private static IEnumerable <byte[]> EnumerateData(IEnumerator <string> enumerator, Encoding encoding)
{
var buffer = new byte[bufferSize];
while (enumerator.MoveNext())
{
if (enumerator.Current == null)
{
continue;
}
if (enumerator.Current.StartsWith(yEnd))
{
// skip rest if there is some
while (enumerator.MoveNext())
{
}
yield break;
}
byte[] encodedBytes = encoding.GetBytes(enumerator.Current);
int decodedCount = YencLineDecoder.Decode(encodedBytes, buffer, 0);
var decodedBytes = new byte[decodedCount];
Buffer.BlockCopy(buffer, 0, decodedBytes, 0, decodedCount);
yield return(decodedBytes);
}
}
/// <summary>
/// Decodes yEnc-encoded text into a <see cref="YencArticle"/>
/// using the specified charcter encoding.
/// </summary>
/// <param name="encodedLines">The yEnc-encoded lines to decode.</param>
/// <param name="encoding">The charcter encoding to use.</param>
/// <returns>A <see cref="YencArticle"/> containing the decoded binary data and meta-data.</returns>
public static YencArticle Decode(IEnumerable <string> encodedLines, Encoding encoding)
{
Guard.ThrowIfNull(encodedLines, nameof(encodedLines));
Guard.ThrowIfNull(encoding, nameof(encoding));
using (IEnumerator <string> enumerator = encodedLines.GetEnumerator())
{
IDictionary <string, string> headers = YencMeta.GetHeaders(enumerator);
int part = headers.GetAndConvert(YencKeywords.Part, int.Parse);
if (part > 0)
{
headers.Merge(YencMeta.GetPartHeaders(enumerator), false);
}
YencHeader header = YencMeta.ParseHeader(headers);
YencFooter footer = null;
// create buffer for part or entire file if single part
var decodedBytes = new byte[header.PartSize];
var decodedBytesIndex = 0;
while (enumerator.MoveNext())
{
if (enumerator.Current == null)
{
continue;
}
if (enumerator.Current.StartsWith(yEnd))
{
footer = YencMeta.ParseFooter(YencMeta.ParseLine(enumerator.Current));
// skip remainder if there is some
while (enumerator.MoveNext())
{
}
break;
}
byte[] encodedBytes = encoding.GetBytes(enumerator.Current);
decodedBytesIndex += YencLineDecoder.Decode(encodedBytes, decodedBytes, decodedBytesIndex);
}
return(new YencArticle(header, footer, decodedBytes));
}
}