Testing of different methods of appending data to a json file

JsonAppend.php

<?php
...
private function _appendJson($file, $data, $first = false) {
    $fd = fopen($file, 'r+');
    fseek($fd, -1, SEEK_END);
    fwrite($fd, ($first ? '' : ',') . json_encode($data) . ']');
    fclose($fd);
}

// wrong file format. Just measuring speed
private function _appendFile($file, $data, $first = false) {
    File::append($file, ($first ? '' : ',') . json_encode($data));
}

private function _appendSubstr($file, $data, $first = false) {
    $fs = file_get_contents($file);
    $cts = substr($fs, 0, -1) . ($first ? '' : ',') . json_encode($data) . "]";
    file_put_contents($file, $cts);
}
    
/**
 * Execute the console command.
 *
 * @return mixed
 */
public function handle()
{
    $this->info("Testing ");

    $data = explode(",", '1527411080,27.11:00:20,,847,126,712,0,0,0,1,0.732');
    $file = Storage::path('test.json');

    foreach(['_appendFile', '_appendJson', '_appendSubstr'] as $method) {
        File::put($file, '[]');

        $s = microtime(true);
        for($ax = 0; $ax < 1000; $ax++) {
            $this->$method($file, $data, !$ax);
        }
        $t = round(microtime(true) - $s, 3);
        $f = round(1000 / $t);

        $this->info("done $method with $f appends per second");
    }
}

result.txt

Testing 
done _appendFile with 33333 appends per second
done _appendJson with 38462 appends per second
done _appendSubstr with 3484 appends per second

Actually it was obviously, that fseek is the fastest method.