Finding the size of the reponse using SOAP::Lite

[ianbell]

Hi all,

I'm working on a website which aggregates a number of webservice feeds, some of which are REST (and are accessed using LWP), and some which are SOAP (accessed using SOAP::Lite)

I'm trying to add in some benchmarking for these feeds, and i need to find out the size (in bytes) of the response to requests. for the RESTful ones, this is easy, i can just do content_length() on the LWP response.

Is there an similar way to do this with SOAP::Lite? I can't seem to find one.

The only approach I can find is to use the set the outputxml option in SOAP::Lite to true, and parse the returned XML myself, but I want to avoid this if I can.

Ian

[AltBlue]

for the RESTful ones, this is easy, i can just do content_length() on the LWP response.

content_length?! Take care, as it does not do what you might think: it just returns the value of the Content-Length header, which - of course - may be missing... or just plain wrong (as I've seen already too many wanna-be-smart web apps that have no idea about its meaning).

Is there an similar way to do this with SOAP::Lite?

Quite similar in fact, as SOAP::Lite uses the same LWP modules for HTTP transport.

The usual way to reach those HTTP::Response objects is to enable runtime tracing of transport events. Here's an example:

use strict;
use warnings;
use SOAP::Lite +trace => [
    transport => sub {
        my ($in) = @_;
        return if ref $in ne 'HTTP::Response';
        printf "Response length: %d bytes.\n", bytes::length( $in->con
+tent );
      }
];

my $sv = SOAP::Lite->new->service('.../foo.wsdl');
$sv->fooMethod( 'foo', 'bar' );

[spivey49]

I'm not a Soap expert, but from what I've read you should have access to the raw response. From there I would imagine you would be able to evaluate the response like a string and find the legnth in bytes.

Something like this maybe:

{
use bytes;
my $response_bytes= length($response);
}

Posting the reponse portion of your client might help

[cbrandtbuffalo]

You might be able to use the trace/debug options to dump the output, then redirect it to a file or a variable and measure the size that way. See SOAP::Trace. Note the module versions as there have been some updates lately.

[ianbell]

OK, I think i've found a solution. It's not great but it'll do.

Things based on trace aren't ideal, as I want to stick the results in a db, and i don't want to interfere with the normal behaviour too much.

For the RESTful ones I'm going to start using length($response) (thanks for the tip on Content-Length, AltBlue)

For the SOAP, I have two possibilities. I can either use outputxml and parse the SOAP response myself, or I can re-serialize the SOAP::Data response and just do a length() on the results.

I think I'll do the latter. It'll be inaccurate, but it's ok as long as I'm consistent, since I'm trying to get results for the feeds relative to each other.

Ian