i need to download about 2 million files from the SEC website. each file has a unique url and is on average 10kB. this is my current implementation:
List<string> urls = new List<string>();
// ... initialize urls ...
WebBrowser browser = new WebBrowser();
foreach (string url in urls)
{
browser.Navigate(url);
while (browser.ReadyState != WebBrowserReadyState.Complete) Application.DoEvents();
StreamReader sr = new StreamReader(browser.DocumentStream);
StreamWriter sw = new StreamWriter(), url.Substring(url.LastIndexOf('/')));
sw.Write(sr.ReadToEnd());
sr.Close();
sw.Close();
}
the projected time is about 12 days... is there a faster way?
Edit: btw, the local file handling takes only 7% of the time
Edit: this is my final implementation:
void Main(void)
{
ServicePointManager.DefaultConnectionLimit = 10000;
List<string> urls = new List<string>();
// ... initialize urls ...
int retries = urls.AsParallel().WithDegreeOfParallelism(8).Sum(arg => downloadFile(arg));
}
public int downloadFile(string url)
{
int retries = 0;
retry:
try
{
HttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create(url);
webrequest.Timeout = 10000;
webrequest.ReadWriteTimeout = 10000;
webrequest.Proxy = null;
webrequest.KeepAlive = false;
webresponse = (HttpWebResponse)webrequest.GetResponse();
using (Stream sr = webrequest.GetResponse().GetResponseStream())
using (FileStream sw = File.Create(url.Substring(url.LastIndexOf('/'))))
{
sr.CopyTo(sw);
}
}
catch (Exception ee)
{
if (ee.Message != "The remote server returned an error: (404) Not Found." && ee.Message != "The remote server returned an error: (403) Forbidden.")
{
if (ee.Message.StartsWith("The operation has timed out") || ee.Message == "Unable to connect to the remote server" || ee.Message.StartsWith("The request was aborted: ") || ee.Message.StartsWith("Unable to read data from the trans-port con-nec-tion: ") || ee.Message == "The remote server returned an error: (408) Request Timeout.") retries++;
else MessageBox.Show(ee.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
goto retry;
}
}
return retries;
}
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