For performance reasons, I use SqlConnection and SqlReaderStream to return the byte[] stream from the SQL Server database :
private static SqlConnection GetConnection() { var sqlConnectionStringBuilder = new SqlConnectionStringBuilder( ConfigurationManager.ConnectionStrings["StudentsSystemEntities"].ConnectionString) { Pooling = true }; var connection = new SqlConnection(sqlConnectionStringBuilder.ConnectionString); connection.Open(); return connection; } public FileDownloadModel GetFileById(Guid fileId) { var connection = GetConnection(); var command = new SqlCommand( @"SELECT [FileSize], [FileExtension], [Content] FROM [dbo].[Files] WHERE [FileId] = @fileId;", connection); var paramFilename = new SqlParameter(@"fileId", SqlDbType.UniqueIdentifier) { Value = fileId }; command.Parameters.Add(paramFilename); var reader = command.ExecuteReader( CommandBehavior.SequentialAccess | CommandBehavior.SingleResult | CommandBehavior.SingleRow | CommandBehavior.CloseConnection); if (reader.Read() == false) return null; var file = new FileDownloadModel { FileSize = reader.GetInt32(0), FileExtension = reader.GetString(1), Content = new SqlReaderStream(reader, 2) }; return file; }
I use this GetFileById method in an ASP.NET MVC action :
[HttpGet] public ActionResult Get(string id) { // Validations omitted var file = this.filesRepository.GetFileById(guid); this.Response.Cache.SetCacheability(HttpCacheability.Public); this.Response.Cache.SetMaxAge(TimeSpan.FromDays(365)); this.Response.Cache.SetSlidingExpiration(true); this.Response.AddHeader("Content-Length", file.FileSize.ToString()); var contentType = MimeMapping.GetMimeMapping( string.Format("file.{0}", file.FileExtension)); // this.Response.BufferOutput = false; return new FileStreamResult(file.Content, contentType); }
I connect MVC FileStreamResult to SqlReaderStream in the following line:
return new FileStreamResult(file.Content, contentType);
When I try to upload a resource using Chrome (or Firefox ...) , the whole file is uploaded, but I get the following error:
ATTENTION: the request is not finished yet!
Answer headers:
HTTP/1.1 200 OK Cache-Control: public, max-age=31536000 Content-Length: 33429 Content-Type: image/png Server: Microsoft-IIS/10.0 X-AspNetMvc-Version: 5.2 X-AspNet-Version: 4.0.30319 X-SourceFiles: =?UTF-8?B?QzpcR
Additional Information:
- I do not use Chrome extensions
- The only problem is this
Get action. All other actions are usually loaded. FilesController (in which the Get action) inherits directly from the Controller class- The file loads successfully, but the browser is still waiting for the server:
- The same thing that I have with Firefox
What are the possible causes of the problem?
SqlReaderStream class source code
public class SqlReaderStream : Stream { private readonly int columnIndex; private SqlDataReader reader; private long position; public SqlReaderStream( SqlDataReader reader, int columnIndex) { this.reader = reader; this.columnIndex = columnIndex; } public override long Position { get { return this.position; } set { throw new NotImplementedException(); } } public override bool CanRead { get { return true; } } public override bool CanSeek { get { return false; } } public override bool CanWrite { get { return false; } } public override long Length { get { throw new NotImplementedException(); } } public override void Flush() { } public override int Read(byte[] buffer, int offset, int count) { var bytesRead = this.reader.GetBytes( this.columnIndex, this.position, buffer, offset, count); this.position += bytesRead; return (int)bytesRead; } public override long Seek(long offset, SeekOrigin origin) { throw new NotImplementedException(); } public override void SetLength(long value) { throw new NotImplementedException(); } public override void Write(byte[] buffer, int offset, int count) { throw new NotImplementedException(); } protected override void Dispose(bool disposing) { if (disposing && null != this.reader) { this.reader.Dispose(); this.reader = null; } base.Dispose(disposing); } }