private TValue[] TryGetBatchMixed(IReadOnlyCollection <TKey> keys, BatchLoad batch)
{
// construct a list of keys to load
var keysToLoad = new List <TKey>(batch.ToLoadCount);
var originalIndexes = new List <int>(batch.ToLoadCount);
int i = 0;
foreach (var key in keys)
{
if (!batch.AlreadyLoading[i])
{
keysToLoad.Add(key);
originalIndexes.Add(i);
}
i++;
}
// the following line may block
TValue[] loaded = keysToLoad.Count > 0 ? _batchDataSource.GetBatch(keysToLoad) : new TValue[0];
// set the results of the all the TCS we added
i = 0;
foreach (var l in loaded)
{
int idx = originalIndexes[i];
Task.Run(() => batch.TaskCompletionSources[idx].TrySetResult(l));
i++;
}
// remove all keys that we loaded
RemoveAllKeys(keysToLoad);
// construct results from TCS results
return(ResultsFromBatchTCS(keys, batch));
}
private TValue[] UpdateCacheAndResults(BatchLoad batch, TValue[] fromDataSource)
{
lock (SyncRoot)
{
int keyIdx = 0;
foreach (var loaded in fromDataSource)
{
if (!ValueEquality.Equals(loaded, default(TValue)))
{
var idx = batch.MissedKeyIdx[keyIdx];
TValue cached;
if (batch.Version != Version && TryGetAnyGen(batch.MissedKeys[keyIdx], out cached))
{
// another thread loaded our value
batch.Results[idx] = cached;
unchecked { Version++; }
}
else
{
// we loaded the value, store it in the cache
AddToGen0(batch.MissedKeys[keyIdx], loaded);
batch.Results[idx] = loaded;
}
}
keyIdx++;
}
}
return(batch.Results);
}
static TValue[] ResultsFromBatchTCS(IReadOnlyCollection <TKey> keys, BatchLoad batch)
{
var results = new TValue[keys.Count];
int i = 0;
foreach (var tcs in batch.TaskCompletionSources)
{
results[i] = tcs.Task.Result;
i++;
}
return(results);
}
private BatchLoad TryGetBatchFromCache(IReadOnlyCollection <TKey> keys)
{
var batch = new BatchLoad(keys.Count, Version);
int i = 0;
foreach (var key in keys)
{
TValue value;
if (TryGetAnyGen(key, out value))
{
batch.Results[i] = value;
}
else
{
batch.MissedKeys.Add(key);
batch.MissedKeyIdx.Add(i);
}
i++;
}
return(batch);
}
