/**
* Creates a new MetaInfo from the given BDecoder. The BDecoder must have a complete dictionary
* describing the torrent.
*/
private MetaInfo(BDecoder be) throws IOException {
// Note that evaluation order matters here...
this(be.bdecodeMap().getMap());
byte[] origInfohash = be.get_special_map_digest();
// shouldn't ever happen
if (!DataHelper.eq(origInfohash, info_hash))
throw new InvalidBEncodingException("Infohash mismatch, please report");
}
/**
* Efficiently returns the name and the 20 byte SHA1 hash of the info dictionary in a torrent file
* Caller must close stream.
*
* @param infoHashOut 20-byte out parameter
* @since 0.8.5
*/
public static String getNameAndInfoHash(InputStream in, byte[] infoHashOut) throws IOException {
BDecoder bd = new BDecoder(in);
Map<String, BEValue> m = bd.bdecodeMap().getMap();
BEValue ibev = m.get("info");
if (ibev == null) throw new InvalidBEncodingException("Missing info map");
Map<String, BEValue> i = ibev.getMap();
BEValue rvbev = i.get("name");
if (rvbev == null) throw new InvalidBEncodingException("Missing name");
byte[] h = bd.get_special_map_digest();
System.arraycopy(h, 0, infoHashOut, 0, 20);
return rvbev.getString();
}