Package org.infinispan.stream.impl

Class LockedStreamImpl<K,V>

java.lang.Object
org.infinispan.stream.impl.LockedStreamImpl<K,V>
All Implemented Interfaces:
AutoCloseable, BaseStream<CacheEntry<K,V>,LockedStream<K,V>>, BaseCacheStream<CacheEntry<K,V>,LockedStream<K,V>>, LockedStream<K,V>
Direct Known Subclasses:
TxLockedStreamImpl
public class LockedStreamImpl<K,V> extends Object implements LockedStream<K,V>
Lock Stream implementation that locks a key using the LockManager before and after executing the various code.

This implementation doesn't work properly when using an optimistic transactional cache. Care should be made to prevent that usage if possible.

Since:
9.0
Author:
wburns

  • Constructor Details

  • Method Details

    • filter

      public LockedStream<K,V> filter(Predicate<? super CacheEntry<K,V>> predicate)
      Description copied from interface: LockedStream
      Returns a locked stream consisting of the elements of this stream that match the given predicate.

      This filter is after the lock is acquired for the given key. This way the filter will see the same value as the consumer is given.

      Specified by:
      filter in interface LockedStream<K,V>
      Parameters:
      predicate - predicate
      Returns:
      a LockedStream with the filter applied

    • forEach

      public void forEach(BiConsumer<Cache<K,V>,? super CacheEntry<K,V>> biConsumer)
      Description copied from interface: LockedStream
      Performs an action for each element of this stream on the primary owner of the given key.

      This method is performed while holding exclusive lock over the given entry and will be released only after the consumer has completed. In the function, entry.setValue(newValue) is equivalent to cache.put(entry.getKey(), newValue).

      If using pessimistic transactions this lock is not held using a transaction and thus the user can start a transaction in this consumer which also must be completed before returning. A transaction can be started in the consumer and if done it will share the same lock used to obtain the key.

      Remember that if you are using an explicit transaction or an async method that these must be completed before the consumer returns to guarantee that they are operating within the scope of the lock for the given key. Failure to do so will lead into possible inconsistency as they will be performing operations without the proper locking.

      Some methods on the provided cache may not work as expected. These include Cache.putForExternalRead(Object, Object), AdvancedCache.lock(Object[]), AdvancedCache.lock(Collection), and AdvancedCache.removeGroup(String). If these methods are used inside of the Consumer on the cache it will throw a IllegalStateException. This is due to possible interactions with locks while using these commands.

      Specified by:
      forEach in interface LockedStream<K,V>
      Parameters:
      biConsumer - the biConsumer to run for each entry under their lock

    • invokeAll

      public <R> Map<K,R> invokeAll(BiFunction<Cache<K,V>,? super CacheEntry<K,V>,R> biFunction)
      Description copied from interface: LockedStream
      Performs a BiFunction for each element of this stream on the primary owner of each entry returning a value. The returned value from the function will be sent back to the user mapped to the key that generated it, with all of these stored in a map. Both the BiFunction and the returned value must be Serializable in some way. This method will return only after all entries have been processed.

      This method is currently marked as Experimental since this method returns a Map and requires blocking. This operation could take a deal of time and as such should be done using an asynchronous API. Most likely this return type will be changed to use some sort of asynchronous return value. This method is here until this can be implemented.

      This BiFunction is invoked while holding an exclusive lock over the given entry that will be released only after the function has completed. In the function, entry.setValue(newValue) is equivalent to cache.put(entry.getKey(), newValue).

      If using pessimistic transactions this lock is not held using a transaction and thus the user can start a transaction in this consumer which also must be completed before returning. A transaction can be started in the biFunction and if done it will share the same lock used to obtain the key.

      Remember if you are using an explicit transaction or an async method that these must be completed before the consumer returns to guarantee that they are operating within the scope of the lock for the given key. Failure to do so will lead into possible inconsistency as they will be performing operations without the proper locking.

      Some methods on the provided cache may not work as expected. These include Cache.putForExternalRead(Object, Object), AdvancedCache.lock(Object[]), AdvancedCache.lock(Collection), and AdvancedCache.removeGroup(String). If these methods are used inside of the Consumer on the cache it will throw a IllegalStateException. This is due to possible interactions with locks while using these commands.

      Specified by:
      invokeAll in interface LockedStream<K,V>
      Type Parameters:
      R - the return type
      Parameters:
      biFunction - the biFunction to run for each entry under their lock
      Returns:
      a map with each key mapped to the value returned from the bi function

    • sequentialDistribution

      public LockedStream<K,V> sequentialDistribution()
      Description copied from interface: LockedStream
      This would disable sending requests to all other remote nodes compared to one at a time. This can reduce memory pressure on the originator node at the cost of performance.

      Parallel distribution is enabled by default except for CacheStream.iterator() and CacheStream.spliterator()

      Specified by:
      sequentialDistribution in interface BaseCacheStream<K,V>
      Specified by:
      sequentialDistribution in interface LockedStream<K,V>
      Returns:
      a stream with parallel distribution disabled

    • parallelDistribution

      public LockedStream<K,V> parallelDistribution()
      Description copied from interface: LockedStream
      This would enable sending requests to all other remote nodes when a terminal operator is performed. This requires additional overhead as it must process results concurrently from various nodes, but should perform faster in the majority of cases.

      Parallel distribution is enabled by default except for CacheStream.iterator() and CacheStream.spliterator()

      Specified by:
      parallelDistribution in interface BaseCacheStream<K,V>
      Specified by:
      parallelDistribution in interface LockedStream<K,V>
      Returns:
      a stream with parallel distribution enabled.

    • filterKeySegments

      public LockedStream<K,V> filterKeySegments(IntSet segments)
      Description copied from interface: LockedStream
      Filters which entries are returned by what segment they are present in. This method can be substantially more efficient than using a regular CacheStream.filter(Predicate) method as this can control what nodes are asked for data and what entries are read from the underlying CacheStore if present.
      Specified by:
      filterKeySegments in interface BaseCacheStream<K,V>
      Specified by:
      filterKeySegments in interface LockedStream<K,V>
      Parameters:
      segments - The segments to use for this stream operation. Any segments not in this set will be ignored.
      Returns:
      a stream with the segments filtered.

    • filterKeys

      public LockedStream<K,V> filterKeys(Set<?> keys)
      Description copied from interface: LockedStream
      Filters which entries are returned by only returning ones that map to the given key. This method will be faster than a regular CacheStream.filter(Predicate) if the filter is holding references to the same keys.
      Specified by:
      filterKeys in interface BaseCacheStream<K,V>
      Specified by:
      filterKeys in interface LockedStream<K,V>
      Parameters:
      keys - The keys that this stream will only operate on.
      Returns:
      a stream with the keys filtered.

    • distributedBatchSize

      public LockedStream<K,V> distributedBatchSize(int batchSize)
      Description copied from interface: LockedStream
      Controls how many keys are returned from a remote node when using a stream terminal operation with a distributed cache to back this stream. This value is ignored when terminal operators that don't track keys are used. Key tracking terminal operators are CacheStream.iterator(), CacheStream.spliterator(), CacheStream.forEach(Consumer). Please see those methods for additional information on how this value may affect them.

      This value may be used in the case of a a terminal operator that doesn't track keys if an intermediate operation is performed that requires bringing keys locally to do computations. Examples of such intermediate operations are CacheStream.sorted(), CacheStream.sorted(Comparator), CacheStream.distinct(), CacheStream.limit(long), CacheStream.skip(long)

      This value is always ignored when this stream is backed by a cache that is not distributed as all values are already local.

      Specified by:
      distributedBatchSize in interface BaseCacheStream<K,V>
      Specified by:
      distributedBatchSize in interface LockedStream<K,V>
      Parameters:
      batchSize - The size of each batch. This defaults to the state transfer chunk size.
      Returns:
      a stream with the batch size updated

    • segmentCompletionListener

      public LockedStream segmentCompletionListener(BaseCacheStream.SegmentCompletionListener listener)
      Description copied from interface: LockedStream
      This method is not supported when using a LockedStream
      Specified by:
      segmentCompletionListener in interface BaseCacheStream<K,V>
      Specified by:
      segmentCompletionListener in interface LockedStream<K,V>
      Parameters:
      listener - The listener that will be called back as segments are completed.
      Returns:
      a stream with the listener registered.

    • disableRehashAware

      public LockedStream<K,V> disableRehashAware()
      Description copied from interface: LockedStream
      Disables tracking of rehash events that could occur to the underlying cache. If a rehash event occurs while a terminal operation is being performed it is possible for some values that are in the cache to not be found. Note that you will never have an entry duplicated when rehash awareness is disabled, only lost values.

      Most terminal operations will run faster with rehash awareness disabled even without a rehash occuring. However if a rehash occurs with this disabled be prepared to possibly receive only a subset of values.

      Specified by:
      disableRehashAware in interface BaseCacheStream<K,V>
      Specified by:
      disableRehashAware in interface LockedStream<K,V>
      Returns:
      a stream with rehash awareness disabled.

    • timeout

      public LockedStream timeout(long timeout, TimeUnit unit)
      Description copied from interface: LockedStream
      Sets the timeout for the acquisition of the lock for each entry.
      Specified by:
      timeout in interface BaseCacheStream<K,V>
      Specified by:
      timeout in interface LockedStream<K,V>
      Parameters:
      timeout - the maximum time to wait
      unit - the time unit of the timeout argument
      Returns:
      a LockedStream with the timeout applied

    • iterator

      public Iterator<CacheEntry<K,V>> iterator()
      Description copied from interface: LockedStream
      This method is not supported when using a LockedStream
      Specified by:
      iterator in interface BaseStream<K,V>
      Specified by:
      iterator in interface LockedStream<K,V>

    • spliterator

      public Spliterator<CacheEntry<K,V>> spliterator()
      Description copied from interface: LockedStream
      This method is not supported when using a LockedStream
      Specified by:
      spliterator in interface BaseStream<K,V>
      Specified by:
      spliterator in interface LockedStream<K,V>

    • isParallel

      public boolean isParallel()
      Specified by:
      isParallel in interface BaseStream<K,V>

    • sequential

      public LockedStream<K,V> sequential()
      Specified by:
      sequential in interface BaseStream<K,V>

    • parallel

      public LockedStream<K,V> parallel()
      Specified by:
      parallel in interface BaseStream<K,V>

    • unordered

      public LockedStream<K,V> unordered()
      Specified by:
      unordered in interface BaseStream<K,V>

    • onClose

      public LockedStream<K,V> onClose(Runnable closeHandler)
      Specified by:
      onClose in interface BaseStream<K,V>

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface BaseStream<K,V>