HttpBase.cs

#region License
/*
 * HttpBase.cs
 *
 * The MIT License
 *
 * Copyright (c) 2012-2014 sta.blockhead
 * Copyright © 2016 Nivloc Enterprises Ltd
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
#if SSHARP
using Crestron.SimplSharp;
using Crestron.SimplSharp.CrestronIO;
using SSMono;
using SSMono.Web;
using Timer = Crestron.SimplSharp.CTimer;
#else
using System.IO;
using System.Threading;
#endif
using WebSocketSharp.Net;

namespace WebSocketSharp
	{
	internal abstract class HttpBase
		{
		#region Private Fields

		private NameValueCollection _headers;
		private const int _headersMaxLength = 8192;
		private Version _version;

		#endregion

		#region Internal Fields

		internal byte[] EntityBodyData;

		#endregion

		#region Protected Fields

		protected const string CrLf = "\r\n";

		#endregion

		#region Protected Constructors

		protected HttpBase (Version version, NameValueCollection headers)
			{
			_version = version;
			_headers = headers;
			}

		#endregion

		#region Public Properties

		public string EntityBody
			{
			get
				{
#if NETCF
				if (EntityBodyData == null || EntityBodyData.Length == 0)
#else
				if (EntityBodyData == null || EntityBodyData.LongLength == 0)
#endif
					return String.Empty;

				Encoding enc = null;

				var contentType = _headers["Content-Type"];
				if (contentType != null && contentType.Length > 0)
					enc = WebSocketSharp.Net.HttpUtility.GetEncoding (contentType);

				return (enc ?? Encoding.UTF8).GetString (EntityBodyData);
				}
			}

		public NameValueCollection Headers
			{
			get
				{
				return _headers;
				}
			}

		public Version ProtocolVersion
			{
			get
				{
				return _version;
				}
			}

		#endregion

		#region Private Methods

		private static byte[] readEntityBody (Stream stream, string length)
			{
			long len;
#if NETCF
			if (!Int64Ex.TryParse (length, out len))
#else
			if (!Int64.TryParse (length, out len))
#endif
				throw new ArgumentException ("Cannot be parsed.", "length");

			if (len < 0)
				throw new ArgumentOutOfRangeException ("length", "Less than zero.");

			return len > 1024
				 ? stream.ReadBytes (len, 1024)
				 : len > 0
					 ? stream.ReadBytes ((int)len)
					 : null;
			}

		private static string[] readHeaders (Stream stream, int maxLength)
			{
			var buff = new List<byte> ();
			var cnt = 0;
			Action<int> add = i =>
			{
				if (i == -1)
					throw new EndOfStreamException ("The header cannot be read from the data source.");

				buff.Add ((byte)i);
				cnt++;
			};

			var read = false;
			while (cnt < maxLength)
				{
				if (stream.ReadByte ().EqualsWith ('\r', add) &&
					stream.ReadByte ().EqualsWith ('\n', add) &&
					stream.ReadByte ().EqualsWith ('\r', add) &&
					stream.ReadByte ().EqualsWith ('\n', add))
					{
					read = true;
					break;
					}
				}

			if (!read)
				throw new WebSocketException ("The length of header part is greater than the max length.");

			return Encoding.UTF8.GetString (buff.ToArray ())
				 .Replace (CrLf + " ", " ")
				 .Replace (CrLf + "\t", " ")
				 .Split (new[] { CrLf }, StringSplitOptions.RemoveEmptyEntries);
			}

		#endregion

		#region Protected Methods

		protected static T Read<T> (Stream stream, Func<string[], T> parser, int millisecondsTimeout)
		 where T : HttpBase
			{
			var timeout = false;
			var timer = new Timer (
			 state =>
				 {
				 timeout = true;
				 stream.Close ();
				 },
			 null,
			 millisecondsTimeout,
			 -1);

			T http = null;
			Exception exception = null;
			try
				{
				http = parser (readHeaders (stream, _headersMaxLength));
				var contentLen = http.Headers["Content-Length"];
				if (contentLen != null && contentLen.Length > 0)
					http.EntityBodyData = readEntityBody (stream, contentLen);
				}
			catch (Exception ex)
				{
				exception = ex;
				}
			finally
				{
				timer.Change (-1, -1);
				timer.Dispose ();
				}

			var msg = timeout
					 ? "A timeout has occurred while reading an HTTP request/response."
					 : exception != null
						? "An exception has occurred while reading an HTTP request/response."
#if SSHARP
							+ String.Format (" [{0}]", exception.Message)
#endif
						: null;

			if (msg != null)
				throw new WebSocketException (msg, exception);

			return http;
			}

		#endregion

		#region Public Methods

		public byte[] ToByteArray ()
			{
			return Encoding.UTF8.GetBytes (ToString ());
			}

		#endregion
		}
	}