ehcache

net.sf.ehcache.store
Class TxCopyingCacheStore<T extends Store>

java.lang.Object
  extended by net.sf.ehcache.store.TxCopyingCacheStore<T>
Type Parameters:
T - the store type it wraps
All Implemented Interfaces:
Store

public final class TxCopyingCacheStore<T extends Store>
extends Object

Copies elements, either on read, write or both before using the underlying store to actually store things. When copying both ways, the store might not see the same types being stored. Also exposes a method to get the old value from an entry currently mutated in a transaction.

Author:
ljacomet

Field Summary
 
Fields inherited from interface net.sf.ehcache.store.Store
CLUSTER_COHERENT, NODE_COHERENT
 
Constructor Summary
TxCopyingCacheStore(T store, boolean copyOnRead, boolean copyOnWrite, ReadWriteCopyStrategy<Element> copyStrategyInstance, ClassLoader loader)
          Creates a copying instance of store, that wraps the actual storage
 
Method Summary
 void addStoreListener(StoreListener listener)
          Add a listener to the store.
 boolean bufferFull()
          Some store types, such as the disk stores can fill their write buffers if puts come in too fast.
 boolean containsKey(Object key)
          A check to see if a key is in the Store.
 boolean containsKeyInMemory(Object key)
          A check to see if a key is in the Store and is currently held in memory.
 boolean containsKeyOffHeap(Object key)
          A check to see if a key is in the Store and is currently held off-heap.
 boolean containsKeyOnDisk(Object key)
          A check to see if a key is in the Store and is currently held on disk.
 void dispose()
          Prepares for shutdown.
 Results executeQuery(StoreQuery query)
          Execute the given query on this store
 void expireElements()
          Expire all elements.
 void flush()
          Flush elements to persistent store.
 Element get(Object key)
          Gets an item from the cache.
 Map<Object,Element> getAll(Collection<?> keys)
          Retries the elements associated with a set of keys and update the statistics Keys which are not present in the cache will have null values associated with them in the returned map
 Map<Object,Element> getAllQuiet(Collection<?> keys)
          Retries the elements associated with a set of keys without updating the statistics Keys which are not present in the cache will have null values associated with them in the returned map
protected  CopyStrategyHandler getCopyStrategyHandler()
          Accessor to the CopyStrategyHandler
 Policy getInMemoryEvictionPolicy()
           
 int getInMemorySize()
          Returns the current local in-memory store size
 long getInMemorySizeInBytes()
          Gets the size of the in-memory portion of the store, in bytes.
 Object getInternalContext()
          This should not be used, and will generally return null
 List getKeys()
          Gets an Array of the keys for all elements in the disk store.
 Object getMBean()
          Optional implementation specific MBean exposed by the store.
 int getOffHeapSize()
          Returns the current local off-heap store size
 long getOffHeapSizeInBytes()
          Gets the size of the off-heap portion of the store, in bytes.
 Element getOldElement(Object key)
          Gets an element from the store, choosing the old value in case the element is currently mutated inside a transaction.
 int getOnDiskSize()
          Returns the current local on-disk store size
 long getOnDiskSizeInBytes()
          Gets the size of the on-disk portion of the store, in bytes.
 Element getQuiet(Object key)
          Gets an Element from the Store, without updating statistics
<S> Attribute<S>
getSearchAttribute(String attributeName)
          Retrieve the given named search attribute
 Set<Attribute> getSearchAttributes()
           
 int getSize()
          Returns the current local store size
 Status getStatus()
          Returns the cache status.
 int getTerracottaClusteredSize()
          Returns the current Terracotta clustered store size
 T getUnderlyingStore()
          Accessor to the underlying store
 boolean hasAbortedSizeOf()
          Checks if the cache may contain elements for which the SizeOf engine gave up and only partially calculated the size.
 boolean isCacheCoherent()
          Indicates whether this store provides a coherent view of all the elements in a cache.
 boolean isClusterCoherent()
          Returns true if the cache is in coherent mode cluster-wide.
 boolean isNodeCoherent()
          Returns true if the cache is in coherent mode for the current node.
 boolean put(Element e)
          Puts an item into the store.
 void putAll(Collection<Element> elements)
          Puts a collection of elements into the store.
 Element putIfAbsent(Element element)
          Put an element in the store if no element is currently mapped to the elements key.
 boolean putWithWriter(Element element, CacheWriterManager writerManager)
          Puts an item into the store and the cache writer manager in an atomic operation
 void recalculateSize(Object key)
          Recalculate size of the element mapped to the key
 Element remove(Object key)
          Removes an item from the cache.
 void removeAll()
          Remove all of the elements from the store.
 void removeAll(Collection<?> keys)
          Removes a collection of elements from the cache.
 Element removeElement(Element element, ElementValueComparator comparator)
          Remove the Element mapped to the key for the supplied element if the value of the supplied Element is equal to the value of the cached Element.
 void removeStoreListener(StoreListener listener)
          Remove listener from store.
 Element removeWithWriter(Object key, CacheWriterManager writerManager)
          Removes an item from the store and the cache writer manager in an atomic operation.
 Element replace(Element element)
          Replace the cached element only if an Element is currently cached for this key
 boolean replace(Element old, Element element, ElementValueComparator comparator)
          Replace the cached element only if the value of the current Element is equal to the value of the supplied old Element.
 void setAttributeExtractors(Map<String,AttributeExtractor> extractors)
          Inform this store of the configured attribute extractors.
 void setInMemoryEvictionPolicy(Policy policy)
          Sets the eviction policy strategy.
 void setNodeCoherent(boolean coherent)
          Sets the cache in coherent or incoherent mode for the current node depending on the parameter.
 void waitUntilClusterCoherent()
          This method waits until the cache is in coherent mode in all the connected nodes.
static ElementValueComparator wrap(ElementValueComparator comparator, CacheConfiguration cacheConfiguration)
          Wraps the given ElementValueComparator if the configuration requires copy on read
static Store wrapTxStore(AbstractTransactionStore cacheStore, CacheConfiguration cacheConfiguration)
          Wraps the Store instance passed in, should any copy occur
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TxCopyingCacheStore

public TxCopyingCacheStore(T store,
                           boolean copyOnRead,
                           boolean copyOnWrite,
                           ReadWriteCopyStrategy<Element> copyStrategyInstance,
                           ClassLoader loader)
Creates a copying instance of store, that wraps the actual storage

Parameters:
store - the real store
copyOnRead - whether to copy on reads
copyOnWrite - whether to copy on writes
copyStrategyInstance - the copy strategy to use on every copy operation
loader - classloadaer of the containing cache
Method Detail

getOldElement

public Element getOldElement(Object key)
Gets an element from the store, choosing the old value in case the element is currently mutated inside a transaction.

Parameters:
key - the key to look for
Returns:
the matching element, null if not found

wrapTxStore

public static Store wrapTxStore(AbstractTransactionStore cacheStore,
                                CacheConfiguration cacheConfiguration)
Wraps the Store instance passed in, should any copy occur

Parameters:
cacheStore - the store
cacheConfiguration - the cache config for that store
Returns:
the wrapped Store if copying is required, or the Store instance passed in

wrap

public static ElementValueComparator wrap(ElementValueComparator comparator,
                                          CacheConfiguration cacheConfiguration)
Wraps the given ElementValueComparator if the configuration requires copy on read

Parameters:
comparator - the comparator to wrap
cacheConfiguration - the cache configuration
Returns:
the comparator passed if no copy needed, a wrapped comparator otherwise

addStoreListener

public void addStoreListener(StoreListener listener)
Description copied from interface: Store
Add a listener to the store.

Specified by:
addStoreListener in interface Store

removeStoreListener

public void removeStoreListener(StoreListener listener)
Description copied from interface: Store
Remove listener from store.

Specified by:
removeStoreListener in interface Store

put

public boolean put(Element e)
            throws CacheException
Description copied from interface: Store
Puts an item into the store.

Specified by:
put in interface Store
Returns:
true if this is a new put for the key or element is null. Returns false if it was an update.
Throws:
CacheException

putAll

public void putAll(Collection<Element> elements)
            throws CacheException
Description copied from interface: Store
Puts a collection of elements into the store.

Specified by:
putAll in interface Store
Parameters:
elements - Collection of elements to be put in the store
Throws:
CacheException

putWithWriter

public boolean putWithWriter(Element element,
                             CacheWriterManager writerManager)
                      throws CacheException
Description copied from interface: Store
Puts an item into the store and the cache writer manager in an atomic operation

Specified by:
putWithWriter in interface Store
Returns:
true if this is a new put for the key or element is null. Returns false if it was an update.
Throws:
CacheException

get

public Element get(Object key)
Description copied from interface: Store
Gets an item from the cache.

Specified by:
get in interface Store

getQuiet

public Element getQuiet(Object key)
Description copied from interface: Store
Gets an Element from the Store, without updating statistics

Specified by:
getQuiet in interface Store
Returns:
The element

getKeys

public List getKeys()
Description copied from interface: Store
Gets an Array of the keys for all elements in the disk store.

Specified by:
getKeys in interface Store
Returns:
An List of Serializable keys

remove

public Element remove(Object key)
Description copied from interface: Store
Removes an item from the cache.

Specified by:
remove in interface Store

removeAll

public void removeAll(Collection<?> keys)
Description copied from interface: Store
Removes a collection of elements from the cache.

Specified by:
removeAll in interface Store

removeWithWriter

public Element removeWithWriter(Object key,
                                CacheWriterManager writerManager)
                         throws CacheException
Description copied from interface: Store
Removes an item from the store and the cache writer manager in an atomic operation.

Specified by:
removeWithWriter in interface Store
Throws:
CacheException

removeAll

public void removeAll()
               throws CacheException
Description copied from interface: Store
Remove all of the elements from the store.

If there are registered CacheEventListeners they are notified of the expiry or removal of the Element as each is removed.

Specified by:
removeAll in interface Store
Throws:
CacheException

putIfAbsent

public Element putIfAbsent(Element element)
                    throws NullPointerException
Description copied from interface: Store
Put an element in the store if no element is currently mapped to the elements key.

Specified by:
putIfAbsent in interface Store
Parameters:
element - element to be added
Returns:
the element previously cached for this key, or null if none.
Throws:
NullPointerException - if the element is null, or has a null key

removeElement

public Element removeElement(Element element,
                             ElementValueComparator comparator)
                      throws NullPointerException
Description copied from interface: Store
Remove the Element mapped to the key for the supplied element if the value of the supplied Element is equal to the value of the cached Element. This is a CAS operation. It is consistent even against a distributed cache that is not coherent. If the old value is stale when this operation is attempted the remove does not take place.

Specified by:
removeElement in interface Store
Parameters:
element - Element to be removed
comparator - ElementValueComparator to use to compare elements
Returns:
the Element removed or null if no Element was removed
Throws:
NullPointerException - if the element is null, or has a null key

replace

public boolean replace(Element old,
                       Element element,
                       ElementValueComparator comparator)
                throws NullPointerException,
                       IllegalArgumentException
Description copied from interface: Store
Replace the cached element only if the value of the current Element is equal to the value of the supplied old Element.

Specified by:
replace in interface Store
Parameters:
old - Element to be test against
element - Element to be cached
comparator - ElementValueComparator to use to compare elements
Returns:
true is the Element was replaced
Throws:
NullPointerException - if the either Element is null or has a null key
IllegalArgumentException - if the two Element keys are non-null but not equal

replace

public Element replace(Element element)
                throws NullPointerException
Description copied from interface: Store
Replace the cached element only if an Element is currently cached for this key

Specified by:
replace in interface Store
Parameters:
element - Element to be cached
Returns:
the Element previously cached for this key, or null if no Element was cached
Throws:
NullPointerException - if the Element is null or has a null key

dispose

public void dispose()
Description copied from interface: Store
Prepares for shutdown.

Specified by:
dispose in interface Store

getSize

public int getSize()
Description copied from interface: Store
Returns the current local store size

Specified by:
getSize in interface Store
Returns:
the count of the Elements in the Store on the local machine

getInMemorySize

public int getInMemorySize()
Description copied from interface: Store
Returns the current local in-memory store size

Specified by:
getInMemorySize in interface Store
Returns:
the count of the Elements in the Store and in-memory on the local machine

getOffHeapSize

public int getOffHeapSize()
Description copied from interface: Store
Returns the current local off-heap store size

Specified by:
getOffHeapSize in interface Store
Returns:
the count of the Elements in the Store and off-heap on the local machine

getOnDiskSize

public int getOnDiskSize()
Description copied from interface: Store
Returns the current local on-disk store size

Specified by:
getOnDiskSize in interface Store
Returns:
the count of the Elements in the Store and on-disk on the local machine

getTerracottaClusteredSize

public int getTerracottaClusteredSize()
Description copied from interface: Store
Returns the current Terracotta clustered store size

Specified by:
getTerracottaClusteredSize in interface Store
Returns:
the count of the Elements in the Store across the cluster

getInMemorySizeInBytes

public long getInMemorySizeInBytes()
Description copied from interface: Store
Gets the size of the in-memory portion of the store, in bytes.

This method may be expensive to run, depending on implementation. Implementers may choose to return an approximate size.

Specified by:
getInMemorySizeInBytes in interface Store
Returns:
the approximate in-memory size of the store in bytes

getOffHeapSizeInBytes

public long getOffHeapSizeInBytes()
Description copied from interface: Store
Gets the size of the off-heap portion of the store, in bytes.

Specified by:
getOffHeapSizeInBytes in interface Store
Returns:
the approximate off-heap size of the store in bytes

getOnDiskSizeInBytes

public long getOnDiskSizeInBytes()
Description copied from interface: Store
Gets the size of the on-disk portion of the store, in bytes.

Specified by:
getOnDiskSizeInBytes in interface Store
Returns:
the on-disk size of the store in bytes

hasAbortedSizeOf

public boolean hasAbortedSizeOf()
Description copied from interface: Store
Checks if the cache may contain elements for which the SizeOf engine gave up and only partially calculated the size.

Specified by:
hasAbortedSizeOf in interface Store
Returns:
true if at least one partially sized element may be in the cache

getStatus

public Status getStatus()
Description copied from interface: Store
Returns the cache status.

Specified by:
getStatus in interface Store

containsKey

public boolean containsKey(Object key)
Description copied from interface: Store
A check to see if a key is in the Store.

Specified by:
containsKey in interface Store
Parameters:
key - The Element key
Returns:
true if found. No check is made to see if the Element is expired. 1.2

containsKeyOnDisk

public boolean containsKeyOnDisk(Object key)
Description copied from interface: Store
A check to see if a key is in the Store and is currently held on disk.

Specified by:
containsKeyOnDisk in interface Store
Parameters:
key - The Element key
Returns:
true if found. No check is made to see if the Element is expired.

containsKeyOffHeap

public boolean containsKeyOffHeap(Object key)
Description copied from interface: Store
A check to see if a key is in the Store and is currently held off-heap.

Specified by:
containsKeyOffHeap in interface Store
Parameters:
key - The Element key
Returns:
true if found. No check is made to see if the Element is expired.

containsKeyInMemory

public boolean containsKeyInMemory(Object key)
Description copied from interface: Store
A check to see if a key is in the Store and is currently held in memory.

Specified by:
containsKeyInMemory in interface Store
Parameters:
key - The Element key
Returns:
true if found. No check is made to see if the Element is expired.

expireElements

public void expireElements()
Description copied from interface: Store
Expire all elements.

Specified by:
expireElements in interface Store

flush

public void flush()
           throws IOException
Description copied from interface: Store
Flush elements to persistent store.

Specified by:
flush in interface Store
Throws:
IOException - if any IO error occurs

bufferFull

public boolean bufferFull()
Description copied from interface: Store
Some store types, such as the disk stores can fill their write buffers if puts come in too fast. The thread will wait for a short time before checking again.

Specified by:
bufferFull in interface Store
Returns:
true if the store write buffer is backed up.

getInMemoryEvictionPolicy

public Policy getInMemoryEvictionPolicy()
Specified by:
getInMemoryEvictionPolicy in interface Store
Returns:
the current eviction policy. This may not be the configured policy, if it has been dynamically set.
See Also:
Store.setInMemoryEvictionPolicy(Policy)

setInMemoryEvictionPolicy

public void setInMemoryEvictionPolicy(Policy policy)
Description copied from interface: Store
Sets the eviction policy strategy. The Store will use a policy at startup. The store may allow changing the eviction policy strategy dynamically. Otherwise implementations will throw an exception if this method is called.

Specified by:
setInMemoryEvictionPolicy in interface Store
Parameters:
policy - the new policy

getInternalContext

public Object getInternalContext()
Description copied from interface: Store
This should not be used, and will generally return null

Specified by:
getInternalContext in interface Store
Returns:
some internal context (probably null)

isCacheCoherent

public boolean isCacheCoherent()
Description copied from interface: Store
Indicates whether this store provides a coherent view of all the elements in a cache. Note that this is same as calling Store.isClusterCoherent() (introduced since 2.0) Use Store.isNodeCoherent() to find out if the cache is coherent in the current node in the cluster

Specified by:
isCacheCoherent in interface Store
Returns:
true if the store is coherent; or false if the store potentially splits the cache storage with another store or isn't internally coherent

isClusterCoherent

public boolean isClusterCoherent()
                          throws TerracottaNotRunningException
Description copied from interface: Store
Returns true if the cache is in coherent mode cluster-wide. Returns false otherwise.

It applies to coherent clustering mechanisms only e.g. Terracotta

Specified by:
isClusterCoherent in interface Store
Returns:
true if the cache is in coherent mode cluster-wide, false otherwise
Throws:
TerracottaNotRunningException

isNodeCoherent

public boolean isNodeCoherent()
                       throws TerracottaNotRunningException
Description copied from interface: Store
Returns true if the cache is in coherent mode for the current node. Returns false otherwise.

It applies to coherent clustering mechanisms only e.g. Terracotta

Specified by:
isNodeCoherent in interface Store
Returns:
true if the cache is in coherent mode cluster-wide, false otherwise
Throws:
TerracottaNotRunningException

setNodeCoherent

public void setNodeCoherent(boolean coherent)
                     throws UnsupportedOperationException,
                            TerracottaNotRunningException
Description copied from interface: Store
Sets the cache in coherent or incoherent mode for the current node depending on the parameter. Calling setNodeCoherent(true) when the cache is already in coherent mode or calling setNodeCoherent(false) when already in incoherent mode will be a no-op.

It applies to coherent clustering mechanisms only e.g. Terracotta

Specified by:
setNodeCoherent in interface Store
Parameters:
coherent - true transitions to coherent mode, false to incoherent mode
Throws:
UnsupportedOperationException - if this store does not support cache coherence, like RMI replication
TerracottaNotRunningException

waitUntilClusterCoherent

public void waitUntilClusterCoherent()
                              throws UnsupportedOperationException,
                                     TerracottaNotRunningException,
                                     InterruptedException
Description copied from interface: Store
This method waits until the cache is in coherent mode in all the connected nodes. If the cache is already in coherent mode it returns immediately

It applies to coherent clustering mechanisms only e.g. Terracotta

Specified by:
waitUntilClusterCoherent in interface Store
Throws:
UnsupportedOperationException - if this store does not support cache coherence, like RMI replication
InterruptedException
TerracottaNotRunningException

getMBean

public Object getMBean()
Description copied from interface: Store
Optional implementation specific MBean exposed by the store.

Specified by:
getMBean in interface Store
Returns:
implementation specific management bean

setAttributeExtractors

public void setAttributeExtractors(Map<String,AttributeExtractor> extractors)
Description copied from interface: Store
Inform this store of the configured attribute extractors. Stores that will not invoke extractors are free to ignore this call

Specified by:
setAttributeExtractors in interface Store

executeQuery

public Results executeQuery(StoreQuery query)
                     throws SearchException
Description copied from interface: Store
Execute the given query on this store

Specified by:
executeQuery in interface Store
Parameters:
query - query to execute
Returns:
query results
Throws:
SearchException

getSearchAttribute

public <S> Attribute<S> getSearchAttribute(String attributeName)
Description copied from interface: Store
Retrieve the given named search attribute

Specified by:
getSearchAttribute in interface Store
Type Parameters:
S - type of the attribute
Parameters:
attributeName - the name of the attribute to retrieve
Returns:
the search attribute or null if non-existent

getSearchAttributes

public Set<Attribute> getSearchAttributes()
Specified by:
getSearchAttributes in interface Store
Returns:
all search attributes known to this store at the time of invoking the method

getAllQuiet

public Map<Object,Element> getAllQuiet(Collection<?> keys)
Description copied from interface: Store
Retries the elements associated with a set of keys without updating the statistics Keys which are not present in the cache will have null values associated with them in the returned map

Specified by:
getAllQuiet in interface Store
Parameters:
keys - a collection of keys to look for
Returns:
a map of keys and their corresponding values

getAll

public Map<Object,Element> getAll(Collection<?> keys)
Description copied from interface: Store
Retries the elements associated with a set of keys and update the statistics Keys which are not present in the cache will have null values associated with them in the returned map

Specified by:
getAll in interface Store
Parameters:
keys - a collection of keys to look for
Returns:
a map of keys and their corresponding values

recalculateSize

public void recalculateSize(Object key)
Description copied from interface: Store
Recalculate size of the element mapped to the key

Specified by:
recalculateSize in interface Store
Parameters:
key - the key

getUnderlyingStore

public T getUnderlyingStore()
Accessor to the underlying store

Returns:
the underlying store

getCopyStrategyHandler

protected CopyStrategyHandler getCopyStrategyHandler()
Accessor to the CopyStrategyHandler

Returns:
the copy strategy handler

ehcache

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