jellyfin/Emby.Server.Implementations/HttpServer/HttpResultFactory.cs
2019-01-27 12:12:44 +01:00

777 lines
28 KiB
C#

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Net;
using System.Runtime.Serialization;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using Emby.Server.Implementations.Services;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Controller.Net;
using MediaBrowser.Model.IO;
using MediaBrowser.Model.Serialization;
using MediaBrowser.Model.Services;
using Microsoft.Extensions.Logging;
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 IBrotliCompressor _brotliCompressor;
/// <summary>
/// Initializes a new instance of the <see cref="HttpResultFactory" /> class.
/// </summary>
public HttpResultFactory(ILoggerFactory loggerfactory, IFileSystem fileSystem, IJsonSerializer jsonSerializer, IBrotliCompressor brotliCompressor)
{
_fileSystem = fileSystem;
_jsonSerializer = jsonSerializer;
_brotliCompressor = brotliCompressor;
_logger = loggerfactory.CreateLogger("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(IRequest requestContext, byte[] content, string contentType, IDictionary<string, string> responseHeaders = null)
{
return GetHttpResult(requestContext, content, contentType, true, responseHeaders);
}
public object GetResult(string content, string contentType, IDictionary<string, string> responseHeaders = null)
{
return GetHttpResult(null, content, contentType, true, responseHeaders);
}
public object GetResult(IRequest requestContext, Stream content, string contentType, IDictionary<string, string> responseHeaders = null)
{
return GetHttpResult(requestContext, content, contentType, true, responseHeaders);
}
public object GetResult(IRequest requestContext, string content, string contentType, IDictionary<string, string> responseHeaders = null)
{
return GetHttpResult(requestContext, content, contentType, true, responseHeaders);
}
public object GetRedirectResult(string url)
{
var responseHeaders = new Dictionary<string, string>();
responseHeaders["Location"] = url;
var result = new HttpResult(Array.Empty<byte>(), "text/plain", HttpStatusCode.Redirect);
AddResponseHeaders(result, responseHeaders);
return result;
}
/// <summary>
/// Gets the HTTP result.
/// </summary>
private IHasHeaders GetHttpResult(IRequest requestContext, Stream content, string contentType, bool addCachePrevention, IDictionary<string, string> responseHeaders = null)
{
var result = new StreamWriter(content, contentType, _logger);
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>();
}
if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out string expires))
{
responseHeaders["Expires"] = "-1";
}
AddResponseHeaders(result, responseHeaders);
return result;
}
/// <summary>
/// Gets the HTTP result.
/// </summary>
private IHasHeaders GetHttpResult(IRequest requestContext, byte[] content, string contentType, bool addCachePrevention, IDictionary<string, string> responseHeaders = null)
{
string compressionType = null;
bool isHeadRequest = false;
if (requestContext != null)
{
compressionType = GetCompressionType(requestContext, content, contentType);
isHeadRequest = string.Equals(requestContext.Verb, "head", StringComparison.OrdinalIgnoreCase);
}
IHasHeaders result;
if (string.IsNullOrEmpty(compressionType))
{
var contentLength = content.Length;
if (isHeadRequest)
{
content = Array.Empty<byte>();
}
result = new StreamWriter(content, contentType, contentLength, _logger);
}
else
{
result = GetCompressedResult(content, compressionType, responseHeaders, isHeadRequest, contentType);
}
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>();
}
if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out string expires))
{
responseHeaders["Expires"] = "-1";
}
AddResponseHeaders(result, responseHeaders);
return result;
}
/// <summary>
/// Gets the HTTP result.
/// </summary>
private IHasHeaders GetHttpResult(IRequest requestContext, string content, string contentType, bool addCachePrevention, IDictionary<string, string> responseHeaders = null)
{
IHasHeaders result;
var bytes = Encoding.UTF8.GetBytes(content);
var compressionType = requestContext == null ? null : GetCompressionType(requestContext, bytes, contentType);
var isHeadRequest = requestContext == null ? false : string.Equals(requestContext.Verb, "head", StringComparison.OrdinalIgnoreCase);
if (string.IsNullOrEmpty(compressionType))
{
var contentLength = bytes.Length;
if (isHeadRequest)
{
bytes = Array.Empty<byte>();
}
result = new StreamWriter(bytes, contentType, contentLength, _logger);
}
else
{
result = GetCompressedResult(bytes, compressionType, responseHeaders, isHeadRequest, contentType);
}
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>();
}
if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out string expires))
{
responseHeaders["Expires"] = "-1";
}
AddResponseHeaders(result, responseHeaders);
return result;
}
/// <summary>
/// Gets the optimized result.
/// </summary>
/// <typeparam name="T"></typeparam>
public object GetResult<T>(IRequest requestContext, T result, IDictionary<string, string> responseHeaders = null)
where T : class
{
if (result == null)
{
throw new ArgumentNullException(nameof(result));
}
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
}
responseHeaders["Expires"] = "-1";
return ToOptimizedResultInternal(requestContext, result, responseHeaders);
}
private string GetCompressionType(IRequest request, byte[] content, string responseContentType)
{
if (responseContentType == null)
{
return null;
}
// Per apple docs, hls manifests must be compressed
if (!responseContentType.StartsWith("text/", StringComparison.OrdinalIgnoreCase) &&
responseContentType.IndexOf("json", StringComparison.OrdinalIgnoreCase) == -1 &&
responseContentType.IndexOf("javascript", StringComparison.OrdinalIgnoreCase) == -1 &&
responseContentType.IndexOf("xml", StringComparison.OrdinalIgnoreCase) == -1 &&
responseContentType.IndexOf("application/x-mpegURL", StringComparison.OrdinalIgnoreCase) == -1)
{
return null;
}
if (content.Length < 1024)
{
return null;
}
return GetCompressionType(request);
}
private static string GetCompressionType(IRequest request)
{
var acceptEncoding = request.Headers["Accept-Encoding"];
if (acceptEncoding != null)
{
//if (_brotliCompressor != null && acceptEncoding.IndexOf("br", StringComparison.OrdinalIgnoreCase) != -1)
// return "br";
if (acceptEncoding.IndexOf("deflate", StringComparison.OrdinalIgnoreCase) != -1)
return "deflate";
if (acceptEncoding.IndexOf("gzip", StringComparison.OrdinalIgnoreCase) != -1)
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)
{
return ToOptimizedResultInternal(request, dto);
}
private object ToOptimizedResultInternal<T>(IRequest request, T dto, IDictionary<string, string> responseHeaders = null)
{
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 GetHttpResult(request, SerializeToXmlString(dto), contentType, false, responseHeaders);
case "application/json":
case "text/json":
return GetHttpResult(request, _jsonSerializer.SerializeToString(dto), contentType, false, responseHeaders);
default:
break;
}
var isHeadRequest = string.Equals(request.Verb, "head", StringComparison.OrdinalIgnoreCase);
var ms = new MemoryStream();
var writerFn = RequestHelper.GetResponseWriter(HttpListenerHost.Instance, contentType);
writerFn(dto, ms);
ms.Position = 0;
if (isHeadRequest)
{
using (ms)
{
return GetHttpResult(request, Array.Empty<byte>(), contentType, true, responseHeaders);
}
}
return GetHttpResult(request, ms, contentType, true, responseHeaders);
}
private IHasHeaders GetCompressedResult(byte[] content,
string requestedCompressionType,
IDictionary<string, string> responseHeaders,
bool isHeadRequest,
string contentType)
{
if (responseHeaders == null)
{
responseHeaders = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
}
content = Compress(content, requestedCompressionType);
responseHeaders["Content-Encoding"] = requestedCompressionType;
responseHeaders["Vary"] = "Accept-Encoding";
var contentLength = content.Length;
if (isHeadRequest)
{
var result = new StreamWriter(Array.Empty<byte>(), contentType, contentLength, _logger);
AddResponseHeaders(result, responseHeaders);
return result;
}
else
{
var result = new StreamWriter(content, contentType, contentLength, _logger);
AddResponseHeaders(result, responseHeaders);
return result;
}
}
private byte[] Compress(byte[] bytes, string compressionType)
{
if (string.Equals(compressionType, "br", StringComparison.OrdinalIgnoreCase))
return CompressBrotli(bytes);
if (string.Equals(compressionType, "deflate", StringComparison.OrdinalIgnoreCase))
return Deflate(bytes);
if (string.Equals(compressionType, "gzip", StringComparison.OrdinalIgnoreCase))
return GZip(bytes);
throw new NotSupportedException(compressionType);
}
private byte[] CompressBrotli(byte[] bytes)
{
return _brotliCompressor.Compress(bytes);
}
private static byte[] Deflate(byte[] bytes)
{
// In .NET FX incompat-ville, you can't access compressed bytes without closing DeflateStream
// Which means we must use MemoryStream since you have to use ToArray() on a closed Stream
using (var ms = new MemoryStream())
using (var zipStream = new DeflateStream(ms, CompressionMode.Compress))
{
zipStream.Write(bytes, 0, bytes.Length);
zipStream.Dispose();
return ms.ToArray();
}
}
private static byte[] GZip(byte[] buffer)
{
using (var ms = new MemoryStream())
using (var zipStream = new GZipStream(ms, CompressionMode.Compress))
{
zipStream.Write(buffer, 0, buffer.Length);
zipStream.Dispose();
return ms.ToArray();
}
}
public static string GetRealContentType(string contentType)
{
return contentType == null
? null
: contentType.Split(';')[0].ToLowerInvariant().Trim();
}
private static 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);
using (var reader = new StreamReader(ms))
{
return reader.ReadToEnd();
}
}
}
}
/// <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)
{
bool noCache = (requestContext.Headers.Get("Cache-Control") ?? string.Empty).IndexOf("no-cache", StringComparison.OrdinalIgnoreCase) != -1;
if (!noCache)
{
if (IsNotModified(requestContext, cacheKey))
{
AddAgeHeader(responseHeaders, lastDateModified);
AddExpiresHeader(responseHeaders, cacheKeyString, cacheDuration);
var result = new HttpResult(Array.Empty<byte>(), contentType ?? "text/html", HttpStatusCode.NotModified);
AddResponseHeaders(result, responseHeaders);
return result;
}
}
AddCachingHeaders(responseHeaders, cacheKeyString, cacheDuration);
return null;
}
public Task<object> GetStaticFileResult(IRequest requestContext,
string path,
FileShareMode fileShare = FileShareMode.Read)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(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(nameof(path));
}
if (fileShare != FileShareMode.Read && fileShare != FileShareMode.ReadWrite)
{
throw new ArgumentException("FileShare must be either Read or ReadWrite");
}
if (string.IsNullOrEmpty(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)
{
options.ResponseHeaders = options.ResponseHeaders ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
var contentType = options.ContentType;
var etag = requestContext.Headers.Get("If-None-Match");
var cacheKey = etag != null ? new Guid(etag.Trim('\"')) : Guid.Empty;
if (!cacheKey.Equals(Guid.Empty))
{
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 rangeHeader = requestContext.Headers.Get("Range");
if (!isHeadRequest && !string.IsNullOrEmpty(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);
// Generate an ETag based on identifying information - TODO read contents from filesystem instead?
var responseId = $"{hasHeaders.ContentType}{options.Path}{hasHeaders.TotalContentLength}";
var hashedId = MD5.Create().ComputeHash(Encoding.Default.GetBytes(responseId));
hasHeaders.Headers["ETag"] = new Guid(hashedId).ToString("N");
return hasHeaders;
}
var stream = await factoryFn().ConfigureAwait(false);
// Generate an etag based on stream content
var streamHash = MD5.Create().ComputeHash(stream);
var newEtag = new Guid(streamHash).ToString("N");
// reset position so the response can re-use it -- TODO is this ok?
stream.Position = 0;
var totalContentLength = options.ContentLength;
if (!totalContentLength.HasValue)
{
try
{
totalContentLength = stream.Length;
}
catch (NotSupportedException)
{
}
}
if (!string.IsNullOrWhiteSpace(rangeHeader) && totalContentLength.HasValue)
{
var hasHeaders = new RangeRequestWriter(rangeHeader, totalContentLength.Value, stream, contentType, isHeadRequest, _logger)
{
OnComplete = options.OnComplete
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
hasHeaders.Headers["ETag"] = newEtag;
return hasHeaders;
}
else
{
if (totalContentLength.HasValue)
{
responseHeaders["Content-Length"] = totalContentLength.Value.ToString(UsCulture);
}
if (isHeadRequest)
{
using (stream)
{
return GetHttpResult(requestContext, Array.Empty<byte>(), contentType, true, responseHeaders);
}
}
var hasHeaders = new StreamWriter(stream, contentType, _logger)
{
OnComplete = options.OnComplete,
OnError = options.OnError
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
hasHeaders.Headers["ETag"] = newEtag;
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, TimeSpan? cacheDuration)
{
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 static 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 static 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)
{
var ifNoneMatchHeader = requestContext.Headers.Get("If-None-Match");
bool hasCacheKey = !cacheKey.Equals(Guid.Empty);
// Validate If-None-Match
if (hasCacheKey && !string.IsNullOrEmpty(ifNoneMatchHeader))
{
if (Guid.TryParse(ifNoneMatchHeader, out var ifNoneMatch)
&& cacheKey.Equals(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 static 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 static void AddResponseHeaders(IHasHeaders hasHeaders, IEnumerable<KeyValuePair<string, string>> responseHeaders)
{
foreach (var item in responseHeaders)
{
hasHeaders.Headers[item.Key] = item.Value;
}
}
}
public interface IBrotliCompressor
{
byte[] Compress(byte[] content);
}
}