private async Task LoadAsync(TimeSpan timeout, bool shouldReload, CancellationToken token)
{
var acquired = false;
try
{
acquired = await _lock.WaitAsync(timeout, token);
if (!acquired)
{
_logger.LogInformation("Another thread is already reloading the auxiliary data.");
}
else
{
if (!shouldReload && Initialized)
{
return;
}
_logger.LogInformation("Starting the reload of auxiliary data.");
var stopwatch = Stopwatch.StartNew();
// Load the auxiliary files in parallel.
const string downloadsName = nameof(_data.Downloads);
const string verifiedPackagesName = nameof(_data.VerifiedPackages);
var downloadsTask = LoadAsync(_data?.Downloads, _downloadDataClient.ReadLatestIndexedAsync);
var verifiedPackagesTask = LoadAsync(_data?.VerifiedPackages, _verifiedPackagesDataClient.ReadLatestAsync);
await Task.WhenAll(downloadsTask, verifiedPackagesTask);
var downloads = await downloadsTask;
var verifiedPackages = await verifiedPackagesTask;
// Keep track of what was actually reloaded and what didn't change.
var reloadedNames = new List <string>();
var notModifiedNames = new List <string>();
(ReferenceEquals(_data?.Downloads, downloads) ? notModifiedNames : reloadedNames).Add(downloadsName);
(ReferenceEquals(_data?.VerifiedPackages, verifiedPackages) ? notModifiedNames : reloadedNames).Add(verifiedPackagesName);
// Reference assignment is atomic, so this is what makes the data available for readers.
_data = new AuxiliaryData(
DateTimeOffset.UtcNow,
downloads,
verifiedPackages);
// Track the counts regarding the string cache status.
_telemetryService.TrackAuxiliaryFilesStringCache(
_stringCache.StringCount,
_stringCache.CharCount,
_stringCache.RequestCount,
_stringCache.HitCount);
_stringCache.ResetCounts();
stopwatch.Stop();
_telemetryService.TrackAuxiliaryFilesReload(reloadedNames, notModifiedNames, stopwatch.Elapsed);
_logger.LogInformation(
"Done reloading auxiliary data. Took {Duration}. Reloaded: {Reloaded}. Not modified: {NotModified}",
stopwatch.Elapsed,
reloadedNames,
notModifiedNames);
}
}
finally
{
if (acquired)
{
_lock.Release();
}
}
}