/// <summary>
/// Parses the next <see cref="BList"/> from the reader.
/// </summary>
/// <param name="reader">The reader to parse from.</param>
/// <param name="cancellationToken"></param>
/// <returns>The parsed <see cref="BList"/>.</returns>
/// <exception cref="InvalidBencodeException{BList}">Invalid bencode.</exception>
public override async ValueTask <BList> ParseAsync(PipeBencodeReader reader, CancellationToken cancellationToken = default)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
var startPosition = reader.Position;
// Lists must start with 'l'
if (await reader.ReadCharAsync(cancellationToken).ConfigureAwait(false) != 'l')
{
throw InvalidBencodeException <BList> .UnexpectedChar('l', reader.PreviousChar, startPosition);
}
var list = new BList();
// Loop until next character is the end character 'e' or end of stream
while (await reader.PeekCharAsync(cancellationToken).ConfigureAwait(false) != 'e' &&
await reader.PeekCharAsync(cancellationToken).ConfigureAwait(false) != default)
{
// Decode next object in stream
var bObject = await BencodeParser.ParseAsync(reader, cancellationToken).ConfigureAwait(false);
list.Add(bObject);
}
if (await reader.ReadCharAsync(cancellationToken).ConfigureAwait(false) != 'e')
{
throw InvalidBencodeException <BList> .MissingEndChar(startPosition);
}
return(list);
}
/// <summary>
/// Parses the next <see cref="BDictionary"/> and its contained keys and values from the reader.
/// </summary>
/// <param name="reader">The reader to parse from.</param>
/// <param name="cancellationToken"></param>
/// <returns>The parsed <see cref="BDictionary"/>.</returns>
/// <exception cref="InvalidBencodeException{BDictionary}">Invalid bencode.</exception>
public override async ValueTask <BDictionary> ParseAsync(PipeBencodeReader reader, CancellationToken cancellationToken = default)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
var startPosition = reader.Position;
// Dictionaries must start with 'd'
if (await reader.ReadCharAsync(cancellationToken).ConfigureAwait(false) != 'd')
{
throw InvalidBencodeException <BDictionary> .UnexpectedChar('d', reader.PreviousChar, startPosition);
}
var dictionary = new BDictionary();
// Loop until next character is the end character 'e' or end of stream
while (await reader.PeekCharAsync(cancellationToken).ConfigureAwait(false) != 'e' &&
await reader.PeekCharAsync(cancellationToken).ConfigureAwait(false) != default)
{
BString key;
try
{
// Decode next string in stream as the key
key = await BencodeParser.ParseAsync <BString>(reader, cancellationToken).ConfigureAwait(false);
}
catch (BencodeException 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 = await BencodeParser.ParseAsync(reader, cancellationToken).ConfigureAwait(false);
}
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 (await reader.ReadCharAsync(cancellationToken).ConfigureAwait(false) != 'e')
{
throw InvalidBencodeException <BDictionary> .MissingEndChar(startPosition);
}
return(dictionary);
}