parse-usage-data.js

// https://treeherder.mozilla.org/#/jobs?repo=try&revision=aaccf2c1ff6b66b52bcfa1390b78bb781b86f672&filter-tier=1&filter-tier=2&filter-tier=3&selectedJob=148874008

var fs = require("fs");
var bsplit = require('buffer-split');

function readLines(path) {
  const buf = fs.readFileSync(path); // omitting encoding returns a Buffer
  const delim = Buffer.from('\n');
  const result = bsplit(buf, delim);
  return result
    .filter(x => x.toString().indexOf("SetBoundElement") > -1)
    .map(x => x.toString().match(/SetBoundElement Called (.+)/)[1]);
}

var lines = readLines('live_backing.log');

var obj = {}
for (var line of lines) {
  obj[line] = obj[line] ? obj[line] + 1 : 1;
}


console.log(obj);