public void PeekAfterSeek()
{
var str = "abcdefghijkl";
using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(str)))
using (var bs = new BencodeStream(ms))
{
Assert.AreEqual(0, bs.Position);
Assert.AreEqual('a', bs.PeekChar());
bs.Seek(1, SeekOrigin.Current);
Assert.AreEqual(1, bs.Position);
Assert.AreEqual('b', bs.PeekChar());
}
}
public void PeekAfterPositionChangeOnBaseStream()
{
var str = "abcdefghijkl";
using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(str)))
using (var bs = new BencodeStream(ms))
{
Assert.AreEqual(0, bs.Position);
Assert.AreEqual('a', bs.PeekChar());
bs.BaseStream.Position = 1;
Assert.AreEqual(1, bs.Position);
Assert.AreEqual('b', bs.PeekChar());
}
}
public static BList DecodeList(BencodeStream stream, Encoding encoding)
{
if (stream == null) throw new ArgumentNullException("stream");
if (encoding == null) throw new ArgumentNullException("encoding");
if (stream.Length < 2)
throw new BencodeDecodingException<BList>("Minimum valid length is 2 (an empty list: 'le')", stream.Position);
// Lists must start with 'l'
if (stream.ReadChar() != 'l')
throw new BencodeDecodingException<BList>(string.Format("Must begin with 'l' but began with '{0}'.", stream.ReadPreviousChar()), stream.Position);
var list = new BList();
// Loop until next character is the end character 'e' or end of stream
while (stream.Peek() != 'e' && stream.Peek() != -1)
{
// Decode next object in stream
var bObject = Decode(stream, encoding);
if (bObject == null)
throw new BencodeDecodingException<BList>(string.Format("Invalid object beginning with '{0}'", stream.PeekChar()), stream.Position);
list.Add(bObject);
}
if (stream.ReadChar() != 'e')
throw new BencodeDecodingException<BList>("Missing end character 'e'.", stream.Position);
return list;
}
/// <summary>
/// Decodes the specified stream using the specified encoding.
/// </summary>
/// <param name="stream">The stream to decode.</param>
/// /// <param name="encoding">The encoding used by <see cref="BString"/> when calling <c>ToString()</c> with no arguments.</param>
/// <returns>An <see cref="IBObject"/> representing the bencoded stream.</returns>
/// <exception cref="ArgumentNullException">stream</exception>
public static IBObject Decode(BencodeStream stream, Encoding encoding)
{
if (stream == null) throw new ArgumentNullException("stream");
if (encoding == null) throw new ArgumentNullException("encoding");
switch (stream.PeekChar())
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': return DecodeString(stream, encoding);
case 'i': return DecodeNumber(stream);
case 'l': return DecodeList(stream, encoding);
case 'd': return DecodeDictionary(stream, encoding);
}
// TODO: Throw BencodeDecodingException because next char was not a valid start of a BObject?
return null;
}