zulip/static/js/debug.js

128 lines
3.3 KiB
JavaScript

/* eslint-disable no-console */
// This module is included from webpack in development mode. To access it from
// the browser console, run:
// var debug = require("./static/js/debug");
/*
debug.print_elapsed_time("foo", foo)
evaluates to foo() and prints the elapsed time
to the console along with the name "foo". */
export function print_elapsed_time(name, fun) {
const t0 = Date.now();
const out = fun();
const t1 = Date.now();
console.log(name + ": " + (t1 - t0) + " ms");
return out;
}
export function check_duplicate_ids() {
const ids = new Set();
const collisions = [];
let total_collisions = 0;
for (const o of Array.prototype.slice.call(document.querySelectorAll("*"))) {
if (o.id && ids.has(o.id)) {
const el = collisions.find((c) => c.id === o.id);
ids.add(o.id);
total_collisions += 1;
if (!el) {
const tag = o.tagName.toLowerCase();
collisions.push({
id: o.id,
count: 1,
node:
"<" +
tag +
" className='" +
o.className +
"' id='" +
o.id +
"'>" +
"</" +
tag +
">",
});
} else {
el.count += 1;
}
} else if (o.id) {
ids.add(o.id);
}
}
return {
collisions,
total_collisions,
};
}
/* An IterationProfiler is used for profiling parts of looping
* constructs (like a for loop or _.each). You mark sections of the
* iteration body and the IterationProfiler will sum the costs of those
* sections over all iterations.
*
* Example:
*
* let ip = new debug.IterationProfiler();
* _.each(myarray, function (elem) {
* ip.iteration_start();
*
* cheap_op(elem);
* ip.section("a");
* expensive_op(elem);
* ip.section("b");
* another_expensive_op(elem);
*
* ip.iteration_stop();
* });
* ip.done();
*
* The console output will look something like:
* _iteration_overhead 0.8950002520577982
* _rest_of_iteration 153.415000159293413
* a 2.361999897402711
* b 132.625999901327305
*
* The _rest_of_iteration section is the region of the iteration body
* after section b.
*/
export class IterationProfiler {
sections = new Map();
last_time = window.performance.now();
iteration_start() {
this.section("_iteration_overhead");
}
iteration_stop() {
const now = window.performance.now();
const diff = now - this.last_time;
if (diff > 1) {
this.sections.set(
"_rest_of_iteration",
(this.sections.get("_rest_of_iteration") || 0) + diff,
);
}
this.last_time = now;
}
section(label) {
const now = window.performance.now();
this.sections.set(label, (this.sections.get(label) || 0) + (now - this.last_time));
this.last_time = now;
}
done() {
this.section("_iteration_overhead");
for (const [prop, cost] of this.sections) {
console.log(prop, cost);
}
}
}