private async Task <bool> SafeAddOrReplaceWithMerging(TKey key, IAsyncCacheData <TKey, TValue> data,
CancellationToken token)
{
var dbdata = await _keyBasedFetcher.GetAsync(key, token).ConfigureAwait(false);
if (dbdata == null || dbdata.Count == 0)
{
return(false);
}
TValue value;
if (dbdata.Count == 1)
{
value = dbdata[0].Value;
data.AddOrReplace(key, value);
}
else
{
value = dbdata[0].Value;
for (var i = 1; i < dbdata.Count; i++)
{
TValue outVal;
if (dbdata[i].MergeCurrentDataForKeyConflict(value, out outVal))
{
value = outVal;
}
}
data.AddOrReplace(key, value);
}
return(true);
}
public override Task <bool> AddOrReplaceForAsync(TKey key, IAsyncCacheData <TKey, TValue> data,
CancellationToken token)
{
//We do NOT do key look up in FILE data.
//if there is a fallback, we ask it
var fallback = Fallback;
Thread.MemoryBarrier();
return(fallback != null?fallback.AddOrReplaceForAsync(key, data, token) : Task.FromResult(false));
}
private async Task <bool> SafeAddOrReplaceWithoutMerging(TKey key, IAsyncCacheData <TKey, TValue> data,
CancellationToken token)
{
var hasRow = await _keyBasedFetcher.HasRowAsync(key, token).ConfigureAwait(false);
if (!hasRow)
{
return(false);
}
data.AddOrReplace(key, default(TValue));
return(true);
}
internal override void Merge(IAsyncCacheData <TKey, TValue> target, CancellationToken token)
{
for (var i = 0; i < SyncRoots.Length; i++)
{
var syncRoot = SyncRoots[i];
lock (syncRoot)
{
token.ThrowIfCancellationRequested();
target.AddOrReplace(_data[i].AsEnumerable());
}
}
}
public override Task <bool> AddOrReplaceForAsync(TKey key, IAsyncCacheData <TKey, TValue> data,
CancellationToken token)
{
try
{
_localCts.Token.ThrowIfCancellationRequested();
return(SafeAddOrReplaceFor(key, data, token));
}
catch (OperationCanceledException)
{
throw;
}
catch (Exception e)
{
throw new AsyncCacheException(AsyncCacheErrorCode.InvalidCache, "Unknown error", e);
}
}
private Task <bool> SafeAddOrReplaceFor(TKey key, IAsyncCacheData <TKey, TValue> data, CancellationToken token)
{
return(data.ValueTypeCanBeMerged
? SafeAddOrReplaceWithMerging(key, data, token)
: SafeAddOrReplaceWithoutMerging(key, data, token));
}
internal override void Merge(IAsyncCacheData <TKey, TValue> target, CancellationToken token)
{
}
public abstract Task <bool> AddOrReplaceForAsync(TKey key, IAsyncCacheData <TKey, TValue> data, CancellationToken token);
internal abstract void Merge(IAsyncCacheData <TKey, TValue> target, CancellationToken token);
