How to generate random slug from word list - php

Question

I am trying to create a random slug based on a dictionary of about ~100 words. I have come up with the following solution but I have been thinking about it too long and can't tell if it is efficient and cannot figure out how to properly test it.
class SlugModel
{
/**
* Get random words from the slug_words table
* #param int $limit how many words should be fetched
* #return array the array of random words
*/
public static function getRandomSlugWords($limit)
{
// returns random words in an array. Ex:
return array('pop', 'funk', 'bass', 'electro');
}
/**
* Generate a random slug based on contents of slug_words
* #return str the slug
*/
public static function generateSlug($limit=4)
{
do {
$words = self::getRandomSlugWords($limit);
$slugified = implode('-', $words);
if(PlaylistModel::doesSlugAlreadyExist($slugified)) // returns true or false
{
// try a few different combinations before requesting new words from database
for ($i=0; $i < $limit; $i++)
{
$words[] = array_shift($words); // take the first and shift it to the end
$slugified = implode('-', $words);
if(!PlaylistModel::doesSlugAlreadyExist($slugified)) // break only if it does NOT exist
break;
}
}
} while (PlaylistModel::doesSlugAlreadyExist($slugified));
return $slugified;
}
}
I think this code works but I also think it can be made more efficient or I may be overthinking it. I could also have it as simple as
do {
$words = self::getRandomSlugWords($limit);
$slugified = implode('-', $words);
} while (PlaylistModel::doesSlugAlreadyExist($slugified));
But I am trying to test different combinations of the same words before pinging the database with another request for different words (I am using RAND() to get randomized results and trying to minimize this).
Any insight is appreciated! Thank you!

Answer 1

I think doing a single query for getting limit+N random words is a better (faster, resource friendly) approach. For example, whenever we need a slug made up from 4 elements, let us select 8 words.
SELECT slug FROM `slugs` ORDER BY RAND() LIMIT 8;
In this case, we will shuffle an array containing twice the items we will use - there are 24 permutations of 4 by 4, while there are 1680 permutations of 8 by 4 -, leaving us with more probable valid slugs with less queries.
In that case, we would have a
public static function getRandomSlugs($limit)
{
shuffle(self::$slugs); // 8 words from database
return array_slice(self::$slugs, 0, $limit); // we only need 4
}
and make our way in using a
public function generateSlug($limit = 4)
{
do {
$slugs = self::getRandomSlugs($limit); // Get N slugs
$mySlug = implode('-', $slugs); // Join the elements
} while ($this->slugExists($mySlug));
return $mySlug;
}
Checking if a slug is already taken can be done in a couple ways; selecting from database where the column is your slug, or setting up the table as unique and checking the return on inserting the data.
Anyhow, remember to keep the methods short, precise, and clean.