public override async Task <Tuple <bool, INuGetResource> > TryCreate(
SourceRepository source,
CancellationToken token)
{
ListResource resource = null;
var serviceIndex = await source.GetResourceAsync <ServiceIndexResourceV3>(token);
if (serviceIndex != null)
{
var baseUrl = serviceIndex.GetServiceEntryUri(ServiceTypes.LegacyGallery);
if (baseUrl != null)
{
var httpSource = await source.GetResourceAsync <HttpSourceResource>(token);
var serviceDocument =
await ODataServiceDocumentUtils.CreateODataServiceDocumentResourceV2(
baseUrl.AbsoluteUri, httpSource.HttpSource, DateTime.UtcNow, NullLogger.Instance, token);
var parser = new V2FeedParser(httpSource.HttpSource, serviceDocument.BaseAddress, source.PackageSource.Source);
var feedCapabilityResource = new LegacyFeedCapabilityResourceV2Feed(parser, serviceDocument.BaseAddress);
resource = new V2FeedListResource(parser, feedCapabilityResource, serviceDocument.BaseAddress);
}
}
var result = new Tuple <bool, INuGetResource>(resource != null, resource);
return(result);
}
public override async Task <Tuple <bool, INuGetResource> > TryCreate(SourceRepository source, CancellationToken token)
{
ODataServiceDocumentResourceV2 serviceDocument = null;
ODataServiceDocumentCacheInfo cacheInfo = null;
var url = source.PackageSource.Source;
var utcNow = DateTime.UtcNow;
var entryValidCutoff = utcNow.Subtract(MaxCacheDuration);
// check the cache before downloading the file
if (!_cache.TryGetValue(url, out cacheInfo) || entryValidCutoff > cacheInfo.CachedTime)
{
// Track if the semaphore needs to be released
var release = false;
try
{
await _semaphore.WaitAsync(token);
release = true;
token.ThrowIfCancellationRequested();
// check the cache again, another thread may have finished this one waited for the lock
if (!_cache.TryGetValue(url, out cacheInfo) || entryValidCutoff > cacheInfo.CachedTime)
{
var client = (await source.GetResourceAsync <HttpSourceResource>(token)).HttpSource;
serviceDocument = await ODataServiceDocumentUtils.CreateODataServiceDocumentResourceV2(url, client, utcNow, NullLogger.Instance, token);
// cache the value even if it is null to avoid checking it again later
var cacheEntry = new ODataServiceDocumentCacheInfo
{
CachedTime = utcNow,
ServiceDocument = serviceDocument
};
// If the cache entry has expired it will already exist
_cache.AddOrUpdate(url, cacheEntry, (key, value) => cacheEntry);
}
}
finally
{
if (release)
{
_semaphore.Release();
}
}
}
if (serviceDocument == null && cacheInfo != null)
{
serviceDocument = cacheInfo.ServiceDocument;
}
return(new Tuple <bool, INuGetResource>(serviceDocument != null, serviceDocument));
}
