Drop ETag and use Last-Modified header (#890)

Drop ETag and use Last-Modified since performance is much better
This commit is contained in:
Claus Vium 2019-02-13 21:08:59 +01:00 committed by Bond-009
parent af8f86b3de
commit c720504e39
2 changed files with 24 additions and 80 deletions

View File

@ -422,18 +422,20 @@ namespace Emby.Server.Implementations.HttpServer
/// <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)
private object GetCachedResult(IRequest requestContext, IDictionary<string, string> responseHeaders, StaticResultOptions options)
{
bool noCache = (requestContext.Headers.Get("Cache-Control") ?? string.Empty).IndexOf("no-cache", StringComparison.OrdinalIgnoreCase) != -1;
AddCachingHeaders(responseHeaders, options.CacheDuration, noCache, options.DateLastModified);
if (!noCache)
{
if (IsNotModified(requestContext, cacheKey))
{
AddAgeHeader(responseHeaders, lastDateModified);
AddExpiresHeader(responseHeaders, cacheKeyString, cacheDuration);
DateTime.TryParse(requestContext.Headers.Get("If-Modified-Since"), out var ifModifiedSinceHeader);
var result = new HttpResult(Array.Empty<byte>(), contentType ?? "text/html", HttpStatusCode.NotModified);
if (IsNotModified(ifModifiedSinceHeader, options.CacheDuration, options.DateLastModified))
{
AddAgeHeader(responseHeaders, options.DateLastModified);
var result = new HttpResult(Array.Empty<byte>(), options.ContentType ?? "text/html", HttpStatusCode.NotModified);
AddResponseHeaders(result, responseHeaders);
@ -441,8 +443,6 @@ namespace Emby.Server.Implementations.HttpServer
}
}
AddCachingHeaders(responseHeaders, cacheKeyString, cacheDuration);
return null;
}
@ -487,9 +487,6 @@ namespace Emby.Server.Implementations.HttpServer
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);
@ -520,7 +517,6 @@ namespace Emby.Server.Implementations.HttpServer
return GetStaticResult(requestContext, new StaticResultOptions
{
CacheDuration = cacheDuration,
CacheKey = cacheKey,
ContentFactory = factoryFn,
ContentType = contentType,
DateLastModified = lastDateModified,
@ -534,14 +530,10 @@ namespace Emby.Server.Implementations.HttpServer
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))
if (!string.IsNullOrEmpty(requestContext.Headers.Get("If-Modified-Since")))
{
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);
var result = GetCachedResult(requestContext, options.ResponseHeaders, options);
if (result != null)
{
@ -553,6 +545,8 @@ namespace Emby.Server.Implementations.HttpServer
var isHeadRequest = options.IsHeadRequest || string.Equals(requestContext.Verb, "HEAD", StringComparison.OrdinalIgnoreCase);
var factoryFn = options.ContentFactory;
var responseHeaders = options.ResponseHeaders;
AddCachingHeaders(responseHeaders, options.CacheDuration, false, options.DateLastModified);
AddAgeHeader(responseHeaders, options.DateLastModified);
var rangeHeader = requestContext.Headers.Get("Range");
@ -566,21 +560,10 @@ namespace Emby.Server.Implementations.HttpServer
};
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)
@ -603,7 +586,6 @@ namespace Emby.Server.Implementations.HttpServer
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
hasHeaders.Headers["ETag"] = newEtag;
return hasHeaders;
}
else
@ -628,7 +610,6 @@ namespace Emby.Server.Implementations.HttpServer
};
AddResponseHeaders(hasHeaders, options.ResponseHeaders);
hasHeaders.Headers["ETag"] = newEtag;
return hasHeaders;
}
}
@ -641,37 +622,28 @@ namespace Emby.Server.Implementations.HttpServer
/// <summary>
/// Adds the caching responseHeaders.
/// </summary>
private void AddCachingHeaders(IDictionary<string, string> responseHeaders, string cacheKey, TimeSpan? cacheDuration)
private void AddCachingHeaders(IDictionary<string, string> responseHeaders, TimeSpan? cacheDuration,
bool noCache, DateTime? lastModifiedDate)
{
if (cacheDuration.HasValue)
{
responseHeaders["Cache-Control"] = "public, max-age=" + Convert.ToInt32(cacheDuration.Value.TotalSeconds);
}
else if (!string.IsNullOrEmpty(cacheKey))
{
responseHeaders["Cache-Control"] = "public";
}
else
if (noCache)
{
responseHeaders["Cache-Control"] = "no-cache, no-store, must-revalidate";
responseHeaders["pragma"] = "no-cache, no-store, must-revalidate";
return;
}
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");
responseHeaders["Cache-Control"] = "public, max-age=" + cacheDuration.Value.TotalSeconds;
}
else if (string.IsNullOrEmpty(cacheKey))
else
{
responseHeaders["Expires"] = "-1";
responseHeaders["Cache-Control"] = "public";
}
if (lastModifiedDate.HasValue)
{
responseHeaders["Last-Modified"] = lastModifiedDate.ToString();
}
}
@ -687,32 +659,6 @@ namespace Emby.Server.Implementations.HttpServer
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].

View File

@ -12,8 +12,6 @@ namespace MediaBrowser.Controller.Net
public string ContentType { get; set; }
public TimeSpan? CacheDuration { get; set; }
public DateTime? DateLastModified { get; set; }
public Guid CacheKey { get; set; }
public Func<Task<Stream>> ContentFactory { get; set; }
public bool IsHeadRequest { get; set; }