perfy

A simple, light-weight Node.js utility for measuring code execution performance in high-resolution real times.

© 2021, Onur Yıldırım (@onury). MIT License.

Installation

    npm install perfy --save

Usage

var perfy = require('perfy');

Simple. Just call perfy.start('name') and the performance instance will be created and start time will be set until you call perfy.end('name') which returns a result object containing the high-res elapsed time information (and destroys the created instance).

perfy.start('loop-stuff');
// some heavy stuff here...
var result = perfy.end('loop-stuff');
console.log(result.time); // —> 1.459 (sec.)

... or you could:

perfy.exec('async-stuff', function (done) {
    // some heavy stuff here...
    var result = done();
    console.log(result.time); // —> 1.459 (sec.)
});

Documentation

.start(name [, autoDestroy])

Initializes a new performance instance with the given name; and marks the current high-resolution real time.

Parameters:

• name String — Required. Unique name of the performance instance to be started. Setting an existing name will overwrite this item. Use .exists() method to check for existence.
• autoDestroy Boolean — Optional. Default: true. Specifies whether this performance instance should be destroyed when .end() is called.

returns perfy

.end(name)

Ends the performance instance with the given name; and calculates the elapsed high-resolution real time. Note that if autoDestroy is not disabled when .start() is called; corresponding performance instance is immediately destroyed after returning the result.

Parameters:

• name String — Required. Unique name of the performance instance to be ended.

returns Object — A result object with the following properties.

• name String — Initialized name of the performance instance.
• seconds Number — Seconds portion of the elapsed time. e.g. 1
• milliseconds Number — Nanoseconds portion converted to milliseconds. 235.125283
• nanoseconds Number — Nanoseconds portion of the elapsed time. e.g. 235125283
• time Number — Float representation of full elapsed time in seconds. e.g. 1.235
• fullSeconds Number — Alias of .time.
• fullMilliseconds Number — Float representation of full elapsed time in milliseconds. e.g. 1235.125
• fullNanoseconds Number — Float representation of full elapsed time in nanoseconds. e.g. 1235125283
• summary String — Text summary shorthand for elapsed time.
• startTime Number — UTC start time of the execution (low-resolution). e.g. 1533302465251
• endTime Number — UTC end time of the execution (low-resolution). e.g. 1533302466486

.exec([name,] fn)

Initializes a new performance instance right before executing the given function, and automatically ends after the execution is done.

Parameters:

• name String — Optional. Unique name of the performance instance. Set this if you want the keep the instance for later use (such as getting the result at a later time).
• fn Function — Required. Function to be executed. This function is invoked with an optional done argument which is only required if you are running an asynchronous operation. You should omit the done argument if it's a synchronous operation.

returns Object|perfy — Returns a result object if running a synchronous operation (by omitting done).

function syncOp() {
    // sync operation
}
var result = perfy.exec(syncOp);

Otherwise (if asynchronous), immediately returns the perfy object and result will be returned by calling done() from within fn.

perfy.exec(function (done) {
    // a-sync operation
    var result = done();
    // perfy.count() === 0 // (auto-destroyed)
});

You can also save this performance instance by setting the name.

perfy.exec('async-op', function (done) {
    // a-sync operation
    done();
    perfy.exists('async-op'); // —> true (saved)
});

.result(name)

Gets the calculated result of the performance instance for the given name. To be used with non-destroyed, ended instances. If instance is not yet ended or does not exist at all, returns null.

Parameters:

• name String — Required. Unique name of the performance instance.

returns Object — A result object (see .end() method).

.exists(name)

Specifies whether a performance instance exists with the given name. This method will return false for an item, if called after .end(name) is called since the instance is destroyed.

Parameters:

• name String — Required. Name of the performance instance to be checked.

returns Boolean

.destroy(name)

Destroys the performance instance with the given name.

Parameters:

• name String — Required. Name of the performance instance to be destroyed.

returns perfy

.destroyAll()

Destroys all existing performance instances.

returns perfy

.names()

Gets the names of existing performance instances.

returns Array

.count()

Gets the total number of existing performance instances.

returns Number

More Examples:

Basic:

perfy.start('metric-1');
var result1 = perfy.end('metric-1');
console.log(result1.seconds + ' sec, ' + result1.milliseconds.toFixed(3) + ' ms.');
// —> 1 sec, 234 ms.
// OR
console.log(result1.time + ' sec. ');
// —> 1.234 sec.

Auto-Destroy:

perfy.start('metric-2').count(); // —> 1 (metric-1 is already destroyed)
var result2 = perfy.end('metric-2');
perfy.count(); // —> 0 (metric-2 is also destroyed after .end() is called)

Keep the instance (disable autoDestroy):

perfy.start('metric-3', false);
perfy.end('metric-3').time; // —> 0.123
perfy.exists('metric-3'); // —> true

Destroy all:

perfy.destroyAll().count(); // —> 0

Save/exec async:

perfy
    .exec('async-op', function (done) {
        var result = done(); // === perfy.result('async-op')
        perfy.count(); // 1
    })
    .count(); // 0 (sync)

Changelog

• v1.1.5 (2018-08-03)

  • Added .fullMilliseconds to result object. (PR #2 by @anho)
  • Added .fullNanoseconds and .fullSeconds (alias of .time) to result object.
  • (Dev) Removed grunt in favour of npm scripts.

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• v1.1.2 (2016-03-23)

  • Fixed time and summary padding issue. (PR #1 by @gunnarlium)
  • Other minor dev improvements.

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• v1.1.0 (2015-10-16)

  • Added .exec() convenience method.
  • .exists() will throw if no name is specified.

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• v1.0.1 (2015-10-12)

  • .result(name) will not throw (and return null) even if the perf-instance does not exist. It will throw if no name is specified.

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• v1.0.0 (2015-10-12)

  • First release.

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