test read last line

[andriyor]

test using https://github.com/bestiejs/benchmark.js

var Benchmark = require('benchmark');
var suite = new Benchmark.Suite;

suite.add('read-last-lines', function() {
    const readLastLines = require('read-last-lines');
    readLastLines.read('../successful_usernames.txt', 1)
        .then((lines) => {lines});
})
.add('readline', function() {
    const fs = require('fs');
    const readline = require('readline');

    const rl = readline.createInterface({
        input: fs.createReadStream('../successful_usernames.txt'),
        crlfDelay: Infinity
    });

    const lines = [];
    rl.on('line', (line) => lines.push(line));
    lines[lines.length -1];
})
.on('cycle', function(event) {
    console.log(String(event.target));
})
.on('complete', function() {
    console.log('Fastest is ' + this.filter('fastest').map('name'));
})
.run({ 'async': true });

10 lines file

read-last-lines x 19,104 ops/sec ±17.67% (39 runs sampled)
readline x 30,909 ops/sec ±14.72% (30 runs sampled)
Fastest is readline

readline x 37,104 ops/sec ±12.05% (41 runs sampled)
read-last-lines x 23,370 ops/sec ±7.10% (44 runs sampled)
Fastest is readline

1k lines file

readline x 15,055 ops/sec ±18.16% (26 runs sampled)
read-last-lines x 24,809 ops/sec ±9.32% (49 runs sampled)
Fastest is read-last-lines

readline x 15,452 ops/sec ±21.35% (25 runs sampled)
read-last-lines x 24,406 ops/sec ±9.02% (46 runs sampled)
Fastest is read-last-lines

Read last line of a large file with NodeJs
https://stackoverflow.com/questions/40107433/read-last-line-of-a-large-file-with-nodejs

    var fs = require('fs');
    var readline = require('readline');
    var stream = require('stream');
    var instream = fs.createReadStream('../successful_usernames.txt');
    var outstream = new stream;
    var rl = readline.createInterface(instream, outstream);
    var lastLine = '';
    rl.on('line', function(line) {
        if (line == '' || line == require("os").EOL) {
            lastLine;
            return;
        }
        lastLine = line;
    });

readline x 28,174 ops/sec ±18.58% (31 runs sampled)
read-last-lines x 23,450 ops/sec ±9.56% (48 runs sampled)
Fastest is readline

readline x 24,192 ops/sec ±17.60% (39 runs sampled)
read-last-lines x 26,433 ops/sec ±7.53% (44 runs sampled)
Fastest is read-last-lines,readline

const fs = require('fs');
    const readline = require('readline');
    const Stream = require('stream');

    getLastLine = (fileName, minLength) => {
        let inStream = fs.createReadStream(fileName);
        let outStream = new Stream;
        return new Promise((resolve, reject)=> {
            let rl = readline.createInterface(inStream, outStream);

            let lastLine = '';
            rl.on('line', function (line) {
                if (line.length >= minLength) {
                    lastLine = line;
                }
            });

            rl.on('error', reject)

            rl.on('close', function () {
                resolve(lastLine)
            });
        })
    };
    const fileName = '../successful_usernames.txt';
    getLastLine(fileName, 1)
        .then((lastLine)=> {
            lastLine
        })
        .catch((err)=> {
            err
        })

readline x 21,294 ops/sec ±17.92% (39 runs sampled)
read-last-lines x 27,032 ops/sec ±7.18% (45 runs sampled)
Fastest is read-last-lines,readline

readline x 24,050 ops/sec ±21.25% (31 runs sampled)
read-last-lines x 25,332 ops/sec ±8.47% (39 runs sampled)
Fastest is read-last-lines,readline