using MediaBrowser.Common.Extensions; using MediaBrowser.Controller.Net; using Microsoft.Extensions.Logging; using MediaBrowser.Model.Serialization; 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.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 { /// /// Class HttpResultFactory /// public class HttpResultFactory : IHttpResultFactory { /// /// The _logger /// private readonly ILogger _logger; private readonly IFileSystem _fileSystem; private readonly IJsonSerializer _jsonSerializer; private IBrotliCompressor _brotliCompressor; /// /// Initializes a new instance of the class. /// public HttpResultFactory(ILoggerFactory loggerfactory, IFileSystem fileSystem, IJsonSerializer jsonSerializer, IBrotliCompressor brotliCompressor) { _fileSystem = fileSystem; _jsonSerializer = jsonSerializer; _brotliCompressor = brotliCompressor; _logger = loggerfactory.CreateLogger("HttpResultFactory"); } /// /// Gets the result. /// /// The content. /// Type of the content. /// The response headers. /// System.Object. public object GetResult(IRequest requestContext, byte[] content, string contentType, IDictionary responseHeaders = null) { return GetHttpResult(requestContext, content, contentType, true, responseHeaders); } public object GetResult(string content, string contentType, IDictionary responseHeaders = null) { return GetHttpResult(null, content, contentType, true, responseHeaders); } public object GetResult(IRequest requestContext, Stream content, string contentType, IDictionary responseHeaders = null) { return GetHttpResult(requestContext, content, contentType, true, responseHeaders); } public object GetResult(IRequest requestContext, string content, string contentType, IDictionary responseHeaders = null) { return GetHttpResult(requestContext, content, contentType, true, responseHeaders); } public object GetRedirectResult(string url) { var responseHeaders = new Dictionary(); responseHeaders["Location"] = url; var result = new HttpResult(Array.Empty(), "text/plain", HttpStatusCode.Redirect); AddResponseHeaders(result, responseHeaders); return result; } /// /// Gets the HTTP result. /// private IHasHeaders GetHttpResult(IRequest requestContext, Stream content, string contentType, bool addCachePrevention, IDictionary responseHeaders = null) { var result = new StreamWriter(content, contentType, _logger); if (responseHeaders == null) { responseHeaders = new Dictionary(); } string expires; if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out expires)) { responseHeaders["Expires"] = "-1"; } AddResponseHeaders(result, responseHeaders); return result; } /// /// Gets the HTTP result. /// private IHasHeaders GetHttpResult(IRequest requestContext, byte[] content, string contentType, bool addCachePrevention, IDictionary 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(); } result = new StreamWriter(content, contentType, contentLength, _logger); } else { result = GetCompressedResult(content, compressionType, responseHeaders, isHeadRequest, contentType); } if (responseHeaders == null) { responseHeaders = new Dictionary(); } string expires; if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out expires)) { responseHeaders["Expires"] = "-1"; } AddResponseHeaders(result, responseHeaders); return result; } /// /// Gets the HTTP result. /// private IHasHeaders GetHttpResult(IRequest requestContext, string content, string contentType, bool addCachePrevention, IDictionary 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(); } result = new StreamWriter(bytes, contentType, contentLength, _logger); } else { result = GetCompressedResult(bytes, compressionType, responseHeaders, isHeadRequest, contentType); } if (responseHeaders == null) { responseHeaders = new Dictionary(); } string expires; if (addCachePrevention && !responseHeaders.TryGetValue("Expires", out expires)) { responseHeaders["Expires"] = "-1"; } AddResponseHeaders(result, responseHeaders); return result; } /// /// Gets the optimized result. /// /// public object GetResult(IRequest requestContext, T result, IDictionary responseHeaders = null) where T : class { if (result == null) { throw new ArgumentNullException(nameof(result)); } if (responseHeaders == null) { responseHeaders = new Dictionary(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; } /// /// Returns the optimized result for the IRequestContext. /// Does not use or store results in any cache. /// /// /// /// public object ToOptimizedResult(IRequest request, T dto) { return ToOptimizedResultInternal(request, dto); } private object ToOptimizedResultInternal(IRequest request, T dto, IDictionary 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(), contentType, true, responseHeaders); } } return GetHttpResult(request, ms, contentType, true, responseHeaders); } private IHasHeaders GetCompressedResult(byte[] content, string requestedCompressionType, IDictionary responseHeaders, bool isHeadRequest, string contentType) { if (responseHeaders == null) { responseHeaders = new Dictionary(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(), 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].ToLower().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); var reader = new StreamReader(ms); return reader.ReadToEnd(); } } } /// /// Pres the process optimized result. /// private object GetCachedResult(IRequest requestContext, IDictionary 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(Array.Empty(), contentType ?? "text/html", HttpStatusCode.NotModified); AddResponseHeaders(result, responseHeaders); return result; } } AddCachingHeaders(responseHeaders, cacheKeyString, lastDateModified, cacheDuration); return null; } public Task 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 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(StringComparer.OrdinalIgnoreCase); return GetStaticResult(requestContext, options); } /// /// Gets the file stream. /// /// The path. /// The file share. /// Stream. private Stream GetFileStream(string path, FileShareMode fileShare) { return _fileSystem.GetFileStream(path, FileOpenMode.Open, FileAccessMode.Read, fileShare); } public Task GetStaticResult(IRequest requestContext, Guid cacheKey, DateTime? lastDateModified, TimeSpan? cacheDuration, string contentType, Func> factoryFn, IDictionary 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 GetStaticResult(IRequest requestContext, StaticResultOptions options) { var cacheKey = options.CacheKey; options.ResponseHeaders = options.ResponseHeaders ?? new Dictionary(StringComparer.OrdinalIgnoreCase); var contentType = options.ContentType; 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 requestedCompressionType = GetCompressionType(requestContext); 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); return hasHeaders; } var stream = await factoryFn().ConfigureAwait(false); 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); return hasHeaders; } else { if (totalContentLength.HasValue) { responseHeaders["Content-Length"] = totalContentLength.Value.ToString(UsCulture); } if (isHeadRequest) { using (stream) { return GetHttpResult(requestContext, Array.Empty(), contentType, true, responseHeaders); } } var hasHeaders = new StreamWriter(stream, contentType, _logger) { OnComplete = options.OnComplete, OnError = options.OnError }; AddResponseHeaders(hasHeaders, options.ResponseHeaders); return hasHeaders; } } /// /// The us culture /// private static readonly CultureInfo UsCulture = new CultureInfo("en-US"); /// /// Adds the caching responseHeaders. /// private void AddCachingHeaders(IDictionary 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); } /// /// Adds the expires header. /// private static void AddExpiresHeader(IDictionary 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"; } } /// /// Adds the age header. /// /// The responseHeaders. /// The last date modified. private static void AddAgeHeader(IDictionary responseHeaders, DateTime? lastDateModified) { if (lastDateModified.HasValue) { responseHeaders["Age"] = Convert.ToInt64((DateTime.UtcNow - lastDateModified.Value).TotalSeconds).ToString(CultureInfo.InvariantCulture); } } /// /// Determines whether [is not modified] [the specified cache key]. /// /// The request context. /// The cache key. /// The last date modified. /// Duration of the cache. /// true if [is not modified] [the specified cache key]; otherwise, false. 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"); var hasCacheKey = !cacheKey.Equals(Guid.Empty); // Validate If-None-Match if ((hasCacheKey || !string.IsNullOrEmpty(ifNoneMatchHeader))) { Guid ifNoneMatch; ifNoneMatchHeader = (ifNoneMatchHeader ?? string.Empty).Trim('\"'); if (Guid.TryParse(ifNoneMatchHeader, out ifNoneMatch)) { if (hasCacheKey && cacheKey.Equals(ifNoneMatch)) { return true; } } } return false; } /// /// Determines whether [is not modified] [the specified if modified since]. /// /// If modified since. /// Duration of the cache. /// The date modified. /// true if [is not modified] [the specified if modified since]; otherwise, false. 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; } /// /// When the browser sends the IfModifiedDate, it's precision is limited to seconds, so this will account for that /// /// The date. /// DateTime. private static DateTime NormalizeDateForComparison(DateTime date) { return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, date.Kind); } /// /// Adds the response headers. /// /// The has options. /// The response headers. private static void AddResponseHeaders(IHasHeaders hasHeaders, IEnumerable> responseHeaders) { foreach (var item in responseHeaders) { hasHeaders.Headers[item.Key] = item.Value; } } } public interface IBrotliCompressor { byte[] Compress(byte[] content); } }