profilr
v0.2.4
Published
tiny profiling library
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8
Readme
profilr is a very tiny profiling library for your functions. It tracks down the execution time of each call and emits events.
It also supports functions that return a Promise
, so async
/await
can be tracked too. :)
It tries to add as less as possible overhead to the decorated or wrapped functions.
Basically profilr is unoptionated in what you're doing with this events. It does not log or evaluate something.
You have to add a consumer for this events. See the Consumers
section.
##Install
npm i profilr --save
##Usage profilr is written in TypeScript and typings are available. It can be used with TypeScript decorators, babel decorators and as a function wrapper.
import { profile, useProfilr } from 'profilr';
useProfilr(true);
class MyService {
constructor() {
// fnName will be an empty string, but events will be labeled with 'getNumberOfRows'
const getNumberOfRows = profile(() => 5, 'getNumberOfRows');
// fnName will be 'getNumberOfColumns'
const getNumberOfColumns = profile(function getNumberOfColumns() { return 5 });
}
@profile() // fnName will be 'expensiveComputation'
expensiveComputation (): number {
return 1*1;
}
@profile({ custom: 'foo' }) // fnName will be 'remoteApiCall'
remoteApiCall (): Promise<number> {
return new Promise((resolve) => resolve(5));
}
}
See tests for more usage information.
##Consumers First consumer will be a react devtool like known from redux and mobx, but its not finished yet.
Stay tuned!
##API All functions are available at the top level import.
###useProfilr
useProfilr(active: boolean)
Enables or disables profilr. The decorated or wrapped functions will still have some logic from profilr, but the overhead is negligible. profilr is enabled by default.
###profile
profile
is a function wrapper or class method decorator which can be used to profile your function calls.
Function wrapper signatures:
function profile<T extends Function> (fn: T): T;
function profile<T extends Function> (fn: T, label: string): T;
function profile<T extends Function> (fn: T, options: ProfileOptions): T;
function profile<T extends Function> (fn: T, label: string, options: ProfileOptions): T;
Class method decorators:
function profile (): (target: any, propertyKey: string, descriptor: PropertyDescriptor) => PropertyDescriptor;
function profile (label: string): (target: any, propertyKey: string, descriptor: PropertyDescriptor) => PropertyDescriptor;
function profile (options: ProfileOptions): (target: any, propertyKey: string, descriptor: PropertyDescriptor) => PropertyDescriptor;
function profile (label: string, options: ProfileOptions): (target: any, propertyKey: string, descriptor: PropertyDescriptor) => PropertyDescriptor;
Parameter | Description
------------ | -------------
fn
| Function to be profiled
label
| Consumers can group several functions based on this string.
options
| Configuration object. For now it only holds a custom
field, which can be used to send custom data to a consumer.
###registerEventCallback
function registerEventCallback(cb: EventCallback): () => void
Registers a callback for events produced by profilr. It returns a dispose function. Only one parameter will be passed to the callback and it looks like this example:
{
id: 1, // each profiled function has an unique id
fnName: 'map', // inferred name of function
label: 'Part of Array prototype', // label
duration: 50, // duration in ms
result: [], // result of this call
options: {
custom: 'test' // custom data
}
}
##Dependencies profilr comes without dependencies, but it needs a Reflect Metadata API polyfill if your environment does not support it.