public static IResult Verify(FdbServerUrl url, string fileName)
{
return(Try.Wrap(() =>
{
var checksum = url.Sha512Hash;
using (var hashAlgorithm = SHA512.Create())
{
using (var destination = File.OpenRead(fileName))
{
var hash = hashAlgorithm.ComputeHash(destination);
var hashString = ToHex(hash);
if (hashString.Equals(checksum, StringComparison.OrdinalIgnoreCase))
{
return new SuccessResult();
}
else
{
return new FailureResult("File checksum did not match stored checksum.");
}
}
}
}));
}
public static IResult CheckAvailability(FdbServerUrl url)
{
var fileName = GetCacheFileName(url);
if (!File.Exists(fileName))
{
return(new FailureResult("Cache does not contain version " + url.Version));
}
return(IntegrityVerifier.Verify(url, fileName));
}
public static Task <IResult> Download(FdbServerUrl url, string destinationFile)
=> Try.Wrap(async() =>
{
using (var webclient = new HttpClient())
{
var serverDownloadTask = webclient.GetStreamAsync(url.Uri);
using (var destination = File.OpenWrite(destinationFile))
{
var stream = await serverDownloadTask.ConfigureAwait(false);
await stream.CopyToAsync(destination).ConfigureAwait(false);
await destination.FlushAsync().ConfigureAwait(false);
}
}
});
private static string GetCacheFileName(FdbServerUrl url)
{
string fileName = Path.Combine(GetCacheFolder(), Path.GetFileName(url.Uri.LocalPath));
return(fileName);
}
internal static IResult Retrieve(FdbServerUrl url, string outputFile)
{
return(CheckAvailability(url)
.Then(_ => Try.Wrap(() => File.Copy(GetCacheFileName(url), outputFile, true))));
}
public static Task <IResult> Load(FdbServerUrl url) => FdbServerDownloader.Download(url, GetCacheFileName(url));
