org.gridgain.grid.cache.datastructures

Interface GridCacheDataStructures

All Known Implementing Classes:

GridCacheDataStructuresImpl, GridCacheDataStructuresProxy

public interface GridCacheDataStructures

Facade for working with distributed cache data structures. All cache data structures are similar in APIs to 'java.util.concurrent' package, but all operations on them are grid-aware. For example, if you increment GridCacheAtomicLong on one node, another node will know about the change. Or if you add an element to GridCacheQueue on one node, you can poll it on another node.

Method Summary

Methods

Modifier and Type	Method and Description
GridCacheAtomicLong	atomicLong(String name, long initVal, boolean create) Will get a atomic long from cache and create one if it has not been created yet and create flag is true.
<T> GridCacheAtomicReference<T>	atomicReference(String name, T initVal, boolean create) Will get a atomic reference from cache and create one if it has not been created yet and create flag is true.
GridCacheAtomicSequence	atomicSequence(String name, long initVal, boolean create) Will get an atomic sequence from cache and create one if it has not been created yet and create flag is true.
<T,S> GridCacheAtomicStamped<T,S>	atomicStamped(String name, T initVal, S initStamp, boolean create) Will get a atomic stamped from cache and create one if it has not been created yet and create flag is true.
GridCacheCountDownLatch	countDownLatch(String name, int cnt, boolean autoDel, boolean create) Gets or creates count down latch.
<T> GridCacheQueue<T>	queue(String name, int cap, boolean collocated, boolean create) Will get a named queue from cache and create one if it has not been created yet and create flag is true.
boolean	removeAtomicLong(String name) Remove atomic long from cache.
boolean	removeAtomicReference(String name) Remove atomic reference from cache.
boolean	removeAtomicSequence(String name) Remove sequence from cache.
boolean	removeAtomicStamped(String name) Remove atomic stamped from cache.
boolean	removeCountDownLatch(String name) Removes count down latch from cache.
boolean	removeQueue(String name) Remove queue from cache.
boolean	removeQueue(String name, int batchSize) Remove queue from cache.
boolean	removeSet(String name) Removes set from cache.
<T> GridCacheSet<T>	set(String name, boolean collocated, boolean create) Will get a named set from cache and create one if it has not been created yet and create flag is true.

Method Detail

atomicSequence

@Nullable
GridCacheAtomicSequence atomicSequence(String name,
                                              long initVal,
                                              boolean create)
                                       throws GridException

Will get an atomic sequence from cache and create one if it has not been created yet and create flag is true.

Parameters:

name - Sequence name.

initVal - Initial value for sequence. If sequence already cached, initVal will be ignored.

create - Boolean flag indicating whether data structure should be created if does not exist.

Returns:

Sequence for the given name.

Throws:

GridException - If sequence could not be fetched or created.

removeAtomicSequence

boolean removeAtomicSequence(String name)
                             throws GridException

Remove sequence from cache.

Parameters:

name - Sequence name.

Returns:

True if sequence has been removed, false otherwise.

Throws:

GridException - If remove failed.

atomicLong

@Nullable
GridCacheAtomicLong atomicLong(String name,
                                      long initVal,
                                      boolean create)
                               throws GridException

Will get a atomic long from cache and create one if it has not been created yet and create flag is true.

Parameters:

name - Name of atomic long.

initVal - Initial value for atomic long. If atomic long already cached, initVal will be ignored.

create - Boolean flag indicating whether data structure should be created if does not exist.

Returns:

Atomic long.

Throws:

GridException - If atomic long could not be fetched or created.

removeAtomicLong

boolean removeAtomicLong(String name)
                         throws GridException

Remove atomic long from cache.

Parameters:

name - Name of atomic long.

Returns:

True if atomic long has been removed, false otherwise.

Throws:

GridException - If removing failed.

queue

@Nullable
<T> GridCacheQueue<T> queue(String name,
                                   int cap,
                                   boolean collocated,
                                   boolean create)
                        throws GridException

Will get a named queue from cache and create one if it has not been created yet and create flag is true. If queue is present in cache already, queue properties will not be changed. Use collocation for GridCacheMode.PARTITIONED caches if you have lots of relatively small queues as it will make fetching, querying, and iteration a lot faster. If you have few very large queues, then you should consider turning off collocation as they simply may not fit in a single node's memory. However note that in this case to get a single element off the queue all nodes may have to be queried.

Parameters:

name - Name of queue.

cap - Capacity of queue, 0 for unbounded queue.

collocated - If true then all items within the same queue will be collocated on the same node. Otherwise elements of the same queue maybe be cached on different nodes. If you have lots of relatively small queues, then you should use collocation. If you have few large queues, then you should turn off collocation. This parameter works only for GridCacheMode.PARTITIONED cache.

create - Boolean flag indicating whether data structure should be created if does not exist.

Returns:

Queue with given properties.

Throws:

GridException - If remove failed.

removeQueue

boolean removeQueue(String name)
                    throws GridException

Remove queue from cache. Internally one transaction will be created for all elements in the queue. If you anticipate that queue may be large, then it's better to use removeQueue(String, int) which allows to specify batch size. In that case transaction will be split into multiple transactions which will have upto batchSize elements in it.

Parameters:

name - Name queue.

Returns:

True if queue has been removed and false if it's not cached.

Throws:

GridException - If remove failed.

removeQueue

boolean removeQueue(String name,
                  int batchSize)
                    throws GridException

Remove queue from cache. Internally multiple transactions will be created with no more than batchSize elements in them. For larger queues, this method is preferrable over removeQueue(String) which will create only one transaction for the whole operation.

Parameters:

name - Name queue.

batchSize - Batch size.

Returns:

True if queue has been removed and false if it's not cached.

Throws:

GridException - If remove failed.

set

@Nullable
<T> GridCacheSet<T> set(String name,
                               boolean collocated,
                               boolean create)
                    throws GridException

Will get a named set from cache and create one if it has not been created yet and create flag is true.

Parameters:

name - Set name.

collocated - If true then all items within the same set will be collocated on the same node. Otherwise elements of the same set maybe be cached on different nodes. This parameter works only for GridCacheMode.PARTITIONED cache.

create - Flag indicating whether set should be created if does not exist.

Returns:

Set with given properties.

Throws:

GridException - If failed.

removeSet

boolean removeSet(String name)
                  throws GridException

Removes set from cache.

Parameters:

name - Set name.

Returns:

True if set has been removed and false if it's not cached.

Throws:

GridException - If failed.

atomicReference

@Nullable
<T> GridCacheAtomicReference<T> atomicReference(String name,
                                                       @Nullable
                                                       T initVal,
                                                       boolean create)
                                            throws GridException

Will get a atomic reference from cache and create one if it has not been created yet and create flag is true.

Parameters:

name - Atomic reference name.

initVal - Initial value for atomic reference. If atomic reference already cached, initVal will be ignored.

create - Boolean flag indicating whether data structure should be created if does not exist.

Returns:

Atomic reference for the given name.

Throws:

GridException - If atomic reference could not be fetched or created.

removeAtomicReference

boolean removeAtomicReference(String name)
                              throws GridException

Remove atomic reference from cache.

Parameters:

name - Atomic reference name.

Returns:

True if atomic reference has been removed, false otherwise.

Throws:

GridException - If remove failed.

atomicStamped

@Nullable
<T,S> GridCacheAtomicStamped<T,S> atomicStamped(String name,
                                                       @Nullable
                                                       T initVal,
                                                       @Nullable
                                                       S initStamp,
                                                       boolean create)
                                          throws GridException

Will get a atomic stamped from cache and create one if it has not been created yet and create flag is true.

Parameters:

name - Atomic stamped name.

initVal - Initial value for atomic stamped. If atomic stamped already cached, initVal will be ignored.

initStamp - Initial stamp for atomic stamped. If atomic stamped already cached, initStamp will be ignored.

create - Boolean flag indicating whether data structure should be created if does not exist.

Returns:

Atomic stamped for the given name.

Throws:

GridException - If atomic stamped could not be fetched or created.

removeAtomicStamped

boolean removeAtomicStamped(String name)
                            throws GridException

Remove atomic stamped from cache.

Parameters:

name - Atomic stamped name.

Returns:

True if atomic stamped has been removed, false otherwise.

Throws:

GridException - If remove failed.

countDownLatch

@Nullable
GridCacheCountDownLatch countDownLatch(String name,
                                              int cnt,
                                              boolean autoDel,
                                              boolean create)
                                       throws GridException

Gets or creates count down latch. If count down latch is not found in cache and create flag is true, it is created using provided name and count parameter.

Parameters:

name - Name of the latch.

cnt - Count for new latch creation.

autoDel - True to automatically delete latch from cache when its count reaches zero.

create - Boolean flag indicating whether data structure should be created if does not exist.

Returns:

Count down latch for the given name.

Throws:

GridException - If operation failed.

removeCountDownLatch

boolean removeCountDownLatch(String name)
                             throws GridException

Removes count down latch from cache.

Parameters:

name - Name of the latch.

Returns:

Count down latch for the given name.

Throws:

GridException - If operation failed.