Block Timer

A node.js timer implementation for timing blocks of code that are run one or more times.

This is useful to discover how long certain blocks of your code take, and / or how many times they are run, without specifically being tied to certain functions or your stack trace.

Installation

npm install --save block-timer

Usage

Create a new Timer() instance and then start and stop named timer blocks on it.

When you are done, call timer.log(), output timer.toString() or simply console.log(timer) to see the results.

Each named timer block can be run multiple times in one of two modes:

• sequentially (start, stop, start, stop...)
• in parallel (each run is given an id)

When a timer is run multiple times, the total number of timers run, total time taken and average timer per run will be displayed in the results.

Remember that parallel timers may run at the same time, which will result in overlap when calculating the total time taken; i.e. 5 timers running at the same time for 1 second each will add up to 5 seconds total, when the real time elapsed is 1 second

If a named block is run sequentially and started while already running, or stopped while not running, an error will be thrown.

You cannot mix sequential and parallel modes for a single named timer block.

Creating a Timer Instance

Assume there's something that takes 1ms after each timer start

var Timer = require('block-timer');
var timer = new Timer();
// or
var timer = Timer.create();

Sequential Timers

timer.start('block 1');
for (var i = 0; i <= 5; i++) {
    timer.start('block 2');
    timer.stop('block 2');
}
timer.stop('block 1');
console.log(timer);

Will display:

TIMER RESULTS:
*   block 1: 6ms
*   block 2: 5 x 1ms = 5ms

Parallel Timers

Assume there's something async that takes 1ms after each timer start

timer.start('block 1');
for (var i = 0; i < 5; i++) {
    timer.start('block 2', i);
}
for (var i = 0; i < 5; i++) {
    timer.stop('block 2', i);
}
timer.stop('block 1');
console.log(timer);

Will display:

TIMER RESULTS:
*   block 1: 2ms
*   block 2: 5 x 1ms = 5ms

Disabling the Timer

You can disable the timer by calling timer.stub() or by using an instance of new Timer.Stub() instead.

This provides an easy way of removing the timer and any overhead it creates, without actually commenting it out or removing it from your code.

API

new Timer() or Timer.create() returns a new Timer instance

timer.start(name) starts (or restarts) a sequential timer

timer.start(name, id) starts a parallel timer by id

timer.stop(name) stops a sequential timer

timer.stop(name, id) stops a parallel timer by id

timer.toString() returns the formatted results of all timers

timer.log() logs the formatted results to the console

Stub API

new Timer.Stub() or Timer.stub() returns a new Timer.Stub instance

timer.stub() replaces all methods with stubs in an existing Timer instance

Stubs match the real Timer API but do nothing, except for stub.toString() which returns an empty string.

License

The MIT License (MIT)

Copyright (c) 2014 Jed Watson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.