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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Diagnostics.CodeAnalysis;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Logging;
using Microsoft.Net.Http.Headers;
namespace Microsoft.AspNetCore.Http.HttpResults;
/// <summary>
/// A <see cref="IResult" /> that on execution writes the file specified
/// using a virtual path to the response using mechanisms provided by the host.
/// </summary>
public sealed class VirtualFileHttpResult : IResult, IFileHttpResult, IContentTypeHttpResult
{
private string _fileName;
/// <summary>
/// Creates a new <see cref="VirtualFileHttpResult"/> instance with
/// the provided <paramref name="fileName"/> and the provided <paramref name="contentType"/>.
/// </summary>
/// <param name="fileName">The path to the file. The path must be an absolute path.</param>
/// <param name="contentType">The Content-Type header of the response.</param>
internal VirtualFileHttpResult(string fileName, string? contentType)
: this(fileName, contentType, fileDownloadName: null)
{
}
/// <summary>
/// Creates a new <see cref="VirtualFileHttpResult"/> instance with
/// the provided <paramref name="fileName"/>, the provided <paramref name="contentType"/>
/// and the provided <paramref name="fileDownloadName"/>.
/// </summary>
/// <param name="fileName">The path to the file. The path must be an absolute path.</param>
/// <param name="contentType">The Content-Type header of the response.</param>
/// <param name="fileDownloadName">The suggested file name.</param>
internal VirtualFileHttpResult(
string fileName,
string? contentType,
string? fileDownloadName)
: this(fileName, contentType, fileDownloadName, enableRangeProcessing: false)
{
}
/// <summary>
/// Creates a new <see cref="VirtualFileHttpResult"/> instance with the provided values.
/// </summary>
/// <param name="fileName">The path to the file. The path must be an absolute path.</param>
/// <param name="contentType">The Content-Type header of the response.</param>
/// <param name="fileDownloadName">The suggested file name.</param>
/// <param name="enableRangeProcessing">Set to <c>true</c> to enable range requests processing.</param>
/// <param name="lastModified">The <see cref="DateTimeOffset"/> of when the file was last modified.</param>
/// <param name="entityTag">The <see cref="EntityTagHeaderValue"/> associated with the file.</param>
internal VirtualFileHttpResult(
string fileName,
string? contentType,
string? fileDownloadName,
bool enableRangeProcessing,
DateTimeOffset? lastModified = null,
EntityTagHeaderValue? entityTag = null)
{
FileName = fileName;
ContentType = contentType ?? ContentTypeConstants.BinaryContentType;
FileDownloadName = fileDownloadName;
EnableRangeProcessing = enableRangeProcessing;
LastModified = lastModified;
EntityTag = entityTag;
}
/// <inheritdoc />
public string ContentType { get; internal set; }
/// <inheritdoc />
public string? FileDownloadName { get; internal set; }
/// <inheritdoc />
public DateTimeOffset? LastModified { get; internal set; }
/// <inheritdoc />
public EntityTagHeaderValue? EntityTag { get; internal init; }
/// <inheritdoc />
public bool EnableRangeProcessing { get; internal init; }
/// <inheritdoc />
public long? FileLength { get; internal set; }
/// <summary>
/// Gets or sets the path to the file that will be sent back as the response.
/// </summary>
public string FileName
{
get => _fileName;
[MemberNotNull(nameof(_fileName))]
internal set => _fileName = value ?? throw new ArgumentNullException(nameof(value));
}
/// <inheritdoc/>
public Task ExecuteAsync(HttpContext httpContext)
{
ArgumentNullException.ThrowIfNull(httpContext);
var hostingEnvironment = httpContext.RequestServices.GetRequiredService<IWebHostEnvironment>();
var fileInfo = GetFileInformation(hostingEnvironment.WebRootFileProvider);
if (!fileInfo.Exists)
{
throw new FileNotFoundException($"Could not find file: {FileName}.", FileName);
}
LastModified = LastModified ?? fileInfo.LastModified;
FileLength = fileInfo.Length;
// Creating the logger with a string to preserve the category after the refactoring.
var loggerFactory = httpContext.RequestServices.GetRequiredService<ILoggerFactory>();
var logger = loggerFactory.CreateLogger("Microsoft.AspNetCore.Http.Result.VirtualFileResult");
var (range, rangeLength, completed) = HttpResultsHelper.WriteResultAsFileCore(
httpContext,
logger,
FileDownloadName,
FileLength,
ContentType,
EnableRangeProcessing,
LastModified,
EntityTag);
return completed ?
Task.CompletedTask :
ExecuteCoreAsync(httpContext, range, rangeLength, fileInfo);
}
private static Task ExecuteCoreAsync(HttpContext httpContext, RangeItemHeaderValue? range, long rangeLength, IFileInfo fileInfo)
{
var response = httpContext.Response;
var offset = 0L;
var count = (long?)null;
if (range != null)
{
offset = range.From ?? 0L;
count = rangeLength;
}
return response.SendFileAsync(
fileInfo!,
offset,
count);
}
internal IFileInfo GetFileInformation(IFileProvider fileProvider)
{
var normalizedPath = FileName;
if (normalizedPath.StartsWith('~'))
{
normalizedPath = normalizedPath.Substring(1);
}
var fileInfo = fileProvider.GetFileInfo(normalizedPath);
return fileInfo;
}
}
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