Package com.espertech.esper.common.internal.epl.historical.datacache

Interface HistoricalDataCache

All Known Implementing Classes:
HistoricalDataCacheClearableMap, HistoricalDataCacheExpiringImpl, HistoricalDataCacheLRUImpl, HistoricalDataCacheNullImpl
public interface HistoricalDataCache
Implementations serve as caches for historical or reference data retrieved via lookup keys consisting or one or more rows represented by a list of events.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    destroy()
     
    EventTable[]
    getCached(Object methodParams)
    Ask the cache if the keyed value is cached, returning a list or rows if the key is in the cache, or returning null to indicate no such key cached.
    boolean
    isActive()
    Returns true if the cache is active and currently caching, or false if the cache is inactive and not currently caching
    void
    put(Object methodParams, EventTable[] rows)
    Puts into the cache a key and a list of rows, or an empty list if zero rows.

  • Method Details

    • getCached

      EventTable[] getCached(Object methodParams)
      Ask the cache if the keyed value is cached, returning a list or rows if the key is in the cache, or returning null to indicate no such key cached. Zero rows may also be cached.
      Parameters:
      methodParams - is the keys to look up in the cache
      Returns:
      a list of rows that can be empty is the key was found in the cache, or null if the key is not found in the cache

    • put

      void put(Object methodParams, EventTable[] rows)
      Puts into the cache a key and a list of rows, or an empty list if zero rows.

      The put method is designed to be called when the cache does not contain a key as determined by the get method. Implementations typically simply overwrite any keys put into the cache that already existed in the cache.

      Parameters:
      methodParams - is the keys to the cache entry
      rows - is a number of rows

    • isActive

      boolean isActive()
      Returns true if the cache is active and currently caching, or false if the cache is inactive and not currently caching
      Returns:
      true for caching enabled, false for no caching taking place

    • destroy

      void destroy()