OpenSensorHub Toolkit

# Batch & ReplaySpeed

# Batch

When the DataSource connects to the server, it starts retrieving data from the remote stream. Each data is then parsed and sent to the BroadcastChannel for later retrieval, either manually or by the DataSynchronizer or Views.

It is possible to perform this process for a single data or for a batch of data. Thus, by specifying the batchSize parameter of a DataSource, we will recover not one but a batch of data whose size is specified by the parameter.

For example:

  • batchSize = 1 => we recover a single piece of data
  • batchSize = 1000 => we get 1000 data at once

If you don't specify batchSize or replaySpeed, you will get the whole data at once.

This parameter can be very useful if you want to load archive data at once, for example, which you do not need to see the evolution of, such as to create a chart with the temperature data of a given year.

# ReplaySpeed

This property allows to modify the same frequency of reception of archive data compared to their original frequency.

Thus, if you specify the following values:

  • replaySpeed = 1 => receives the data at the original frequency
  • replaySpeed = 2 => receives data 2X faster
  • replaySpeed = 10 => receives data 10X faster
  • replaySpeed = 0.5 => receives data 2X slower

# Case of Real time data

In the case of real time, these parameters will be ignored even if they are specified.

# Example

const genericOpts = {
    protocol: "ws",
    service: "SOS",
    endpointUrl: "sensiasoft.net:8181/sensorhub/sos",
    offeringID: "urn:mysos:offering03",
    observedProperty: "http://sensorml.com/ont/swe/property/Weather",
    startTime: "2016-08-11T19:58:00Z",
    endTime: "2016-08-11T20:58:00Z",
    bufferingTime: 0,
};


let chartDataSource0 = new SosGetResultJson("weather0", {
    ...genericOpts,
    replaySpeed: 1,
    batchSize: 10
});

let chartDataSource1 = new SosGetResultJson("weather1", {
    ...genericOpts,
    replaySpeed: 1
});

let chartDataSource2 = new SosGetResultJson("weather2", {
    ...genericOpts,
    batchSize: 1000
});

let chartDataSource3 = new SosGetResultJson("weather3", {
    ...genericOpts
});

let chartDataSource4 = new SosGetResultJson("weather4", {
    ...genericOpts,
    startTime: "now",
    endTime: "2055-01-01Z"
});



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