public class CacheMap

Object
CacheMap

A cache map is essentially a hashtable that indexes entries based on age and is limited to a fixed size. Hence when an entry is placed into the cache map and the cache size needs to increase, the least referenced entry is removed. A cache hit is made both on fetching and putting, hence frequently fetched elements will never be removed from a sufficiently large cache. Cache can work purely in memory or swap data into storage based on user definitions. Notice that this class isn’t threadsafe.

Constructors

`public CacheMap()`	Default constructor
`public CacheMap(String prefix)`	Creates a cache map with a prefix string

Methods

`public int getCacheSize()`	Indicates the size of the memory cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!
`public void setCacheSize(int cacheSize)`	Indicates the size of the memory cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!
`public void put(Object key, Object value)`	Puts the given key/value pair in the cache
`public void delete(Object key)`	Deletes a cached entry
`public` `Object get(Object key)`	Returns the object matching the given key
`public void clearAllCache()`	Clears the caches for this cache object
`public void clearMemoryCache()`	Clears the memory cache
`public` `Vector getKeysInCache()`	Returns the keys for all the objects currently in cache, this is useful to traverse all the objects and refresh them without actually deleting the cache and fetching them from scratch.
`public void clearStorageCache()`	Clears the storage cache
`public int getStorageCacheSize()`	Indicates the size of the storage cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!
`public void setStorageCacheSize(int storageCacheSize)`	Indicates the size of the storage cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!
`public` `String getCachePrefix()`	A prefix prepended to storage entries to differentiate them
`public void setCachePrefix(String cachePrefix)`	A prefix prepended to storage entries to differentiate them
`public boolean isAlwaysStore()`	When set to true indicates that all entries should be persisted to storage for a constantly persisting cache
`public void setAlwaysStore(boolean alwaysStore)`	When set to true indicates that all entries should be persisted to storage for a constantly persisting cache

Inherited methods

From Object

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

Constructor details

CacheMap

public CacheMap()

Default constructor

CacheMap

public CacheMap(String prefix)

Creates a cache map with a prefix string

Parameters

prefix String: string to prepend to the cache entries in storage

Method details

getCacheSize

public int getCacheSize()

Indicates the size of the memory cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!

Returns

the cacheSize

setCacheSize

public void setCacheSize(int cacheSize)

Indicates the size of the memory cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!

Parameters

cacheSize int: the cacheSize to set

put

public void put(Object key, Object value)

Puts the given key/value pair in the cache

Parameters

key Object: the key
value Object: the value

delete

public void delete(Object key)

Deletes a cached entry

Parameters

key Object: entry to remove from the cache

get

public Object get(Object key)

Returns the object matching the given key

Parameters

key Object: key object

Returns

value from a previous put or null

clearAllCache

public void clearAllCache()

Clears the caches for this cache object

clearMemoryCache

public void clearMemoryCache()

Clears the memory cache

getKeysInCache

public Vector getKeysInCache()

Returns the keys for all the objects currently in cache, this is useful to traverse all the objects and refresh them without actually deleting the cache and fetching them from scratch.

Important this vector is a copy of a current state, keys might not exist anymore or might change, others might be added in the interim.

Returns

a vector containing a snapshot of the current elements within the cache.

clearStorageCache

public void clearStorageCache()

Clears the storage cache

getStorageCacheSize

public int getStorageCacheSize()

Indicates the size of the storage cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!

Returns

the storageCacheSize

setStorageCacheSize

public void setStorageCacheSize(int storageCacheSize)

Indicates the size of the storage cache after which the cache won’t grow further Size is indicated by number of elements stored and not by KB or similar benchmark!

Parameters

storageCacheSize int: the storageCacheSize to set

getCachePrefix

public String getCachePrefix()

A prefix prepended to storage entries to differentiate them

Returns

the cachePrefix

setCachePrefix

public void setCachePrefix(String cachePrefix)

A prefix prepended to storage entries to differentiate them

Parameters

cachePrefix String: the cachePrefix to set

isAlwaysStore

public boolean isAlwaysStore()

When set to true indicates that all entries should be persisted to storage for a constantly persisting cache

Returns

the alwaysStore

setAlwaysStore

public void setAlwaysStore(boolean alwaysStore)

When set to true indicates that all entries should be persisted to storage for a constantly persisting cache

Parameters

alwaysStore boolean: the alwaysStore to set