I've got it to work with:

unsigned long
find_index (key, data)
        unsigned long         key
        SV    *               data
    INIT:
       STRLEN          datalen;
       char * s;
       if ((!SvROK(data))
          || (SvTYPE(SvRV(data)) != SVt_PV))
       {
          XSRETURN_UNDEF;
       }
       s = SvPV(SvRV(data), datalen);
    CODE:
      RETVAL = find_index (key, s, datalen);
    OUTPUT:
      RETVAL

I'm still not sure if SvPV copies its internal data somewhere or just returns a pointer to it.

Comments please

dino

In reply to Re: Re: Re: Passing a very large string by reference to a c library by dino
in thread Passing a very large string by reference to a c library by dino

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.