You will need to replace this:
final long idx = num % BASE;

Otherwise it explodes for long longs.

*Better privacy
*Better capacity
*Shorter URLs with longer numbers
*Support for long datatype

https://gist.github.com/firepacket/00f6a64acfa61365d56e79cd5c564095

in 64bit php, the following code

<?php 
define ( "NUM", 1023372036854775122 );
for($i = NUM; $i < PHP_INT_MAX; ++ $i) {
    $encoded = ShortURL::encode ( $i );
    $decoded = ShortURL::decode ( $encoded );
    if ($i !== $decoded) {
        var_dump ( $i, $encoded, $decoded );
        die ( 'FAILED after ' . (($i - NUM) + 1) . ' attempt(s)' . PHP_EOL );
    }
}
die ( 'SUCCESS' );

should echo SUCCESS (but due to #8 , we know it would fail at 9223372036854775296, but it's much worse than that) , in 64bit php, it echoes

int(1023372036854775124)
string(11) "bDt2WgSwgz3"
int(1023372036854775073)
FAILED after 3 attempt(s)

somehow 1023372036854775124 turned into 1023372036854775073

Hi!
I'm using the SQL Server class.
Is there any way to make the output encoded string to always be, let says, 12 characters?

Thanks

If you make a number larger than 1999999999, it won't convert backwards.

HI Ujjawal,

Thanks for these excellent examples. Its not an issue but a question about implementation.

How this implementation ensures the concurrency issue?. Is it an auto-incremented id from the database and then we should pass that to this code?

the following code should echo FOUND after 1 attempt(s) ,
and it works as expected in 32bit php, but in 64bit php it echos FOUND after 513 attempt(s)

for($i = PHP_INT_MAX; $i > 0; -- $i) {
    if (! is_float ( ShortURL::decode ( ShortURL::encode ( $i ) ) )) {
        //var_dump ( $i );
        die ( 'FOUND after '.((PHP_INT_MAX-$i)+1).' attempt(s)' );
    }
}
die ( 'NOT FOUND' );

Created a C implementation

All numbers from 1 to 2,147,483,647 inclusively can be safely encoded and decoded again in all implementations.

I think this not supporting number bigger than 2,147,483,647 is a weakness, That must be Useful to support long/big-int numbers.

I was testing my Go version of the code and just found that if the path in Decode(s string) starts with 2, the index converts to 0, and the result is that the string cannot be reversed to the original. I have added test cases to benchmark and test. Please have a look:

https://github.com/sandeepkalra/ShortURL/blob/master/Go/shortUrl.go

Am I missing something?

I have created a Swift 4 version, based on the Scala implementation, and would like to submit a pull request.

We are hoping to use this for creating order IDs that can't be guessed, and are finding that using mixed case is not ideal for a couple reasons.

If we take out all the uppercase letters, would there be any issues that arise with regard to uniqueness?