public bool TryDownloadAndSaveObject(string firstTwoShaDigits, string remainingShaDigits)
{
DateTime negativeCacheRequestTime;
string objectId = firstTwoShaDigits + remainingShaDigits;
if (this.objectNegativeCache.TryGetValue(objectId, out negativeCacheRequestTime))
{
if (negativeCacheRequestTime > DateTime.Now.Subtract(NegativeCacheTTL))
{
return(false);
}
this.objectNegativeCache.TryRemove(objectId, out negativeCacheRequestTime);
}
DownloadAndSaveObjectResult result = this.TryDownloadAndSaveObject(objectId);
switch (result)
{
case DownloadAndSaveObjectResult.Success:
return(true);
case DownloadAndSaveObjectResult.ObjectNotOnServer:
this.objectNegativeCache.AddOrUpdate(objectId, DateTime.Now, (unused1, unused2) => DateTime.Now);
return(false);
case DownloadAndSaveObjectResult.Error:
return(false);
default:
throw new InvalidOperationException("Unknown DownloadAndSaveObjectResult value");
}
}
protected override DownloadAndSaveObjectResult TryDownloadAndSaveObject(string objectId, CancellationToken cancellationToken, bool retryOnFailure)
{
DateTime negativeCacheRequestTime;
if (this.objectNegativeCache.TryGetValue(objectId, out negativeCacheRequestTime))
{
if (negativeCacheRequestTime > DateTime.Now.Subtract(NegativeCacheTTL))
{
return(DownloadAndSaveObjectResult.ObjectNotOnServer);
}
this.objectNegativeCache.TryRemove(objectId, out negativeCacheRequestTime);
}
DownloadAndSaveObjectResult result = base.TryDownloadAndSaveObject(objectId, cancellationToken, retryOnFailure);
if (result == DownloadAndSaveObjectResult.ObjectNotOnServer)
{
this.objectNegativeCache.AddOrUpdate(objectId, DateTime.Now, (unused1, unused2) => DateTime.Now);
}
return(result);
}
