private EvictionStrategyHandler GetCurrentEvictionStrategy(int startIDX,
CacheItem <TValue, TKey>[] d, out ReplacementArgs <TValue, TKey> args)
{
args = null;
switch (Config.Strategy)
{
case ReplacementStrategy.LRU: return(EvictionStrategyLRU);
case ReplacementStrategy.MRU: return(EvictionStrategyMRU);
default: {
args = new ReplacementArgs <TValue, TKey>(startIDX, startIDX + Config.ItemsPerSet - 1, idx => { return(d[idx]); });
return(EvictionStrategyCustom);
}
}
}
private bool EvictionStrategyCustom(CacheItem <TValue, TKey> currentCandidate,
CacheItem <TValue, TKey> testItem, ReplacementArgs <TValue, TKey> args, ref bool candidateFound)
{
if (m_replacementHandler != null && args != null && (args.CommitItemWithIndexForEvicton < 0))
{
m_replacementHandler(args);
int committedITDX = args.CommitItemWithIndexForEvicton;
if (committedITDX > -1 && committedITDX >= args.StartIndex && committedITDX <= args.EndIndex)
{
candidateFound = true;
return(true);
}
else
{
args.CommitItemWithIndexForEvicton = -1; // reset in case custom provider supplied invalid index value
}
}
return(false);
}
/// <summary>
/// MRU eviction strategy handler
/// </summary>
/// <param name="currentCandidate"></param>
/// <param name="testItem"></param>
/// <param name="args"></param>
/// <param name="candidateFound"></param>
/// <returns></returns>
private bool EvictionStrategyMRU(CacheItem <TValue, TKey> currentCandidate,
CacheItem <TValue, TKey> testItem, ReplacementArgs <TValue, TKey> args, ref bool candidateFound) => ((currentCandidate == null) || currentCandidate.TimeStamp < testItem.TimeStamp);