Package org.h2.util

Interface Cache

All Known Implementing Classes:
CacheLRU, CacheSecondLevel, CacheTQ

public interface Cache
The cache keeps frequently used objects in the main memory.
  • Method Details

    • getAllChanged

      ArrayList<CacheObject> getAllChanged()
      Get all objects in the cache that have been changed.
      Returns:
      the list of objects
    • clear

      void clear()
      Clear the cache.
    • get

      CacheObject get(int pos)
      Get an element in the cache if it is available. This will move the item to the front of the list.
      Parameters:
      pos - the unique key of the element
      Returns:
      the element or null
    • put

      void put(CacheObject r)
      Add an element to the cache. Other items may fall out of the cache because of this. It is not allowed to add the same record twice.
      Parameters:
      r - the object
    • update

      CacheObject update(int pos, CacheObject record)
      Update an element in the cache. This will move the item to the front of the list.
      Parameters:
      pos - the unique key of the element
      record - the element
      Returns:
      the element
    • remove

      boolean remove(int pos)
      Remove an object from the cache.
      Parameters:
      pos - the unique key of the element
      Returns:
      true if the key was in the cache
    • find

      CacheObject find(int pos)
      Get an element from the cache if it is available. This will not move the item to the front of the list.
      Parameters:
      pos - the unique key of the element
      Returns:
      the element or null
    • setMaxMemory

      void setMaxMemory(int size)
      Set the maximum memory to be used by this cache.
      Parameters:
      size - the maximum size in KB
    • getMaxMemory

      int getMaxMemory()
      Get the maximum memory to be used.
      Returns:
      the maximum size in KB
    • getMemory

      int getMemory()
      Get the used size in KB.
      Returns:
      the current size in KB