/// <summary>
/// Parses the next <see cref="BList"/> from the stream.
/// </summary>
/// <param name="stream">The stream to parse from.</param>
/// <returns>The parsed <see cref="BList"/>.</returns>
/// <exception cref="InvalidBencodeException{BList}">Invalid bencode</exception>
public override BList Parse(BencodeStream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
if (stream.Length < MinimumLength)
{
throw InvalidBencodeException <BList> .BelowMinimumLength(MinimumLength, stream.Length, stream.Position);
}
// Lists must start with 'l'
if (stream.ReadChar() != 'l')
{
throw InvalidBencodeException <BList> .UnexpectedChar('l', 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 = BencodeParser.Parse(stream);
list.Add(bObject);
}
if (stream.ReadChar() != 'e')
{
throw InvalidBencodeException <BList> .InvalidEndChar(stream.ReadPreviousChar(), stream.Position);
}
return(list);
}
/// <summary>
/// Parses the next <see cref="BDictionary"/> from the stream and its contained keys and values.
/// </summary>
/// <param name="stream">The stream to parse from.</param>
/// <returns>The parsed <see cref="BDictionary"/>.</returns>
/// <exception cref="InvalidBencodeException{BDictionary}">Invalid bencode</exception>
public override BDictionary Parse(BencodeStream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
var startPosition = stream.Position;
if (stream.Length < MinimumLength)
{
throw InvalidBencodeException <BDictionary> .BelowMinimumLength(MinimumLength, stream.Length, startPosition);
}
// Dictionaries must start with 'd'
if (stream.ReadChar() != 'd')
{
throw InvalidBencodeException <BDictionary> .UnexpectedChar('d', stream.ReadPreviousChar(), startPosition);
}
var dictionary = new BDictionary();
// Loop until next character is the end character 'e' or end of stream
while (stream.Peek() != 'e' && stream.Peek() != -1)
{
BString key;
try
{
// Decode next string in stream as the key
key = BencodeParser.Parse <BString>(stream);
}
catch (BencodeException <BString> ex)
{
throw InvalidException("Could not parse dictionary key. Keys must be strings.", ex, startPosition);
}
IBObject value;
try
{
// Decode next object in stream as the value
value = BencodeParser.Parse(stream);
}
catch (BencodeException ex)
{
throw InvalidException(
$"Could not parse dictionary value for the key '{key}'. There needs to be a value for each key.",
ex, startPosition);
}
if (dictionary.ContainsKey(key))
{
throw InvalidException(
$"The dictionary already contains the key '{key}'. Duplicate keys are not supported.", startPosition);
}
dictionary.Add(key, value);
}
if (stream.ReadChar() != 'e')
{
if (stream.EndOfStream)
{
throw InvalidBencodeException <BDictionary> .MissingEndChar();
}
throw InvalidBencodeException <BDictionary> .InvalidEndChar(stream.ReadPreviousChar(), stream.Position);
}
return(dictionary);
}