Method interface vs Function Interface

2001-06-09 Thread victor 

I have recently came across a mod_perl document that suggested Perl's
Method Interface is more 'memory friendly' compare to Perl's Function
Interface.

I'm not too sure I've got the meaning of this 'Method Interface' and
'Function Interface' correctly, is it referring to the procedural
function call and the Object Oriented Method invoking?  or is it trying
to suggest to use 'use' instead of 'require'?


Quote From : http://perl.apache.org/dist/mod_perl.html

Importing Functions
   When possible, avoid importing of a module functions into your
namespace. The aliases which are created can take up quite a
   bit of space. Try to use method interfaces and fully qualified
Package::function names instead. Here's a freshly started httpd
   who's served one request for a script using the CGI.pm method
interface:

TTY   PID USERNAME  PRI NI   SIZE   RES  STATE   TIME %WCPU
%CPU COMMAND
  p4  5016 dougm 154 20  3808K  2636K sleep   0:01  9.62
4.07 httpd

   Here's a freshly started httpd who's served one request for the
same script using the CGI.pm function interface:

TTY   PID USERNAME  PRI NI   SIZE   RES  STATE   TIME %WCPU
%CPU COMMAND
  p4  5036 dougm 154 20  3900K  2708K sleep   0:01  3.19
2.18 httpd

   Now do the math: take that difference, figure in how many other
scripts import the same functions and how many children you
   have running. It adds up!

Re: Method interface vs Function Interface

2001-06-09 Thread Markus Peter 

On Sun, 10 Jun 2001 [EMAIL PROTECTED] wrote:

> I have recently came across a mod_perl document that suggested Perl's
> Method Interface is more 'memory friendly' compare to Perl's Function
> Interface.
>
> I'm not too sure I've got the meaning of this 'Method Interface' and
> 'Function Interface' correctly, is it referring to the procedural
> function call and the Object Oriented Method invoking?  or is it trying
> to suggest to use 'use' instead of 'require'?

Quite a lot of Perl modules allow you to "import" functions or even
variables, that means to make them available within your current
namespace. (e.g. you can call "foo()" instead of "Foo::foo()"). Some of
them even export functions per default.

This importing requires adding entries into the so called "symbol table",
which then of course means consuming more memory.

So it's basically suggesting you either use the object oriented interface
- if available - ( Foo->foo() ) or you use fully qualified function names
( Foo::foo() ). Also, as a rule of thumb, to avoid importing functions,
you can use require instead of use as this usually even avoids importing
default exports.

-- 
Markus Peter - SPiN AG
[EMAIL PROTECTED]