New: Implemented Torrent Download Clients: uTorrent, Transmission and Deluge. And several public and private Torrent Indexers.

src/MonoTorrent/BEncoding/BEncodedString.cs

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+using System;
+using System.IO;
+using System.Collections;
+using System.Text;
+using MonoTorrent.Common;
+using MonoTorrent.Messages;
+
+namespace MonoTorrent.BEncoding
+{
+    /// <summary>
+    /// Class representing a BEncoded string
+    /// </summary>
+    public class BEncodedString : BEncodedValue, IComparable<BEncodedString>
+    {
+        #region Member Variables
+
+        /// <summary>
+        /// The value of the BEncodedString
+        /// </summary>
+        public string Text
+        {
+            get { return Encoding.UTF8.GetString(textBytes); }
+            set { textBytes = Encoding.UTF8.GetBytes(value); }
+        }
+
+        /// <summary>
+        /// The underlying byte[] associated with this BEncodedString
+        /// </summary>
+        public byte[] TextBytes
+        {
+            get { return this.textBytes; }
+        }
+        private byte[] textBytes;
+        #endregion
+
+
+        #region Constructors
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        public BEncodedString()
+            : this(new byte[0])
+        {
+        }
+
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        /// <param name="value"></param>
+        public BEncodedString(char[] value)
+            : this(System.Text.Encoding.UTF8.GetBytes(value))
+        {
+        }
+
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        /// <param name="value">Initial value for the string</param>
+        public BEncodedString(string value)
+            : this(System.Text.Encoding.UTF8.GetBytes(value))
+        {
+        }
+
+
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        /// <param name="value"></param>
+        public BEncodedString(byte[] value)
+        {
+            this.textBytes = value;
+        }
+
+
+        public static implicit operator BEncodedString(string value)
+        {
+            return new BEncodedString(value);
+        }
+        public static implicit operator BEncodedString(char[] value)
+        {
+            return new BEncodedString(value);
+        }
+        public static implicit operator BEncodedString(byte[] value)
+        {
+            return new BEncodedString(value);
+        }
+        #endregion
+
+
+        #region Encode/Decode Methods
+
+
+        /// <summary>
+        /// Encodes the BEncodedString to a byte[] using the supplied Encoding
+        /// </summary>
+        /// <param name="buffer">The buffer to encode the string to</param>
+        /// <param name="offset">The offset at which to save the data to</param>
+        /// <param name="e">The encoding to use</param>
+        /// <returns>The number of bytes encoded</returns>
+        public override int Encode(byte[] buffer, int offset)
+        {
+            int written = offset;
+            written += Message.WriteAscii(buffer, written, textBytes.Length.ToString ());
+            written += Message.WriteAscii(buffer, written, ":");
+            written += Message.Write(buffer, written, textBytes);
+            return written - offset;
+        }
+
+
+        /// <summary>
+        /// Decodes a BEncodedString from the supplied StreamReader
+        /// </summary>
+        /// <param name="reader">The StreamReader containing the BEncodedString</param>
+        internal override void DecodeInternal(RawReader reader)
+        {
+            if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            int letterCount;
+            string length = string.Empty;
+
+            while ((reader.PeekByte() != -1) && (reader.PeekByte() != ':'))         // read in how many characters
+                length += (char)reader.ReadByte();                                 // the string is
+
+            if (reader.ReadByte() != ':')                                           // remove the ':'
+                throw new BEncodingException("Invalid data found. Aborting");
+
+            if (!int.TryParse(length, out letterCount))
+                throw new BEncodingException(string.Format("Invalid BEncodedString. Length was '{0}' instead of a number", length));
+
+            this.textBytes = new byte[letterCount];
+            if (reader.Read(textBytes, 0, letterCount) != letterCount)
+                throw new BEncodingException("Couldn't decode string");
+        }
+        #endregion
+
+
+        #region Helper Methods
+        public string Hex
+        {
+            get { return BitConverter.ToString(TextBytes); }
+        }
+
+        public override int LengthInBytes()
+        {
+            // The length is equal to the length-prefix + ':' + length of data
+            int prefix = 1; // Account for ':'
+
+            // Count the number of characters needed for the length prefix
+            for (int i = textBytes.Length; i != 0; i = i/10)
+                prefix += 1;
+
+            if (textBytes.Length == 0)
+                prefix++;
+
+            return prefix + textBytes.Length;
+        }
+
+        public int CompareTo(object other)
+        {
+            return CompareTo(other as BEncodedString);
+        }
+
+
+        public int CompareTo(BEncodedString other)
+        {
+            if (other == null)
+                return 1;
+
+            int difference=0;
+            int length = this.textBytes.Length > other.textBytes.Length ? other.textBytes.Length : this.textBytes.Length;
+
+            for (int i = 0; i < length; i++)
+                if ((difference = this.textBytes[i].CompareTo(other.textBytes[i])) != 0)
+                    return difference;
+
+            if (this.textBytes.Length == other.textBytes.Length)
+                return 0;
+
+            return this.textBytes.Length > other.textBytes.Length ? 1 : -1;
+        }
+
+        #endregion
+
+
+        #region Overridden Methods
+
+        public override bool Equals(object obj)
+        {
+            if (obj == null)
+                return false;
+
+            BEncodedString other;
+            if (obj is string)
+                other = new BEncodedString((string)obj);
+            else if (obj is BEncodedString)
+                other = (BEncodedString)obj;
+            else
+                return false;
+
+            return Toolbox.ByteMatch(this.textBytes, other.textBytes);
+        }
+
+        public override int GetHashCode()
+        {
+            int hash = 0;
+            for (int i = 0; i < this.textBytes.Length; i++)
+                hash += this.textBytes[i];
+
+            return hash;
+        }
+
+        public override string ToString()
+        {
+            return System.Text.Encoding.UTF8.GetString(textBytes);
+        }
+
+        #endregion
+    }
+}