const { Stats } = require("@​opencensus/core");
const stats = new Stats();

// Counts/groups the lengths of lines read in.
const mLineLengths = stats.createMeasureInt64(
  "demo/line_lengths",
  MeasureUnit.BYTE,
  "The distribution of line lengths"
);

// Create tag keys
const tagKeys = ["method", "status"];

// Create and register the view
stats.createView(
  "demo/lines_in",
  mLineLengths,
  AggregationType.COUNT,
  tagKeys,
  "The number of lines from standard input"
);

// Records measurements
stats.record({
  measure: mLineLengths,
  tags,
  value: 2
});

// Gets the global stats instance
const { globalStats } = require("@​opencensus/core");

// Counts/groups the lengths of lines read in.
const mLineLengths = globalStats.createMeasureInt64(
  "demo/line_lengths",
  MeasureUnit.BYTE,
  "The distribution of line lengths"
);

// Creates the method and status key
const methodKey = {name: "method"};
const statusKey = {name: "status"};

// Creates the view
const view = globalStats.createView(
  "demo/lines_in",
  mLineLengths,
  AggregationType.COUNT,
  [methodKey, statusKey],
  "The number of lines from standard input"
);

// Registers the view
globalStats.registerView(view);

// Creates tags map -> key/value pair
const tagMap = new TagMap();
tagMap.set(methodKey, {value: 'REPL'});
tagMap.set(statusKey, {value: 'OK'});

// Creates measurements (measure + value)
const measurements = [{
  measure: mLineLengths,
  value: 2
}];

// Records measurement with tagMap
globalStats.record(measurements, tagMap);