ae.teletronics.cache

Class ChangingValueCache<K,V>

java.lang.Object

ae.teletronics.cache.ChangingValueCache<K,V>

Type Parameters:

K - Type of the cache-key

V - Type of the cache-value

Direct Known Subclasses:

ChangingValueAndLevelMultiCache

@ThreadSafe
public class ChangingValueCache<K,V>
extends Object

Key-value cache, where values can change. Several threads can collaborate in building the values. Therefore put operation has been replaced by modify operation - knowing about how to create the initial value if the entry is not already present in the cache, and knowing about how to modify the value (whether or not it existed in cache already)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ChangingValueCache.Builder<K,V> Builder for building ChangingValueCache instances

Field Summary

Fields

Modifier and Type	Field and Description
protected ThreadLocal<V>	alreadyWorkingOn
protected com.google.common.cache.Cache<K,V>	cache
protected com.google.common.base.Function<V,V>	defaultModifier
protected com.google.common.base.Supplier<V>	defaultNewCreator
protected com.google.common.collect.Interner<Integer>	newOrMovingCacheEntryInterner

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ChangingValueCache()

Method Summary

Modifier and Type	Method and Description
static <K,V> ChangingValueCache.Builder<K,V>	builder() Get a builder for building a ChangingValueCache instance
V	getAddIfNotPresent(K key) Calling getAddIfNotPresent(Object, Supplier) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) null
V	getAddIfNotPresent(K key, com.google.common.base.Supplier<V> newCreator) Get a cache-value of a cache-entry with a provided key, adding the cache-entry if not already present
protected Collection<com.google.common.cache.Cache<K,V>>	getAllCaches()
V	getIfPresent(K key) Get a cache-value of a cache-entry with a provided key
V	modify(K key, boolean createIfNotExists) Calling modify(Object, Supplier, Function, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) null * modifier (Function<V, V>) null * createIfNotExists (boolean) Provided createIfNotExist
V	modify(K key, com.google.common.base.Function<V,V> modifier, boolean createIfNotExists) Calling modify(Object, Supplier, Function, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) null * modifier (Function<V, V>) Provided modifier * createIfNotExists (boolean) Provided createIfNotExist
V	modify(K key, com.google.common.base.Supplier<V> newCreator, boolean createIfNotExists) Calling modify(Object, Supplier, Function, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) Provided new-creator * modifier (Function<V, V>) null * createIfNotExists (boolean) Provided createIfNotExist
V	modify(K key, com.google.common.base.Supplier<V> newCreator, com.google.common.base.Function<V,V> modifier, boolean createIfNotExists) Calling modify(Object, Supplier, Function, boolean, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) Provided new-creator * modifier (Function<V, V>) Provided modifier * createIfNotExists (boolean) Provided createIfNotExist * supportRecursiveCalls (boolean) false
V	modify(K key, com.google.common.base.Supplier<V> newCreator, com.google.common.base.Function<V,V> modifier, boolean createIfNotExists, boolean supportRecursiveCalls) Modify cache-entry using provided new-creator and modifier
void	modifyAll(com.google.common.base.Predicate<K> keyPredicate, com.google.common.base.Predicate<V> valuePredicate) Calling modifyAll(Predicate, Predicate, Function) with * keyPredicate (Predicate<K>) Provided keyPredicate * valuePredicate (Predicate<V>) Provided valuePredicate * modifier (Function<V, V>) null * supportRecursiveCalls (boolean) false
void	modifyAll(com.google.common.base.Predicate<K> keyPredicate, com.google.common.base.Predicate<V> valuePredicate, com.google.common.base.Function<V,V> modifier) Calling modifyAll(Predicate, Predicate, Function, boolean) with * keyPredicate (Predicate<K>) Provided keyPredicate * valuePredicate (Predicate<V>) Provided valuePredicate * modifier (Function<V, V>) Provided modifier * supportRecursiveCalls (boolean) false
void	modifyAll(com.google.common.base.Predicate<K> keyPredicate, com.google.common.base.Predicate<V> valuePredicate, com.google.common.base.Function<V,V> modifier, boolean supportRecursiveCalls) Sequentially calling modify(Object, Supplier, Function, boolean, boolean) for a selected set of existing cache-entries.
protected V	modifyImpl(K key, com.google.common.base.Supplier<V> newCreator, com.google.common.base.Function<V,V> modifier, boolean createIfNotExists, boolean supportRecursiveCalls)
long	size()

Methods inherited from class java.lang.Object

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

Field Detail

defaultNewCreator

protected com.google.common.base.Supplier<V> defaultNewCreator

defaultModifier

protected com.google.common.base.Function<V,V> defaultModifier

cache

protected com.google.common.cache.Cache<K,V> cache

newOrMovingCacheEntryInterner

protected final com.google.common.collect.Interner<Integer> newOrMovingCacheEntryInterner

alreadyWorkingOn

protected ThreadLocal<V> alreadyWorkingOn

Constructor Detail

ChangingValueCache

protected ChangingValueCache()

Method Detail

builder

public static <K,V> ChangingValueCache.Builder<K,V> builder()

Get a builder for building a ChangingValueCache instance

Type Parameters:

K - Type of the cache-key of the built cache

V - Type of the cache-value of the built cache

Returns:

The builder to be used

modify

public final V modify(K key,
                      boolean createIfNotExists)

Calling modify(Object, Supplier, Function, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) null * modifier (Function<V, V>) null * createIfNotExists (boolean) Provided createIfNotExist

Parameters:

key - To be forwarded to modify call

createIfNotExists - To be forwarded to modify call

Returns:

The value now on the cache-entry

modify

public final V modify(K key,
                      com.google.common.base.Function<V,V> modifier,
                      boolean createIfNotExists)

Calling modify(Object, Supplier, Function, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) null * modifier (Function<V, V>) Provided modifier * createIfNotExists (boolean) Provided createIfNotExist

Parameters:

key - To be forwarded to modify call

modifier - To be forwarded to modify call

createIfNotExists - To be forwarded to modify call

Returns:

The value now on the cache-entry

modify

public final V modify(K key,
                      com.google.common.base.Supplier<V> newCreator,
                      boolean createIfNotExists)

Calling modify(Object, Supplier, Function, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) Provided new-creator * modifier (Function<V, V>) null * createIfNotExists (boolean) Provided createIfNotExist

Parameters:

key - To be forwarded to modify call

newCreator - To be forwarded to modify call

createIfNotExists - To be forwarded to modify call

Returns:

The value now on the cache-entry

modify

public final V modify(K key,
                      com.google.common.base.Supplier<V> newCreator,
                      com.google.common.base.Function<V,V> modifier,
                      boolean createIfNotExists)

Calling modify(Object, Supplier, Function, boolean, boolean) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) Provided new-creator * modifier (Function<V, V>) Provided modifier * createIfNotExists (boolean) Provided createIfNotExist * supportRecursiveCalls (boolean) false

Parameters:

key - To be forwarded to modify call

newCreator - To be forwarded to modify call

modifier - To be forwarded to modify call

createIfNotExists - To be forwarded to modify call

Returns:

The value now on the cache-entry

modify

public final V modify(K key,
                      com.google.common.base.Supplier<V> newCreator,
                      com.google.common.base.Function<V,V> modifier,
                      boolean createIfNotExists,
                      boolean supportRecursiveCalls)

Modify cache-entry using provided new-creator and modifier

Parameters:

key - Key for cache-entry

newCreator - Used to generate the new cache-value, if it does not already exist (if null default new-creator will be used)

modifier - Used to modify the cache-value (if null default modifier will be used)

createIfNotExists - Create the entry if it does not already exist

supportRecursiveCalls - Support modifier that (directly or indirectly) calls modify on THE SAME cache-key (and the same thread). Be careful setting this to true * Modifier that calls modify on cache-key that is NOT the same will not work correctly - it will when set to false (default) * Will add a small performance-hit

Returns:

The value now on the cache-entry

modifyAll

public final void modifyAll(com.google.common.base.Predicate<K> keyPredicate,
                            com.google.common.base.Predicate<V> valuePredicate)

Calling modifyAll(Predicate, Predicate, Function) with * keyPredicate (Predicate<K>) Provided keyPredicate * valuePredicate (Predicate<V>) Provided valuePredicate * modifier (Function<V, V>) null * supportRecursiveCalls (boolean) false

Parameters:

keyPredicate - To be forwarded to modifyAll call

valuePredicate - To be forwarded to modifyAll call

modifyAll

public final void modifyAll(com.google.common.base.Predicate<K> keyPredicate,
                            com.google.common.base.Predicate<V> valuePredicate,
                            com.google.common.base.Function<V,V> modifier)

Calling modifyAll(Predicate, Predicate, Function, boolean) with * keyPredicate (Predicate<K>) Provided keyPredicate * valuePredicate (Predicate<V>) Provided valuePredicate * modifier (Function<V, V>) Provided modifier * supportRecursiveCalls (boolean) false

Parameters:

keyPredicate - To be forwarded to modifyAll call

valuePredicate - To be forwarded to modifyAll call

modifier - To be forwarded to modifyAll call

modifyAll

public final void modifyAll(com.google.common.base.Predicate<K> keyPredicate,
                            com.google.common.base.Predicate<V> valuePredicate,
                            com.google.common.base.Function<V,V> modifier,
                            boolean supportRecursiveCalls)

Sequentially calling modify(Object, Supplier, Function, boolean, boolean) for a selected set of existing cache-entries. Called with * key (K) The cache-key of the cache-entry in the selected set * newCreator (Supplier<V>) null * modifier (Function<V, V>) Provided modifier * boolean createIfNotExists false * boolean supportRecursiveCalls Provided supportRecursiveCalls

Parameters:

keyPredicate - A cache-entry is (potentially - if valuePredicate also accepts) included in the selected set iff feeding keyPredicate with cache-key returns true

valuePredicate - A cache-entry is (potentially - if keyPredicate also accepts) included in the selected set iff feeding valuePredicate with cache-value returns true

modifier - Used for the modify calls

supportRecursiveCalls - Used for the modify calls The existing cache-entry has to match both criteria to be included in the set

modifyImpl

protected V modifyImpl(K key,
                       com.google.common.base.Supplier<V> newCreator,
                       com.google.common.base.Function<V,V> modifier,
                       boolean createIfNotExists,
                       boolean supportRecursiveCalls)

getAllCaches

protected Collection<com.google.common.cache.Cache<K,V>> getAllCaches()

getIfPresent

public V getIfPresent(K key)

Get a cache-value of a cache-entry with a provided key

Parameters:

key - The key of the cache-entry

Returns:

The cache-value (or null if not present in cache)

size

public long size()

Returns:

Number of cache-entries in the cache

getAddIfNotPresent

public V getAddIfNotPresent(K key)

Calling getAddIfNotPresent(Object, Supplier) (and returning value from) with * key (K) Provided key * newCreator (Supplier<V>) null

Parameters:

key - To be forwarded to getAddIfNotPresent call

Returns:

The cache-value

getAddIfNotPresent

public V getAddIfNotPresent(K key,
                            com.google.common.base.Supplier<V> newCreator)

Get a cache-value of a cache-entry with a provided key, adding the cache-entry if not already present

Parameters:

key - The key of the cache entry

newCreator - Used to generate the new cache-value, if it does not already exist (if null default new-creator will be used)

Returns:

The cache-value