing its length.");
}
return(ReadString(length));
}
/// <summary>Reads a string that is length prefixed.</summary>
/// <param name="source">The stream to use.</param>
/// <param name="encoding">The encoding to use. If <see langword="null"/> is specified then the default is used.</param>
/// <param name="length">The length.</param>
/// <returns>The read value.</returns>
/// <remarks>
/// The method reads the 4-byte length followed by the string. The length is in characters.
/// </remarks>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="length"/> is invalid.</exception>
/// <exception cref="EndOfStreamException">The end of stream was reached.</exception>
/// <exception cref="IOException">An IO error occurred.</exception>
/// <exception cref="ObjectDisposedException">The stream is closed.</exception>
public static string ReadLengthPrefixedString(this Stream source, StringLengthPrefix length, Encoding encoding)
{
//Read the length
int len = 0;
switch (length)
{
case StringLengthPrefix.One: len = ReadSByte(source); break;
case StringLengthPrefix.Two: len = ReadInt16(source); break;
case StringLengthPrefix.Four: len = ReadInt32(source); break;
default: throw new ArgumentOutOfRangeException("length", "The length is invalid.");
}
;
//Read the (now) fixed size string
return(ReadFixedString(source, len, encoding ?? Encoding.Default));
}
/// <exception cref="IOException">An I/O error occurs.</exception>
/// <exception cref="ObjectDisposedException">The stream is closed.</exception>
public void Write(string?value, StringLengthPrefix lengthPrefix)
{
var length = value is null ? 0 : Encoding.UTF8.GetByteCount(value);
switch (lengthPrefix)
{
case StringLengthPrefix.Byte:
Write((byte)length);
break;
case StringLengthPrefix.Int32:
Write(length);
break;
}
if (value is not null)
{
WriteBytes(Encoding.UTF8.GetBytes(value));
}
}
/// <summary>Writes a length prefixed string.</summary>
/// <param name="source">The stream to use.</param>
/// <param name="value">The value to write.</param>
/// <param name="length">The length prefix to use.</param>
/// <param name="encoding">The encoding to use. If <see langword="null"/> is specified then the default is used.</param>
/// <returns>The number of bytes written.</returns>
/// <remarks>
/// The string length is written followed by the string. The length is in characters.
/// </remarks>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="length"/> is invalid.</exception>
/// <exception cref="IOException">An IO error occurred.</exception>
/// <exception cref="ObjectDisposedException">The stream is closed.</exception>
public static int WriteLengthPrefixedString(this Stream source, string value, StringLengthPrefix length, Encoding encoding)
{
value = value ?? "";
int bytesWritten = 0;
switch (length)
{
case StringLengthPrefix.One: source.Write((byte)value.Length); bytesWritten += 1; break;
case StringLengthPrefix.Two: source.Write((short)value.Length); bytesWritten += 2; break;
case StringLengthPrefix.Four: source.Write((int)value.Length); bytesWritten += 4; break;
default: throw new ArgumentOutOfRangeException("length", "The length is invalid.");
}
;
return(WriteFixedString(source, value, value.Length, encoding ?? Encoding.Default) + bytesWritten);
}
/// <summary>Writes a length prefixed string.</summary>
/// <param name="source">The stream to use.</param>
/// <param name="value">The value to write.</param>
/// <param name="length">The length prefix to use.</param>
/// <returns>The number of characters written.</returns>
/// <remarks>
/// The string length is written followed by the string. The length is in characters.
/// </remarks>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="length"/> is invalid.</exception>
/// <exception cref="IOException">An IO error occurred.</exception>
/// <exception cref="ObjectDisposedException">The stream is closed.</exception>
public static int WriteLengthPrefixedString(this Stream source, string value, StringLengthPrefix length)
{
return(WriteLengthPrefixedString(source, value, length, null));
}
/// <summary>Reads a string that is length prefixed..</summary>
/// <param name="source">The stream to use.</param>
/// <param name="length">The length.</param>
/// <returns>The read value.</returns>
/// <remarks>
/// The method reads the length followed by the string. The length is in characters.
/// </remarks>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="length"/> is invalid.</exception>
/// <exception cref="EndOfStreamException">The end of stream was reached.</exception>
/// <exception cref="IOException">An IO error occurred.</exception>
/// <exception cref="ObjectDisposedException">The stream is closed.</exception>
public static string ReadLengthPrefixedString(this Stream source, StringLengthPrefix length)
{
return(ReadLengthPrefixedString(source, length, null));
}
