rabbit.cache
Class NCache

java.lang.Object
  java.lang.Thread
      rabbit.cache.NCache

All Implemented Interfaces:

java.lang.Runnable

public class NCache

extends java.lang.Thread

The NCache is like a Hashtable in lookup/insert/delete The NCache is persistent over sessions (saves itself to disk). The NCache is selfcleaning, that is it removes old stuff.

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

NCache()
Create a cache that uses some dir.

NCache(java.lang.String dir)
Create a cache for the given directory.

NCache(java.lang.String dir, long maxSize)
Create a cache for the given directory with given parameters.

NCache(java.lang.String dir, long maxSize, long cacheTime)
Create a cachehandler.

Method Summary

void	addEntry(NCacheEntry ent) Insert a CacheEntry into the cache.
void	clear() Clear the Cache from files.
void	flush() Make sure that the cache is written to the disk.
java.lang.String	getCacheDir() Get the name of the directory where the cache stores its files.
long	getCacheTime() Get the number of miliseconds the cache stores things usually.
long	getCurrentSize() Get the current size of the cache
java.util.Enumeration	getEntries() Get the CacheEntries in the cache.
NCacheEntry	getEntry(java.lang.Object o) Get the CacheEntry assosiated with given object.
long	getMaxSize() Get the maximum size for this cache.
long	getNumberOfEntries() Get the current number of entries in the cache.
NCacheEntry	newEntry(java.lang.Object o) Reserve space for a CacheEntry with key o.
void	remove(java.lang.Object o) Remove the Entry with key o from the cache.
void	run() Loop in a cleaning loop.
void	setCacheDir(java.lang.String newDir) Sets the cachedir.
void	setCacheTime(long newCacheTime) Set the standard expiry-time for CacheEntries
void	setMaxSize(long newMaxSize) Set the maximum size for this cache.
void	setup(java.util.Properties config) Configure the cache system from the given config.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

NCache

public NCache()

Create a cache that uses some dir.

NCache

public NCache(java.lang.String dir)

Create a cache for the given directory.

Parameters:

dir - the name of the directory where the cache should store its files.

NCache

public NCache(java.lang.String dir,
              long maxSize)

Create a cache for the given directory with given parameters.

Parameters:

dir - the name of the directory where the cache should store its files.

maxSize - the maximum size of the proxy.

NCache

public NCache(java.lang.String dir,
              long maxSize,
              long cacheTime)

Create a cachehandler.

Parameters:

dir - the basedir for the cachehandler.

maxSize - the maximum size of the proxy.

cacheTime - how long the proxy should keep things unless specified otherwise.

Method Detail

getCacheDir

public java.lang.String getCacheDir()

Get the name of the directory where the cache stores its files.

Returns:

the name of the cachedir

setCacheDir

public void setCacheDir(java.lang.String newDir)

Sets the cachedir. This will flush the cache and make it try to read in the cache from the new dir.

Parameters:

newDir - the name of the new directory to use.

getMaxSize

public long getMaxSize()

Get the maximum size for this cache.

Returns:

the maximum size in bytes this cache.

setMaxSize

public void setMaxSize(long newMaxSize)

Set the maximum size for this cache.

Parameters:

newMaxSize - the new maximum size for the cache.

getCacheTime

public long getCacheTime()

Get the number of miliseconds the cache stores things usually. This is the standard expiretime for objects, but you can set it for CacheEntries individially if you want to. NOTE 1: dont trust that an object will be in the cache this long. NOTE 2: dont trust that an object will be removed from the cache when it expires.

Returns:

the number of miliseconds objects are stored normally.

setCacheTime

public void setCacheTime(long newCacheTime)

Set the standard expiry-time for CacheEntries

Parameters:

newCacheTime - the number of miliseconds to keep objects normally.

getCurrentSize

public long getCurrentSize()

Get the current size of the cache

Returns:

the current size of the cache in bytes.

getNumberOfEntries

public long getNumberOfEntries()

Get the current number of entries in the cache.

Returns:

the current number of entries in the cache.

getEntry

public NCacheEntry getEntry(java.lang.Object o)

Get the CacheEntry assosiated with given object.

Parameters:

o - the key.

Returns:

the NCacheEntry or null (if not found).

newEntry

public NCacheEntry newEntry(java.lang.Object o)

Reserve space for a CacheEntry with key o.

Parameters:

o - the key for the NCacheEntry.

Returns:

a new CacheEntry initialized for the cache.

addEntry

public void addEntry(NCacheEntry ent)

Insert a CacheEntry into the cache.

Parameters:

ent - the CacheEntry to store.

remove

public void remove(java.lang.Object o)

Remove the Entry with key o from the cache.

Parameters:

o - the key for the CacheEntry.

clear

public void clear()

Clear the Cache from files.

getEntries

public java.util.Enumeration getEntries()

Get the CacheEntries in the cache.

Returns:

an Enumeration of the CacheEntries.

flush

public void flush()

Make sure that the cache is written to the disk.

run

public void run()

Loop in a cleaning loop.

setup

public void setup(java.util.Properties config)
           throws IllegalConfigurationException

Configure the cache system from the given config.

Parameters:

config - the Property describing the cache settings.

Throws:

IllegalConfigurationException - if some setting is strange.