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com.tangosol.net.cache
Class ReadWriteBackingMap

java.lang.Object
java.util.AbstractMap
com.tangosol.net.cache.ReadWriteBackingMap

All Implemented Interfaces:

CacheMap, ObservableMap, java.util.Map

Direct Known Subclasses:

ReadWriteSplittingBackingMap, VersionedBackingMap

public class ReadWriteBackingMap

extends java.util.AbstractMap

implements CacheMap

Backing Map implementation that provides a size-limited cache of a persistent store and supports configurable write-behind and refresh- ahead caching. This implementation is not intended to support null keys or null values.

Author:

cp 2002.11.25, jh 2005.02.08

Nested Class Summary

class	ReadWriteBackingMap.BinaryEntryStoreWrapper A wrapper around the original BinaryEntryStore to allow operations to be overridden and extended.
static class	ReadWriteBackingMap.CacheLoaderCacheStore A CacheStore wrapped around a CacheLoader.
class	ReadWriteBackingMap.CacheStoreWrapper A wrapper around the original CacheStore to allow operations to be overridden and extended.
class	ReadWriteBackingMap.Entry A queue entry that is scheduled to come out of the front of the queue no earlier than some specific point in time.
protected class	ReadWriteBackingMap.EntrySet A set of entries corresponding to this backing map.
static class	ReadWriteBackingMap.EvictingBackupMap A Map implementation used for a backup map that evicts all data that has been successfully written.
protected class	ReadWriteBackingMap.InternalMapListener A MapListener implementation that listens to the internal cache and routes those events to anyone listening to this ReadWriteBackingMap.
protected class	ReadWriteBackingMap.KeySet A set of entries backed by this backing map.
protected static class	ReadWriteBackingMap.ReadLatch A synchronization construct used to coordinate asynchronous loads by the refresh-ahead thread with cache accesses by other threads.
class	ReadWriteBackingMap.ReadQueue A queue of keys that should be read from the underlying CacheStore.
class	ReadWriteBackingMap.ReadThread A thread that removes keys from a ReadWriteBackingMap.ReadQueue, reads the value for the key from the underlying CacheStore, and caches the value in the internal ReadWriteBackingMap cache.
class	ReadWriteBackingMap.StoreWrapper Abstract wrapper around a cache store to allow operations to be overridden and extended.
protected class	ReadWriteBackingMap.ValuesCollection A collection of values backed by this map.
class	ReadWriteBackingMap.WriteQueue A queue that only releases entries after a configurable period of time.
class	ReadWriteBackingMap.WriteThread This is the write-behind thread that pulls things from the write-behind queue and writes them to the CacheStore that the backing map uses.

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry, java.util.AbstractMap.SimpleImmutableEntry

Field Summary

protected static Binary	BIN_STORE_PENDING The binary form of the decoration indicating that the CacheStore on the primary member has not yet written the value.
protected static float	GUARD_RECOVERY The recovery threshold to use for guarded execution of write-behind/refresh-ahead threads.
protected MapListenerSupport	m_listenerSupport MapListenerSupport object.
static long	MIN_REQUEUE_DELAY The minimum "retry after requeue" time interval.
protected static Binary	NO_VALUE Marker object used to indicate to the write-behind thread that an entry has been removed from the queue.

Fields inherited from interface com.tangosol.net.cache.CacheMap

EXPIRY_DEFAULT, EXPIRY_NEVER

Constructor Summary

ReadWriteBackingMap(BackingMapManagerContext ctxService, ObservableMap mapInternal, java.util.Map mapMisses, BinaryEntryStore storeBinary, boolean fReadOnly, int cWriteBehindSeconds, double dflRefreshAheadFactor)
Construct a ReadWriteBackingMap based on a BinaryEntryStore.

ReadWriteBackingMap(BackingMapManagerContext ctxService, ObservableMap mapInternal, java.util.Map mapMisses, CacheLoader loader)
Construct a ReadWriteBackingMap based on a CacheLoader (CacheStore).

ReadWriteBackingMap(BackingMapManagerContext ctxService, ObservableMap mapInternal, java.util.Map mapMisses, CacheLoader loader, boolean fReadOnly, int cWriteBehindSeconds, double dflRefreshAheadFactor)
Construct a ReadWriteBackingMap based on a CacheLoader (CacheStore).

Method Summary

void	addMapListener(MapListener listener) Add a standard map listener that will receive all events (inserts, updates, deletes) that occur against the map, with the key, old-value and new-value included.
void	addMapListener(MapListener listener, Filter filter, boolean fLite) Add a map listener that receives events based on a filter evaluation.
void	addMapListener(MapListener listener, java.lang.Object oKey, boolean fLite) Add a map listener for a specific key.
protected void	cancelOutstandingReads(java.lang.Object oKey) Cancel any outstanding asynchronous reads for a key.
void	clear() Remove everything from the Map.
protected void	configureCacheStore(ReadWriteBackingMap.StoreWrapper store, boolean fReadOnly) Set up the StoreWrapper that this backing map will use.
protected void	configureInternalCache(ObservableMap mapInternal) Configure the internal cache that this backing map uses to store its "in-memory" data.
protected void	configureReadThread(double dflRefreshAheadFactor) Set up the optional refresh-ahead thread and queue that this backing map will use.
protected void	configureWriteThread(int cWriteBehindSeconds) Set up the optional write-behind thread and queue that this backing map will use.
boolean	containsKey(java.lang.Object oKey) Returns true if this map contains a mapping for the specified key.
boolean	containsValue(java.lang.Object oValue) Returns true if this CachingMap maps one or more keys to the specified value.
java.util.Set	entrySet() Returns an set view of the mappings contained in this map.
boolean	equals(java.lang.Object o) Compares the specified object with this map for equality.
protected long	extractExpiry(ReadWriteBackingMap.Entry entry) Return the expiration value for the given entry.
void	flush() Flush the write-behind queue, writing everything immediately.
protected void	flush(ReadWriteBackingMap.WriteQueue queue, ReadWriteBackingMap.StoreWrapper store) Flush the write-behind queue, writing everything immediately.
java.lang.Object	get(java.lang.Object oKey) Returns the value to which this map maps the specified key.
java.util.Map	getAll(java.util.Collection colKeys) Retrieve values for all the specified keys.
protected java.lang.Object	getCachedOrPending(java.lang.Object oKey) Get a value from the internal cache in a way that respects a potentially pending write-behind operation.
CacheService	getCacheService() Return the CacheService.
ReadWriteBackingMap.StoreWrapper	getCacheStore() Get the representative of the "persistent" storage for this backing map.
long	getCacheStoreTimeoutMillis() Return the timeout used for CacheStore operations, or 0 if no timeout is specified.
BackingMapManagerContext	getContext() Get the context information provided by the CacheService.
ConcurrentMap	getControlMap() Get the concurrency control map for this backing map.
protected java.lang.Object	getFromInternalCache(java.lang.Object oKey) Get the the value for a given key.
ObservableMap	getInternalCache() Get the representative of the "in-memory" storage for this backing map.
protected ConfigurableCacheMap	getInternalConfigurableCache() Get the map that provides internal storage for this backing map.
protected MapListener	getInternalListener() Obtain the MapListener that listens to the internal cache and routes those events to anyone listening to this ReadWriteBackingMap, creating such a listener if one does not already exist.
java.util.Map	getMissesCache() Get the optional map used to cache CacheLoader (or CacheStore) misses.
ReadWriteBackingMap.ReadQueue	getReadQueue() Get the queue of keys that are yet to be read.
protected ReadWriteBackingMap.ReadThread	getReadThread() Get the refresh-ahead thread.
double	getRefreshAheadFactor() Return the refresh-ahead factor.
protected java.util.Map	getSyntheticEventsMap() Get the map of keys for which the events should be marked as synthetic (internal).
double	getWriteBatchFactor() Return the write-batch factor.
long	getWriteBehindMillis() Return the number of milliseconds between write-behind writes to the CacheStore or 0 if write-behind is not enabled.
int	getWriteBehindSeconds() Return the number of seconds between write-behind writes to the CacheStore or 0 if write-behind is not enabled.
int	getWriteMaxBatchSize() Get the maximum size of the write-behind batch.
ReadWriteBackingMap.WriteQueue	getWriteQueue() Get the queue of entries that are yet to be written.
int	getWriteRequeueThreshold() Return the maximum size of the write-behind queue for which failed CacheStore write operations are requeued or 0 if write-behind requeueing is disabled.
protected ReadWriteBackingMap.WriteThread	getWriteThread() Get the write-behind thread.
int	hashCode() Returns the hash code value for this map.
protected void	heartbeat() Issue a service guardian "heartbeat" for the current thread.
protected CacheStore	instantiateCacheLoaderCacheStore(CacheLoader loader) Factory pattern: Instantiate a CacheLoaderCacheStore wrapper around a passed CacheLoader.
protected ReadWriteBackingMap.StoreWrapper	instantiateCacheStoreWrapper(BinaryEntryStore store) Factory pattern: Instantiate a StoreWrapper wrapper around the passed BinaryEntryStore.
protected ReadWriteBackingMap.StoreWrapper	instantiateCacheStoreWrapper(CacheStore store) Factory pattern: Instantiate a StoreWrapper wrapper around the passed CacheStore.
protected ConcurrentMap	instantiateControlMap() Factory pattern: Create the concurrency control map for this backing map.
protected ReadWriteBackingMap.Entry	instantiateEntry(java.lang.Object oKey, java.lang.Object oValue, java.lang.Object oValueOrig) Factory pattern: instantiate a queue entry.
protected ReadWriteBackingMap.Entry	instantiateEntry(java.lang.Object oKey, java.lang.Object oValue, java.lang.Object oValueOrig, long cExpiry) Factory pattern: instantiate a queue entry.
protected ReadWriteBackingMap.EntrySet	instantiateEntrySet() Factory pattern: instantiate an entry set for this backing map.
protected MapListener	instantiateInternalListener() Factory pattern: Create a MapListener that listens to the internal cache and routes those events to anyone listening to this ReadWriteBackingMap.
protected ReadWriteBackingMap.KeySet	instantiateKeySet() Factory pattern: instantiate a key set for this backing map.
protected ReadWriteBackingMap.ReadLatch	instantiateReadLatch(java.lang.Object oKey) Factory pattern: Instantiate a new read latch the given key.
protected ReadWriteBackingMap.ReadQueue	instantiateReadQueue() Factory pattern: Instantiate a new ReadQueue object.
protected ReadWriteBackingMap.ReadThread	instantiateReadThread() Factory pattern: Instantiate the refresh-ahead thread.
protected ReadWriteBackingMap.ValuesCollection	instantiateValuesCollection() Factory pattern.
protected ReadWriteBackingMap.WriteQueue	instantiateWriteQueue() Factory pattern: Instantiate a new WriteQueue object.
protected ReadWriteBackingMap.WriteThread	instantiateWriteThread() Factory pattern: Instantiate the write-behind thread.
boolean	isActive() Determine if the backing map is still active.
boolean	isReadOnly() Determine if the backing map should send data changes through the CacheStore, or should just keep them in memory.
boolean	isRefreshAhead() Determine if the backing map preemptively reads soon-to-be expired entries on a refresh-ahead thread.
boolean	isRethrowExceptions() Determine if exceptions caught during synchronous CacheStore operations are rethrown to the calling thread; if false, exceptions are logged.
boolean	isWriteBehind() Determine if the backing map writes changes on a write-behind thread through the CacheStore.
boolean	isWriteThrough() Determine if the backing map writes changes immediately through the CacheStore.
java.util.Set	keySet() Returns an set view of the keys contained in this map.
java.lang.Object	put(java.lang.Object oKey, java.lang.Object oValue) Associates the specified value with the specified key in this map.
java.lang.Object	put(java.lang.Object oKey, java.lang.Object oValue, long cMillis) Associates the specified value with the specified key in this map.
void	putAll(java.util.Map map) Associates the specified values with the respective keys in this map.
protected java.lang.Object	putInternal(java.lang.Object oKey, java.lang.Object oValue, long cMillis) An actual implementation for the extended put() method.
protected void	putToInternalCache(java.lang.Object oKey, java.lang.Object oVal) Add the key and value pair to the internal cache in such a way that the resulting map event would be marked as "synthetic".
protected void	putToInternalCache(java.lang.Object oKey, java.lang.Object oVal, long cMillis) Add the key and value pair to the internal cache in such a way that the resulting map event would be marked as "synthetic".
protected void	putToInternalCache(ReadWriteBackingMap.Entry entry) Add the key and value pair to the internal cache in such a way that the resulting map event would be marked as "synthetic".
protected java.lang.Object	putToInternalMap(java.lang.Object binKey, java.lang.Object binValue, long cExpiry) Put the specified key in internal format and value in internal format into the internal backing map.
void	release() Release the backing map when it is no longer being used.
java.lang.Object	remove(java.lang.Object oKey) Removes the mapping for this key from this map if present.
protected ReadWriteBackingMap.Entry	removeFromWriteQueue(java.lang.Object binKey) Remove the specified entry from the WriteQueue.
protected java.lang.Object	removeInternal(java.lang.Object oKey, boolean fBlind) Implementation of the remove() API.
void	removeMapListener(MapListener listener) Remove a standard map listener that previously signed up for all events.
void	removeMapListener(MapListener listener, Filter filter) Remove a map listener that previously signed up for events based on a filter evaluation.
void	removeMapListener(MapListener listener, java.lang.Object oKey) Remove a map listener that previously signed up for events about a specific key.
void	setCacheName(java.lang.String sCacheName) Set the cache name for ReadThread and WriteThread if not already set.
void	setCacheStoreTimeoutMillis(long cStoreTimeoutMillis) Set the timeout used for CacheStore operations.
void	setRefreshAheadFactor(double dflRefreshAheadFactor) Set the refresh-ahead factor, expressed as a percentage of the internal cache expiration interval.
void	setRethrowExceptions(boolean fRethrow) Set the value of the flag that determines if exceptions caught during synchronous CacheStore operations are rethrown to the calling thread; if false, exceptions are logged.
void	setWriteBatchFactor(double dflWriteBatchFactor) Set the write-batch factor, expressed as a percentage of the write-behind interval.
void	setWriteBehindMillis(long cMillis) Set the number of milliseconds between write-behind writes to the CacheStore.
void	setWriteBehindSeconds(int cSecs) Set the number of seconds between write-behind writes to the CacheStore.
void	setWriteMaxBatchSize(int cWriteMaxBatchSize) Set the maximum size of a batch.
void	setWriteRequeueThreshold(int cThreshold) Set the maximum size of the write-behind queue for which failed CacheStore write operations are requeued.
int	size() Returns the number of key-value mappings in this map.
protected void	terminateReadThread() Terminate the refresh-ahead thread.
protected void	terminateWriteThread() Terminate the write-behind thread.
java.lang.String	toString() For debugging purposes, format the contents of the Map in a human- readable format.
protected void	updateThreadName(Daemon daemon, java.lang.String sName) Append the provided name to the Daemon's thread name if not already appended.
java.util.Collection	values() Returns a collection view of the values contained in this map.
protected boolean	waitFor(java.lang.Object o, long cMillis) Wait for notification on the specified object for no longer than the specified wait time.

Methods inherited from class java.util.AbstractMap

clone, isEmpty

Methods inherited from interface java.util.Map

isEmpty

Field Detail

NO_VALUE

protected static final Binary NO_VALUE

Marker object used to indicate to the write-behind thread that an entry has been removed from the queue.

BIN_STORE_PENDING

protected static final Binary BIN_STORE_PENDING

The binary form of the decoration indicating that the CacheStore on the primary member has not yet written the value.

GUARD_RECOVERY

protected static final float GUARD_RECOVERY

The recovery threshold to use for guarded execution of write-behind/refresh-ahead threads.

See Also:

Constant Field Values

MIN_REQUEUE_DELAY

public static final long MIN_REQUEUE_DELAY

The minimum "retry after requeue" time interval. Default value is 60 sec and can be overridden by the system property:

 tangosol.coherence.rwbm.requeue.delay
 

m_listenerSupport

protected MapListenerSupport m_listenerSupport

MapListenerSupport object.

Constructor Detail

ReadWriteBackingMap

public ReadWriteBackingMap(BackingMapManagerContext ctxService,
                           ObservableMap mapInternal,
                           java.util.Map mapMisses,
                           CacheLoader loader)

Construct a ReadWriteBackingMap based on a CacheLoader (CacheStore).

Parameters:

ctxService - the context provided by the CacheService which is using this backing map

mapInternal - the ObservableMap used to store the data internally in this backing map

mapMisses - the Map used to cache CacheLoader misses (optional)

loader - the CacheLoader responsible for the persistence of the cached data (optional)

ReadWriteBackingMap

public ReadWriteBackingMap(BackingMapManagerContext ctxService,
                           ObservableMap mapInternal,
                           java.util.Map mapMisses,
                           CacheLoader loader,
                           boolean fReadOnly,
                           int cWriteBehindSeconds,
                           double dflRefreshAheadFactor)

Construct a ReadWriteBackingMap based on a CacheLoader (CacheStore).

Parameters:

ctxService - the context provided by the CacheService which is using this backing map

mapInternal - the ObservableMap used to store the data internally in this backing map

mapMisses - the Map used to cache CacheStore misses (optional)

loader - the CacheLoader responsible for the persistence of the cached data (optional)

fReadOnly - pass true is the specified loader is in fact a CacheStore that needs to be used only for read operations; changes to the cache will not be persisted

cWriteBehindSeconds - number of seconds to write if there is a CacheStore; zero disables write-behind caching, which (combined with !fReadOnly) implies write-through

dflRefreshAheadFactor - the interval before an entry expiration time (expressed as a percentage of the internal cache expiration interval) during which an asynchronous load request for the entry will be scheduled; zero disables refresh-ahead; only applicable when the mapInternal parameter is an instance of ConfigurableCacheMap

ReadWriteBackingMap

public ReadWriteBackingMap(BackingMapManagerContext ctxService,
                           ObservableMap mapInternal,
                           java.util.Map mapMisses,
                           BinaryEntryStore storeBinary,
                           boolean fReadOnly,
                           int cWriteBehindSeconds,
                           double dflRefreshAheadFactor)

Construct a ReadWriteBackingMap based on a BinaryEntryStore.

Parameters:

ctxService - the context provided by the CacheService which is using this backing map

mapInternal - the ObservableMap used to store the data internally in this backing map

mapMisses - the Map used to cache CacheStore misses (optional)

storeBinary - the BinaryEntryStore responsible for the persistence of the cached data (optional)

fReadOnly - pass true is the specified loader is in fact a CacheStore that needs to be used only for read operations; changes to the cache will not be persisted

cWriteBehindSeconds - number of seconds to write if there is a CacheStore; zero disables write-behind caching, which (combined with !fReadOnly) implies write-through

dflRefreshAheadFactor - the interval before an entry expiration time (expressed as a percentage of the internal cache expiration interval) during which an asynchronous load request for the entry will be scheduled; zero disables refresh-ahead; only applicable when the mapInternal parameter is an instance of ConfigurableCacheMap

Since:

Coherence 3.6

Method Detail

getContext

public BackingMapManagerContext getContext()

Get the context information provided by the CacheService.

Returns:

the CacheService's BackingMapManagerContext object that it provided to the BackingMapManager that created this backing map

getCacheService

public CacheService getCacheService()

Return the CacheService.

Returns:

the CacheService

isRethrowExceptions

public boolean isRethrowExceptions()

Determine if exceptions caught during synchronous CacheStore operations are rethrown to the calling thread; if false, exceptions are logged.

Returns:

true if CacheStore exceptions are rethrown to the calling thread

setRethrowExceptions

public void setRethrowExceptions(boolean fRethrow)

Set the value of the flag that determines if exceptions caught during synchronous CacheStore operations are rethrown to the calling thread; if false, exceptions are logged.

Parameters:

fRethrow - true to indicate that exceptions should be rethrown

getRefreshAheadFactor

public double getRefreshAheadFactor()

Return the refresh-ahead factor.

The refresh-ahead factor is used to calculate the "soft-expiration" time for cache entries. Soft-expiration is the point in time prior to the actual expiration after which any access request for an entry will schedule an asynchronous load request for the entry.

The value of this property is expressed as a percentage of the internal cache expiration interval. If zero, refresh-ahead scheduling is disabled.

Returns:

the refresh-ahead factor

setRefreshAheadFactor

public void setRefreshAheadFactor(double dflRefreshAheadFactor)

Set the refresh-ahead factor, expressed as a percentage of the internal cache expiration interval. Valid values are doubles in the interval [0.0, 1.0].

This method has no effect if refresh-ahead is disabled.

Parameters:

dflRefreshAheadFactor - the new refresh-ahead factor

See Also:

getRefreshAheadFactor()

isReadOnly

public boolean isReadOnly()

Determine if the backing map should send data changes through the CacheStore, or should just keep them in memory.

Returns:

false to send changes to CacheStore (a read-write cache), or true to just keep them in memory (a read-only cache)

isRefreshAhead

public boolean isRefreshAhead()

Determine if the backing map preemptively reads soon-to-be expired entries on a refresh-ahead thread.

Returns:

true if refresh-ahead is enabled

getWriteMaxBatchSize

public int getWriteMaxBatchSize()

Get the maximum size of the write-behind batch.

Returns:

the maximum number of entries in the write-behind batch

setWriteMaxBatchSize

public void setWriteMaxBatchSize(int cWriteMaxBatchSize)

Set the maximum size of a batch. The size is used to reduce the size of the write-behind batches and the amount of [scratch] memory used to keep de-serialized entries passed to the storeAll operations.

This method has no effect if write-behind is disabled.

Parameters:

cWriteMaxBatchSize - the maximum batch size

getWriteBatchFactor

public double getWriteBatchFactor()

Return the write-batch factor.

The write-batch factor is used to calculate the "soft-ripe" time for write-behind queue entries. A queue entry is considered to be "ripe" for a write operation if it has been in the write-behind queue for no less than the write-behind interval. The "soft-ripe" time is the point in time prior to the actual ripe time after which an entry will be included in a batched asynchronous write operation to the CacheStore (along with all other ripe and soft-ripe entries). In other words, a soft-ripe entry is an entry that has been in the write-behind queue for at least the following duration:

 D' = (1.0 - F)*D

where:

 D = write-behind delay
 F = write-batch factor

Conceptually, the write-behind thread uses the following logic when performing a batched update:

1. The thread waits for a queued entry to become ripe.
2. When an entry becomes ripe, the thread dequeues all ripe and soft-ripe entries in the queue.
3. The thread then writes all ripe and soft-ripe entries either via store() (if there is only the single ripe entry) or storeAll() (if there are multiple ripe/soft-ripe entries).
4. The thread then repeats (1).

This property is only applicable if asynchronous writes are enabled and the CacheStore implements the storeAll() method.

The value of this property is expressed as a percentage of the write-behind interval. Valid values are doubles in the interval [0.0, 1.0].

Returns:

the write-batch factor

setWriteBatchFactor

public void setWriteBatchFactor(double dflWriteBatchFactor)

Set the write-batch factor, expressed as a percentage of the write-behind interval. Valid values are doubles in the interval [0.0, 1.0].

This method has no effect if write-behind is disabled.

Parameters:

dflWriteBatchFactor - the new write-batch factor

See Also:

getWriteBatchFactor()

isWriteBehind

public boolean isWriteBehind()

Determine if the backing map writes changes on a write-behind thread through the CacheStore.

Returns:

true implies changes are queued to be written asynchronously

getWriteBehindSeconds

public int getWriteBehindSeconds()

Return the number of seconds between write-behind writes to the CacheStore or 0 if write-behind is not enabled.

Returns:

the number of seconds between write-behind writes

setWriteBehindSeconds

public void setWriteBehindSeconds(int cSecs)

Set the number of seconds between write-behind writes to the CacheStore.

This method has not effect if write-behind is not enabled.

Parameters:

cSecs - the new write-behind delay in seconds

getWriteBehindMillis

public long getWriteBehindMillis()

Return the number of milliseconds between write-behind writes to the CacheStore or 0 if write-behind is not enabled.

Returns:

the number of milliseconds between write-behind writes

Since:

Coherence 3.4

setWriteBehindMillis

public void setWriteBehindMillis(long cMillis)

Set the number of milliseconds between write-behind writes to the CacheStore.

This method has not effect if write-behind is not enabled.

Parameters:

cMillis - the new write-behind delay in milliseconds

Since:

Coherence 3.4

getWriteRequeueThreshold

public int getWriteRequeueThreshold()

Return the maximum size of the write-behind queue for which failed CacheStore write operations are requeued or 0 if write-behind requeueing is disabled.

Returns:

the write-behind requeue threshold

setWriteRequeueThreshold

public void setWriteRequeueThreshold(int cThreshold)

Set the maximum size of the write-behind queue for which failed CacheStore write operations are requeued.

This method has not effect if write-behind is not enabled.

Parameters:

cThreshold - the new write-behind requeue threshold

isWriteThrough

public boolean isWriteThrough()

Determine if the backing map writes changes immediately through the CacheStore.

Returns:

true implies that changes to the backing map are written synchronously to the CacheStore

getCacheStoreTimeoutMillis

public long getCacheStoreTimeoutMillis()

Return the timeout used for CacheStore operations, or 0 if no timeout is specified.

Returns:

the CacheStore timeout

setCacheStoreTimeoutMillis

public void setCacheStoreTimeoutMillis(long cStoreTimeoutMillis)

Set the timeout used for CacheStore operations. A value of 0 indicates to use the default guardian timeout of the associated service.

Parameters:

cStoreTimeoutMillis - the CacheStore timeout, or 0 for the default guardian timeout

setCacheName

public void setCacheName(java.lang.String sCacheName)

Set the cache name for ReadThread and WriteThread if not already set.

Parameters:

sCacheName - the name of the cache

clear

public void clear()

Remove everything from the Map.

Specified by:

clear in interface java.util.Map

Overrides:

clear in class java.util.AbstractMap

containsKey

public boolean containsKey(java.lang.Object oKey)

Returns true if this map contains a mapping for the specified key.

Specified by:

containsKey in interface java.util.Map

Overrides:

containsKey in class java.util.AbstractMap

Parameters:

oKey - the key to test for

Returns:

true if this map contains a mapping for the specified key, false otherwise.

containsValue

public boolean containsValue(java.lang.Object oValue)

Returns true if this CachingMap maps one or more keys to the specified value.

Specified by:

containsValue in interface java.util.Map

Overrides:

containsValue in class java.util.AbstractMap

Parameters:

oValue - the value to test for

Returns:

true if this CachingMap maps one or more keys to the specified value, false otherwise

get

public java.lang.Object get(java.lang.Object oKey)

Returns the value to which this map maps the specified key.

Specified by:

get in interface java.util.Map

Overrides:

get in class java.util.AbstractMap

Parameters:

oKey - the key object

Returns:

the value to which this map maps the specified key, or null if the map contains no mapping for this key

put

public java.lang.Object put(java.lang.Object oKey,
                            java.lang.Object oValue)

Associates the specified value with the specified key in this map.

Specified by:

put in interface CacheMap

Specified by:

put in interface java.util.Map

Overrides:

put in class java.util.AbstractMap

Parameters:

oKey - key with which the specified value is to be associated

oValue - value to be associated with the specified key

Returns:

previous value associated with specified key, or null if there was no mapping for key. A null return can also indicate that the map previously associated null with the specified key, if the implementation supports null values.

remove

public java.lang.Object remove(java.lang.Object oKey)

Removes the mapping for this key from this map if present. Expensive: updates both the underlying cache and the local cache.

Specified by:

remove in interface java.util.Map

Overrides:

remove in class java.util.AbstractMap

Parameters:

oKey - key whose mapping is to be removed from the map

Returns:

previous value associated with specified key, or null if there was no mapping for key. A null return can also indicate that the map previously associated null with the specified key, if the implementation supports null values.

putAll

public void putAll(java.util.Map map)

Associates the specified values with the respective keys in this map. Be aware that the keys will be locked in the order they are returned from iterating over the map passed in and unlocked at the end of the method. This method is called internally within Coherence and the keys will have been locked at the Service level already, so concurrent calls to this method with the same keys will not be an issue. If this method is somehow called directly by application code, which is not recommended, then it is advisable to pass in a sorted map that sorts the keys by their natural ordering.

Specified by:

putAll in interface java.util.Map

Overrides:

putAll in class java.util.AbstractMap

Parameters:

map - keys and values which are to be associated in this map

putToInternalMap

protected java.lang.Object putToInternalMap(java.lang.Object binKey,
                                            java.lang.Object binValue,
                                            long cExpiry)

Put the specified key in internal format and value in internal format into the internal backing map. If the cExpiry parameter is greater than the default expiry value CacheMap.EXPIRY_DEFAULT and the internal map is not an instance of CacheMap then an exception will be thrown.

Parameters:

binKey - the key in internal format

binValue - the value in internal format; null if the value should be cached as "missing"

cExpiry - the cache entry expiry value

Returns:

any previous value tht was mapped to the key.

Throws:

java.lang.UnsupportedOperationException - if the value of cExpiry is greater than CacheMap.EXPIRY_DEFAULT and the internal map is not an instance of CacheMap.

removeInternal

protected java.lang.Object removeInternal(java.lang.Object oKey,
                                          boolean fBlind)

Implementation of the remove() API.

Parameters:

oKey - key whose mapping is to be removed from the map

fBlind - if true, the return value will be ignored

Returns:

previous value associated with specified key, or null

size

public int size()

Returns the number of key-value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Specified by:

size in interface java.util.Map

Overrides:

size in class java.util.AbstractMap

Returns:

the number of key-value mappings in this map

entrySet

public java.util.Set entrySet()

Returns an set view of the mappings contained in this map.

Specified by:

entrySet in interface java.util.Map

Specified by:

entrySet in class java.util.AbstractMap

Returns:

a set view of the mappings contained in this map

keySet

public java.util.Set keySet()

Returns an set view of the keys contained in this map.

Specified by:

keySet in interface java.util.Map

Overrides:

keySet in class java.util.AbstractMap

Returns:

a set view of the keys contained in this map

values

public java.util.Collection values()

Returns a collection view of the values contained in this map.

Specified by:

values in interface java.util.Map

Overrides:

values in class java.util.AbstractMap

Returns:

a collection view of the values contained in this map

put

public java.lang.Object put(java.lang.Object oKey,
                            java.lang.Object oValue,
                            long cMillis)

Associates the specified value with the specified key in this map.

Specified by:

put in interface CacheMap

Parameters:

oKey - key with which the specified value is to be associated

oValue - value to be associated with the specified key

cMillis - the number of milliseconds until the entry will expire; pass zero to use the cache's default ExpiryDelay settings; pass -1 to indicate that the entry should never expire

Returns:

previous value associated with specified key, or null if there was no mapping for key

getAll

public java.util.Map getAll(java.util.Collection colKeys)

Retrieve values for all the specified keys.

Specified by:

getAll in interface CacheMap

Parameters:

colKeys - a collection of keys that may be in the named cache

Returns:

a Map of keys to values for the specified keys passed in colKeys

putToInternalCache

protected void putToInternalCache(java.lang.Object oKey,
                                  java.lang.Object oVal)

Add the key and value pair to the internal cache in such a way that the resulting map event would be marked as "synthetic".

Parameters:

oKey - the key in internal format

oVal - the value in internal format; null if the value should be cached as "missing"

putToInternalCache

protected void putToInternalCache(ReadWriteBackingMap.Entry entry)

Add the key and value pair to the internal cache in such a way that the resulting map event would be marked as "synthetic".

Parameters:

entry - cache entry

putToInternalCache

protected void putToInternalCache(java.lang.Object oKey,
                                  java.lang.Object oVal,
                                  long cMillis)

Add the key and value pair to the internal cache in such a way that the resulting map event would be marked as "synthetic".

Parameters:

oKey - the key in internal format

oVal - the value in internal format; null if the value should be cached as "missing"

cMillis - the cache entry expiry value

cancelOutstandingReads

protected void cancelOutstandingReads(java.lang.Object oKey)

Cancel any outstanding asynchronous reads for a key.

Parameters:

oKey - the key in internal format

getFromInternalCache

protected java.lang.Object getFromInternalCache(java.lang.Object oKey)

Get the the value for a given key. If the entry is present in the internal cache and refresh-ahead is configured, check if a reload operation needs to be scheduled. If the entry is missing, check for a potentially pending refresh-ahead operation and potentially pending write-behind.

Parameters:

oKey - the key in internal format

Returns:

the value or null if the value is not found

getCachedOrPending

protected java.lang.Object getCachedOrPending(java.lang.Object oKey)

Get a value from the internal cache in a way that respects a potentially pending write-behind operation.

Parameters:

oKey - the key

Returns:

the corresponding value

putInternal

protected java.lang.Object putInternal(java.lang.Object oKey,
                                       java.lang.Object oValue,
                                       long cMillis)

An actual implementation for the extended put() method.

Parameters:

oKey - key with which the specified value is to be associated

oValue - value to be associated with the specified key

cMillis - the number of milliseconds until the entry will expire

Returns:

previous value associated with specified key, or null if there was no mapping for key.

waitFor

protected boolean waitFor(java.lang.Object o,
                          long cMillis)

Wait for notification on the specified object for no longer than the specified wait time.

Note: the caller must hold synchronization on the object being waited on.

Parameters:

o - the object to wait for notification on

cMillis - the maximum time in milliseconds to wait; pass 0 for forever

Returns:

true iff notification was received, the timeout has passed, or the thread was spuriously wakened; false if this thread was interrupted

heartbeat

protected void heartbeat()

Issue a service guardian "heartbeat" for the current thread.

extractExpiry

protected long extractExpiry(ReadWriteBackingMap.Entry entry)

Return the expiration value for the given entry.

Parameters:

entry - the entry

Returns:

the expiration value

updateThreadName

protected void updateThreadName(Daemon daemon,
                                java.lang.String sName)

Append the provided name to the Daemon's thread name if not already appended.

Parameters:

daemon - the Daemon to be modified

sName - the name to append to the Daemon's thread name

instantiateEntrySet

protected ReadWriteBackingMap.EntrySet instantiateEntrySet()

Factory pattern: instantiate an entry set for this backing map.

Returns:

a new EntrySet object

instantiateKeySet

protected ReadWriteBackingMap.KeySet instantiateKeySet()

Factory pattern: instantiate a key set for this backing map.

Returns:

a new KeySet object

instantiateValuesCollection

protected ReadWriteBackingMap.ValuesCollection instantiateValuesCollection()

Factory pattern.

Returns:

a new instance of the ValuesCollection class (or subclass thereof)

addMapListener

public void addMapListener(MapListener listener)

Add a standard map listener that will receive all events (inserts, updates, deletes) that occur against the map, with the key, old-value and new-value included. This has the same result as the following call:

   addMapListener(listener, (Filter) null, false);
 

Specified by:

addMapListener in interface ObservableMap

Parameters:

listener - the MapEvent listener to add

removeMapListener

public void removeMapListener(MapListener listener)

Remove a standard map listener that previously signed up for all events. This has the same result as the following call:

   removeMapListener(listener, (Filter) null);
 

Specified by:

removeMapListener in interface ObservableMap

Parameters:

listener - the listener to remove

addMapListener

public void addMapListener(MapListener listener,
                           java.lang.Object oKey,
                           boolean fLite)

Add a map listener for a specific key.

The listeners will receive MapEvent objects, but if fLite is passed as true, they might not contain the OldValue and NewValue properties.

To unregister the MapListener, use the ObservableMap.removeMapListener(MapListener, Object) method.

Specified by:

addMapListener in interface ObservableMap

Parameters:

listener - the MapEvent listener to add

oKey - the key that identifies the entry for which to raise events

fLite - true to indicate that the MapEvent objects do not have to include the OldValue and NewValue property values in order to allow optimizations

removeMapListener

public void removeMapListener(MapListener listener,
                              java.lang.Object oKey)

Remove a map listener that previously signed up for events about a specific key.

Specified by:

removeMapListener in interface ObservableMap

Parameters:

listener - the listener to remove

oKey - the key that identifies the entry for which to raise events

addMapListener

public void addMapListener(MapListener listener,
                           Filter filter,
                           boolean fLite)

Add a map listener that receives events based on a filter evaluation.

The listeners will receive MapEvent objects, but if fLite is passed as true, they might not contain the OldValue and NewValue properties.

To unregister the MapListener, use the ObservableMap.removeMapListener(MapListener, Filter) method.

Specified by:

addMapListener in interface ObservableMap

Parameters:

listener - the MapEvent listener to add

filter - a filter that will be passed MapEvent objects to select from; a MapEvent will be delivered to the listener only if the filter evaluates to true for that MapEvent (see MapEventFilter); null is equivalent to a filter that alway returns true

fLite - true to indicate that the MapEvent objects do not have to include the OldValue and NewValue property values in order to allow optimizations

removeMapListener

public void removeMapListener(MapListener listener,
                              Filter filter)

Remove a map listener that previously signed up for events based on a filter evaluation.

Specified by:

removeMapListener in interface ObservableMap

Parameters:

listener - the listener to remove

filter - the filter that was passed into the corresponding addMapListener() call

equals

public boolean equals(java.lang.Object o)

Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings.

Specified by:

equals in interface java.util.Map

Overrides:

equals in class java.util.AbstractMap

Parameters:

o - object to be compared for equality with this map

Returns:

true if the specified object is equal to this map

hashCode

public int hashCode()

Returns the hash code value for this map.

Specified by:

hashCode in interface java.util.Map

Overrides:

hashCode in class java.util.AbstractMap

Returns:

the hash code value for this map

toString

public java.lang.String toString()

For debugging purposes, format the contents of the Map in a human- readable format.

Overrides:

toString in class java.util.AbstractMap

Returns:

a String representation of this ReadWriteBackingMap

getInternalCache

public ObservableMap getInternalCache()

Get the representative of the "in-memory" storage for this backing map.

Returns:

the ObservableMap object (never null) that this backing map uses to store entries

getInternalConfigurableCache

protected ConfigurableCacheMap getInternalConfigurableCache()

Get the map that provides internal storage for this backing map. If the internal storage is a ConfigurableCacheMap, then this accessor returns the same reference as getInternalCache(); otherwise it returns null. The refresh-ahead implementation relies on the internal storage providing the ConfigurableCacheMap interface, so this method will always return a non-null value if refresh-ahead is enabled.

Returns:

the cache for this backing map or null if the internal map is not an implementation of the ConfigurableCacheMap interface

configureInternalCache

protected void configureInternalCache(ObservableMap mapInternal)

Configure the internal cache that this backing map uses to store its "in-memory" data.

Parameters:

mapInternal - the internal map

getMissesCache

public java.util.Map getMissesCache()

Get the optional map used to cache CacheLoader (or CacheStore) misses.

Returns:

the Map that this backing map uses to cache CacheLoader (or CacheStore) misses or null if misses are not cached

getControlMap

public ConcurrentMap getControlMap()

Get the concurrency control map for this backing map.

Returns:

the ObservableMap object (never null) that this backing map uses to store entries

instantiateControlMap

protected ConcurrentMap instantiateControlMap()

Factory pattern: Create the concurrency control map for this backing map.

Returns:

a new concurrency control map

getSyntheticEventsMap

protected java.util.Map getSyntheticEventsMap()

Get the map of keys for which the events should be marked as synthetic (internal).

Returns:

the map of keys to mark events as internal

getInternalListener

protected MapListener getInternalListener()

Obtain the MapListener that listens to the internal cache and routes those events to anyone listening to this ReadWriteBackingMap, creating such a listener if one does not already exist.

Returns:

a routing MapListener

instantiateInternalListener

protected MapListener instantiateInternalListener()

Factory pattern: Create a MapListener that listens to the internal cache and routes those events to anyone listening to this ReadWriteBackingMap.

Returns:

a new routing MapListener

release

public void release()

Release the backing map when it is no longer being used.

isActive

public boolean isActive()

Determine if the backing map is still active.

Returns:

true if the backing map is still active

instantiateReadLatch

protected ReadWriteBackingMap.ReadLatch instantiateReadLatch(java.lang.Object oKey)

Factory pattern: Instantiate a new read latch the given key.

Parameters:

oKey - the key

Returns:

the read latch

getReadQueue

public ReadWriteBackingMap.ReadQueue getReadQueue()

Get the queue of keys that are yet to be read.

Returns:

the refresh-ahead queue object

instantiateReadQueue

protected ReadWriteBackingMap.ReadQueue instantiateReadQueue()

Factory pattern: Instantiate a new ReadQueue object.

Returns:

a new ReadQueue object

getWriteQueue

public ReadWriteBackingMap.WriteQueue getWriteQueue()

Get the queue of entries that are yet to be written.

Returns:

the write-behind queue object

flush

public void flush()

Flush the write-behind queue, writing everything immediately.

flush

protected void flush(ReadWriteBackingMap.WriteQueue queue,
                     ReadWriteBackingMap.StoreWrapper store)

Flush the write-behind queue, writing everything immediately.

Parameters:

queue - the write-behind queue to flush

store - the CacheStore to flush to

removeFromWriteQueue

protected ReadWriteBackingMap.Entry removeFromWriteQueue(java.lang.Object binKey)

Remove the specified entry from the WriteQueue.

Parameters:

binKey - the key

Returns:

the currently queued entry (could be NO_VALUE marker or null)

instantiateEntry

protected ReadWriteBackingMap.Entry instantiateEntry(java.lang.Object oKey,
                                                     java.lang.Object oValue,
                                                     java.lang.Object oValueOrig)

Factory pattern: instantiate a queue entry.

Parameters:

oKey - the key for the new entry

oValue - the entry's value; could be null representing a non-existing or removed entry

oValueOrig - the entry's original value; could be null representing a non-existing entry

Returns:

a new Entry

instantiateEntry

protected ReadWriteBackingMap.Entry instantiateEntry(java.lang.Object oKey,
                                                     java.lang.Object oValue,
                                                     java.lang.Object oValueOrig,
                                                     long cExpiry)

Factory pattern: instantiate a queue entry.

Parameters:

oKey - the key for the new entry

oValue - the entry's value; could be null representing a non-existing or removed entry

oValueOrig - the entry's original value; could be null representing a non-existing entry

cExpiry - the expiry delay, or CacheMap.EXPIRY_NEVER or CacheMap.EXPIRY_DEFAULT

Returns:

a new Entry

instantiateWriteQueue

protected ReadWriteBackingMap.WriteQueue instantiateWriteQueue()

Factory pattern: Instantiate a new WriteQueue object.

Returns:

a new WriteQueue object

getReadThread

protected ReadWriteBackingMap.ReadThread getReadThread()

Get the refresh-ahead thread.

Returns:

the refresh-ahead thread or null if refresh-ahead is not enabled

configureReadThread

protected void configureReadThread(double dflRefreshAheadFactor)

Set up the optional refresh-ahead thread and queue that this backing map will use.

This method has no effect if the given refresh-ahead factor is zero or the cache returned by getInternalConfigurableCache() is null or non-expiring.

Parameters:

dflRefreshAheadFactor - the refresh-ahead factor expressed as a percentage of the internal cache expiry

instantiateReadThread

protected ReadWriteBackingMap.ReadThread instantiateReadThread()

Factory pattern: Instantiate the refresh-ahead thread.

Returns:

a new refresh-ahead thread

terminateReadThread

protected void terminateReadThread()

Terminate the refresh-ahead thread.

getWriteThread

protected ReadWriteBackingMap.WriteThread getWriteThread()

Get the write-behind thread.

Returns:

the write-behind thread or null if there is no CacheStore to write to

configureWriteThread

protected void configureWriteThread(int cWriteBehindSeconds)

Set up the optional write-behind thread and queue that this backing map will use.

This method has no effect if the given write-behind delay is zero or isReadOnly() returns true.

Parameters:

cWriteBehindSeconds - write-behind delay

instantiateWriteThread

protected ReadWriteBackingMap.WriteThread instantiateWriteThread()

Factory pattern: Instantiate the write-behind thread.

Returns:

a new write-behind thread

terminateWriteThread

protected void terminateWriteThread()

Terminate the write-behind thread.

getCacheStore

public ReadWriteBackingMap.StoreWrapper getCacheStore()

Get the representative of the "persistent" storage for this backing map.

Returns:

the cache store wrapper object that this backing map uses for persistence or null if there is no persistent store behind this backing map

configureCacheStore

protected void configureCacheStore(ReadWriteBackingMap.StoreWrapper store,
                                   boolean fReadOnly)

Set up the StoreWrapper that this backing map will use.

Parameters:

store - the StoreWrapper that this backing map will delegate persistence responsibilities to

fReadOnly - pass true to prevent the usage of the cache store write operations

instantiateCacheStoreWrapper

protected ReadWriteBackingMap.StoreWrapper instantiateCacheStoreWrapper(CacheStore store)

Factory pattern: Instantiate a StoreWrapper wrapper around the passed CacheStore. (Supports CacheStore extension by delegation pattern.)

Parameters:

store - the CacheStore to wrap

Returns:

the StoreWrapper wrapper that can supplement and override the operations of the supplied CacheStore

instantiateCacheStoreWrapper

protected ReadWriteBackingMap.StoreWrapper instantiateCacheStoreWrapper(BinaryEntryStore store)

Factory pattern: Instantiate a StoreWrapper wrapper around the passed BinaryEntryStore. (Supports BinaryEntryStore extension by delegation pattern.)

Parameters:

store - the BinaryEntryStore to wrap

Returns:

the StoreWrapper wrapper that can supplement and override the operations of the supplied BinaryEntryStore

instantiateCacheLoaderCacheStore

protected CacheStore instantiateCacheLoaderCacheStore(CacheLoader loader)

Factory pattern: Instantiate a CacheLoaderCacheStore wrapper around a passed CacheLoader.

Parameters:

loader - the CacheLoader to wrap; never null

Returns:

a CacheStore instance

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