org.springframework.extensions.surf.cache
Class PersistentCache

java.lang.Object
  org.springframework.extensions.surf.cache.BasicCache
      org.springframework.extensions.surf.cache.PersistentCache

All Implemented Interfaces:

ContentCache

public class PersistentCache
extends BasicCache

This is a more advanced version of a cache that passivates objects to disk. If objects are cleaned out of the WeakHashMap, they are still retained on disk and can be reloaded from disk. Thus, the disk provides the true "persistent" cache and the in-memory cache still exists for performance purposes.

Author:

muzquiano

Field Summary

Fields inherited from class org.springframework.extensions.surf.cache.BasicCache

cache, timeout

Constructor Summary

PersistentCache(long default_timeout, String cacheDir)
Instantiates a new persistent cache.

Method Summary

protected boolean	existsOnDisk(String pathID) Returns whether the disk-cached object for the given pathID exists.
Object	get(String key) Gets content stored in the cache
protected File	getCacheFile(String pathID) Returns the literal java.io.File path for the given path ID.
protected CacheItem	loadFromDisk(String pathID) Loads a content item from disk if it exists.
void	put(String key, Object obj, long timeout) Places content into the cache
void	remove(String key) Removes a content object from the cache.
protected void	removeFromDisk(String pathID) Removes a content item cached file from disk for the given path id.
protected boolean	writeToDisk(String pathID, CacheItem item) Serializes the given content item to disk for the given path string.

Methods inherited from class org.springframework.extensions.surf.cache.BasicCache

invalidate, keys, put, values

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PersistentCache

public PersistentCache(long default_timeout,
                       String cacheDir)

Instantiates a new persistent cache.

Parameters:

default_timeout - the default_timeout

cacheDir - the cache dir

Method Detail

get

public Object get(String key)

Description copied from interface: ContentCache

Gets content stored in the cache

Specified by:

get in interface ContentCache

Overrides:

get in class BasicCache

Parameters:

key - the key

Returns:

the object

remove

public void remove(String key)

Description copied from interface: ContentCache

Removes a content object from the cache.

Specified by:

remove in interface ContentCache

Overrides:

remove in class BasicCache

Parameters:

key - the key

put

public void put(String key,
                Object obj,
                long timeout)

Description copied from interface: ContentCache

Places content into the cache

Specified by:

put in interface ContentCache

Overrides:

put in class BasicCache

Parameters:

key - the key

obj - the obj

timeout - the timeout in milliseconds

existsOnDisk

protected boolean existsOnDisk(String pathID)

Returns whether the disk-cached object for the given pathID exists.

Parameters:

pathID - the path id

Returns:

true, if exists on disk

loadFromDisk

protected CacheItem loadFromDisk(String pathID)

Loads a content item from disk if it exists. Returns null if the item doesn't exist on disk. If the file on disk is corrupt, the file is cleaned up.

Parameters:

pathID - the path id

Returns:

the cache item

writeToDisk

protected boolean writeToDisk(String pathID,
                              CacheItem item)

Serializes the given content item to disk for the given path string.

Parameters:

pathID - the path id

item - the item

Returns:

true, if write to disk

removeFromDisk

protected void removeFromDisk(String pathID)

Removes a content item cached file from disk for the given path id.

Parameters:

pathID - the path id

getCacheFile

protected File getCacheFile(String pathID)

Returns the literal java.io.File path for the given path ID.

Parameters:

pathID - the path id

Returns:

the cache file