/// <summary>
/// Configures an expiry-time cache of the given maximum age in seconds and purge interval in seconds.
/// <para />
/// Specifies the cache reference type to be weak references. Weak reference cache entries become
/// eligible for garbage collection and are removed from cache when the garbage collection requires so.
/// </summary>
/// <param name="maxAgeSeconds">
/// is the maximum number of seconds before a method invocation result is considered stale
/// (also known as time-to-live)
/// </param>
/// <param name="purgeIntervalSeconds">is the interval at which the runtime purges stale data from the cache</param>
public void SetExpiryTimeCache(
double maxAgeSeconds,
double purgeIntervalSeconds)
{
DataCacheDesc = new ConfigurationCommonCacheExpiryTime(
maxAgeSeconds,
purgeIntervalSeconds,
CacheReferenceType.DEFAULT);
}
/// <summary>
/// Creates a cache implementation for the strategy as defined by the cache descriptor.
/// </summary>
/// <param name="cacheDesc">cache descriptor</param>
/// <param name="agentInstanceContext">agent instance context</param>
/// <param name="streamNum">stream number</param>
/// <param name="scheduleCallbackId">callback id</param>
/// <returns>data cache implementation</returns>
public HistoricalDataCache GetDataCache(
ConfigurationCommonCache cacheDesc,
AgentInstanceContext agentInstanceContext,
int streamNum,
int scheduleCallbackId)
{
if (cacheDesc == null) {
return new HistoricalDataCacheNullImpl();
}
if (cacheDesc is ConfigurationCommonCacheLRU) {
ConfigurationCommonCacheLRU lruCache = (ConfigurationCommonCacheLRU) cacheDesc;
return new HistoricalDataCacheLRUImpl(lruCache.Size);
}
if (cacheDesc is ConfigurationCommonCacheExpiryTime) {
ConfigurationCommonCacheExpiryTime expCache = (ConfigurationCommonCacheExpiryTime) cacheDesc;
return MakeTimeCache(expCache, agentInstanceContext, streamNum, scheduleCallbackId);
}
throw new IllegalStateException("Cache implementation class not configured");
}
public HistoricalEventViewableMethod(
HistoricalEventViewableMethodFactory factory,
PollExecStrategy pollExecStrategy,
AgentInstanceContext agentInstanceContext)
: base(factory, pollExecStrategy, agentInstanceContext)
{
try {
ConfigurationCommonMethodRef configCache =
agentInstanceContext.ImportServiceRuntime.GetConfigurationMethodRef(factory.ConfigurationName);
ConfigurationCommonCache dataCacheDesc = configCache != null ? configCache.DataCacheDesc : null;
this.DataCache = agentInstanceContext.HistoricalDataCacheFactory.GetDataCache(
dataCacheDesc,
agentInstanceContext,
factory.StreamNumber,
factory.ScheduleCallbackId);
}
catch (EPException) {
throw;
}
catch (Exception e) {
throw new EPException("Failed to obtain cache: " + e.Message, e);
}
}
/// <summary>
/// Configures a LRU cache of the given size for the method invocation.
/// </summary>
/// <param name="size">is the maximum number of entries before method invocation results are evicted</param>
public void SetLRUCache(int size)
{
DataCacheDesc = new ConfigurationCommonCacheLRU(size);
}
