Level 39
By default, the store method will generate a unique ID to serve as the filename
1 like
Apr 29, 2022
7
Level 10
Is this collision free?
I have a form where I am uploading images and I want the hash which is generated as the filename for the uploaded image to be collision free. Now I want to know if the way I am doing it is safe.
This is the function which is handling this. The file class is using the Str::random function so not very safe, right?
protected function uploadFile(UploadedFile|File $logo): ?String
{
return Storage::putFile('company/logos', $logo);
}
Level 10
@sr57 Ah thank you, that helps :)
Level 50
This is the function that generates the file name. Either from hash or 40 character random string.
The chance of collision is very low. But, you can also use putFileAs with unique name generated via algorithms like UUID or other unique identifier generators. With which, the collision chance is miniscule.
1 like
Level 39
Good precision but you should put numbers behind 'very low' and minuscule, in order to see that in real life 'very low' is largely enough.
If you want to be 100% unique, you have to test if the name already exists and in that case generate a new one.
Level 10
@sr57 How could something look like?
Level 39
Many different ways
-
generate an "almost unique" name as before , test if this name still exists with file_exists
-
store your filename in db and use a query rather than file exists
-
catch the error and regenerate a new filename in case of error (limited number of time to avoid infinite loop)
-
as I did before using Laravel, use microtime(true) (with rand if some needed some obfuscation) to create your unique file name.
That said, sure you'll get other errors (disk full, inode limit, ...) before needed this..
1 like
Level 10
@sr57 Thanks for the suggestions
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