public async Task Invoke(HttpContext context)
{
var path = context.Request.Path;
// Delegate to the diagnostics page if it is requested
if (diagnosticsPage.MatchesPath(path.Value))
{
await diagnosticsPage.Invoke(context);
return;
}
// We only handle requests with an image extension, period.
if (!PathHelpers.IsImagePath(path))
{
await next.Invoke(context);
return;
}
var imageJobInfo = new ImageJobInfo(context, options, blobProvider);
if (!imageJobInfo.Authorized)
{
await NotAuthorized(context);
return;
}
// If the file is definitely missing hand to the next middleware
// Remote providers will fail late rather than make 2 requests
if (!imageJobInfo.PrimaryBlobMayExist())
{
await next.Invoke(context);
return;
}
var memoryCacheEnabled = memoryCache != null && options.AllowMemoryCaching && imageJobInfo.NeedsCaching();
var diskCacheEnabled = diskCache != null && options.AllowDiskCaching && imageJobInfo.NeedsCaching();
var distributedCacheEnabled = distributedCache != null && options.AllowDistributedCaching && imageJobInfo.NeedsCaching();
var sqliteCacheEnabled = sqliteCache != null && options.AllowSqliteCaching && imageJobInfo.NeedsCaching();
string cacheKey = null;
if (memoryCacheEnabled || diskCacheEnabled || distributedCacheEnabled | sqliteCacheEnabled)
{
cacheKey = await imageJobInfo.GetFastCacheKey();
if (context.Request.Headers.TryGetValue(HeaderNames.IfNoneMatch, out var etag) && cacheKey == etag)
{
context.Response.StatusCode = StatusCodes.Status304NotModified;
context.Response.ContentLength = 0;
context.Response.ContentType = null;
return;
}
}
try
{
if (sqliteCacheEnabled)
{
await ProcessWithSqliteCache(context, cacheKey, imageJobInfo);
}
else if (diskCacheEnabled)
{
await ProcessWithDiskCache(context, cacheKey, imageJobInfo);
}
else if (memoryCacheEnabled)
{
await ProcessWithMemoryCache(context, cacheKey, imageJobInfo);
// ReSharper disable once ConditionIsAlwaysTrueOrFalse
}
else if (distributedCacheEnabled)
{
await ProcessWithDistributedCache(context, cacheKey, imageJobInfo);
}
else
{
await ProcessWithNoCache(context, imageJobInfo);
}
}
catch (BlobMissingException e)
{
await NotFound(context, e);
}
}
// ReSharper disable once UnusedMember.Global
public async Task Invoke(HttpContext context)
{
// For instrumentation
globalInfoProvider.CopyHttpContextInfo(context);
var path = context.Request.Path;
// Delegate to the diagnostics page if it is requested
if (DiagnosticsPage.MatchesPath(path.Value))
{
await diagnosticsPage.Invoke(context);
return;
}
// Delegate to licenses page if requested
if (licensePage.MatchesPath(path.Value))
{
await licensePage.Invoke(context);
return;
}
// Respond to /imageflow.ready
if ("/imageflow.ready".Equals(path.Value, StringComparison.Ordinal))
{
options.Licensing.FireHeartbeat();
using (new JobContext())
{
await StringResponseNoCache(context, 200, "Imageflow.Server is ready to accept requests.");
}
return;
}
// Respond to /imageflow.health
if ("/imageflow.health".Equals(path.Value, StringComparison.Ordinal))
{
options.Licensing.FireHeartbeat();
await StringResponseNoCache(context, 200, "Imageflow.Server is healthy.");
return;
}
// We only handle requests with an image extension or if we configured a path prefix for which to handle
// extensionless requests
if (!ImageJobInfo.ShouldHandleRequest(context, options))
{
await next.Invoke(context);
return;
}
options.Licensing.FireHeartbeat();
var imageJobInfo = new ImageJobInfo(context, options, blobProvider);
if (!imageJobInfo.Authorized)
{
await NotAuthorized(context, imageJobInfo.AuthorizedMessage);
return;
}
if (imageJobInfo.LicenseError)
{
if (options.EnforcementMethod == EnforceLicenseWith.Http422Error)
{
await StringResponseNoCache(context, 422, options.Licensing.InvalidLicenseMessage);
return;
}
if (options.EnforcementMethod == EnforceLicenseWith.Http402Error)
{
await StringResponseNoCache(context, 402, options.Licensing.InvalidLicenseMessage);
return;
}
}
// If the file is definitely missing hand to the next middleware
// Remote providers will fail late rather than make 2 requests
if (!imageJobInfo.PrimaryBlobMayExist())
{
await next.Invoke(context);
return;
}
string cacheKey = null;
var cachingPath = imageJobInfo.NeedsCaching() ? options.ActiveCacheBackend : CacheBackend.NoCache;
if (cachingPath != CacheBackend.NoCache)
{
cacheKey = await imageJobInfo.GetFastCacheKey();
if (context.Request.Headers.TryGetValue(HeaderNames.IfNoneMatch, out var etag) && cacheKey == etag)
{
GlobalPerf.Singleton.IncrementCounter("etag_hit");
context.Response.StatusCode = StatusCodes.Status304NotModified;
context.Response.ContentLength = 0;
context.Response.ContentType = null;
return;
}
GlobalPerf.Singleton.IncrementCounter("etag_miss");
}
try
{
switch (cachingPath)
{
case CacheBackend.ClassicDiskCache:
await ProcessWithDiskCache(context, cacheKey, imageJobInfo);
break;
case CacheBackend.NoCache:
await ProcessWithNoCache(context, imageJobInfo);
break;
case CacheBackend.StreamCache:
await ProcessWithStreamCache(context, cacheKey, imageJobInfo);
break;
default:
throw new ArgumentOutOfRangeException();
}
GlobalPerf.Singleton.IncrementCounter("middleware_ok");
}
catch (BlobMissingException e)
{
await NotFound(context, e);
}
catch (Exception e)
{
var errorName = e.GetType().Name;
var errorCounter = "middleware_" + errorName;
GlobalPerf.Singleton.IncrementCounter(errorCounter);
GlobalPerf.Singleton.IncrementCounter("middleware_errors");
throw;
}
finally
{
// Increment counter for type of file served
var imageExtension = PathHelpers.GetImageExtensionFromContentType(context.Response.ContentType);
if (imageExtension != null)
{
GlobalPerf.Singleton.IncrementCounter("module_response_ext_" + imageExtension);
}
}
}