/// <inheritdoc cref="IDownloader.Download(IPackage, string)" />
public virtual Task Download(IPackage package, string cwd, bool output)
{
if (string.IsNullOrEmpty(package.GetDistUri()))
{
throw new RuntimeException("The given package is missing url information.");
}
var downloadedFilePath = GetDownloadedFilePath(package, cwd);
fileSystem.Delete(cwd);
void DoDownload(string uri)
{
var processedUri = ProcessUri(package, uri);
if (eventDispatcher != null)
{
var preFileDownloadEvent = new PreFileDownloadEventArgs(PluginEvents.PreFileDownload, transport, processedUri);
eventDispatcher.Dispatch(this, preFileDownloadEvent);
}
try
{
var checksum = package.GetDistShasum();
var cacheKey = GetCacheKey(package, processedUri);
void DownloadFromHttp(int retries = 3)
{
SException processException = null;
while (retries-- > 0)
{
try
{
transport.Copy(
processedUri,
downloadedFilePath,
new ReportDownloadProgress(io, $"{GetDownloadingPrompt(package)}: "));
break;
}
catch (TransportException ex)
{
// clean up immediately. otherwise it will lead to failure forever.
fileSystem.Delete(downloadedFilePath);
// if we got an http response with a proper code, then
// requesting again will probably not help, abort.
var serverProblems = new[]
{
HttpStatusCode.InternalServerError,
HttpStatusCode.BadGateway,
HttpStatusCode.ServiceUnavailable,
HttpStatusCode.GatewayTimeout,
};
if (ex.HttpStatusCode != 0 &&
(!Array.Exists(serverProblems, (code) => code == ex.HttpStatusCode) || retries <= 0))
{
throw;
}
processException = ex;
Thread.Sleep(500);
}
}
if (processException != null)
{
ExceptionDispatchInfo.Capture(processException).Throw();
}
if (cache != null && cache.CopyFrom(cacheKey, downloadedFilePath))
{
lastCacheWrites[package.GetName()] = cacheKey;
}
}
// use from cache if it is present and has a valid checksum
// or we have no checksum to check against
if (cache != null && cache.Sha1(cacheKey, checksum) && cache.CopyTo(cacheKey, downloadedFilePath))
{
if (output)
{
io.WriteError($" - Loading <info>{package.GetName()}</info> (<comment>{package.GetVersionPrettyFull()}</comment>) from cache", false);
}
}
else
{
if (output)
{
io.WriteError(GetDownloadingPrompt(package), false);
}
DownloadFromHttp();
}
// Verify the file to ensure that the file is not damaged.
if (!fileSystem.Exists(downloadedFilePath, FileSystemOptions.File))
{
throw new UnexpectedException($"{uri} could not be saved to {downloadedFilePath} , make sure the directory is writable and you have internet connectivity.");
}
if (!string.IsNullOrEmpty(checksum))
{
using (var stream = fileSystem.Read(downloadedFilePath))
{
if (Security.Sha1(stream) != checksum)
{
throw new UnexpectedException($"The checksum verification of the file failed (downloaded from {uri})");
}
}
}
}
catch
{
fileSystem.Delete(downloadedFilePath);
ClearLastCacheWrite(package);
throw;
}
finally
{
if (output)
{
io.OverwriteError(string.Empty, false);
}
}
}
void Start()
{
var uris = package.GetDistUris();
// The performance popped from the tail will be better
// than popping out from the head
Array.Reverse(uris);
while (uris.Length > 0)
{
var uri = Arr.Pop(ref uris);
try
{
DoDownload(uri);
break;
}
catch (SException ex)
{
if (io.IsDebug)
{
io.WriteError(string.Empty);
io.WriteError($"Faild: [{ex.GetType()}] {ex.Message}");
}
else if (uris.Length > 0)
{
io.WriteError(string.Empty);
io.WriteError($" Failed, trying the next URL ({ex.Message})");
}
if (uris.Length <= 0)
{
throw;
}
}
}
}
return(Task.Run(Start));
}
