If not, you use some random method to generate tinyURLs until you get one that's not already in your database ...

Personally (i.e. I don't know if they are doing that way), I would just count issued tinyURLs (the count might come directly from the database), and represent that number in some number base, e.g. 62 for the printable chars you've specified.

The advantage would be that it's simpler in the following ways: (1) I wouldn't have to check whether some randomly generated number is already in use, and (2) would be able to have the number of required digits grow just as needed, so the tinyURL is always as compact as possible. (With a random number, I'd have to choose ahead what width to use. Also, as full utilisation of the set is being approached, searching for a remaining free number would require more and more iterations...).

In reply to Re^2: Long url to tiny url. by almut
in thread Long url to tiny url. by valavanp

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.