TextCodec produces malformed trace identity, trace/span ids should be exactly 16 characters

[shadz3rg]

Hello,
Jaeger guideline states Senders SHOULD generate hex strings of exactly 16 or 32 characters in length,
but algo chosen for span id generator and hex converter produces value not consistent in length (depends on randomized id, making it so hard to debug as 9/10 span ids is correct), in that case it should be padded with leading zeros.
Most recievers will be fine with it and will auto-correct value, but integrating software with abstract request-ids can be tricky and hard to maintain consistency.

Quick gist, run N times:

<?php
$rng = random_int(0, PHP_INT_MAX);
var_dump($rng);
 
$hex = sprintf('%x', (string) $rng);
var_dump('got', $hex);

$hex = sprintf('%016x', (string) $rng);
var_dump('expected', $hex);

Will result:

[sergeyklay]

Fixed in v1.5.0. Feel free to open a new issue if the problem appears again. Thank you for contributing.