You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
jellyfin/MediaBrowser.Common/Net/Handlers/BaseHandler.cs

442 lines
15 KiB

using MediaBrowser.Common.Logging;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
namespace MediaBrowser.Common.Net.Handlers
{
public abstract class BaseHandler
{
public abstract bool HandlesRequest(HttpListenerRequest request);
private Stream CompressedStream { get; set; }
public virtual bool? UseChunkedEncoding
{
get
{
return null;
}
}
private bool _totalContentLengthDiscovered;
private long? _totalContentLength;
public long? TotalContentLength
{
get
{
if (!_totalContentLengthDiscovered)
{
_totalContentLength = GetTotalContentLength();
_totalContentLengthDiscovered = true;
}
return _totalContentLength;
}
}
protected virtual bool SupportsByteRangeRequests
{
get
{
return false;
}
}
/// <summary>
/// The original HttpListenerContext
/// </summary>
protected HttpListenerContext HttpListenerContext { get; set; }
/// <summary>
/// The original QueryString
/// </summary>
protected NameValueCollection QueryString
{
get
{
return HttpListenerContext.Request.QueryString;
}
}
private List<KeyValuePair<long, long?>> _requestedRanges;
protected IEnumerable<KeyValuePair<long, long?>> RequestedRanges
{
get
{
if (_requestedRanges == null)
{
_requestedRanges = new List<KeyValuePair<long, long?>>();
if (IsRangeRequest)
{
// Example: bytes=0-,32-63
string[] ranges = HttpListenerContext.Request.Headers["Range"].Split('=')[1].Split(',');
foreach (string range in ranges)
{
string[] vals = range.Split('-');
long start = 0;
long? end = null;
if (!string.IsNullOrEmpty(vals[0]))
{
start = long.Parse(vals[0]);
}
if (!string.IsNullOrEmpty(vals[1]))
{
end = long.Parse(vals[1]);
}
_requestedRanges.Add(new KeyValuePair<long, long?>(start, end));
}
}
}
return _requestedRanges;
}
}
protected bool IsRangeRequest
{
get
{
return HttpListenerContext.Request.Headers.AllKeys.Contains("Range");
}
}
/// <summary>
/// Gets the MIME type to include in the response headers
/// </summary>
public abstract Task<string> GetContentType();
/// <summary>
/// Gets the status code to include in the response headers
/// </summary>
protected int StatusCode { get; set; }
/// <summary>
/// Gets the cache duration to include in the response headers
/// </summary>
public virtual TimeSpan CacheDuration
{
get
{
return TimeSpan.FromTicks(0);
}
}
public virtual bool ShouldCompressResponse(string contentType)
{
return true;
}
private bool ClientSupportsCompression
{
get
{
string enc = HttpListenerContext.Request.Headers["Accept-Encoding"] ?? string.Empty;
return enc.IndexOf("deflate", StringComparison.OrdinalIgnoreCase) != -1 || enc.IndexOf("gzip", StringComparison.OrdinalIgnoreCase) != -1;
}
}
private string CompressionMethod
{
get
{
string enc = HttpListenerContext.Request.Headers["Accept-Encoding"] ?? string.Empty;
if (enc.IndexOf("deflate", StringComparison.OrdinalIgnoreCase) != -1)
{
return "deflate";
}
if (enc.IndexOf("gzip", StringComparison.OrdinalIgnoreCase) != -1)
{
return "gzip";
}
return null;
}
}
public virtual async Task ProcessRequest(HttpListenerContext ctx)
{
HttpListenerContext = ctx;
string url = ctx.Request.Url.ToString();
Logger.LogInfo("Http Server received request at: " + url);
Logger.LogInfo("Http Headers: " + string.Join(",", ctx.Request.Headers.AllKeys.Select(k => k + "=" + ctx.Request.Headers[k])));
ctx.Response.AddHeader("Access-Control-Allow-Origin", "*");
ctx.Response.KeepAlive = true;
try
{
if (SupportsByteRangeRequests && IsRangeRequest)
{
ctx.Response.Headers["Accept-Ranges"] = "bytes";
}
// Set the initial status code
// When serving a range request, we need to return status code 206 to indicate a partial response body
StatusCode = SupportsByteRangeRequests && IsRangeRequest ? 206 : 200;
ctx.Response.ContentType = await GetContentType().ConfigureAwait(false);
TimeSpan cacheDuration = CacheDuration;
DateTime? lastDateModified = await GetLastDateModified().ConfigureAwait(false);
if (ctx.Request.Headers.AllKeys.Contains("If-Modified-Since"))
{
DateTime ifModifiedSince;
if (DateTime.TryParse(ctx.Request.Headers["If-Modified-Since"], out ifModifiedSince))
{
// If the cache hasn't expired yet just return a 304
if (IsCacheValid(ifModifiedSince.ToUniversalTime(), cacheDuration, lastDateModified))
{
StatusCode = 304;
}
}
}
await PrepareResponse().ConfigureAwait(false);
Logger.LogInfo("Responding with status code {0} for url {1}", StatusCode, url);
if (IsResponseValid)
{
bool compressResponse = ShouldCompressResponse(ctx.Response.ContentType) && ClientSupportsCompression;
await ProcessUncachedRequest(ctx, compressResponse, cacheDuration, lastDateModified).ConfigureAwait(false);
}
else
{
ctx.Response.StatusCode = StatusCode;
ctx.Response.SendChunked = false;
}
}
catch (Exception ex)
{
// It might be too late if some response data has already been transmitted, but try to set this
ctx.Response.StatusCode = 500;
Logger.LogException(ex);
}
finally
{
DisposeResponseStream();
}
}
private async Task ProcessUncachedRequest(HttpListenerContext ctx, bool compressResponse, TimeSpan cacheDuration, DateTime? lastDateModified)
{
long? totalContentLength = TotalContentLength;
// By default, use chunked encoding if we don't know the content length
bool useChunkedEncoding = UseChunkedEncoding == null ? (totalContentLength == null) : UseChunkedEncoding.Value;
// Don't force this to true. HttpListener will default it to true if supported by the client.
if (!useChunkedEncoding)
{
ctx.Response.SendChunked = false;
}
// Set the content length, if we know it
if (totalContentLength.HasValue)
{
ctx.Response.ContentLength64 = totalContentLength.Value;
}
// Add the compression header
if (compressResponse)
{
ctx.Response.AddHeader("Content-Encoding", CompressionMethod);
}
// Add caching headers
if (cacheDuration.Ticks > 0)
{
CacheResponse(ctx.Response, cacheDuration, lastDateModified);
}
// Set the status code
ctx.Response.StatusCode = StatusCode;
if (IsResponseValid)
{
// Finally, write the response data
Stream outputStream = ctx.Response.OutputStream;
if (compressResponse)
{
if (CompressionMethod.Equals("deflate", StringComparison.OrdinalIgnoreCase))
{
CompressedStream = new DeflateStream(outputStream, CompressionLevel.Fastest, false);
}
else
{
CompressedStream = new GZipStream(outputStream, CompressionLevel.Fastest, false);
}
outputStream = CompressedStream;
}
await WriteResponseToOutputStream(outputStream).ConfigureAwait(false);
}
else
{
ctx.Response.SendChunked = false;
}
}
private void CacheResponse(HttpListenerResponse response, TimeSpan duration, DateTime? dateModified)
{
DateTime now = DateTime.UtcNow;
DateTime lastModified = dateModified ?? now;
response.Headers[HttpResponseHeader.CacheControl] = "public, max-age=" + Convert.ToInt32(duration.TotalSeconds);
response.Headers[HttpResponseHeader.Expires] = now.Add(duration).ToString("r");
response.Headers[HttpResponseHeader.LastModified] = lastModified.ToString("r");
}
/// <summary>
/// Gives subclasses a chance to do any prep work, and also to validate data and set an error status code, if needed
/// </summary>
protected virtual Task PrepareResponse()
{
return Task.FromResult<object>(null);
}
protected abstract Task WriteResponseToOutputStream(Stream stream);
protected virtual void DisposeResponseStream()
{
if (CompressedStream != null)
{
CompressedStream.Dispose();
}
HttpListenerContext.Response.OutputStream.Dispose();
}
private bool IsCacheValid(DateTime ifModifiedSince, TimeSpan cacheDuration, DateTime? dateModified)
{
if (dateModified.HasValue)
{
DateTime lastModified = NormalizeDateForComparison(dateModified.Value);
ifModifiedSince = NormalizeDateForComparison(ifModifiedSince);
return lastModified <= ifModifiedSince;
}
DateTime cacheExpirationDate = ifModifiedSince.Add(cacheDuration);
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>
private DateTime NormalizeDateForComparison(DateTime date)
{
return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, date.Kind);
}
protected virtual long? GetTotalContentLength()
{
return null;
}
protected virtual Task<DateTime?> GetLastDateModified()
{
DateTime? value = null;
return Task.FromResult(value);
}
private bool IsResponseValid
{
get
{
return StatusCode == 200 || StatusCode == 206;
}
}
private Hashtable _formValues;
/// <summary>
/// Gets a value from form POST data
/// </summary>
protected async Task<string> GetFormValue(string name)
{
if (_formValues == null)
{
_formValues = await GetFormValues(HttpListenerContext.Request).ConfigureAwait(false);
}
if (_formValues.ContainsKey(name))
{
return _formValues[name].ToString();
}
return null;
}
/// <summary>
/// Extracts form POST data from a request
/// </summary>
private async Task<Hashtable> GetFormValues(HttpListenerRequest request)
{
var formVars = new Hashtable();
if (request.HasEntityBody)
{
if (request.ContentType.IndexOf("application/x-www-form-urlencoded", StringComparison.OrdinalIgnoreCase) != -1)
{
using (Stream requestBody = request.InputStream)
{
using (var reader = new StreamReader(requestBody, request.ContentEncoding))
{
string s = await reader.ReadToEndAsync().ConfigureAwait(false);
string[] pairs = s.Split('&');
for (int x = 0; x < pairs.Length; x++)
{
string pair = pairs[x];
int index = pair.IndexOf('=');
if (index != -1)
{
string name = pair.Substring(0, index);
string value = pair.Substring(index + 1);
formVars.Add(name, value);
}
}
}
}
}
}
return formVars;
}
}
}