public static Task Update()
{
return(Task.Factory.StartNew(() =>
{
lock (_lock)
{
string lastModifiedFile = System.IO.Path.Combine(Root, LastModified);
string tmpFile = System.IO.Path.Combine(Root, Guid.NewGuid().ToString());
countriesRawFile = System.IO.Path.Combine(Root, countriesRawFile);
string allCountriesFile = System.IO.Path.Combine(Root, dataFile + ".zip");
string countryInfoFile = System.IO.Path.Combine(Root, "countryInfo.txt");
string featureCodes_enFile = System.IO.Path.Combine(Root, "featureCodes_en.txt");
string timeZonesFile = System.IO.Path.Combine(Root, "timeZones.txt");
//check to see if we have read/write persmission to disk
bool canReadWrite = false;
try
{
System.IO.File.WriteAllText(tmpFile, "testing write access");
string contents = System.IO.File.ReadAllText(tmpFile);
canReadWrite = !string.IsNullOrEmpty(contents);
System.IO.File.Delete(tmpFile);
}
catch (Exception)
{
}
//load file: GeoData-LastModified.txt
//if available then
//try to http head the data source url: http://download.geonames.org/export/dump/allCountries.zip
//pull off last-modified header
//if newer than the file last-modified, do a GET to download
//else
// do a get to download
bool shouldDownload = !System.IO.File.Exists(lastModifiedFile);
if (canReadWrite && System.IO.File.Exists(lastModifiedFile))
{
var lastModified = System.IO.File.ReadAllText(lastModifiedFile);
DateTime lastModifiedDate;
if (!DateTime.TryParse(lastModified, out lastModifiedDate))
{
shouldDownload = true;
}
else
{
var request = new WebClientRequest();
request.Headers = new WebHeaderCollection();
var client = new ParallelWebClient(request);
client.OpenReadTask(allCountriesUrl, "HEAD").ContinueWith(t =>
{
var headers = client.ResponseHeaders;
foreach (string h in headers.Keys)
{
if (h.ToLowerInvariant() == "last-modified")
{
var header = headers[h];
DateTime headerDate = DateTime.Now;
DateTime.TryParse(header.ToString(), out headerDate);
if (lastModifiedDate < headerDate)
{
shouldDownload = true;
}
break;
}
}
}).Wait();
}
}
if (canReadWrite && shouldDownload)
{
var downloadTasks = new List <Task>();
var request = new WebClientRequest();
request.Headers = new WebHeaderCollection();
var client = new ParallelWebClient(request);
downloadTasks.Add(
client.DownloadData(allCountriesUrl).ContinueWith(t =>
{
if (System.IO.File.Exists(allCountriesFile))
{
System.IO.File.Delete(allCountriesFile);
}
System.IO.File.WriteAllBytes(allCountriesFile, t.Result);
var headers = client.ResponseHeaders;
foreach (string h in headers.Keys)
{
if (h.ToLowerInvariant() == "last-modified")
{
var header = headers[h];
DateTime headerDate = DateTime.Now;
DateTime.TryParse(header.ToString(), out headerDate);
System.IO.File.WriteAllText(lastModifiedFile, headerDate.ToString());
break;
}
}
})
);
downloadTasks.Add(client.DownloadData(countryInfoUrl).ContinueWith(t =>
{
if (System.IO.File.Exists(countryInfoFile))
{
System.IO.File.Delete(countryInfoFile);
}
System.IO.File.WriteAllBytes(countryInfoFile, t.Result);
}));
downloadTasks.Add(client.DownloadData(featureCodes_enUrl).ContinueWith(t =>
{
if (System.IO.File.Exists(featureCodes_enFile))
{
System.IO.File.Delete(featureCodes_enFile);
}
System.IO.File.WriteAllBytes(featureCodes_enFile, t.Result);
}));
downloadTasks.Add(client.DownloadData(timeZonesUrl).ContinueWith(t =>
{
if (System.IO.File.Exists(timeZonesFile))
{
System.IO.File.Delete(timeZonesFile);
}
System.IO.File.WriteAllBytes(timeZonesFile, t.Result);
}));
Task.WaitAll(downloadTasks.ToArray());
//downloaded, now convert zip into serialized dat file
if (System.IO.File.Exists(allCountriesFile))
{
if (System.IO.File.Exists(countriesRawFile))
{
System.IO.File.Delete(countriesRawFile);
}
ICSharpCode.SharpZipLib.Zip.FastZip fz = new FastZip();
fz.ExtractZip(allCountriesFile, Root, FastZip.Overwrite.Always, null, null, null, true);
if (System.IO.File.Exists(countriesRawFile))
{
GeoData gd = GeoNameParser.ParseFile(countriesRawFile, timeZonesFile,
featureCodes_enFile, countryInfoFile);
Serialize.SerializeBinaryToDisk(gd, DataFile);
}
if (System.IO.File.Exists(allCountriesFile))
{
System.IO.File.Delete(allCountriesFile);
}
if (System.IO.File.Exists(countriesRawFile))
{
System.IO.File.Delete(countriesRawFile);
}
if (System.IO.File.Exists(countryInfoFile))
{
System.IO.File.Delete(countryInfoFile);
}
if (System.IO.File.Exists(featureCodes_enFile))
{
System.IO.File.Delete(featureCodes_enFile);
}
if (System.IO.File.Exists(timeZonesFile))
{
System.IO.File.Delete(timeZonesFile);
}
}
}
}
}));
}