[sr-dev] how to assign value to a pvar?

[Juha Heinanen]

it was easy to write the code that counts the number of record routes in
a message.  first i though that i can return the count as result of the
script function, but that didn't work out because if script function
returns 0, it will terminate execution of the script.

so i though to give the function a pvar argument to which the count
is stored, e.g.,

rr_count("$var(count)");

so far i have not been able to assign the count to the pvar argument and
have already spent three hours on such a simple assignment statement.  in
pvar.h there is function 

int pv_set_spec_value(struct sip_msg* msg, pv_spec_p sp, int op,
		pv_value_t *value);

that sounds like it might do the trick, but there is no documentation on
op argument and i have not yet found in sr sources any place there that
function is really used.  also i have not found in any of sr modules any
script function that would assign something to a pvar argument?  is
there one so that i could take a look or it that an impossible thing to
do? 

i have tried various versions, such as

    pv_val.ri = count;
    pv_val.flags = PV_VAL_INT;
    if (_count) {
	if (pv_set_spec_value(msg, (pv_spec_t *)_count, EQ_T, &pv_val) == 0) {

where _count is pvar fixed up argument of rr_count function, but no luck
so far.  i just get

Nov 10 05:42:51 localhost /usr/sbin/sip-proxy[27707]: ERROR: pv [pv_svar.c:117]: out of pkg mem!
Nov 10 05:42:51 localhost /usr/sbin/sip-proxy[27707]: ERROR: pv [pv_core.c:1620]: error - cannot set svar [tmp] 

can anyone help here?  if not, i'll have to make rr_count to return the
actual count + 1 so that i can return it as result of the rr_count
function.

-- juha