Package com.broadleafcommerce.enterprise.workflow.clone

Class CloneLibCacheConcurrentMapWrapper

java.lang.Object

com.broadleafcommerce.enterprise.workflow.clone.CloneLibCacheConcurrentMapWrapper

All Implemented Interfaces:

CloneLibCacheWrapper

public class CloneLibCacheConcurrentMapWrapper
extends Object
implements CloneLibCacheWrapper

CloneLibCacheWrapper implementation that uses a ConcurrentHashMap as the backing cache. This cache has high performance and concurrency for gets. Adds are slightly less efficient because of some synchronization. Removals are even less efficient because of synchronization, but should constitute a much less frequent circumstance.

Author:

Jeff Fischer

See Also:

• CloneLibCacheWrapper

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CLONELIB_REFRESH_CACHE

Fields inherited from interface com.broadleafcommerce.enterprise.workflow.clone.CloneLibCacheWrapper

MODE_COMPLETE, MODE_PARTIAL, MODE_UNSET

Constructor Summary

Constructors

Constructor	Description
CloneLibCacheConcurrentMapWrapper(long maxSize, long ttl)

Method Summary

Modifier and Type	Method	Description
void	addCacheItem(WorkflowCloneLibrary item)	Add a WorkflowCloneLibrary instance to the cache.
void	auditKey(String key)	Audit a cache member based on the key for ttl status.
void	auditSize()	Audit the entire cache based on total size.
boolean	clear()	Queue all items in the cache for removal.
void	dequeueForAdd(WorkflowCloneLibrary item)	Remove a specific queued add item from the backing cache's add queue.
void	destroy()	Perform any operations required to clean up the cache on container exit.
List<WorkflowCloneLibrary>	getAddQueue()	Retrieve the list of all items currently queued for addition.
WorkflowCloneLibrary	getByCloneKey(String key)	Retrieve an item from the backing cache using a fetch key based on the clone id.
protected WorkflowCloneLibrary	getByKey(String key)
WorkflowCloneLibrary	getByOriginalKey(String key)	Retrieve an item from the backing cache using a fetch key based on the original id.
WorkflowCloneLibrary	getByOriginalKeyFromInternalCacheOnly(String key)	Retrieve an item from the backing cache using a fetch key based on the original id.
int	getMode()
AbsentAwareMap<String,CloneLibCacheItem>	getRefreshCache()	Provide a threadlocal temporary cache.
long	getUniqueElementCount()	Retrieve the number of unique members represented in the cache.
boolean	isRemovalQueueEmpty()	Whether or not there are any cache members queued for removal via CloneLibCacheWrapper.reliableRemoveCacheItemGroup(Set).
void	queueForAdd(List<WorkflowCloneLibrary> group)	Queue a group of elements for addition to the queue.
void	releaseCacheItems()	Any cache items that have been reserved against the current thread will be released.
void	reliableRemoveCacheItemGroup(Set<WorkflowCloneLibrary> group)	Remove a WorkflowCloneLibrary instance list from the cache.
boolean	removeCacheItems(Set<WorkflowCloneLibrary> items)	Remove a WorkflowCloneLibrary instance list from the cache.
WorkflowCloneLibrary	reserveCacheItem(String key)	Reserve a cache item using the key for the item.
void	setMode(int mode)	Establish how the cache will deal with cache misses and manage the size of the cache.

Methods inherited from class java.lang.Object

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

Field Details

CLONELIB_REFRESH_CACHE

public static final String CLONELIB_REFRESH_CACHE

See Also:

• Constant Field Values

Constructor Details

CloneLibCacheConcurrentMapWrapper

public CloneLibCacheConcurrentMapWrapper(long maxSize,
 long ttl)

Method Details

clear

public boolean clear()

Description copied from interface: CloneLibCacheWrapper

Queue all items in the cache for removal. This should only be applied when CloneLibCacheWrapper.getMode() is CloneLibCacheWrapper.MODE_PARTIAL.

Specified by:

clear in interface CloneLibCacheWrapper

Returns:

queue the cache members for removal

addCacheItem

public void addCacheItem(WorkflowCloneLibrary item)

Description copied from interface: CloneLibCacheWrapper

Add a WorkflowCloneLibrary instance to the cache.

Specified by:

addCacheItem in interface CloneLibCacheWrapper

Parameters:

item - an instance to add to the cache

queueForAdd

public void queueForAdd(List<WorkflowCloneLibrary> group)

Description copied from interface: CloneLibCacheWrapper

Queue a group of elements for addition to the queue. The group of elements should be present in the cache in their entirety (or not at all) at the time of a call to CloneLibCacheWrapper.getByCloneKey(String) or CloneLibCacheWrapper.getByOriginalKey(String).

Specified by:

queueForAdd in interface CloneLibCacheWrapper

Parameters:

group - the group of items to add as a unit

dequeueForAdd

public void dequeueForAdd(WorkflowCloneLibrary item)

Description copied from interface: CloneLibCacheWrapper

Remove a specific queued add item from the backing cache's add queue.

Specified by:

dequeueForAdd in interface CloneLibCacheWrapper

Parameters:

item - the item to remove from the queue

getAddQueue

public List<WorkflowCloneLibrary> getAddQueue()

Description copied from interface: CloneLibCacheWrapper

Retrieve the list of all items currently queued for addition.

Specified by:

getAddQueue in interface CloneLibCacheWrapper

Returns:

the queued items

See Also:

• CloneLibCacheWrapper.queueForAdd(List)

setMode

public void setMode(int mode)

Description copied from interface: CloneLibCacheWrapper

Establish how the cache will deal with cache misses and manage the size of the cache. A mode of CloneLibCacheWrapper.MODE_COMPLETE signifies the cache is populated with the entire contents of the database table backing the WorkflowCloneLibraryImpl entity. In this mode, cache misses are understood to not be present in the datastore and are not further managed in the cache. A mode of CloneLibCacheWrapper.MODE_PARTIAL signifies the cache is only partially populated with the contents of the database table and new entries are added on demand. In this mode, cache misses are kept track of in the cache, which can result in larger overall cache sizes. A mode of CloneLibCacheWrapper.MODE_UNSET simply means the mode has not been specified, or has not yet been determined.

CloneLibCacheWrapper.MODE_COMPLETE is useful in multitenant situations where there are many sites, but few site-level overrides. In such a situation, it is efficient to keep the entire override cache in memory. See CloneCache.fetchAllReferencesMaxMulti for more information on how to set the threshold for determining the number of cache members for which CloneLibCacheWrapper.MODE_COMPLETE is qualified.

CloneLibCacheWrapper.MODE_PARTIAL is useful in multitenant scenarios where there are many site-level overrides, but only a portion of those overrides are accessed frequently. See CloneCache.defaultCacheImplementationMaxSizeHint and CloneCache.defaultCacheImplementationTtlMilliseconds for more information on sizing hints to the system regarding max cache size and member time-to-live.

Specified by:

setMode in interface CloneLibCacheWrapper

Parameters:

mode - the cache management mode

getMode

public int getMode()

Specified by:

getMode in interface CloneLibCacheWrapper

Returns:

the cache management mode

See Also:

• CloneLibCacheWrapper.setMode(int)

destroy

public void destroy()

Description copied from interface: CloneLibCacheWrapper

Perform any operations required to clean up the cache on container exit.

Specified by:

destroy in interface CloneLibCacheWrapper

See Also:

• PreDestroy

reliableRemoveCacheItemGroup

public void reliableRemoveCacheItemGroup(Set<WorkflowCloneLibrary> group)

Description copied from interface: CloneLibCacheWrapper

Remove a WorkflowCloneLibrary instance list from the cache. This removal will retry should the system be unable to initially remove one or more of the items from the cache. Possible reasons for not being able to remove include one or more of the removal requests targeting reserved items (see CloneLibCacheWrapper.reserveCacheItem(String)).

Specified by:

reliableRemoveCacheItemGroup in interface CloneLibCacheWrapper

Parameters:

group - a representative instance list used to search the cache for matching cache members to remove

removeCacheItems

public boolean removeCacheItems(Set<WorkflowCloneLibrary> items)

Description copied from interface: CloneLibCacheWrapper

Remove a WorkflowCloneLibrary instance list from the cache. May not succeed if an item in the list is currently reserved by another thread.

Specified by:

removeCacheItems in interface CloneLibCacheWrapper

Parameters:

items - a representative instance list used to search the cache for matching cache members to remove

Returns:

Whether or not the item was removed from the cache (either the item was not in the cache, or it was reserved by another thread)

reserveCacheItem

public WorkflowCloneLibrary reserveCacheItem(String key)

Description copied from interface: CloneLibCacheWrapper

Reserve a cache item using the key for the item. This reservation is against the current thread. Reserved items cannot be removed from the cache. If the item was successfully reserved, it is returned. Otherwise, it will return null.

Specified by:

reserveCacheItem in interface CloneLibCacheWrapper

Parameters:

key - the cache key

Returns:

the cache member or null if not found

See Also:

• CloneLibCacheWrapper.releaseCacheItems()

isRemovalQueueEmpty

public boolean isRemovalQueueEmpty()

Description copied from interface: CloneLibCacheWrapper

Whether or not there are any cache members queued for removal via CloneLibCacheWrapper.reliableRemoveCacheItemGroup(Set).

Specified by:

isRemovalQueueEmpty in interface CloneLibCacheWrapper

Returns:

if cache members are queued for removal

releaseCacheItems

public void releaseCacheItems()

Description copied from interface: CloneLibCacheWrapper

Any cache items that have been reserved against the current thread will be released. This has the impact of freeing up a cache item for removal should all reservations be released.

Specified by:

releaseCacheItems in interface CloneLibCacheWrapper

See Also:

• CloneLibCacheWrapper.reserveCacheItem(String)

auditSize

public void auditSize()

Description copied from interface: CloneLibCacheWrapper

Audit the entire cache based on total size. Oldest cache members are removed first in order to reach the cache max size target. The system max a best-effort attempt to maintain a cache size that is not larger than the configured max size, but the cache size may occasionally be exceeded. Cache members that are reserved are not removed until released. This only applies to a CloneLibCacheWrapper.getMode() of CloneLibCacheWrapper.MODE_PARTIAL.

Specified by:

auditSize in interface CloneLibCacheWrapper

See Also:

• CloneLibCacheWrapper.releaseCacheItems()
• CloneCache.defaultCacheImplementationMaxSizeHint

auditKey

public void auditKey(String key)

Description copied from interface: CloneLibCacheWrapper

Audit a cache member based on the key for ttl status. If the ttl for the item has expired, the cache member will be evicted if it is not reserved. This only applies to a CloneLibCacheWrapper.getMode() of CloneLibCacheWrapper.MODE_PARTIAL.

Specified by:

auditKey in interface CloneLibCacheWrapper

Parameters:

key - the cache key to check

See Also:

• CloneCache.defaultCacheImplementationTtlMilliseconds
• CloneLibCacheWrapper.releaseCacheItems()

getByOriginalKey

public WorkflowCloneLibrary getByOriginalKey(String key)

Description copied from interface: CloneLibCacheWrapper

Retrieve an item from the backing cache using a fetch key based on the original id.

Specified by:

getByOriginalKey in interface CloneLibCacheWrapper

Parameters:

key - the cache item key

Returns:

the cache member

getByCloneKey

public WorkflowCloneLibrary getByCloneKey(String key)

Description copied from interface: CloneLibCacheWrapper

Retrieve an item from the backing cache using a fetch key based on the clone id.

Specified by:

getByCloneKey in interface CloneLibCacheWrapper

Parameters:

key - the cache item key

Returns:

the cache member

getByOriginalKeyFromInternalCacheOnly

public WorkflowCloneLibrary getByOriginalKeyFromInternalCacheOnly(String key)

Description copied from interface: CloneLibCacheWrapper

Retrieve an item from the backing cache using a fetch key based on the original id. This retrieval only utilizes the backing cache and does not look at the CloneLibCacheWrapper.getRefreshCache().

Specified by:

getByOriginalKeyFromInternalCacheOnly in interface CloneLibCacheWrapper

Parameters:

key - the original key

Returns:

the cache member

getUniqueElementCount

public long getUniqueElementCount()

Description copied from interface: CloneLibCacheWrapper

Retrieve the number of unique members represented in the cache. The backing cache may contain multiple keys per unique cache member, so this method should be used to determine the correct count of unique members.

Specified by:

getUniqueElementCount in interface CloneLibCacheWrapper

Returns:

the unique member count

getRefreshCache

public AbsentAwareMap<String,CloneLibCacheItem> getRefreshCache()

Provide a threadlocal temporary cache.

Specified by:

getRefreshCache in interface CloneLibCacheWrapper

Returns:

temporary cache to hold reads for items queued for removal

getByKey

protected WorkflowCloneLibrary getByKey(String key)