MeasurementBufferDatabase

Description

The MeasurementBufferDatabase object is a helper class to buffer Measurement objects in a local database whenever a remote measurement storage client (such as a Cloud of Things client or MQTT measurement writer) is offline or not connected.

This object was introduced in InCore 2.5.

› Inherits:

DatabaseMeasurementWriter

Overview

Properties

bufferDrainChunkSize bufferDrainInterval bufferSize buffering transmitOrder

DatabaseMeasurementWriter.database DatabaseMeasurementWriter.databaseTable DatabaseMeasurementWriter.measurements Object.objectId Object.parent

Methods

DatabaseMeasurementWriter.clear() DatabaseMeasurementWriter.datasetCount() DatabaseMeasurementWriter.store() Object.deserializeProperties() Object.fromJson() Object.serializeProperties() Object.toJson()

Signals

DatabaseMeasurementWriter.measurementsDataChanged() Object.completed()

Enumerations

TransmitOrder

Properties

bufferDrainChunkSize

This property holds how many buffered measurements are sent at once whenever the remote resource is online again. The lowest allowed value is 1.

› Type:

SignedInteger

› Default:

1

› Signal:

bufferDrainChunkSizeChanged()

› Attributes:

Writable

bufferDrainInterval

This property holds the send interval in which buffered measurements are sent whenever the remote resource is online again. The lowest allowed value is 100.

› Type:

SignedInteger

› Default:

2000

› Signal:

bufferDrainIntervalChanged()

› Attributes:

Writable

bufferSize

This property holds the number of Measurement objects which can be buffered at most. If this limit is reached, the oldest measurement will be removed. Setting to 0 disables buffering.

› Type:

SignedInteger

› Default:

100000

› Signal:

bufferSizeChanged()

› Attributes:

Writable

buffering

This property holds whether measurements should be buffered in the local database whenever the remote resource is offline or not connected. Once the remote resource is online again, buffered measurements are sent at a writer-specific interval.

› Type:

Boolean

› Default:

true

› Signal:

bufferingChanged()

› Attributes:

Writable

transmitOrder

This property holds the order in which the Measurement objects are sent whenever a connection is restored.

› Type:

MeasurementBufferDatabase.TransmitOrder

› Default:

MeasurementBufferDatabase.Descending

› Signal:

transmitOrderChanged()

› Attributes:

Writable

Enumerations

TransmitOrder

This enumeration describes the order in which buffered Measurement objects are sent whenever a connection is restored.

Name	Value	Description
MeasurementBufferDatabase.Ascending	0	Send measurements in ascending order - oldest first.
MeasurementBufferDatabase.Descending	1	Send measurements in descending order - latest first.