public static void Download(int streams, long fileID, string downloadPath, string accessToken)
{
string url = $"{_baseURL}{fileID}/download?oauth_token={accessToken}";
using (WebClient client = new WebClient())
{
client.DownloadString(url);
string downloadURL = client.ResponseHeaders["Location"];
if (streams > 1)
{
ParallelDownload result = ParallelDownloader.Download(downloadURL, downloadPath, streams);
}
else
{
byte[] data = client.DownloadData(downloadURL);
string disposition = client.ResponseHeaders["Content-Disposition"];
string fileName = disposition.Substring(disposition.IndexOf("filename") + 9);
if (!downloadPath.EndsWith(Path.DirectorySeparatorChar.ToString()))
{
downloadPath += Path.DirectorySeparatorChar;
}
downloadPath += fileName;
if (System.IO.File.Exists(downloadPath))
{
System.IO.File.Delete(downloadPath);
}
FileStream stream = new FileStream(downloadPath, FileMode.OpenOrCreate);
stream.Write(data, 0, data.Length);
stream.Flush();
stream.Close();
}
}
}
public static ParallelDownload Download(string url, string downloadPath, int parallelStreams = 0, bool validateSSL = false)
{
if (!validateSSL)
{
ServicePointManager.ServerCertificateValidationCallback = delegate { return(true); };
}
ParallelDownload result = new ParallelDownload();
result.FilePath = downloadPath;
if (parallelStreams <= 0)
{
parallelStreams = Environment.ProcessorCount;
}
WebRequest request = WebRequest.Create(url);
request.Method = "HEAD";
string fileName;
long responseLength;
using (WebResponse response = request.GetResponse())
{
responseLength = long.Parse(response.Headers.Get("Content-Length"));
result.Size = responseLength;
string disposition = response.Headers["Content-Disposition"];
fileName = disposition.Substring(disposition.IndexOf("filename") + 9);
}
if (!downloadPath.EndsWith(Path.DirectorySeparatorChar.ToString()))
{
downloadPath += Path.DirectorySeparatorChar;
}
downloadPath += fileName;
if (System.IO.File.Exists(downloadPath))
{
System.IO.File.Delete(downloadPath);
}
using (FileStream destinationStream = new FileStream(downloadPath, FileMode.Append))
{
ConcurrentDictionary <ParallelDownloadStreamRange, string> tempFiles = new ConcurrentDictionary <ParallelDownloadStreamRange, string>();
List <ParallelDownloadStreamRange> readRanges = new List <ParallelDownloadStreamRange>();
for (int chunk = 0; chunk < parallelStreams; chunk++)
{
ParallelDownloadStreamRange range = new ParallelDownloadStreamRange();
range.Start = chunk * (responseLength / parallelStreams);
range.End = ((chunk + 1) * (responseLength / parallelStreams)) - 1;
readRanges.Add(range);
}
ParallelDownloadStreamRange endRange = new ParallelDownloadStreamRange();
endRange.Start = readRanges.Any() ? readRanges.Last().End + 1 : 0;
endRange.End = responseLength - 1;
System.Diagnostics.Stopwatch timer = new System.Diagnostics.Stopwatch();
timer.Start();
Parallel.ForEach(readRanges, new ParallelOptions()
{
MaxDegreeOfParallelism = parallelStreams
}, readRange =>
{
HttpWebRequest webRequest = WebRequest.Create(url) as HttpWebRequest;
webRequest.Method = "GET";
webRequest.AddRange(readRange.Start, readRange.End);
using (HttpWebResponse webResponse = webRequest.GetResponse() as HttpWebResponse)
{
string tempFilePath = Path.GetTempFileName();
using (FileStream stream = new FileStream(tempFilePath, FileMode.Create, FileAccess.Write, FileShare.Write))
{
webResponse.GetResponseStream().CopyTo(stream);
tempFiles.TryAdd(readRange, tempFilePath);
}
}
});
result.FileChunks = tempFiles.Count;
timer.Stop();
result.DownloadedIn = timer.ElapsedMilliseconds;
List <ParallelDownloadStreamRange> ranges = SortKeys(tempFiles.Keys);
foreach (ParallelDownloadStreamRange range in ranges)
{
string file = tempFiles[range];
byte[] bytes = System.IO.File.ReadAllBytes(file);
destinationStream.Write(bytes, 0, bytes.Length);
System.IO.File.Delete(file);
}
destinationStream.Flush();
destinationStream.Close();
return(result);
}
}