jellyfin/Emby.Common.Implementations/HttpClientManager/HttpClientManager.cs
2017-07-22 19:00:32 -04:00

979 lines
34 KiB
C#

using System.Net.Sockets;
using MediaBrowser.Common.Configuration;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Common.Net;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.Net;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Emby.Common.Implementations.HttpClientManager;
using Emby.Common.Implementations.IO;
using MediaBrowser.Model.IO;
using MediaBrowser.Common;
namespace Emby.Common.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>());
}
}
}
}
}