com.snowplowanalytics.snowplow.tracker.emitter

Class InMemoryEventStore

java.lang.Object

com.snowplowanalytics.snowplow.tracker.emitter.InMemoryEventStore

All Implemented Interfaces:

EventStore

public class InMemoryEventStore
extends java.lang.Object
implements EventStore

Buffers events (as TrackerPayloads) in memory for sending via the BatchEmitter. The TrackerPayloads are stored in a queue. When the BatchEmitter calls getEventsBatch(int), the chosen number of TrackerPayloads are removed from the queue. The batch is added to a map of payloads that are currently being sent, and wrapped as a BatchPayload. This BatchPayload wrapper is returned to the Emitter. If the POST request is successful, the payloads are deleted from the map. If not, they are removed from the map and reinserted into the queue to be sent again.

Constructor Summary

Constructors

Constructor and Description
InMemoryEventStore() Create a InMemoryEventStore object with default buffer size (10 000 events).
InMemoryEventStore(int bufferCapacity) Create a InMemoryEventStore object with custom queue capacity.

Method Summary

Modifier and Type	Method and Description
boolean	addEvent(TrackerPayload trackerPayload) Add TrackerPayload to buffer.
java.util.List<TrackerPayload>	cleanupAfterSendingAttempt(boolean needRetry, long batchId) Finish processing events after a request has been made.
java.util.List<TrackerPayload>	getAllEvents() Get a copy of all the TrackerPayloads in the buffer.
BatchPayload	getEventsBatch(int numberToGet) Remove some TrackerPayloads from the buffer.
int	size() Get the current size of the buffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

InMemoryEventStore

public InMemoryEventStore(int bufferCapacity)

Create a InMemoryEventStore object with custom queue capacity. The default is 10 000 events.

Parameters:

bufferCapacity - the maximum number of events to buffer at once

InMemoryEventStore

public InMemoryEventStore()

Create a InMemoryEventStore object with default buffer size (10 000 events).

Method Detail

addEvent

public boolean addEvent(TrackerPayload trackerPayload)

Add TrackerPayload to buffer. Returns false if the buffer was full. Note that the event is lost in this case.

Specified by:

addEvent in interface EventStore

Parameters:

trackerPayload - the payload to add

Returns:

success or not

getEventsBatch

public BatchPayload getEventsBatch(int numberToGet)

Remove some TrackerPayloads from the buffer. They are wrapped as a BatchPayload to return, and also stored in a separate collection inside InMemoryEventStore until the result of their POST request is known.

Specified by:

getEventsBatch in interface EventStore

Parameters:

numberToGet - how many payloads to get

Returns:

a BatchPayload wrapper, or null

cleanupAfterSendingAttempt

public java.util.List<TrackerPayload> cleanupAfterSendingAttempt(boolean needRetry,
                                                                 long batchId)

Finish processing events after a request has been made. If the request was successful, the events are deleted from the InMemoryEventStore. If not, they are reinserted at the beginning of the buffer queue for another attempt.

Specified by:

cleanupAfterSendingAttempt in interface EventStore

Parameters:

needRetry - if true, move events back to the buffer instead of deleting

batchId - the ID of the batch of events

Returns:

newer TrackerPayloads deleted from the queue to make space for older payloads

getAllEvents

public java.util.List<TrackerPayload> getAllEvents()

Get a copy of all the TrackerPayloads in the buffer. This does not include any events currently being sent by the BatchEmitter.

Specified by:

getAllEvents in interface EventStore

Returns:

List of all the stored events

size

public int size()

Get the current size of the buffer. This does not include any events currently being sent by the BatchEmitter.

Specified by:

size in interface EventStore

Returns:

number of events currently in the buffer