Develop Reference

File download in chunks in http-context response C#

I have a below scenario.
Client send request to Server-1 for file download
Server-1 send request to Server-2 for file.
To make this work I need to create a mechanism where once client send request to the Server-1, Server-1 will request to Server-2 which will send file as response output-stream in chunks. Server-1 will send this file chunks to client browser continuously as it keep receiving from server-2.
I have done code as below, theoretically it looks fine but still it is not working.
It is not downloading entire file in client browser, it seems like last chunk is not transferred to the Server-1 or it is not downloading to client browser from Server-1
Server-1 Code (Where client request for File download)
private void ProccesBufferedResponse(HttpWebRequest webRequest, HttpContext context)
{
char[] responseChars = null;
byte[] buffer = null;
if (webRequest == null)
logger.Error("Request string is null for Perfios Docs Download at ProccesBufferedResponse()");
context.Response.Buffer = false;
context.Response.BufferOutput = false;
try
{
WebResponse webResponse = webRequest.GetResponse();
context.Response.ContentType = "application/pdf";
context.Response.AddHeader("Content-disposition", webResponse.Headers["Content-disposition"]);
StreamReader responseStream = new StreamReader(webResponse.GetResponseStream());
while (!responseStream.EndOfStream)
{
responseChars = new char[responseStream.ToString().ToCharArray().Length];
responseStream.Read(responseChars, 0, responseChars.Length);
buffer = Encoding.ASCII.GetBytes(responseChars);
context.Response.Clear();
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
context.Response.Flush();
}
}
catch (Exception ex)
{
throw;
}
finally
{
context.Response.Flush();
context.Response.End();
}
}
Server-2 Code (Where Server-1 will send request for file)
private void DownloadInstaPerfiosDoc(int CompanyID, string fileName, string Foldertype)
{
string folderPath;
string FilePath;
int chunkSize = 1024;
int startIndex = 0;
int endIndex = 0;
int length = 0;
byte[] bytes = null;
DirectoryInfo dir;
folderPath = GetDocumentDirectory(CompanyID, Foldertype);
FilePath = folderPath + "\\" + fileName;
dir = new DirectoryInfo(folderPath);
HttpContext.Current.Response.Buffer = false;
HttpContext.Current.Response.BufferOutput = false;
if (dir.Exists && dir.GetFiles().Length > 0)
{
foreach (var file in dir.GetFiles(fileName))
{
FilePath = folderPath + "\\" + file.Name;
FileStream fsReader = new FileStream(FilePath, FileMode.Open, FileAccess.Read);
HttpContext.Current.Response.ContentType = "application/pdf";
HttpContext.Current.Response.AddHeader("Content-disposition", string.Format("attachment; filename = \"{0}\"", fileName));
int totalChunks = (int)Math.Ceiling((double)fsReader.Length / chunkSize);
for (int i = 0; i < totalChunks; i++)
{
startIndex = i * chunkSize;
if (startIndex + chunkSize > fsReader.Length)
endIndex = (int)fsReader.Length;
else
endIndex = startIndex + chunkSize;
length = (int)endIndex - startIndex;
bytes = new byte[length];
fsReader.Read(bytes, 0, bytes.Length);
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.OutputStream.Write(bytes, 0, bytes.Length);
HttpContext.Current.Response.Flush();
}
}
}
}
Please help me to resolve this issue.

It is possible and feasible. I'll give a pseudo procedure for you to understand the overall idea.
Server1
download action gets hit
create a request to server2
get the response stream of your server2 request
read the response stream in desired chunk sizes until it's consumed completely
write each chunk (as soon as you read) to current response stream
Server2
download action gets hit
write your stream onto your current response stream however you like

Unzip files in Windows Phone 8 - 'System.OutOfMemoryException'

I used the UnZipper class from this (How to unzip files in Windows Phone 8) post in my app for zips with images, but in some rare cases it gives me this error:
A first chance exception of type 'System.OutOfMemoryException' occurred in System.Windows.ni.dll System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown. at System.Windows.Application.GetResourceStreamInternal(StreamResourceInfo zipPackageStreamResourceInfo, Uri resourceUri) at System.Windows.Application.GetResourceStream(StreamResourceInfo zipPackageStreamResourceInfo, Uri uriResource) at ImperiaOnline.Plugins.UnZipper.GetFileStream(String filename) at ImperiaOnline.Plugins.IOHelpers.unzip(String zipFilePath, String zipDestinationPath)
The device has more then twice needed free memory. Can somebody help me with this. Here is my code:
public static void unzip(string zipFilePath,string zipDestinationPath) {
using (IsolatedStorageFile isolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
var dirNames = isolatedStorage.GetDirectoryNames(zipDestinationPath);
bool doesFolderExists = (dirNames.Length > 0) ? true : false;
if (!doesFolderExists)
{
Debug.WriteLine("Folder does not exists");
isolatedStorage.CreateDirectory(zipDestinationPath);
}
try
{
using (IsolatedStorageFileStream zipFile = isolatedStorage.OpenFile(zipFilePath, FileMode.Open, FileAccess.ReadWrite))
{
UnZipper unzip = new UnZipper(zipFile);
bool isModuleFolderDeleted = false;
foreach (string currentFileAndDirectory in unzip.FileNamesInZip())
{
string[] fileLocations = currentFileAndDirectory.Split('/');
string prefix = zipDestinationPath + '/';
int locationsCount = fileLocations.Length;
string fileName = fileLocations.Last();
string currentPath = prefix;
for (int i = 0; i < locationsCount - 1; i++)
{
dirNames = isolatedStorage.GetDirectoryNames(currentPath + fileLocations[i]);
doesFolderExists = (dirNames.Length > 0) ? true : false;
if (!doesFolderExists)
{
isolatedStorage.CreateDirectory(currentPath + fileLocations[i]);
if (i == 2)
{
isModuleFolderDeleted = true;
}
}
else if (i == 2 && !isModuleFolderDeleted)
{
Debug.WriteLine(currentPath + fileLocations[i] + " is deleted and recreated");
DeleteDirectoryRecursively(isolatedStorage, currentPath + fileLocations[i]);
isolatedStorage.CreateDirectory(currentPath + fileLocations[i]);
isModuleFolderDeleted = true;
}
currentPath += fileLocations[i] + '/';
}
var newFileStream = isolatedStorage.CreateFile(currentPath + fileName);
byte[] fileBytes = new byte[unzip.GetFileStream(currentFileAndDirectory).Length];
unzip.GetFileStream(currentFileAndDirectory).Read(fileBytes, 0, fileBytes.Length);
unzip.GetFileStream(currentFileAndDirectory).Close();
try
{
newFileStream.Write(fileBytes, 0, fileBytes.Length);
}
catch (Exception ex)
{
Debug.WriteLine("FILE WRITE EXCEPTION: " + ex);
newFileStream.Close();
newFileStream = null;
zipFile.Close();
unzip.Dispose();
}
newFileStream.Close();
newFileStream = null;
}
zipFile.Close();
unzip.Dispose();
}
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
isolatedStorage.DeleteFile(zipFilePath);
}
}
This error appears here:
var newFileStream = isolatedStorage.CreateFile(currentPath + fileName);
byte[] fileBytes = new byte[unzip.GetFileStream(currentFileAndDirectory).Length]; unzip.GetFileStream(currentFileAndDirectory).Read(fileBytes, 0, fileBytes.Length);
unzip.GetFileStream(currentFileAndDirectory).Close();
I debugged it and it fails on
byte[] fileBytes = new byte[unzip.GetFileStream(currentFileAndDirectory).Length];
I checked GetFileStream method
public Stream GetFileStream(string filename)
{
if (fileEntries == null)
fileEntries = ParseCentralDirectory(); //We need to do this in case the zip is in a format Silverligth doesn't like
long position = this.stream.Position;
this.stream.Seek(0, SeekOrigin.Begin);
Uri fileUri = new Uri(filename, UriKind.Relative);
StreamResourceInfo info = new StreamResourceInfo(this.stream, null);
StreamResourceInfo stream = System.Windows.Application.GetResourceStream(info, fileUri);
this.stream.Position = position;
if (stream != null)
return stream.Stream;
return null;
}
It throws OutOfMemory exception on this row:
StreamResourceInfo stream = System.Windows.Application.GetResourceStream(info, fileUri);

Getting issue while downloading file from blob storage

Hi i have to download a 5 to 6 GB file from blob storage, on downloading i am getting the below mentioned error each time.
Error-:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
My code for downloading:
protected void btn_download_Click1(object sender, EventArgs e)
{
AccountFileTransfer = CloudStorageAccount.Parse("DefaultEndpointsProtocol=http;AccountName=" + ACCOUNTNAME + ";AccountKey=" + ACCOUNTKEY);
if (AccountFileTransfer != null)
{
BlobClientFileTransfer = AccountFileTransfer.CreateCloudBlobClient();
ContainerFileTransfer = BlobClientFileTransfer.GetContainerReference(CONTAINER);
ContainerFileTransfer.CreateIfNotExist();
BlobRequestOptions options = new BlobRequestOptions();
options.Timeout = new TimeSpan(0, 180, 0);
}
var blob = ContainerFileTransfer.GetBlockBlobReference(downloadfile);
var sasUrl = blob.Uri.AbsoluteUri;
CloudBlockBlob blockBlob = new CloudBlockBlob(sasUrl);
//blobSize = Convert.ToInt32(lblfilesize.Text.ToString());
blockSize = 5 * 1024*1024;
Response.Clear();
Response.ContentType = "APPLICATION/OCTET-STREAM";
System.String disHeader = "Attachment; Filename=\"" + blockBlob.Name + "\"";
Response.AppendHeader("Content-Disposition", disHeader);
for ( offset = 0; offset < blobSize; offset += blockSize)
{
using (var blobStream = blockBlob.OpenRead())
{
if ((offset + blockSize) > blobSize)
{
blockSize =(blobSize - offset);
}
byte[] buffer = new byte[blockSize];
blobStream.Read(buffer, 0, buffer.Length);
Response.BinaryWrite(buffer);
Response.Flush();
}
}
Response.End();
}

Downloading a File on ASP.net C#

I have a serious Problem with Download in my ASP.net Project.
I used the same code in 2 pages to download a file :
private bool DownloadAnhang_Tracking(string fileName, string filepath)
{
////File Path and File Name
string filePath = filepath;
string downloadableFileName = fileName;
System.IO.FileInfo filename;
FileStream myFile;
try
{
filename = new System.IO.FileInfo(filePath);
myFile = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
}
catch (IOException ex)
{
this.ShowErrorNotification("Fehler: " + ex.Message);
throw;
}
////Reads file as binary values
BinaryReader binaryReader = new BinaryReader(myFile);
////Check whether file exists in specified location
if (filename.Exists)
{
try
{
long startBytes = 0;
string lastUpdateTiemStamp = File.GetLastWriteTimeUtc(filePath).ToString("r");
string encodedData = HttpUtility.UrlEncode(downloadableFileName, Encoding.UTF8) + lastUpdateTiemStamp;
Response.Clear();
Response.Buffer = false;
Response.AddHeader("Accept-Ranges", "bytes");
Response.AppendHeader("ETag", "\"" + encodedData + "\"");
Response.AppendHeader("Last-Modified", lastUpdateTiemStamp);
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment;filename=" + filename.Name);
Response.AddHeader("Content-Length", (filename.Length - startBytes).ToString());
Response.AddHeader("Connection", "Keep-Alive");
Response.ContentEncoding = Encoding.UTF8;
////Send data
binaryReader.BaseStream.Seek(startBytes, SeekOrigin.Begin);
////Dividing the data in 1024 bytes package
int maxCount = (int)Math.Ceiling((filename.Length - startBytes + 0.0) / 1024);
////Download in block of 1024 bytes
int i;
for (i = 0; i < maxCount && Response.IsClientConnected; i++)
{
Response.BinaryWrite(binaryReader.ReadBytes(1024));
Response.Flush();
}
////if blocks transfered not equals total number of blocks
if (i < maxCount)
{
return false;
}
else
{
return true;
}
}
catch
{
return false;
}
finally
{
Response.End();
binaryReader.Close();
myFile.Close();
}
}
else
{
this.ShowErrorNotification("Der Anhang wurde nicht gefunden!");
}
return false;
}
So used this code in another page, but it doesn't work anymore! I pass the same information to the method but it doesn't work! The Error is from MSAjax:
0x800a139e - Runtime Error in JavaScript:
Sys.WebForms.PageRequestManagerParserErrorException: The message
received from the server could not be parsed. Common causes for this
error are when the response is modified by calls to Response.Write(),
response filters, HttpModules, or server trace is enabled.
I don't get why this code works on page 1 but not on page 2.
Im using ASP.Net 4.5 WebForms with C#

Download function failing with big file sizes

Hi my download function.
protected void downloadFunction(string fileName)
{
string filePath = #"D:\SoftwareFiles\";
LogMessageToFile("Download started " + filePath + fileName);
byte[] array = File.ReadAllBytes(filePath + fileName);
Response.Clear();
Response.ContentType = "application/x-newton-compatible-pkg";
Response.AppendHeader("Content-Disposition",
"attachment;filename=" + fileName);
Response.BinaryWrite(array);
Response.End();
}
When handling filesize of 20, 200mb no problem.
When handling 1gb file, an exception is thrown:
Overflow or underflow in the arithmetic operation.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.ArithmeticException: Overflow or underflow in the arithmetic operation.
What to do?

My guess is that you're running out of memory in the byte[] array.
You can try breaking the file down and reading it in chunks.
I found a code example from a Google search to get you started:
C# file downloader AKA Response.BinaryWrite
using System;
using System.IO;
using System.Web;
public class Download
{
public static void SmallFile(string filename, string filepath, string contentType)
{
try
{
FileStream MyFileStream = new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.Read);
long FileSize;
FileSize = MyFileStream.Length;
byte[] Buffer = new byte[(int)FileSize];
MyFileStream.Read(Buffer, 0, (int)MyFileStream.Length);
MyFileStream.Close();
HttpContext.Current.Response.ContentType = contentType;
HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));
HttpContext.Current.Response.BinaryWrite(Buffer);
}
catch
{
HttpContext.Current.Response.ContentType = "text/html";
HttpContext.Current.Response.Write("Downloading Error!");
}
HttpContext.Current.Response.End();
}
public static void LargeFile(string filename, string filepath, string contentType)
{
Stream iStream = null;
// Buffer to read 10K bytes in chunk
//byte[] buffer = new Byte[10000];
// Buffer to read 1024K bytes in chunk
byte[] buffer = new Byte[1048576];
// Length of the file:
int length;
// Total bytes to read:
long dataToRead;
try
{
// Open the file.
iStream = new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.Read);
// Total bytes to read:
dataToRead = iStream.Length;
HttpContext.Current.Response.ContentType = contentType;
HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));
// Read the bytes.
while (dataToRead > 0)
{
// Verify that the client is connected.
if (HttpContext.Current.Response.IsClientConnected)
{
// Read the data in buffer.
length = iStream.Read(buffer, 0, 10000);
// Write the data to the current output stream.
HttpContext.Current.Response.OutputStream.Write(buffer, 0, length);
// Flush the data to the HTML output.
HttpContext.Current.Response.Flush();
buffer = new Byte[10000];
dataToRead = dataToRead - length;
}
else
{
//prevent infinite loop if user disconnects
dataToRead = -1;
}
}
}
catch (Exception ex)
{
// Trap the error, if any.
//HttpContext.Current.Response.Write("Error : " + ex.Message);
HttpContext.Current.Response.ContentType = "text/html";
HttpContext.Current.Response.Write("Error : file not found");
}
finally
{
if (iStream != null)
{
//Close the file.
iStream.Close();
}
HttpContext.Current.Response.End();
HttpContext.Current.Response.Close();
}
}
public static void ResumableFile(string filename, string fullpath, string contentType)
{
try
{
FileStream myFile = new FileStream(fullpath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
BinaryReader br = new BinaryReader(myFile);
try
{
HttpContext.Current.Response.AddHeader("Accept-Ranges", "bytes");
HttpContext.Current.Response.Buffer = false;
long fileLength = myFile.Length;
long startBytes = 0;
//int pack = 10240; //10K bytes
int pack = 1048576; //1024K bytes
if (HttpContext.Current.Request.Headers["Range"] != null)
{
HttpContext.Current.Response.StatusCode = 206;
string[] range = HttpContext.Current.Request.Headers["Range"].Split(new char[] { '=', '-' });
startBytes = Convert.ToInt64(range[1]);
}
HttpContext.Current.Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
if (startBytes != 0)
{
HttpContext.Current.Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));
}
HttpContext.Current.Response.AddHeader("Connection", "Keep-Alive");
HttpContext.Current.Response.ContentType = contentType;
HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));
br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
int maxCount = (int)Math.Floor((double)((fileLength - startBytes) / pack)) + 1;
for (int i = 0; i < maxCount; i++)
{
if (HttpContext.Current.Response.IsClientConnected)
{
HttpContext.Current.Response.BinaryWrite(br.ReadBytes(pack));
}
else
{
i = maxCount;
}
}
}
catch
{
HttpContext.Current.Response.ContentType = "text/html";
HttpContext.Current.Response.Write("Error : file not found");
}
finally
{
br.Close();
myFile.Close();
}
}
catch
{
HttpContext.Current.Response.ContentType = "text/html";
HttpContext.Current.Response.Write("Error : file not found");
}
}
}