aspnetcore/src/Microsoft.AspNet.StaticFiles/SendFileExtensions.cs

62 lines
2.2 KiB
C#

// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using Microsoft.AspNet.Builder;
using Microsoft.Framework.Internal;
namespace Microsoft.AspNet.StaticFiles
{
/// <summary>
/// Extension methods for the SendFileMiddleware
/// </summary>
public static class SendFileExtensions
{
/// <summary>
/// Provide a SendFile fallback if another component does not.
/// </summary>
/// <param name="builder"></param>
/// <returns></returns>
public static IApplicationBuilder UseSendFileFallback([NotNull] this IApplicationBuilder builder)
{
/* TODO builder.GetItem(typeof(ISendFile))
// Check for advertised support
if (IsSendFileSupported(builder.Properties))
{
return builder;
}
// Otherwise, insert a fallback SendFile middleware and advertise support
SetSendFileCapability(builder.Properties);
*/
return builder.UseMiddleware<SendFileMiddleware>();
}
private static bool IsSendFileSupported(IDictionary<string, object> properties)
{
object obj;
if (properties.TryGetValue(Constants.ServerCapabilitiesKey, out obj))
{
var capabilities = (IDictionary<string, object>)obj;
if (capabilities.TryGetValue(Constants.SendFileVersionKey, out obj)
&& Constants.SendFileVersion.Equals((string)obj, StringComparison.Ordinal))
{
return true;
}
}
return false;
}
private static void SetSendFileCapability(IDictionary<string, object> properties)
{
object obj;
if (properties.TryGetValue(Constants.ServerCapabilitiesKey, out obj))
{
var capabilities = (IDictionary<string, object>)obj;
capabilities[Constants.SendFileVersionKey] = Constants.SendFileVersion;
}
}
}
}