Set Content-Length and increase BufferSize (#6347)

Addresses #6045

src/Microsoft.AspNetCore.Mvc.Core/Internal/FileResultExecutorBase.cs

@@ -19,8 +19,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
     {
         private const string AcceptRangeHeaderValue = "bytes";
 
-        // default buffer size as defined in BufferedStream type
+        protected const int BufferSize = 64 * 1024;
-        protected const int BufferSize = 0x1000;
 
         public FileResultExecutorBase(ILogger logger)
         {
@@ -40,9 +39,9 @@ namespace Microsoft.AspNetCore.Mvc.Internal
 
         protected virtual (RangeItemHeaderValue range, long rangeLength, bool serveBody) SetHeadersAndLog(
             ActionContext context,
-            FileResult result, long?
+            FileResult result,
-            fileLength, DateTimeOffset?
+            long? fileLength,
-            lastModified = null,
+            DateTimeOffset? lastModified = null,
             EntityTagHeaderValue etag = null)
         {
             if (context == null)
@@ -57,15 +56,20 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             SetContentType(context, result);
             SetContentDispositionHeader(context, result);
             Logger.FileResultExecuting(result.FileDownloadName);
-            if (fileLength.HasValue)
-            {
-                SetAcceptRangeHeader(context);
-            }
 
             var request = context.HttpContext.Request;
             var httpRequestHeaders = request.GetTypedHeaders();
             var response = context.HttpContext.Response;
             var httpResponseHeaders = response.GetTypedHeaders();
+            if (fileLength.HasValue)
+            {
+                SetAcceptRangeHeader(context);
+                // Assuming the request is not a range request, the Content-Length header is set to the length of the entire file. 
+                // If the request is a valid range request, this header is overwritten with the length of the range as part of the 
+                // range processing (see method SetContentLength).
+                response.ContentLength = fileLength.Value;
+            }
+
             if (lastModified.HasValue)
             {
                 httpResponseHeaders.LastModified = lastModified;
@@ -276,6 +280,7 @@ namespace Microsoft.AspNetCore.Mvc.Internal
                 fileLength.Value);
 
             response.StatusCode = StatusCodes.Status206PartialContent;
+            // Overwrite the Content-Length header for valid range requests with the range length.
             var rangeLength = SetContentLength(context, range);
             return (range, rangeLength, serveBody: true);
         }

test/Microsoft.AspNetCore.Mvc.Core.Test/FileContentResultTest.cs

@@ -308,9 +308,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status412PreconditionFailed, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(11, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 
@@ -350,9 +350,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status304NotModified, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(11, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/FileStreamResultTest.cs

@@ -297,9 +297,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status412PreconditionFailed, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(11, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 
@@ -340,9 +340,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status304NotModified, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(11, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/PhysicalFileResultTest.cs

@@ -208,9 +208,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status412PreconditionFailed, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(34, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 
@@ -238,9 +238,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status304NotModified, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(34, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 

test/Microsoft.AspNetCore.Mvc.Core.Test/VirtualFileResultTest.cs

@@ -270,9 +270,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status412PreconditionFailed, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(33, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }
 
@@ -312,9 +312,9 @@ namespace Microsoft.AspNetCore.Mvc
             var body = streamReader.ReadToEndAsync().Result;
             Assert.Equal(StatusCodes.Status304NotModified, httpResponse.StatusCode);
             Assert.Equal("bytes", httpResponse.Headers[HeaderNames.AcceptRanges]);
+            Assert.Equal(33, httpResponse.ContentLength);
             Assert.Empty(httpResponse.Headers[HeaderNames.ContentRange]);
             Assert.NotEmpty(httpResponse.Headers[HeaderNames.LastModified]);
-            Assert.Null(httpResponse.ContentLength);
             Assert.Empty(body);
         }