@perfmetrics/cli
v1.0.3
Published
Get performance metrics of js classes/functions with simple metrics reports.
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Perf Metrics
Get performance metrics of js classes/functions with simple metrics reports.
How to use
First you will need to install the lib to get some metrics:
npm install @perfmetrics/lib
Next just call the lib from your code:
const perfMetrics = require("@perfmetrics/lib");
The perfMetrics is a function that takes two arguments:
- target: class, function, object, anything that can be used with proxy.
- log, a callback (by default = console.log) with the arguments: (name, start, end, duration) => ...
name: the name of function, or ClassName.NameFunc
start: start time (higth resolution time in milliseconds)
end: end time (higth resolution time in milliseconds)
duraction: time that takes to execute the function (higth resolution time in milliseconds)
Now lets track a function:
const perfMetrics = require("@perfmetrics/lib");
function quadraticTime(n) { // n^2
let r = [];
for (let i = 0; i < n; i++) {
for (let j = 0; j < n; j++) {
r.push([i, j]);
}
}
}
const quadraticTimePerf = perfMetrics(quadraticTime);
// Now when you call quadraticTimePerf will track all the execution time
// In this case it will be logged to console.log
for (let i = 0; i < 100; i++) {
quadraticTimePerf(1000 + i);
}
Its easy to implement a new logger, but we can use the filestats logger, just install
npm install @perfmetrics/filestats
Then we can change the code to use the logger like this:
const perfMetrics = require("@perfmetrics/lib");
function quadraticTime(n) { // n^2
let r = [];
for (let i = 0; i < n; i++) {
for (let j = 0; j < n; j++) {
r.push([i, j]);
}
}
}
// Output, save file every 1 second
const fsLogger = fileStats("./stats.log", 1000);
const quadraticTimePerf = perfMetrics(quadraticTime, fsLogger);
// Now when you call quadraticTimePerf will track all the execution time
// In this case it will be logged to console.log
for (let i = 0; i < 100; i++) {
quadraticTimePerf(1000 + i);
}
Afther running the code we will get a stats.log file. To generate a report we first install package:
npm install @perfmetrics/cli --global
And finally just run:
perfmetrics -s stats.log --html stats
This will generate a stats.html report like this one: https://fsvieira.github.io/perfmetrics/
To get more information on how to use the cli, just run
perfmetrics -h
For more information check out the examples on the examples folder of this repo.
How it works ?
Using a proxy perfMetrics will try to keep track of the execution time of all functions generated from the proxy funcion/class, the time statistics and function information is logged using a callback function on perfMetrics, currently there in this package there is only a file logger.
Using reporter like node reports/html.js stats.log stats
will create a stats.html report.
Complexity calculation
The complexity is calculated using regressions functions (https://github.com/Tom-Alexander/regression-js) on the collected data. It goes like this:
- Order the duraction data ascending,
- Run multiple methods and choose the 2 (if they exist) with the best r-square score.
This means that more data will give better results. It also means that a function may not correspond to code classification but that can be a good thing, why spending time otimizing functions that never reach the worst case in real cenario usage.
Notes
This is still a work in progress, but alredy a working beta.
What I would like to do in the future:
- Add and improve loggers: using webworker compatible api, rest-api.
- Add more reports, including a live webapp using a rest-api server.
- Compare two reports of same funcitions so that we can understand if there is improvements.