org.apache.flink.contrib.streaming.state.iterator

Class RocksStatesPerKeyGroupMergeIterator

java.lang.Object

org.apache.flink.contrib.streaming.state.iterator.RocksStatesPerKeyGroupMergeIterator

All Implemented Interfaces:

AutoCloseable

public class RocksStatesPerKeyGroupMergeIterator
extends Object
implements AutoCloseable

Iterator that merges multiple RocksDB iterators to partition all states into contiguous key-groups. The resulting iteration sequence is ordered by (key-group, kv-state).

Constructor Summary

Constructors

Constructor and Description
RocksStatesPerKeyGroupMergeIterator(List<org.apache.flink.api.java.tuple.Tuple2<RocksIteratorWrapper,Integer>> kvStateIterators, int keyGroupPrefixByteCount)

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	isNewKeyGroup() Indicates if current key starts a new key-group, i.e.
boolean	isNewKeyValueState() Indicates if current key starts a new k/v-state, i.e.
boolean	isValid() Check if the iterator is still valid.
byte[]	key()
int	keyGroup()
int	kvStateId()
void	next() Advances the iterator.
byte[]	value()

Methods inherited from class java.lang.Object

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

Constructor Detail

RocksStatesPerKeyGroupMergeIterator

public RocksStatesPerKeyGroupMergeIterator(List<org.apache.flink.api.java.tuple.Tuple2<RocksIteratorWrapper,Integer>> kvStateIterators,
                                           int keyGroupPrefixByteCount)

Method Detail

next

public void next()

Advances the iterator. Should only be called if isValid() returned true. Valid flag can only change after calling next().

keyGroup

public int keyGroup()

Returns:

key-group for the current key

key

public byte[] key()

value

public byte[] value()

kvStateId

public int kvStateId()

Returns:

Id of K/V state to which the current key belongs.

isNewKeyValueState

public boolean isNewKeyValueState()

Indicates if current key starts a new k/v-state, i.e. belong to a different k/v-state than it's predecessor.

Returns:

true iff the current key belong to a different k/v-state than it's predecessor.

isNewKeyGroup

public boolean isNewKeyGroup()

Indicates if current key starts a new key-group, i.e. belong to a different key-group than it's predecessor.

Returns:

true iff the current key belong to a different key-group than it's predecessor.

isValid

public boolean isValid()

Check if the iterator is still valid. Getters like key(), value(), etc. as well as next() should only be called if valid returned true. Should be checked after each call to next() before accessing iterator state.

Returns:

True iff this iterator is valid.

close

public void close()

Specified by:

close in interface AutoCloseable