Package org.apache.flink.contrib.streaming.state

Class RocksDBCachingPriorityQueueSet<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

java.lang.Object

org.apache.flink.runtime.state.heap.AbstractHeapPriorityQueueElement

org.apache.flink.contrib.streaming.state.RocksDBCachingPriorityQueueSet<E>

Type Parameters:

E - the type of the contained elements in the queue.

All Implemented Interfaces:

org.apache.flink.runtime.state.heap.HeapPriorityQueueElement, org.apache.flink.runtime.state.InternalPriorityQueue<E>

public class RocksDBCachingPriorityQueueSet<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>
extends org.apache.flink.runtime.state.heap.AbstractHeapPriorityQueueElement
implements org.apache.flink.runtime.state.InternalPriorityQueue<E>

A priority queue with set semantics, implemented on top of RocksDB. This uses a TreeSet to cache the bytes of up to the first n elements from RocksDB in memory to reduce interaction with RocksDB, in particular seek operations. Cache uses a simple write-through policy.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	RocksDBCachingPriorityQueueSet.OrderedByteArraySetCache	Cache that is organized as an ordered set for byte-arrays.

Field Summary

Fields inherited from interface org.apache.flink.runtime.state.heap.HeapPriorityQueueElement

NOT_CONTAINED

Method Summary

Modifier and Type	Method	Description
boolean	add(E toAdd)
void	addAll(Collection<? extends E> toAdd)
boolean	isEmpty()
org.apache.flink.util.CloseableIterator<E>	iterator()
E	peek()
E	poll()
boolean	remove(E toRemove)
int	size()	This implementation comes at a relatively high cost per invocation.

Methods inherited from class org.apache.flink.runtime.state.heap.AbstractHeapPriorityQueueElement

getInternalIndex, setInternalIndex

Methods inherited from class java.lang.Object

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

Method Detail

peek

@Nullable
public E peek()

Specified by:

peek in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

poll

@Nullable
public E poll()

Specified by:

poll in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

add

public boolean add(@Nonnull
                   E toAdd)

Specified by:

add in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

remove

public boolean remove(@Nonnull
                      E toRemove)

Specified by:

remove in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

addAll

public void addAll(@Nullable
                   Collection<? extends E> toAdd)

Specified by:

addAll in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

iterator

@Nonnull
public org.apache.flink.util.CloseableIterator<E> iterator()

Specified by:

iterator in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>

size

public int size()

This implementation comes at a relatively high cost per invocation. It should not be called repeatedly when it is clear that the value did not change. Currently this is only truly used to realize certain higher-level tests.

Specified by:

size in interface org.apache.flink.runtime.state.InternalPriorityQueue<E extends org.apache.flink.runtime.state.heap.HeapPriorityQueueElement>