public async Task <Possible <Stream, Failure> > GetStreamAsync(CasHash hash, UrgencyHint urgencyHint, Guid activityId)
{
Contract.Requires(!IsClosed);
using (var counter = m_counters.GetStreamCounter())
{
using (var eventing = new GetStreamActivity(BasicFilesystemCache.EventSource, activityId, this))
{
eventing.Start(hash, urgencyHint);
if (!m_pinnedToCas.ContainsKey(hash))
{
counter.Miss();
return(eventing.StopFailure(new UnpinnedCasEntryFailure(CacheId, hash)));
}
try
{
Stream result =
CasHash.NoItem.Equals(hash) ?
Stream.Null :
await m_cache.ContendedOpenStreamAsync(m_cache.ToPath(hash), FileMode.Open, FileAccess.Read, FileShare.Read, useAsync : true, handlePendingDelete : true);
counter.FileSize(result.Length);
return(eventing.Returns(result));
}
catch (Exception e)
{
counter.Fail();
return(eventing.StopFailure(new ProduceStreamFailure(CacheId, hash, e)));
}
}
}
}
protected override Task CorruptCasEntry(ICache cache, CasHash hash)
{
// We use this as a Task.Run() just to help prove the test structure
// Other caches are likely to need async behavior so we needed to support
// that. No return result. This must fail if it can not work.
return(Task.Run(() =>
{
BasicFilesystemCache myCache = cache as BasicFilesystemCache;
XAssert.IsNotNull(myCache, "Invalid cache passed to TestBasicFilesyste CorruptCasEntry test method");
using (var f = File.AppendText(myCache.ToPath(hash)))
{
f.Write("!Corrupted!");
}
}));
}