merge common implementations and server implementations

1 files changed, 975 insertions, 0 deletions

diff --git a/Emby.Server.Implementations/HttpClientManager/HttpClientManager.cs b/Emby.Server.Implementations/HttpClientManager/HttpClientManager.cs
new file mode 100644
index 000000000..1017953ba
--- /dev/null
+++ b/Emby.Server.Implementations/HttpClientManager/HttpClientManager.cs
@@ -0,0 +1,975 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Emby.Server.Implementations.IO;
+using MediaBrowser.Common.Configuration;
+using MediaBrowser.Common.Extensions;
+using MediaBrowser.Common.Net;
+using MediaBrowser.Model.IO;
+using MediaBrowser.Model.Logging;
+using MediaBrowser.Model.Net;
+
+namespace Emby.Server.Implementations.HttpClientManager
+{
+    /// <summary>
+    /// Class HttpClientManager
+    /// </summary>
+    public class HttpClientManager : IHttpClient
+    {
+        /// <summary>
+        /// When one request to a host times out, we'll ban all other requests for this period of time, to prevent scans from stalling
+        /// </summary>
+        private const int TimeoutSeconds = 30;
+
+        /// <summary>
+        /// The _logger
+        /// </summary>
+        private readonly ILogger _logger;
+
+        /// <summary>
+        /// The _app paths
+        /// </summary>
+        private readonly IApplicationPaths _appPaths;
+
+        private readonly IFileSystem _fileSystem;
+        private readonly IMemoryStreamFactory _memoryStreamProvider;
+        private readonly Func<string> _defaultUserAgentFn;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpClientManager" /> class.
+        /// </summary>
+        public HttpClientManager(IApplicationPaths appPaths, ILogger logger, IFileSystem fileSystem, IMemoryStreamFactory memoryStreamProvider, Func<string> defaultUserAgentFn)
+        {
+            if (appPaths == null)
+            {
+                throw new ArgumentNullException("appPaths");
+            }
+            if (logger == null)
+            {
+                throw new ArgumentNullException("logger");
+            }
+
+            _logger = logger;
+            _fileSystem = fileSystem;
+            _memoryStreamProvider = memoryStreamProvider;
+            _appPaths = appPaths;
+            _defaultUserAgentFn = defaultUserAgentFn;
+
+            // http://stackoverflow.com/questions/566437/http-post-returns-the-error-417-expectation-failed-c
+            ServicePointManager.Expect100Continue = false;
+
+            // Trakt requests sometimes fail without this
+            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls;
+        }
+
+        /// <summary>
+        /// Holds a dictionary of http clients by host.  Use GetHttpClient(host) to retrieve or create a client for web requests.
+        /// DON'T dispose it after use.
+        /// </summary>
+        /// <value>The HTTP clients.</value>
+        private readonly ConcurrentDictionary<string, HttpClientInfo> _httpClients = new ConcurrentDictionary<string, HttpClientInfo>();
+
+        /// <summary>
+        /// Gets
+        /// </summary>
+        /// <param name="host">The host.</param>
+        /// <param name="enableHttpCompression">if set to <c>true</c> [enable HTTP compression].</param>
+        /// <returns>HttpClient.</returns>
+        /// <exception cref="System.ArgumentNullException">host</exception>
+        private HttpClientInfo GetHttpClient(string host, bool enableHttpCompression)
+        {
+            if (string.IsNullOrEmpty(host))
+            {
+                throw new ArgumentNullException("host");
+            }
+
+            HttpClientInfo client;
+
+            var key = host + enableHttpCompression;
+
+            if (!_httpClients.TryGetValue(key, out client))
+            {
+                client = new HttpClientInfo();
+
+                _httpClients.TryAdd(key, client);
+            }
+
+            return client;
+        }
+
+        private WebRequest CreateWebRequest(string url)
+        {
+            try
+            {
+                return WebRequest.Create(url);
+            }
+            catch (NotSupportedException)
+            {
+                //Webrequest creation does fail on MONO randomly when using WebRequest.Create
+                //the issue occurs in the GetCreator method here: http://www.oschina.net/code/explore/mono-2.8.1/mcs/class/System/System.Net/WebRequest.cs
+
+                var type = Type.GetType("System.Net.HttpRequestCreator, System, Version=4.0.0.0,Culture=neutral, PublicKeyToken=b77a5c561934e089");
+                var creator = Activator.CreateInstance(type, nonPublic: true) as IWebRequestCreate;
+                return creator.Create(new Uri(url)) as HttpWebRequest;
+            }
+        }
+
+        private void AddIpv4Option(HttpWebRequest request, HttpRequestOptions options)
+        {
+            request.ServicePoint.BindIPEndPointDelegate = (servicePount, remoteEndPoint, retryCount) =>
+            {
+                if (remoteEndPoint.AddressFamily == AddressFamily.InterNetwork)
+                {
+                    return new IPEndPoint(IPAddress.Any, 0);
+                }
+                throw new InvalidOperationException("no IPv4 address");
+            };
+        }
+
+        private WebRequest GetRequest(HttpRequestOptions options, string method)
+        {
+            var url = options.Url;
+
+            var uriAddress = new Uri(url);
+            var userInfo = uriAddress.UserInfo;
+            if (!string.IsNullOrWhiteSpace(userInfo))
+            {
+                _logger.Info("Found userInfo in url: {0} ... url: {1}", userInfo, url);
+                url = url.Replace(userInfo + "@", string.Empty);
+            }
+
+            var request = CreateWebRequest(url);
+            var httpWebRequest = request as HttpWebRequest;
+
+            if (httpWebRequest != null)
+            {
+                if (options.PreferIpv4)
+                {
+                    AddIpv4Option(httpWebRequest, options);
+                }
+
+                AddRequestHeaders(httpWebRequest, options);
+
+                if (options.EnableHttpCompression)
+                {
+                    if (options.DecompressionMethod.HasValue)
+                    {
+                        httpWebRequest.AutomaticDecompression = options.DecompressionMethod.Value == CompressionMethod.Gzip
+                            ? DecompressionMethods.GZip
+                            : DecompressionMethods.Deflate;
+                    }
+                    else
+                    {
+                        httpWebRequest.AutomaticDecompression = DecompressionMethods.Deflate;
+                    }
+                }
+                else
+                {
+                    httpWebRequest.AutomaticDecompression = DecompressionMethods.None;
+                }
+            }
+
+
+
+            request.CachePolicy = new System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.BypassCache);
+
+            if (httpWebRequest != null)
+            {
+                if (options.EnableKeepAlive)
+                {
+                    httpWebRequest.KeepAlive = true;
+                }
+            }
+
+            request.Method = method;
+            request.Timeout = options.TimeoutMs;
+
+            if (httpWebRequest != null)
+            {
+                if (!string.IsNullOrEmpty(options.Host))
+                {
+                    httpWebRequest.Host = options.Host;
+                }
+
+                if (!string.IsNullOrEmpty(options.Referer))
+                {
+                    httpWebRequest.Referer = options.Referer;
+                }
+            }
+
+            if (!string.IsNullOrWhiteSpace(userInfo))
+            {
+                var parts = userInfo.Split(':');
+                if (parts.Length == 2)
+                {
+                    request.Credentials = GetCredential(url, parts[0], parts[1]);
+                    // TODO: .net core ??
+                    request.PreAuthenticate = true;
+                }
+            }
+
+            return request;
+        }
+
+        private CredentialCache GetCredential(string url, string username, string password)
+        {
+            //ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
+            CredentialCache credentialCache = new CredentialCache();
+            credentialCache.Add(new Uri(url), "Basic", new NetworkCredential(username, password));
+            return credentialCache;
+        }
+
+        private void AddRequestHeaders(HttpWebRequest request, HttpRequestOptions options)
+        {
+            var hasUserAgent = false;
+
+            foreach (var header in options.RequestHeaders.ToList())
+            {
+                if (string.Equals(header.Key, "Accept", StringComparison.OrdinalIgnoreCase))
+                {
+                    request.Accept = header.Value;
+                }
+                else if (string.Equals(header.Key, "User-Agent", StringComparison.OrdinalIgnoreCase))
+                {
+                    SetUserAgent(request, header.Value);
+                    hasUserAgent = true;
+                }
+                else
+                {
+                    request.Headers.Set(header.Key, header.Value);
+                }
+            }
+
+            if (!hasUserAgent && options.EnableDefaultUserAgent)
+            {
+                SetUserAgent(request, _defaultUserAgentFn());
+            }
+        }
+
+        private void SetUserAgent(HttpWebRequest request, string userAgent)
+        {
+            request.UserAgent = userAgent;
+        }
+
+        /// <summary>
+        /// Gets the response internal.
+        /// </summary>
+        /// <param name="options">The options.</param>
+        /// <returns>Task{HttpResponseInfo}.</returns>
+        public Task<HttpResponseInfo> GetResponse(HttpRequestOptions options)
+        {
+            return SendAsync(options, "GET");
+        }
+
+        /// <summary>
+        /// Performs a GET request and returns the resulting stream
+        /// </summary>
+        /// <param name="options">The options.</param>
+        /// <returns>Task{Stream}.</returns>
+        public async Task<Stream> Get(HttpRequestOptions options)
+        {
+            var response = await GetResponse(options).ConfigureAwait(false);
+
+            return response.Content;
+        }
+
+        /// <summary>
+        /// Performs a GET request and returns the resulting stream
+        /// </summary>
+        /// <param name="url">The URL.</param>
+        /// <param name="resourcePool">The resource pool.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task{Stream}.</returns>
+        public Task<Stream> Get(string url, SemaphoreSlim resourcePool, CancellationToken cancellationToken)
+        {
+            return Get(new HttpRequestOptions
+            {
+                Url = url,
+                ResourcePool = resourcePool,
+                CancellationToken = cancellationToken,
+                BufferContent = resourcePool != null
+            });
+        }
+
+        /// <summary>
+        /// Gets the specified URL.
+        /// </summary>
+        /// <param name="url">The URL.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task{Stream}.</returns>
+        public Task<Stream> Get(string url, CancellationToken cancellationToken)
+        {
+            return Get(url, null, cancellationToken);
+        }
+
+        /// <summary>
+        /// send as an asynchronous operation.
+        /// </summary>
+        /// <param name="options">The options.</param>
+        /// <param name="httpMethod">The HTTP method.</param>
+        /// <returns>Task{HttpResponseInfo}.</returns>
+        /// <exception cref="HttpException">
+        /// </exception>
+        public async Task<HttpResponseInfo> SendAsync(HttpRequestOptions options, string httpMethod)
+        {
+            if (options.CacheMode == CacheMode.None)
+            {
+                return await SendAsyncInternal(options, httpMethod).ConfigureAwait(false);
+            }
+
+            var url = options.Url;
+            var urlHash = url.ToLower().GetMD5().ToString("N");
+
+            var responseCachePath = Path.Combine(_appPaths.CachePath, "httpclient", urlHash);
+
+            var response = await GetCachedResponse(responseCachePath, options.CacheLength, url).ConfigureAwait(false);
+            if (response != null)
+            {
+                return response;
+            }
+
+            response = await SendAsyncInternal(options, httpMethod).ConfigureAwait(false);
+
+            if (response.StatusCode == HttpStatusCode.OK)
+            {
+                await CacheResponse(response, responseCachePath).ConfigureAwait(false);
+            }
+
+            return response;
+        }
+
+        private async Task<HttpResponseInfo> GetCachedResponse(string responseCachePath, TimeSpan cacheLength, string url)
+        {
+            _logger.Info("Checking for cache file {0}", responseCachePath);
+
+            try
+            {
+                if (_fileSystem.GetLastWriteTimeUtc(responseCachePath).Add(cacheLength) > DateTime.UtcNow)
+                {
+                    using (var stream = _fileSystem.GetFileStream(responseCachePath, FileOpenMode.Open, FileAccessMode.Read, FileShareMode.Read, true))
+                    {
+                        var memoryStream = _memoryStreamProvider.CreateNew();
+
+                        await stream.CopyToAsync(memoryStream).ConfigureAwait(false);
+                        memoryStream.Position = 0;
+
+                        return new HttpResponseInfo
+                        {
+                            ResponseUrl = url,
+                            Content = memoryStream,
+                            StatusCode = HttpStatusCode.OK,
+                            ContentLength = memoryStream.Length
+                        };
+                    }
+                }
+            }
+            catch (FileNotFoundException)
+            {
+
+            }
+            catch (DirectoryNotFoundException)
+            {
+
+            }
+
+            return null;
+        }
+
+        private async Task CacheResponse(HttpResponseInfo response, string responseCachePath)
+        {
+            _fileSystem.CreateDirectory(_fileSystem.GetDirectoryName(responseCachePath));
+
+            using (var responseStream = response.Content)
+            {
+                var memoryStream = _memoryStreamProvider.CreateNew();
+                await responseStream.CopyToAsync(memoryStream).ConfigureAwait(false);
+                memoryStream.Position = 0;
+
+                using (var fileStream = _fileSystem.GetFileStream(responseCachePath, FileOpenMode.Create, FileAccessMode.Write, FileShareMode.None, true))
+                {
+                    await memoryStream.CopyToAsync(fileStream).ConfigureAwait(false);
+
+                    memoryStream.Position = 0;
+                    response.Content = memoryStream;
+                }
+            }
+        }
+
+        private async Task<HttpResponseInfo> SendAsyncInternal(HttpRequestOptions options, string httpMethod)
+        {
+            ValidateParams(options);
+
+            options.CancellationToken.ThrowIfCancellationRequested();
+
+            var client = GetHttpClient(GetHostFromUrl(options.Url), options.EnableHttpCompression);
+
+            if ((DateTime.UtcNow - client.LastTimeout).TotalSeconds < TimeoutSeconds)
+            {
+                throw new HttpException(string.Format("Cancelling connection to {0} due to a previous timeout.", options.Url))
+                {
+                    IsTimedOut = true
+                };
+            }
+
+            var httpWebRequest = GetRequest(options, httpMethod);
+
+            if (options.RequestContentBytes != null ||
+                !string.IsNullOrEmpty(options.RequestContent) ||
+                string.Equals(httpMethod, "post", StringComparison.OrdinalIgnoreCase))
+            {
+                try
+                {
+                    var bytes = options.RequestContentBytes ??
+                        Encoding.UTF8.GetBytes(options.RequestContent ?? string.Empty);
+
+                    httpWebRequest.ContentType = options.RequestContentType ?? "application/x-www-form-urlencoded";
+
+                    httpWebRequest.ContentLength = bytes.Length;
+                    (await httpWebRequest.GetRequestStreamAsync().ConfigureAwait(false)).Write(bytes, 0, bytes.Length);
+                }
+                catch (Exception ex)
+                {
+                    throw new HttpException(ex.Message) { IsTimedOut = true };
+                }
+            }
+
+            if (options.ResourcePool != null)
+            {
+                await options.ResourcePool.WaitAsync(options.CancellationToken).ConfigureAwait(false);
+            }
+
+            if ((DateTime.UtcNow - client.LastTimeout).TotalSeconds < TimeoutSeconds)
+            {
+                if (options.ResourcePool != null)
+                {
+                    options.ResourcePool.Release();
+                }
+
+                throw new HttpException(string.Format("Connection to {0} timed out", options.Url)) { IsTimedOut = true };
+            }
+
+            if (options.LogRequest)
+            {
+                _logger.Info("HttpClientManager {0}: {1}", httpMethod.ToUpper(), options.Url);
+            }
+
+            try
+            {
+                options.CancellationToken.ThrowIfCancellationRequested();
+
+                if (!options.BufferContent)
+                {
+                    var response = await GetResponseAsync(httpWebRequest, TimeSpan.FromMilliseconds(options.TimeoutMs)).ConfigureAwait(false);
+
+                    var httpResponse = (HttpWebResponse)response;
+
+                    EnsureSuccessStatusCode(client, httpResponse, options);
+
+                    options.CancellationToken.ThrowIfCancellationRequested();
+
+                    return GetResponseInfo(httpResponse, httpResponse.GetResponseStream(), GetContentLength(httpResponse), httpResponse);
+                }
+
+                using (var response = await GetResponseAsync(httpWebRequest, TimeSpan.FromMilliseconds(options.TimeoutMs)).ConfigureAwait(false))
+                {
+                    var httpResponse = (HttpWebResponse)response;
+
+                    EnsureSuccessStatusCode(client, httpResponse, options);
+
+                    options.CancellationToken.ThrowIfCancellationRequested();
+
+                    using (var stream = httpResponse.GetResponseStream())
+                    {
+                        var memoryStream = _memoryStreamProvider.CreateNew();
+
+                        await stream.CopyToAsync(memoryStream).ConfigureAwait(false);
+
+                        memoryStream.Position = 0;
+
+                        return GetResponseInfo(httpResponse, memoryStream, memoryStream.Length, null);
+                    }
+                }
+            }
+            catch (OperationCanceledException ex)
+            {
+                throw GetCancellationException(options, client, options.CancellationToken, ex);
+            }
+            catch (Exception ex)
+            {
+                throw GetException(ex, options, client);
+            }
+            finally
+            {
+                if (options.ResourcePool != null)
+                {
+                    options.ResourcePool.Release();
+                }
+            }
+        }
+
+        private HttpResponseInfo GetResponseInfo(HttpWebResponse httpResponse, Stream content, long? contentLength, IDisposable disposable)
+        {
+            var responseInfo = new HttpResponseInfo(disposable)
+            {
+                Content = content,
+
+                StatusCode = httpResponse.StatusCode,
+
+                ContentType = httpResponse.ContentType,
+
+                ContentLength = contentLength,
+
+                ResponseUrl = httpResponse.ResponseUri.ToString()
+            };
+
+            if (httpResponse.Headers != null)
+            {
+                SetHeaders(httpResponse.Headers, responseInfo);
+            }
+
+            return responseInfo;
+        }
+
+        private HttpResponseInfo GetResponseInfo(HttpWebResponse httpResponse, string tempFile, long? contentLength)
+        {
+            var responseInfo = new HttpResponseInfo
+            {
+                TempFilePath = tempFile,
+
+                StatusCode = httpResponse.StatusCode,
+
+                ContentType = httpResponse.ContentType,
+
+                ContentLength = contentLength
+            };
+
+            if (httpResponse.Headers != null)
+            {
+                SetHeaders(httpResponse.Headers, responseInfo);
+            }
+
+            return responseInfo;
+        }
+
+        private void SetHeaders(WebHeaderCollection headers, HttpResponseInfo responseInfo)
+        {
+            foreach (var key in headers.AllKeys)
+            {
+                responseInfo.Headers[key] = headers[key];
+            }
+        }
+
+        public Task<HttpResponseInfo> Post(HttpRequestOptions options)
+        {
+            return SendAsync(options, "POST");
+        }
+
+        /// <summary>
+        /// Performs a POST request
+        /// </summary>
+        /// <param name="options">The options.</param>
+        /// <param name="postData">Params to add to the POST data.</param>
+        /// <returns>stream on success, null on failure</returns>
+        public async Task<Stream> Post(HttpRequestOptions options, Dictionary<string, string> postData)
+        {
+            options.SetPostData(postData);
+
+            var response = await Post(options).ConfigureAwait(false);
+
+            return response.Content;
+        }
+
+        /// <summary>
+        /// Performs a POST request
+        /// </summary>
+        /// <param name="url">The URL.</param>
+        /// <param name="postData">Params to add to the POST data.</param>
+        /// <param name="resourcePool">The resource pool.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>stream on success, null on failure</returns>
+        public Task<Stream> Post(string url, Dictionary<string, string> postData, SemaphoreSlim resourcePool, CancellationToken cancellationToken)
+        {
+            return Post(new HttpRequestOptions
+            {
+                Url = url,
+                ResourcePool = resourcePool,
+                CancellationToken = cancellationToken,
+                BufferContent = resourcePool != null
+
+            }, postData);
+        }
+
+        /// <summary>
+        /// Downloads the contents of a given url into a temporary location
+        /// </summary>
+        /// <param name="options">The options.</param>
+        /// <returns>Task{System.String}.</returns>
+        public async Task<string> GetTempFile(HttpRequestOptions options)
+        {
+            var response = await GetTempFileResponse(options).ConfigureAwait(false);
+
+            return response.TempFilePath;
+        }
+
+        public async Task<HttpResponseInfo> GetTempFileResponse(HttpRequestOptions options)
+        {
+            ValidateParams(options);
+
+            _fileSystem.CreateDirectory(_appPaths.TempDirectory);
+
+            var tempFile = Path.Combine(_appPaths.TempDirectory, Guid.NewGuid() + ".tmp");
+
+            if (options.Progress == null)
+            {
+                throw new ArgumentNullException("progress");
+            }
+
+            options.CancellationToken.ThrowIfCancellationRequested();
+
+            var httpWebRequest = GetRequest(options, "GET");
+
+            if (options.ResourcePool != null)
+            {
+                await options.ResourcePool.WaitAsync(options.CancellationToken).ConfigureAwait(false);
+            }
+
+            options.Progress.Report(0);
+
+            if (options.LogRequest)
+            {
+                _logger.Info("HttpClientManager.GetTempFileResponse url: {0}", options.Url);
+            }
+
+            var client = GetHttpClient(GetHostFromUrl(options.Url), options.EnableHttpCompression);
+
+            try
+            {
+                options.CancellationToken.ThrowIfCancellationRequested();
+
+                using (var response = await httpWebRequest.GetResponseAsync().ConfigureAwait(false))
+                {
+                    var httpResponse = (HttpWebResponse)response;
+
+                    EnsureSuccessStatusCode(client, httpResponse, options);
+
+                    options.CancellationToken.ThrowIfCancellationRequested();
+
+                    var contentLength = GetContentLength(httpResponse);
+
+                    if (!contentLength.HasValue)
+                    {
+                        // We're not able to track progress
+                        using (var stream = httpResponse.GetResponseStream())
+                        {
+                            using (var fs = _fileSystem.GetFileStream(tempFile, FileOpenMode.Create, FileAccessMode.Write, FileShareMode.Read, true))
+                            {
+                                await stream.CopyToAsync(fs, StreamDefaults.DefaultCopyToBufferSize, options.CancellationToken).ConfigureAwait(false);
+                            }
+                        }
+                    }
+                    else
+                    {
+                        using (var stream = ProgressStream.CreateReadProgressStream(httpResponse.GetResponseStream(), options.Progress.Report, contentLength.Value))
+                        {
+                            using (var fs = _fileSystem.GetFileStream(tempFile, FileOpenMode.Create, FileAccessMode.Write, FileShareMode.Read, true))
+                            {
+                                await stream.CopyToAsync(fs, StreamDefaults.DefaultCopyToBufferSize, options.CancellationToken).ConfigureAwait(false);
+                            }
+                        }
+                    }
+
+                    options.Progress.Report(100);
+
+                    return GetResponseInfo(httpResponse, tempFile, contentLength);
+                }
+            }
+            catch (Exception ex)
+            {
+                DeleteTempFile(tempFile);
+                throw GetException(ex, options, client);
+            }
+            finally
+            {
+                if (options.ResourcePool != null)
+                {
+                    options.ResourcePool.Release();
+                }
+            }
+        }
+
+        private long? GetContentLength(HttpWebResponse response)
+        {
+            var length = response.ContentLength;
+
+            if (length == 0)
+            {
+                return null;
+            }
+
+            return length;
+        }
+
+        protected static readonly CultureInfo UsCulture = new CultureInfo("en-US");
+
+        private Exception GetException(Exception ex, HttpRequestOptions options, HttpClientInfo client)
+        {
+            if (ex is HttpException)
+            {
+                return ex;
+            }
+
+            var webException = ex as WebException
+                ?? ex.InnerException as WebException;
+
+            if (webException != null)
+            {
+                if (options.LogErrors)
+                {
+                    _logger.ErrorException("Error " + webException.Status + " getting response from " + options.Url, webException);
+                }
+
+                var exception = new HttpException(webException.Message, webException);
+
+                var response = webException.Response as HttpWebResponse;
+                if (response != null)
+                {
+                    exception.StatusCode = response.StatusCode;
+
+                    if ((int)response.StatusCode == 429)
+                    {
+                        client.LastTimeout = DateTime.UtcNow;
+                    }
+                }
+
+                if (!exception.StatusCode.HasValue)
+                {
+                    if (webException.Status == WebExceptionStatus.NameResolutionFailure ||
+                        webException.Status == WebExceptionStatus.ConnectFailure)
+                    {
+                        exception.IsTimedOut = true;
+                    }
+                }
+
+                return exception;
+            }
+
+            var operationCanceledException = ex as OperationCanceledException
+                ?? ex.InnerException as OperationCanceledException;
+
+            if (operationCanceledException != null)
+            {
+                return GetCancellationException(options, client, options.CancellationToken, operationCanceledException);
+            }
+
+            if (options.LogErrors)
+            {
+                _logger.ErrorException("Error getting response from " + options.Url, ex);
+            }
+
+            return ex;
+        }
+
+        private void DeleteTempFile(string file)
+        {
+            try
+            {
+                _fileSystem.DeleteFile(file);
+            }
+            catch (IOException)
+            {
+                // Might not have been created at all. No need to worry.
+            }
+        }
+
+        private void ValidateParams(HttpRequestOptions options)
+        {
+            if (string.IsNullOrEmpty(options.Url))
+            {
+                throw new ArgumentNullException("options");
+            }
+        }
+
+        /// <summary>
+        /// Gets the host from URL.
+        /// </summary>
+        /// <param name="url">The URL.</param>
+        /// <returns>System.String.</returns>
+        private string GetHostFromUrl(string url)
+        {
+            var index = url.IndexOf("://", StringComparison.OrdinalIgnoreCase);
+
+            if (index != -1)
+            {
+                url = url.Substring(index + 3);
+                var host = url.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries).FirstOrDefault();
+
+                if (!string.IsNullOrWhiteSpace(host))
+                {
+                    return host;
+                }
+            }
+
+            return url;
+        }
+
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        /// <summary>
+        /// Releases unmanaged and - optionally - managed resources.
+        /// </summary>
+        /// <param name="dispose"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
+        protected virtual void Dispose(bool dispose)
+        {
+            if (dispose)
+            {
+                _httpClients.Clear();
+            }
+        }
+
+        /// <summary>
+        /// Throws the cancellation exception.
+        /// </summary>
+        /// <param name="options">The options.</param>
+        /// <param name="client">The client.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <param name="exception">The exception.</param>
+        /// <returns>Exception.</returns>
+        private Exception GetCancellationException(HttpRequestOptions options, HttpClientInfo client, CancellationToken cancellationToken, OperationCanceledException exception)
+        {
+            // If the HttpClient's timeout is reached, it will cancel the Task internally
+            if (!cancellationToken.IsCancellationRequested)
+            {
+                var msg = string.Format("Connection to {0} timed out", options.Url);
+
+                if (options.LogErrors)
+                {
+                    _logger.Error(msg);
+                }
+
+                client.LastTimeout = DateTime.UtcNow;
+
+                // Throw an HttpException so that the caller doesn't think it was cancelled by user code
+                return new HttpException(msg, exception)
+                {
+                    IsTimedOut = true
+                };
+            }
+
+            return exception;
+        }
+
+        private void EnsureSuccessStatusCode(HttpClientInfo client, HttpWebResponse response, HttpRequestOptions options)
+        {
+            var statusCode = response.StatusCode;
+
+            var isSuccessful = statusCode >= HttpStatusCode.OK && statusCode <= (HttpStatusCode)299;
+
+            if (!isSuccessful)
+            {
+                if (options.LogErrorResponseBody)
+                {
+                    try
+                    {
+                        using (var stream = response.GetResponseStream())
+                        {
+                            if (stream != null)
+                            {
+                                using (var reader = new StreamReader(stream))
+                                {
+                                    var msg = reader.ReadToEnd();
+
+                                    _logger.Error(msg);
+                                }
+                            }
+                        }
+                    }
+                    catch
+                    {
+
+                    }
+                }
+                throw new HttpException(response.StatusDescription)
+                {
+                    StatusCode = response.StatusCode
+                };
+            }
+        }
+
+        /// <summary>
+        /// Posts the specified URL.
+        /// </summary>
+        /// <param name="url">The URL.</param>
+        /// <param name="postData">The post data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task{Stream}.</returns>
+        public Task<Stream> Post(string url, Dictionary<string, string> postData, CancellationToken cancellationToken)
+        {
+            return Post(url, postData, null, cancellationToken);
+        }
+
+        private Task<WebResponse> GetResponseAsync(WebRequest request, TimeSpan timeout)
+        {
+            var taskCompletion = new TaskCompletionSource<WebResponse>();
+
+            Task<WebResponse> asyncTask = Task.Factory.FromAsync<WebResponse>(request.BeginGetResponse, request.EndGetResponse, null);
+
+            ThreadPool.RegisterWaitForSingleObject((asyncTask as IAsyncResult).AsyncWaitHandle, TimeoutCallback, request, timeout, true);
+            var callback = new TaskCallback { taskCompletion = taskCompletion };
+            asyncTask.ContinueWith(callback.OnSuccess, TaskContinuationOptions.NotOnFaulted);
+
+            // Handle errors
+            asyncTask.ContinueWith(callback.OnError, TaskContinuationOptions.OnlyOnFaulted);
+
+            return taskCompletion.Task;
+        }
+
+        private static void TimeoutCallback(object state, bool timedOut)
+        {
+            if (timedOut)
+            {
+                WebRequest request = (WebRequest)state;
+                if (state != null)
+                {
+                    request.Abort();
+                }
+            }
+        }
+
+        private class TaskCallback
+        {
+            public TaskCompletionSource<WebResponse> taskCompletion;
+
+            public void OnSuccess(Task<WebResponse> task)
+            {
+                taskCompletion.TrySetResult(task.Result);
+            }
+
+            public void OnError(Task<WebResponse> task)
+            {
+                if (task.Exception != null)
+                {
+                    taskCompletion.TrySetException(task.Exception);
+                }
+                else
+                {
+                    taskCompletion.TrySetException(new List<Exception>());
+                }
+            }
+        }
+    }
+}