Async download file in c# - c#

I need help to improve this code but I do not understand where I made a mistake. The file is downloaded but in a corrupted format. I am using cookies also which is a required part of this method.
/*Downlod task */
public static async Task<int> CreateDownloadTask(string urlToDownload,string sDestinationPath, string cookiedstr)
{
int BufferSize = 4096;
int receivedBytes = 0;
int totalBytes = 0;
WebClient client = new WebClient();
client.Headers.Add(HttpRequestHeader.Cookie, cookiedstr);
using (var stream = await client.OpenReadTaskAsync(urlToDownload))
{
using (MemoryStream ms = new MemoryStream())
{
int read = 0;
totalBytes = Int32.Parse(client.ResponseHeaders[HttpResponseHeader.ContentLength]);
var buffer = new byte[BufferSize];
while ((read = await stream.ReadAsync(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
FileStream file = new FileStream(sDestinationPath, FileMode.Append, FileAccess.Write);
ms.Position = 0;
ms.WriteTo(file);
file.Flush();
file.Close();
buffer = new byte[BufferSize];
receivedBytes += read;
Console.WriteLine(receivedBytes + " " + totalBytes);
// DownloadBytesProgress args = new DownloadBytesProgress(urlToDownload, receivedBytes, totalBytes);
}
ms.Close();
}
return receivedBytes;
}
}

Related

The stream does not support concurrent IO read or write operations

I have tried to search for this issue else where in Stack Overflow but couldn't find a proper answer, hence posting my question here. Below is my code, basically i am trying to read content from a file and post it to a web api, and then repeat the same step with another file. The first call passes but the second call fails with the error:
The stream does not support concurrent IO read or write operations at this line requestStream.Write(buffer, 0, bytesRead);.
Could please tell me what am i doing wrong here?
using(FileStream fs = new FileStream(# "C:\Test1.txt", FileMode.Open, FileAccess.Read)) {
byte[] buffer = null;
int bytesRead = 0;
using(Stream requestStream = request.GetRequestStream()) {
buffer = new Byte[checked((uint) Math.Min(1024, (int) fs.Length))];
while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) != 0) {
requestStream.Write(buffer, 0, bytesRead);
}
requestStream.Flush();
}
}
using(FileStream fs = new FileStream(# "C:\Test2.txt", FileMode.Open, FileAccess.Read)) {
byte[] buffer = null;
int bytesRead = 0;
using(Stream requestStream = request.GetRequestStream()) {
buffer = new Byte[checked((uint) Math.Min(1024, (int) fs.Length))];
while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) != 0) {
requestStream.Write(buffer, 0, bytesRead);
}
requestStream.Flush();
}
}
I believe the problem is happening because you are trying to get a request stream that is no more avaliable:
Try this code:
List<string> files = new List<String>();
files.Add(#"C:\Test1.txt");
files.Add(#"C:\Test2.txt");
using (Stream requestStream = request.GetRequestStream())
{
files.ForEach(fileName =>
{
byte[] buffer = null;
int bytesRead = 0;
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
buffer = new Byte[checked((uint)Math.Min(1024, (int)fs.Length))];
while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) != 0)
{
requestStream.Write(buffer, 0, bytesRead);
}
requestStream.Flush();
}
});
}
Update: To have control over endpoints and files, try this:
static void Main(string[] args)
{
string result = SendPost(#"C:\Test1.txt", "https://httpbin.org/post");
if(result.Contains("SUCCESS"))
SendPost(#"C:\Test2.txt", "https://httpbin.org/anotherpost");
}
static string SendPost(string filename, string URL)
{
var httpWebRequest = (HttpWebRequest)WebRequest.Create(URL);
httpWebRequest.ContentType = "text/plain";
httpWebRequest.Method = "POST";
/*proxy config*/
WebProxy proxy = new WebProxy();
Uri newUri = new Uri("http://xxxxxx");
proxy.Address = newUri;
httpWebRequest.Proxy = proxy;
using (var sw = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string[] lines = File.ReadAllLines(filename);
for(int i=0; i<lines.Length; i++)
sw.WriteLine(lines[i]);
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
return result;
}
}

About Parallel.For and Lock

if (File.Exists(copypath)) File.Delete(copypath);
using (FileStream inputstream = new FileStream(plainpath, FileMode.Open))
{
using (FileStream outputstream = new FileStream(copypath, FileMode.CreateNew))
{
Object lock1 = new Object();
long inputlength = inputstream.Length;
Parallel.For((long)0, (long)(inputlength / bufferSize) + ((inputlength%bufferSize)>0?1:0), (i) =>
{
byte[] parallelbuff = new byte[bufferSize];
long cursor = -1;
lock (lock1)
{
cursor = (long)(i * bufferSize);
inputstream.Seek(cursor, SeekOrigin.Begin);
read = inputstream.Read(parallelbuff, 0, buff.Length);
}
if (read > 0)
{
lock (lock1)
{
outputstream.Seek(cursor, SeekOrigin.Begin);
outputstream.Write(parallelbuff, 0, read);
}
}
});
}
}
This is a piece of my .NET 4.5 C# code for copying file from 'plainpath' to 'copypath'.
But it doesn't copy some parts of the original file.
Can you tell me about my mistake in it?

Transfer really large files using WebClient

My requirement is to transfer a zip file of size 400MB or more; The following code works for at least 40MB; But for more I would have to change byte[] bytes = new byte[50000000]; to byte[] bytes = new byte[400000000]; and maxRequestLength to maxRequestLength="409600";
The problem is byte[] bytes = new byte[100000000]; returns an error regarding insufficient space. So how can I transfer large files using WebClient??
WebClient client = new WebClient();
client.AllowWriteStreamBuffering = true;
UriBuilder ub = new UriBuilder("http://localhost:57596/UploadImages.ashx");
ub.Query = "ImageName=" + "DataSet" + DataSetId + ".zip";
client.OpenWriteCompleted += (InputStream, eArguments) =>
{
try
{
using (Stream output = eArguments.Result)
{
output.Write(ImagesAux, 0, (int)ImagesAux.Length);
//numeroimagem++;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
//throw;
}
};
client.OpenWriteAsync(ub.Uri);
in UploadImages.ashx
public void ProcessRequest(HttpContext context)
{
//context.Response.ContentType = "text/plain";
//context.Response.Write("Hello World");
string ImageName = context.Request.QueryString["ImageName"];
string UploadPath = context.Server.MapPath("~/ServerImages/");
using (FileStream stream = File.Create(UploadPath + ImageName))
{
byte[] bytes = new byte[50000000]; //
int bytesToRead = 0;
while ((bytesToRead =
context.Request.InputStream.Read(bytes, 0, bytes.Length)) != 0)
{
stream.Write(bytes, 0, bytesToRead);
stream.Close();
}
}
}
in Web.config
<httpRuntime targetFramework="4.5" maxRequestLength="40960"/>
You should never load everything in memory then write all back to disk, but instead you should load pieces and write them to disk while you are reading them.
When you've done reading you close the stream you are writing to.
Otherwise as soon as you reach sizes as GB you can get an OutOfMemory really quick.
So I would change the writing bytes to disk from this:
using (FileStream stream = File.Create(UploadPath + ImageName))
{
byte[] bytes = new byte[50000000]; //
int bytesToRead = 0;
while ((bytesToRead = context.Request.InputStream.Read(bytes, 0, bytes.Length)) != 0)
{
stream.Write(bytes, 0, bytesToRead);
stream.Close();
}
}
to this:
using (FileStream stream = File.Create(UploadPath + ImageName))
{
byte[] bytes = new byte[1024];
long totalBytes = context.Request.InputStream.Length;
long bytesRead = 0;
int bytesToRead = bytes.Length;
if (totalBytes - bytesRead < bytes.Length)
bytesToRead = (int)(totalBytes - bytesRead);
bytes = new byte[bytesToRead];
while ((bytesToRead = context.Request.InputStream.Read(bytes, bytesRead, bytes.Length)) != 0)
{
stream.Write(bytes, bytesRead, bytes.Length);
bytesRead += bytes.Length;
if (totalBytes - bytesRead < bytes.Length)
bytesToRead = (int)(totalBytes - bytesRead);
bytes = new byte[bytesToRead];
}
stream.Close();
}
1024 would be the buffer size.

overwrite file in Zipping

I try to Zip some .pdf files in C#. My code works fine but when the size of one of the pdfs is big, it is going to overwrite that pdf on the rest of pdfs. I am not sure what is happening. I tried to increase the size of buffer or zip file but still same issue. Do you have any suggestion?
This is my code:
public void ProcessZipRequest(string strQueueID, string strBatchID, string strFtpPath)
{
int intReportCnt = 0;
string strZipFileName = "Order-" + strBatchID + "-" + strQueueID + "-" + DateTime.Now.ToString("MM-dd-yyyy-HH-mm") + ".zip";
strZipFileName = SafeFileName(strZipFileName);
//MemoryStream ms = new MemoryStream();
FileStream ms = new FileStream(#"c:\surf\nikoo.zip", FileMode.Create);
ZipOutputStream oZipStream = new ZipOutputStream(ms); // create zip stream
oZipStream.SetLevel(9); // maximum compression
intReportCnt += 1;
string strRptFilename=string.Empty;
MemoryStream outputStream = new MemoryStream();
if (strQueueID != null)
{
String[] filenames = Directory.GetFiles(#"C:\uploaded");
// setting Report name to path given for Report name
foreach (String filename in filenames)
{
strRptFilename = filename.Substring(filename.LastIndexOf("\\") + 1);
FileStream fs = File.OpenRead(#"C:\uploaded\" + strRptFilename);
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = fs.Read(buffer, 0, bufferSize);
while (readCount>0)
{
outputStream.Write(buffer, 0, readCount);
readCount = fs.Read(buffer, 0, bufferSize);
}
fs.Close();
outputStream.Position = 0;
ZipFile(ref outputStream, strRptFilename, ref oZipStream);
}
}
outputStream.Close();
oZipStream.Finish();
oZipStream.Flush();
oZipStream.IsStreamOwner = false; // False stops the Close also Closing the underlying stream.
oZipStream.Close(); // Must finish the ZipOutputStream before using outputMemStream.
ms.Close();
}
And this is Zipfile Method:
public void ZipFile(ref MemoryStream msFile, string strFilename, ref ZipOutputStream oZipStream)
{
ZipEntry oZipEntry = new ZipEntry(strFilename);
oZipEntry.DateTime = DateTime.Now;
oZipEntry.Size = msFile.Length;
oZipStream.PutNextEntry(oZipEntry);
StreamUtils.Copy(msFile, oZipStream, new byte[4096]);
oZipStream.CloseEntry();
}
I found the issue. I have to create a new MemoyStream in for loop and close it at the end of the loop.
foreach (String filename in filenames)
{
strRptFilename = filename.Substring(filename.LastIndexOf("\\") + 1);
outputStream = new MemoryStream();
FileStream fs = File.OpenRead(#"C:\uploaded\" + strRptFilename);
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = fs.Read(buffer, 0, bufferSize);
while (readCount>0)
{
outputStream.Write(buffer, 0, readCount);
readCount = fs.Read(buffer, 0, bufferSize);
}
fs.Close();
outputStream.Position = 0;
ZipFile(ref outputStream, strRptFilename, ref oZipStream);
fs.Close();
outputStream.Close();
}

decompress a .gz file using GZipStream

I have several .gz files, and I want to decompress them one by one.
I have writen a simple code using GzipStream in C#, but got failed. I wonder a correct and useful method to achieve what I want. Thanks a lot.
private string Extrgz(string infile)
{
string dir = Path.GetDirectoryName(infile);
string decompressionFileName = dir + Path.GetFileNameWithoutExtension(infile) + "_decompression.bin";
using (GZipStream instream = new GZipStream(File.OpenRead(infile), CompressionMode.Compress))// ArgumentException...
{
using (FileStream outputStream = new FileStream(decompressionFileName, FileMode.Append, FileAccess.Write))
{
int bufferSize = 8192, bytesRead = 0;
byte[] buffer = new byte[bufferSize];
while ((bytesRead = instream.Read(buffer, 0, bufferSize)) > 0)
{
outputStream.Write(buffer, 0, bytesRead);
}
}
}
return decompressionFileName;
}
You need to decompress but you set CompressionMode.Compress, replace it with CompressionMode.Decompress.
Example here.
Here:
public static void DeCompressFile(string CompressedFile, string DeCompressedFile)
{
byte[] buffer = new byte[1024 * 1024];
using (System.IO.FileStream fstrmCompressedFile = System.IO.File.OpenRead(CompressedFile)) // fi.OpenRead())
{
using (System.IO.FileStream fstrmDecompressedFile = System.IO.File.Create(DeCompressedFile))
{
using (System.IO.Compression.GZipStream strmUncompress = new System.IO.Compression.GZipStream(fstrmCompressedFile,
System.IO.Compression.CompressionMode.Decompress))
{
int numRead = strmUncompress.Read(buffer, 0, buffer.Length);
while (numRead != 0)
{
fstrmDecompressedFile.Write(buffer, 0, numRead);
fstrmDecompressedFile.Flush();
numRead = strmUncompress.Read(buffer, 0, buffer.Length);
} // Whend
//int numRead = 0;
//while ((numRead = strmUncompress.Read(buffer, 0, buffer.Length)) != 0)
//{
// fstrmDecompressedFile.Write(buffer, 0, numRead);
// fstrmDecompressedFile.Flush();
//} // Whend
strmUncompress.Close();
} // End Using System.IO.Compression.GZipStream strmUncompress
fstrmDecompressedFile.Flush();
fstrmDecompressedFile.Close();
} // End Using System.IO.FileStream fstrmCompressedFile
fstrmCompressedFile.Close();
} // End Using System.IO.FileStream fstrmCompressedFile
} // End Sub DeCompressFile
// http://www.dotnetperls.com/decompress
public static byte[] Decompress(byte[] gzip)
{
byte[] baRetVal = null;
using (System.IO.MemoryStream ByteStream = new System.IO.MemoryStream(gzip))
{
// Create a GZIP stream with decompression mode.
// ... Then create a buffer and write into while reading from the GZIP stream.
using (System.IO.Compression.GZipStream stream = new System.IO.Compression.GZipStream(ByteStream
, System.IO.Compression.CompressionMode.Decompress))
{
const int size = 4096;
byte[] buffer = new byte[size];
using (System.IO.MemoryStream memory = new System.IO.MemoryStream())
{
int count = 0;
count = stream.Read(buffer, 0, size);
while (count > 0)
{
memory.Write(buffer, 0, count);
memory.Flush();
count = stream.Read(buffer, 0, size);
}
baRetVal = memory.ToArray();
memory.Close();
}
stream.Close();
} // End Using System.IO.Compression.GZipStream stream
ByteStream.Close();
} // End Using System.IO.MemoryStream ByteStream
return baRetVal;
} // End Sub Decompress

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