//Starts the background thread for file download and reports the update to the delegates created above.
private void StartAsyncDownloadThread()
{
//trying and catching exception for creating download request.
try
{
//creating a webrequest and defining its method as GET to download file.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(_url);
request.KeepAlive = true;
request.Timeout = 30000;
request.ReadWriteTimeout = 30000;
FileStream DownloadFile;
request.Method = "GET";
//Getting Total Size of the file to download
TotalBytesToDownload = request.GetResponse().ContentLength;
FileInfo FileToDownload = new FileInfo(_downloadLocation);
//Switching cases for resumable and non resumable as per the value passed in the constructor.
if (_mode == DownloadMode.NonResumable)
{
if (File.Exists(_downloadLocation))
{
if (FileToDownload.Length > 0 && FileToDownload.Length < TotalBytesToDownload)
{
if (_DownloadAnyway)
{
FileToDownload.Delete();
}
else
{
UnityEngine.Debug.Log("File Already Exsists");
AsyncThread.Join();
return;
}
}
}
}
else if (_mode == DownloadMode.Resumable)
{
if (File.Exists(_downloadLocation))
{
if (_DownloadAnyway && FileToDownload.Length < TotalBytesToDownload)
{
request = (HttpWebRequest)WebRequest.Create(_url);
request.Method = "GET";
request.AddRange((int)FileToDownload.Length);
UnityEngine.Debug.Log("Request Headers: " + request.Headers.ToString());
}
else
{
UnityEngine.Debug.Log("File Already Exsists");
if (DownloadCompletedEvent != null)
{
DownloadCompletedEvent(new OnDownloadCompletedEvent(null, false));
}
AsyncThread.Join();
return;
}
}
}
///Getting response from the server.
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
//checking if the file exists and it exists and server supports partial content the append the incomming data of else create new file of 0B.
if (File.Exists(_downloadLocation))
{
if (response.StatusCode == HttpStatusCode.PartialContent)
{
DownloadFile = new FileStream(_downloadLocation, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
}
else
{
DownloadFile = new FileStream(_downloadLocation, FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
DownloadFile.SetLength(0);
}
}
else
{
DownloadFile = new FileStream(_downloadLocation, FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
}
BytesDownloaded = DownloadFile.Length;
TotalBytesThisSession = 0;
UnityEngine.Debug.Log("Response Headers: " + response.Headers);
UnityEngine.Debug.Log("Response Status: " + response.StatusDescription);
Stream ResponseStream = response.GetResponseStream();
//Writing Bytes to files
BytesRead = ResponseStream.Read(_Buffer, 0, _Buffer.Length);
while (BytesRead > 0 && !_Cancelled)
{
if (!Paused)
{
_isbusy = true;
DownloadFile.Write(_Buffer, 0, BytesRead);
BytesDownloaded += BytesRead;
TotalBytesThisSession += BytesRead;
BytesRead = ResponseStream.Read(_Buffer, 0, _Buffer.Length);
//Reporting progress if the given event is registered.
if (ProgressChangedEvent != null)
{
ProgressChangedEvent(new OnProgressChangedEvent(BytesDownloaded, TotalBytesToDownload, TotalBytesThisSession, Paused));
}
}
}
//Report the download completion at the end of while loop.
if (DownloadCompletedEvent != null)
{
if (!_Cancelled)
{
DownloadCompletedEvent(new OnDownloadCompletedEvent(null, false));
}
else
{
DownloadCompletedEvent(new OnDownloadCompletedEvent(null, true));
}
}
DownloadFile.Flush();
DownloadFile.Close();
response.Close();
AsyncThread.Abort();
AsyncThread.Join();
_isbusy = false;
}
catch (Exception ex)
{
_isbusy = false;
if (DownloadCompletedEvent != null)
{
DownloadCompletedEvent(new OnDownloadCompletedEvent(ex, false));
}
}
}