org.apache.kafka.streams.state

Interface ReadOnlySessionStore<K,AGG>

Type Parameters:

K - the key type

AGG - the aggregated value type

All Known Subinterfaces:

SessionStore<K,AGG>

public interface ReadOnlySessionStore<K,AGG>

A session store that only supports read operations. Implementations should be thread-safe as concurrent reads and writes are expected.

Method Summary

Modifier and Type	Method and Description
default KeyValueIterator<Windowed<K>,AGG>	backwardFetch(K key) Retrieve all aggregated sessions for the provided key.
default KeyValueIterator<Windowed<K>,AGG>	backwardFetch(K from, K to) Retrieve all aggregated sessions for the given range of keys.
default KeyValueIterator<Windowed<K>,AGG>	backwardFindSessions(K keyFrom, K keyTo, long earliestSessionEndTime, long latestSessionStartTime) Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest.
default KeyValueIterator<Windowed<K>,AGG>	backwardFindSessions(K key, long earliestSessionEndTime, long latestSessionStartTime) Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest.
KeyValueIterator<Windowed<K>,AGG>	fetch(K key) Retrieve all aggregated sessions for the provided key.
KeyValueIterator<Windowed<K>,AGG>	fetch(K from, K to) Retrieve all aggregated sessions for the given range of keys.
default AGG	fetchSession(K key, long startTime, long endTime) Get the value of key from a single session.
default KeyValueIterator<Windowed<K>,AGG>	findSessions(K keyFrom, K keyTo, long earliestSessionEndTime, long latestSessionStartTime) Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest.
default KeyValueIterator<Windowed<K>,AGG>	findSessions(K key, long earliestSessionEndTime, long latestSessionStartTime) Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest.

Method Detail

findSessions

default KeyValueIterator<Windowed<K>,AGG> findSessions(K key,
                                                       long earliestSessionEndTime,
                                                       long latestSessionStartTime)

Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest.

This iterator must be closed after use.

Parameters:

key - the key to return sessions for

earliestSessionEndTime - the end timestamp of the earliest session to search for, where iteration starts.

latestSessionStartTime - the end timestamp of the latest session to search for, where iteration ends.

Returns:

iterator of sessions with the matching key and aggregated values, from earliest to latest session time.

Throws:

NullPointerException - If null is used for key.

backwardFindSessions

default KeyValueIterator<Windowed<K>,AGG> backwardFindSessions(K key,
                                                               long earliestSessionEndTime,
                                                               long latestSessionStartTime)

Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest.

This iterator must be closed after use.

Parameters:

key - the key to return sessions for

earliestSessionEndTime - the end timestamp of the earliest session to search for, where iteration ends.

latestSessionStartTime - the end timestamp of the latest session to search for, where iteration starts.

Returns:

backward iterator of sessions with the matching key and aggregated values, from latest to earliest session time.

Throws:

NullPointerException - If null is used for key.

findSessions

default KeyValueIterator<Windowed<K>,AGG> findSessions(K keyFrom,
                                                       K keyTo,
                                                       long earliestSessionEndTime,
                                                       long latestSessionStartTime)

Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest.

This iterator must be closed after use.

Parameters:

keyFrom - The first key that could be in the range

keyTo - The last key that could be in the range

earliestSessionEndTime - the end timestamp of the earliest session to search for, where iteration starts.

latestSessionStartTime - the end timestamp of the latest session to search for, where iteration ends.

Returns:

iterator of sessions with the matching keys and aggregated values, from earliest to latest session time.

Throws:

NullPointerException - If null is used for any key.

backwardFindSessions

default KeyValueIterator<Windowed<K>,AGG> backwardFindSessions(K keyFrom,
                                                               K keyTo,
                                                               long earliestSessionEndTime,
                                                               long latestSessionStartTime)

Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest.

This iterator must be closed after use.

Parameters:

keyFrom - The first key that could be in the range

keyTo - The last key that could be in the range

earliestSessionEndTime - the end timestamp of the earliest session to search for, where iteration ends.

latestSessionStartTime - the end timestamp of the latest session to search for, where iteration starts.

Returns:

backward iterator of sessions with the matching keys and aggregated values, from latest to earliest session time.

Throws:

NullPointerException - If null is used for any key.

fetchSession

default AGG fetchSession(K key,
                         long startTime,
                         long endTime)

Get the value of key from a single session.

Parameters:

key - the key to fetch

startTime - start timestamp of the session

endTime - end timestamp of the session

Returns:

The value or null if no session associated with the key can be found

Throws:

NullPointerException - If null is used for any key.

fetch

KeyValueIterator<Windowed<K>,AGG> fetch(K key)

Retrieve all aggregated sessions for the provided key. This iterator must be closed after use.

For each key, the iterator guarantees ordering of sessions, starting from the oldest/earliest available session to the newest/latest session.

Parameters:

key - record key to find aggregated session values for

Returns:

KeyValueIterator containing all sessions for the provided key, from oldest to newest session.

Throws:

NullPointerException - If null is used for key.

backwardFetch

default KeyValueIterator<Windowed<K>,AGG> backwardFetch(K key)

Retrieve all aggregated sessions for the provided key. This iterator must be closed after use.

For each key, the iterator guarantees ordering of sessions, starting from the newest/latest available session to the oldest/earliest session.

Parameters:

key - record key to find aggregated session values for

Returns:

backward KeyValueIterator containing all sessions for the provided key, from newest to oldest session.

Throws:

NullPointerException - If null is used for key.

fetch

KeyValueIterator<Windowed<K>,AGG> fetch(K from,
                                        K to)

Retrieve all aggregated sessions for the given range of keys. This iterator must be closed after use.

For each key, the iterator guarantees ordering of sessions, starting from the oldest/earliest available session to the newest/latest session.

Parameters:

from - first key in the range to find aggregated session values for

to - last key in the range to find aggregated session values for

Returns:

KeyValueIterator containing all sessions for the provided key, from oldest to newest session.

Throws:

NullPointerException - If null is used for any of the keys.

backwardFetch

default KeyValueIterator<Windowed<K>,AGG> backwardFetch(K from,
                                                        K to)

Retrieve all aggregated sessions for the given range of keys. This iterator must be closed after use.

For each key, the iterator guarantees ordering of sessions, starting from the newest/latest available session to the oldest/earliest session.

Parameters:

from - first key in the range to find aggregated session values for

to - last key in the range to find aggregated session values for

Returns:

backward KeyValueIterator containing all sessions for the provided key, from newest to oldest session.

Throws:

NullPointerException - If null is used for any of the keys.