Add tolerant parse mode for torrents

Using the tolerant mode skips validation of required fields

Author: Krusen

BencodeNET/Parsing/BObjectParserList.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq;
 using BencodeNET.Objects;
 
 namespace BencodeNET.Parsing
@@ -118,6 +119,16 @@ public IBObjectParser<T> Get<T>() where T : IBObject
             return Get(typeof(T)) as IBObjectParser<T>;
         }
 
+        /// <summary>
+        /// Gets the specific parser of the type specified or null if not found.
+        /// </summary>
+        /// <typeparam name="T">The parser type to get.</typeparam>
+        /// <returns>The parser of the specified type or null if there isn't one.</returns>
+        public T GetSpecific<T>() where T : class, IBObjectParser
+        {
+            return Parsers.FirstOrDefault(x => x.Value is T).Value as T;
+        }
+
         /// <summary>
         /// Removes the parser for the specified type.
         /// </summary>
@@ -137,7 +148,6 @@ public IBObjectParser<T> Get<T>() where T : IBObject
         /// </summary>
         public void Clear() => Parsers.Clear();
 
-
         /// <summary>
         /// Returns an enumerator that iterates through the collection.
         /// </summary>

BencodeNET/Parsing/TorrentParser.cs

@@ -14,16 +14,34 @@ namespace BencodeNET.Parsing
     /// </summary>
     public class TorrentParser : BObjectParser<Torrent>
     {
+        /// <summary>
+        /// The parsing mode used when parsing torrents.
+        /// You can use <see cref="TorrentParserMode.Tolerant"/> if your torrent files are not always following the torrent specification.
+        /// </summary>
+        public TorrentParserMode ParseMode { get; set; }
+
         /// <summary>
         /// Creates an instance using the specified <see cref="IBencodeParser"/> for parsing
         /// the torrent <see cref="BDictionary"/>.
         /// </summary>
         /// <param name="bencodeParser">The parser used for parsing the torrent <see cref="BDictionary"/>.</param>
         public TorrentParser(IBencodeParser bencodeParser)
+            : this(bencodeParser, TorrentParserMode.Strict)
+        {
+        }
+
+        /// <summary>
+        /// Creates an instance using the specified <see cref="IBencodeParser"/> for parsing
+        /// the torrent <see cref="BDictionary"/>.
+        /// </summary>
+        /// <param name="bencodeParser">The parser used for parsing the torrent <see cref="BDictionary"/>.</param>
+        /// <param name="torrentParserMode">The parsing mode to use.</param>
+        public TorrentParser(IBencodeParser bencodeParser, TorrentParserMode torrentParserMode)
         {
             if (bencodeParser == null) throw new ArgumentNullException(nameof(bencodeParser));
 
             BencodeParser = bencodeParser;
+            ParseMode = torrentParserMode;
         }
 
         /// <summary>
@@ -54,7 +72,8 @@ public override Torrent Parse(BencodeStream stream)
         /// <returns>A <see cref="Torrent"/> matching the input.</returns>
         protected Torrent CreateTorrent(BDictionary data)
         {
-            EnsureValidTorrentData(data);
+            if (ParseMode == TorrentParserMode.Strict)
+                EnsureValidTorrentData(data);
 
             var info = data.Get<BDictionary>(TorrentFields.Info);
 

BencodeNET/Parsing/TorrentParserMode.cs

@@ -0,0 +1,18 @@
+namespace BencodeNET.Parsing
+{
+    /// <summary>
+    /// Determines how strict to be when parsing torrent files.
+    /// </summary>
+    public enum TorrentParserMode
+    {
+        /// <summary>
+        /// The parser will throw an exception if some parts of the torrent specification is not followed.
+        /// </summary>
+        Strict,
+
+        /// <summary>
+        ///  The parser will ignore stuff that doesn't follow the torrent specifications.
+        /// </summary>
+        Tolerant
+    }
+}