private async Task <ExistenceResponse> CheckFileExistsAsync(ExistenceRequest request, CancellationToken token)
{
LogRequestHandling();
Debug.Assert(_contentStoreByCacheName != null);
DateTime startTime = DateTime.UtcNow;
Context cacheContext = new Context(new Guid(request.TraceId), _logger);
HashType type = (HashType)request.HashType;
ContentHash hash = request.ContentHash.ToContentHash((HashType)request.HashType);
// Iterate through all known stores, looking for content in each.
// In most of our configurations there is just one store anyway,
// and doing this means both we can callers don't have
// to deal with cache roots and drive letters.
foreach (KeyValuePair <string, IContentStore> entry in _contentStoreByCacheName)
{
IStreamStore store = entry.Value as IStreamStore;
if (store != null)
{
FileExistenceResult result = await store.CheckFileExistsAsync(cacheContext, hash);
if (result.Succeeded)
{
return(new ExistenceResponse {
Header = ResponseHeader.Success(startTime)
});
}
}
}
return(new ExistenceResponse {
Header = ResponseHeader.Failure(startTime, $"{hash} not found in the cache")
});
}