org.apache.flex.compiler.internal.caches

Class ConcurrentCacheStoreBase<T>

java.lang.Object

org.apache.flex.compiler.internal.caches.ConcurrentCacheStoreBase<T>

Direct Known Subclasses:

AssetTagCache, CSSDocumentCache, FileScopeCache, MXMLDataCache, PackageNamespaceDefinitionCache, SWCManager, SWFCache

public abstract class ConcurrentCacheStoreBase<T>
extends Object

A key-value pair cache store that supports concurrent access.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ConcurrentCacheStoreBase() Initialize the cache store.

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract T	createEntryValue(CacheStoreKeyBase key) Concrete class must implement this method to create a cache value object.
T	get(CacheStoreKeyBase key) Get a value from the cache store.
T	remove(CacheStoreKeyBase key) Remove a value from the cache
int	size() Get size of the cache table.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ConcurrentCacheStoreBase

protected ConcurrentCacheStoreBase()

Initialize the cache store.

Method Detail

get

public final T get(CacheStoreKeyBase key)

Get a value from the cache store. If the cache doesn't have a valid entry, it will obtain the value, add to the cache and return the value.

The implementation is thread-safe. The API looks like a "read" access, but when the cache doesn't have a hit, it will write an entry to the cache table. The first attempt queries the cache, so the read-lock allows parallelized read if no other thread is writing the cache. If there's no hit, the second attempt is to create a valid entry, store it in the cache and return it. This requires upgrading the read-lock to a write-lock.

Parameters:

key - cache key

Returns:

cached value

remove

public final T remove(CacheStoreKeyBase key)

Remove a value from the cache

Parameters:

key - cache key

Returns:

value for removed entry if an entry was removed.

size

public int size()

Get size of the cache table.

Returns:

size

createEntryValue

protected abstract T createEntryValue(CacheStoreKeyBase key)

Concrete class must implement this method to create a cache value object. Do NOT add the value to the cache in this method. get(CacheStoreKeyBase) is responsible for reading and writing the cache table.

Parameters:

key - cache key

Returns:

object to be cached.

toString

public String toString()

Overrides:

toString in class Object