jellyfin-server/Emby.Server.Implementations/HttpServer/HttpResultFactory.cs
2017-09-24 16:24:12 -04:00

705 lines
26 KiB
C#

using MediaBrowser.Common.Extensions;
using MediaBrowser.Controller.Net;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.Serialization;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Net;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using Emby.Server.Implementations.Services;
using MediaBrowser.Model.IO;
using MediaBrowser.Model.Services;
using IRequest = MediaBrowser.Model.Services.IRequest;
using MimeTypes = MediaBrowser.Model.Net.MimeTypes;
namespace Emby.Server.Implementations.HttpServer
{
/// <summary>
/// Class HttpResultFactory
/// </summary>
public class HttpResultFactory : IHttpResultFactory
{
/// <summary>
/// The _logger
/// </summary>
private readonly ILogger _logger;
private readonly IFileSystem _fileSystem;
private readonly IJsonSerializer _jsonSerializer;
private readonly IMemoryStreamFactory _memoryStreamFactory;
/// <summary>
/// Initializes a new instance of the <see cref="HttpResultFactory" /> class.
/// </summary>
public HttpResultFactory(ILogManager logManager, IFileSystem fileSystem, IJsonSerializer jsonSerializer, IMemoryStreamFactory memoryStreamFactory)
{
_fileSystem = fileSystem;
_jsonSerializer = jsonSerializer;
_memoryStreamFactory = memoryStreamFactory;
_logger = logManager.GetLogger("HttpResultFactory");
}
/// <summary>
/// Gets the result.
/// </summary>
/// <param name="content">The content.</param>
/// <param name="contentType">Type of the content.</param>
/// <param name="responseHeaders">The response headers.</param>
/// <returns>System.Object.</returns>
public object GetResult(object content, string contentType, IDictionary<string, string> responseHeaders = null)
{
return GetHttpResult(content, contentType, true, responseHeaders);
}
public object GetRedirectResult(string url)
{
var responseHeaders = new Dictionary<string, string>();
responseHeaders["Location"] = url;
var result = new HttpResult(new byte[] { }, "text/plain", HttpStatusCode.Redirect);
AddResponseHeaders(result, responseHeaders);
return result;
}
/// <summary>
/// Gets the HTTP result.
/// </summary>
private IHasHeaders GetHttpResult(object content, string contentType, bool addCachePrevention, IDictionary<string, string> responseHeaders = null)
{
IHasHeaders result;
var stream = content as Stream;
if (stream != null)
{
result = new StreamWriter(stream, contentType, _logger);
}
else
{
var bytes = content as byte[];
if (bytes != null)
{
result = new StreamWriter(bytes, contentType, _logger);
}
else
{
var text = content as string;
if (text != null)
{
result = new StreamWriter(Encoding.UTF8.GetBytes(text), contentType, _logger);
}
else
{
result = new HttpResult(content, contentType, HttpStatusCode.OK);
}
}
}
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>();
}
string expires;
if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out expires))
{
responseHeaders["Expires"] = "-1";
}
AddResponseHeaders(result, responseHeaders);
return result;
}
/// <summary>
/// Gets the optimized result.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="requestContext">The request context.</param>
/// <param name="result">The result.</param>
/// <param name="responseHeaders">The response headers.</param>
/// <returns>System.Object.</returns>
/// <exception cref="System.ArgumentNullException">result</exception>
public object GetOptimizedResult<T>(IRequest requestContext, T result, IDictionary<string, string> responseHeaders = null)
where T : class
{
return GetOptimizedResultInternal<T>(requestContext, result, true, responseHeaders);
}
private object GetOptimizedResultInternal<T>(IRequest requestContext, T result, bool addCachePrevention, IDictionary<string, string> responseHeaders = null)
where T : class
{
if (result == null)
{
throw new ArgumentNullException("result");
}
var optimizedResult = ToOptimizedResult(requestContext, result);
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
}
if (addCachePrevention)
{
responseHeaders["Expires"] = "-1";
}
// Apply headers
var hasHeaders = optimizedResult as IHasHeaders;
if (hasHeaders != null)
{
AddResponseHeaders(hasHeaders, responseHeaders);
}
return optimizedResult;
}
public static string GetCompressionType(IRequest request)
{
var acceptEncoding = request.Headers["Accept-Encoding"];
if (!string.IsNullOrWhiteSpace(acceptEncoding))
{
if (acceptEncoding.Contains("deflate"))
return "deflate";
if (acceptEncoding.Contains("gzip"))
return "gzip";
}
return null;
}
/// <summary>
/// Returns the optimized result for the IRequestContext.
/// Does not use or store results in any cache.
/// </summary>
/// <param name="request"></param>
/// <param name="dto"></param>
/// <returns></returns>
public object ToOptimizedResult<T>(IRequest request, T dto)
{
var contentType = request.ResponseContentType;
switch (GetRealContentType(contentType))
{
case "application/xml":
case "text/xml":
case "text/xml; charset=utf-8": //"text/xml; charset=utf-8" also matches xml
return SerializeToXmlString(dto);
case "application/json":
case "text/json":
return _jsonSerializer.SerializeToString(dto);
default:
{
var ms = new MemoryStream();
var writerFn = RequestHelper.GetResponseWriter(HttpListenerHost.Instance, contentType);
writerFn(dto, ms);
ms.Position = 0;
if (string.Equals(request.Verb, "head", StringComparison.OrdinalIgnoreCase))
{
return GetHttpResult(new byte[] { }, contentType, true);
}
return GetHttpResult(ms, contentType, true);
}
}
}
public static string GetRealContentType(string contentType)
{
return contentType == null
? null
: contentType.Split(';')[0].ToLower().Trim();
}
private string SerializeToXmlString(object from)
{
using (var ms = new MemoryStream())
{
var xwSettings = new XmlWriterSettings();
xwSettings.Encoding = new UTF8Encoding(false);
xwSettings.OmitXmlDeclaration = false;
using (var xw = XmlWriter.Create(ms, xwSettings))
{
var serializer = new DataContractSerializer(from.GetType());
serializer.WriteObject(xw, from);
xw.Flush();
ms.Seek(0, SeekOrigin.Begin);
var reader = new StreamReader(ms);
return reader.ReadToEnd();
}
}
}
/// <summary>
/// Gets the optimized result using cache.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="requestContext">The request context.</param>
/// <param name="cacheKey">The cache key.</param>
/// <param name="lastDateModified">The last date modified.</param>
/// <param name="cacheDuration">Duration of the cache.</param>
/// <param name="factoryFn">The factory fn.</param>
/// <param name="responseHeaders">The response headers.</param>
/// <returns>System.Object.</returns>
/// <exception cref="System.ArgumentNullException">cacheKey
/// or
/// factoryFn</exception>
public object GetOptimizedResultUsingCache<T>(IRequest requestContext, Guid cacheKey, DateTime? lastDateModified, TimeSpan? cacheDuration, Func<T> factoryFn, IDictionary<string, string> responseHeaders = null)
where T : class
{
if (cacheKey == Guid.Empty)
{
throw new ArgumentNullException("cacheKey");
}
if (factoryFn == null)
{
throw new ArgumentNullException("factoryFn");
}
var key = cacheKey.ToString("N");
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
}
// See if the result is already cached in the browser
var result = GetCachedResult(requestContext, responseHeaders, cacheKey, key, lastDateModified, cacheDuration, null);
if (result != null)
{
return result;
}
return GetOptimizedResultInternal(requestContext, factoryFn(), false, responseHeaders);
}
/// <summary>
/// To the cached result.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="requestContext">The request context.</param>
/// <param name="cacheKey">The cache key.</param>
/// <param name="lastDateModified">The last date modified.</param>
/// <param name="cacheDuration">Duration of the cache.</param>
/// <param name="factoryFn">The factory fn.</param>
/// <param name="contentType">Type of the content.</param>
/// <param name="responseHeaders">The response headers.</param>
/// <returns>System.Object.</returns>
/// <exception cref="System.ArgumentNullException">cacheKey</exception>
public object GetCachedResult<T>(IRequest requestContext, Guid cacheKey, DateTime? lastDateModified, TimeSpan? cacheDuration, Func<T> factoryFn, string contentType, IDictionary<string, string> responseHeaders = null)
where T : class
{
if (cacheKey == Guid.Empty)
{
throw new ArgumentNullException("cacheKey");
}
if (factoryFn == null)
{
throw new ArgumentNullException("factoryFn");
}
var key = cacheKey.ToString("N");
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
}
// See if the result is already cached in the browser
var result = GetCachedResult(requestContext, responseHeaders, cacheKey, key, lastDateModified, cacheDuration, contentType);
if (result != null)
{
return result;
}
result = factoryFn();
// Apply caching headers
var hasHeaders = result as IHasHeaders;
if (hasHeaders != null)
{
AddResponseHeaders(hasHeaders, responseHeaders);
return hasHeaders;
}
return GetHttpResult(result, contentType, false, responseHeaders);
}
/// <summary>
/// Pres the process optimized result.
/// </summary>
private object GetCachedResult(IRequest requestContext, IDictionary<string, string> responseHeaders, Guid cacheKey, string cacheKeyString, DateTime? lastDateModified, TimeSpan? cacheDuration, string contentType)
{
responseHeaders["ETag"] = string.Format("\"{0}\"", cacheKeyString);
var noCache = (requestContext.Headers.Get("Cache-Control") ?? string.Empty).IndexOf("no-cache", StringComparison.OrdinalIgnoreCase) != -1;
if (!noCache)
{
if (IsNotModified(requestContext, cacheKey, lastDateModified, cacheDuration))
{
AddAgeHeader(responseHeaders, lastDateModified);
AddExpiresHeader(responseHeaders, cacheKeyString, cacheDuration);
var result = new HttpResult(new byte[] { }, contentType ?? "text/html", HttpStatusCode.NotModified);
AddResponseHeaders(result, responseHeaders);
return result;
}
}
AddCachingHeaders(responseHeaders, cacheKeyString, lastDateModified, cacheDuration);
return null;
}
public Task<object> GetStaticFileResult(IRequest requestContext,
string path,
FileShareMode fileShare = FileShareMode.Read)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path");
}
return GetStaticFileResult(requestContext, new StaticFileResultOptions
{
Path = path,
FileShare = fileShare
});
}
public Task<object> GetStaticFileResult(IRequest requestContext,
StaticFileResultOptions options)
{
var path = options.Path;
var fileShare = options.FileShare;
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path");
}
if (fileShare != FileShareMode.Read && fileShare != FileShareMode.ReadWrite)
{
throw new ArgumentException("FileShare must be either Read or ReadWrite");
}
if (string.IsNullOrWhiteSpace(options.ContentType))
{
options.ContentType = MimeTypes.GetMimeType(path);
}
if (!options.DateLastModified.HasValue)
{
options.DateLastModified = _fileSystem.GetLastWriteTimeUtc(path);
}
var cacheKey = path + options.DateLastModified.Value.Ticks;
options.CacheKey = cacheKey.GetMD5();
options.ContentFactory = () => Task.FromResult(GetFileStream(path, fileShare));
options.ResponseHeaders = options.ResponseHeaders ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
return GetStaticResult(requestContext, options);
}
/// <summary>
/// Gets the file stream.
/// </summary>
/// <param name="path">The path.</param>
/// <param name="fileShare">The file share.</param>
/// <returns>Stream.</returns>
private Stream GetFileStream(string path, FileShareMode fileShare)
{
return _fileSystem.GetFileStream(path, FileOpenMode.Open, FileAccessMode.Read, fileShare);
}
public Task<object> GetStaticResult(IRequest requestContext,
Guid cacheKey,
DateTime? lastDateModified,
TimeSpan? cacheDuration,
string contentType,
Func<Task<Stream>> factoryFn,
IDictionary<string, string> responseHeaders = null,
bool isHeadRequest = false)
{
return GetStaticResult(requestContext, new StaticResultOptions
{
CacheDuration = cacheDuration,
CacheKey = cacheKey,
ContentFactory = factoryFn,
ContentType = contentType,
DateLastModified = lastDateModified,
IsHeadRequest = isHeadRequest,
ResponseHeaders = responseHeaders
});
}
public async Task<object> GetStaticResult(IRequest requestContext, StaticResultOptions options)
{
var cacheKey = options.CacheKey;
options.ResponseHeaders = options.ResponseHeaders ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
var contentType = options.ContentType;
if (cacheKey == Guid.Empty)
{
throw new ArgumentNullException("cacheKey");
}
var key = cacheKey.ToString("N");
// See if the result is already cached in the browser
var result = GetCachedResult(requestContext, options.ResponseHeaders, cacheKey, key, options.DateLastModified, options.CacheDuration, contentType);
if (result != null)
{
return result;
}
// TODO: We don't really need the option value
var isHeadRequest = options.IsHeadRequest || string.Equals(requestContext.Verb, "HEAD", StringComparison.OrdinalIgnoreCase);
var factoryFn = options.ContentFactory;
var responseHeaders = options.ResponseHeaders;
//var requestedCompressionType = GetCompressionType(requestContext);
var rangeHeader = requestContext.Headers.Get("Range");
if (!isHeadRequest && !string.IsNullOrWhiteSpace(options.Path))
{
var hasHeaders = new FileWriter(options.Path, contentType, rangeHeader, _logger, _fileSystem)
{
OnComplete = options.OnComplete,
OnError = options.OnError,
FileShare = options.FileShare
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
return hasHeaders;
}
if (!string.IsNullOrWhiteSpace(rangeHeader))
{
var stream = await factoryFn().ConfigureAwait(false);
var hasHeaders = new RangeRequestWriter(rangeHeader, stream, contentType, isHeadRequest, _logger)
{
OnComplete = options.OnComplete
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
return hasHeaders;
}
else
{
var stream = await factoryFn().ConfigureAwait(false);
responseHeaders["Content-Length"] = stream.Length.ToString(UsCulture);
if (isHeadRequest)
{
stream.Dispose();
return GetHttpResult(new byte[] { }, contentType, true, responseHeaders);
}
var hasHeaders = new StreamWriter(stream, contentType, _logger)
{
OnComplete = options.OnComplete,
OnError = options.OnError
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
return hasHeaders;
}
}
/// <summary>
/// The us culture
/// </summary>
private static readonly CultureInfo UsCulture = new CultureInfo("en-US");
/// <summary>
/// Adds the caching responseHeaders.
/// </summary>
private void AddCachingHeaders(IDictionary<string, string> responseHeaders, string cacheKey, DateTime? lastDateModified, TimeSpan? cacheDuration)
{
// Don't specify both last modified and Etag, unless caching unconditionally. They are redundant
// https://developers.google.com/speed/docs/best-practices/caching#LeverageBrowserCaching
if (lastDateModified.HasValue && (string.IsNullOrEmpty(cacheKey) || cacheDuration.HasValue))
{
AddAgeHeader(responseHeaders, lastDateModified);
responseHeaders["Last-Modified"] = lastDateModified.Value.ToString("r");
}
if (cacheDuration.HasValue)
{
responseHeaders["Cache-Control"] = "public, max-age=" + Convert.ToInt32(cacheDuration.Value.TotalSeconds);
}
else if (!string.IsNullOrEmpty(cacheKey))
{
responseHeaders["Cache-Control"] = "public";
}
else
{
responseHeaders["Cache-Control"] = "no-cache, no-store, must-revalidate";
responseHeaders["pragma"] = "no-cache, no-store, must-revalidate";
}
AddExpiresHeader(responseHeaders, cacheKey, cacheDuration);
}
/// <summary>
/// Adds the expires header.
/// </summary>
private void AddExpiresHeader(IDictionary<string, string> responseHeaders, string cacheKey, TimeSpan? cacheDuration)
{
if (cacheDuration.HasValue)
{
responseHeaders["Expires"] = DateTime.UtcNow.Add(cacheDuration.Value).ToString("r");
}
else if (string.IsNullOrEmpty(cacheKey))
{
responseHeaders["Expires"] = "-1";
}
}
/// <summary>
/// Adds the age header.
/// </summary>
/// <param name="responseHeaders">The responseHeaders.</param>
/// <param name="lastDateModified">The last date modified.</param>
private void AddAgeHeader(IDictionary<string, string> responseHeaders, DateTime? lastDateModified)
{
if (lastDateModified.HasValue)
{
responseHeaders["Age"] = Convert.ToInt64((DateTime.UtcNow - lastDateModified.Value).TotalSeconds).ToString(CultureInfo.InvariantCulture);
}
}
/// <summary>
/// Determines whether [is not modified] [the specified cache key].
/// </summary>
/// <param name="requestContext">The request context.</param>
/// <param name="cacheKey">The cache key.</param>
/// <param name="lastDateModified">The last date modified.</param>
/// <param name="cacheDuration">Duration of the cache.</param>
/// <returns><c>true</c> if [is not modified] [the specified cache key]; otherwise, <c>false</c>.</returns>
private bool IsNotModified(IRequest requestContext, Guid? cacheKey, DateTime? lastDateModified, TimeSpan? cacheDuration)
{
//var isNotModified = true;
var ifModifiedSinceHeader = requestContext.Headers.Get("If-Modified-Since");
if (!string.IsNullOrEmpty(ifModifiedSinceHeader))
{
DateTime ifModifiedSince;
if (DateTime.TryParse(ifModifiedSinceHeader, out ifModifiedSince))
{
if (IsNotModified(ifModifiedSince.ToUniversalTime(), cacheDuration, lastDateModified))
{
return true;
}
}
}
var ifNoneMatchHeader = requestContext.Headers.Get("If-None-Match");
// Validate If-None-Match
if ((cacheKey.HasValue || !string.IsNullOrEmpty(ifNoneMatchHeader)))
{
Guid ifNoneMatch;
ifNoneMatchHeader = (ifNoneMatchHeader ?? string.Empty).Trim('\"');
if (Guid.TryParse(ifNoneMatchHeader, out ifNoneMatch))
{
if (cacheKey.HasValue && cacheKey.Value == ifNoneMatch)
{
return true;
}
}
}
return false;
}
/// <summary>
/// Determines whether [is not modified] [the specified if modified since].
/// </summary>
/// <param name="ifModifiedSince">If modified since.</param>
/// <param name="cacheDuration">Duration of the cache.</param>
/// <param name="dateModified">The date modified.</param>
/// <returns><c>true</c> if [is not modified] [the specified if modified since]; otherwise, <c>false</c>.</returns>
private bool IsNotModified(DateTime ifModifiedSince, TimeSpan? cacheDuration, DateTime? dateModified)
{
if (dateModified.HasValue)
{
var lastModified = NormalizeDateForComparison(dateModified.Value);
ifModifiedSince = NormalizeDateForComparison(ifModifiedSince);
return lastModified <= ifModifiedSince;
}
if (cacheDuration.HasValue)
{
var cacheExpirationDate = ifModifiedSince.Add(cacheDuration.Value);
if (DateTime.UtcNow < cacheExpirationDate)
{
return true;
}
}
return false;
}
/// <summary>
/// When the browser sends the IfModifiedDate, it's precision is limited to seconds, so this will account for that
/// </summary>
/// <param name="date">The date.</param>
/// <returns>DateTime.</returns>
private DateTime NormalizeDateForComparison(DateTime date)
{
return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, date.Kind);
}
/// <summary>
/// Adds the response headers.
/// </summary>
/// <param name="hasHeaders">The has options.</param>
/// <param name="responseHeaders">The response headers.</param>
private void AddResponseHeaders(IHasHeaders hasHeaders, IEnumerable<KeyValuePair<string, string>> responseHeaders)
{
foreach (var item in responseHeaders)
{
hasHeaders.Headers[item.Key] = item.Value;
}
}
}
}