Package org.apache.ibatis.cache.decorators

Class BlockingCache

  • All Implemented Interfaces:
    Cache
    public class BlockingCache
extends Object
implements Cache

    Simple blocking decorator

    Simple and inefficient version of EhCache's BlockingCache decorator. It sets a lock over a cache key when the element is not found in cache. This way, other threads will wait until this element is filled instead of hitting the database.

    By its nature, this implementation can cause deadlock when used incorrectly.

    Author:
    Eduardo Macarron

    • Constructor Detail

      • BlockingCache

        public BlockingCache​(Cache delegate)

    • Method Detail

      • getId

        public String getId()
        Specified by:
        getId in interface Cache
        Returns:
        The identifier of this cache

      • getSize

        public int getSize()
        Description copied from interface: Cache
        Optional. This method is not called by the core.
        Specified by:
        getSize in interface Cache
        Returns:
        The number of elements stored in the cache (not its capacity).

      • putObject

        public void putObject​(Object key,
                      Object value)
        Specified by:
        putObject in interface Cache
        Parameters:
        key - Can be any object but usually it is a CacheKey
        value - The result of a select.

      • getObject

        public Object getObject​(Object key)
        Specified by:
        getObject in interface Cache
        Parameters:
        key - The key
        Returns:
        The object stored in the cache.

      • removeObject

        public Object removeObject​(Object key)
        Description copied from interface: Cache
        As of 3.3.0 this method is only called during a rollback for any previous value that was missing in the cache. This lets any blocking cache to release the lock that may have previously put on the key. A blocking cache puts a lock when a value is null and releases it when the value is back again. This way other threads will wait for the value to be available instead of hitting the database.
        Specified by:
        removeObject in interface Cache
        Parameters:
        key - The key
        Returns:
        Not used

      • clear

        public void clear()
        Description copied from interface: Cache
        Clears this cache instance.
        Specified by:
        clear in interface Cache

      • getTimeout

        public long getTimeout()

      • setTimeout

        public void setTimeout​(long timeout)