public DependencyState GetState(DependencyStateContext context)
{
if (!(context is CacheEntryDependencyStateContext))
{
return(null);
}
// Attempt to get the requested entry from the cache
var cacheContext = (CacheEntryDependencyStateContext)context;
var entry = CacheProvider.Check(cacheContext.Key);
// If the entry doesn't exist, return a "null" state.
if (entry == null)
{
return(new DependencyState(
context: context,
state: 0));
}
// Create a state that is the hash of the matching keys' states.
var hash = entry
.DependencyStates
.Where(state => !(state.Context is CacheEntryDependencyStateContext))
.Aggregate(0L, (agg, state) => agg ^ state.State);
return(new DependencyState(
context: context,
state: hash));
}