/// <summary>
/// Raises the <see cref="E:ProgressChanged" /> event.
/// </summary>
/// <param name="e">The <see cref="WebRequestProgressChangedEventArgs"/> instance containing the event data.</param>
protected virtual void OnProgressChanged(WebRequestProgressChangedEventArgs e)
{
var handler = _progressChanged;
handler?.Invoke(this, e);
}
/// <summary>
/// Processes the response.
/// </summary>
private void ProcessResponse()
{
try
{
// Skip the request if the request contains error
if (!IsSuccessful)
{
Exception = new InvalidOperationException("Failed to get the response stream!");
bufferRead = null;
return;
}
// Skip the rest of the method for HEAD request (which needs only response headers)
if (Request.Method.Equals(KnownHttpVerb.Head.ToString(), StringComparison.OrdinalIgnoreCase))
{
bufferRead = new byte[0];
return;
}
// Get response stream
streamResponse = Response?.GetResponseStream();
if (streamResponse == null)
{
Exception = new InvalidOperationException("Failed to get the response stream!");
bufferRead = null;
return;
}
var charset = Response?.Headers[HttpResponseHeader.ContentType] ?? "windows-1252";
var contentType = new ContentType(charset);
Encoding = contentType.CharSet?.CharsetToEncoding();
const short numReadsBeforeProgUpdateDefault = 32;
var numReadsCounter = numReadsBeforeProgUpdateDefault / 2;
var bytesReadSoFar = 0L;
var totalBytesToRead = TotalBytes;
var lastUpdateTime = DateTime.Now;
var lastUpdateDownloadedSize = 0L;
using (var ms = new MemoryStream())
{
int bytesRead;
do
{
// Read stream content
bytesRead = streamResponse.Read(bufferRead, 0, bufferRead.Length);
bytesReadSoFar += bytesRead;
if (numReadsCounter > numReadsBeforeProgUpdateDefault)
{
// Calculate request progress and report it
var dateTimeNow = DateTime.Now;
var timeDiff = (dateTimeNow - lastUpdateTime).TotalSeconds;
var sizeDiff = bytesReadSoFar - lastUpdateDownloadedSize;
var transferSpeed = Math.Round(sizeDiff / timeDiff / 1024f, 2);
lastUpdateDownloadedSize = bytesReadSoFar;
lastUpdateTime = dateTimeNow;
// Reset reads counter
numReadsCounter = 0;
// Report the progress
var args = new WebRequestProgressChangedEventArgs(bytesReadSoFar, totalBytesToRead, DateTime.Now - transferStart, transferSpeed, 99);
OnProgressChanged(args);
}
else
{
numReadsCounter++;
}
ms.Write(bufferRead, 0, bytesRead);
CheckIfCancelled(bytesReadSoFar, totalBytesToRead);
}
// go if some amount of bytes has been read and stream can go on reading
while (bytesRead > 0 && streamResponse.CanRead);
content = ms.ToArray();
}
OnProgressCompleted(new WebRequestProgressCompletedEventArgs(bytesReadSoFar, totalBytesToRead, DateTime.Now - transferStart, transferStart, false));
}
catch (Exception ex)
{
Exception = ex;
bufferRead = null;
content = null;
throw;
}
finally
{
streamResponse?.Close();
}
}