Objects-as-JSON with Node dtrace-provider

gistfile1.txt

[chris@1c89eadf-3091-4306-ac1b-a75c3050ca29 ~/node-dtrace-provider]$ sudo /usr/sbin/dtrace -Z -s json.d -c 'node jsonargs.js'
dtrace: script 'json.d' matched 0 probes
dtrace: pid 9006 has exited
CPU     ID                    FUNCTION:NAME
  0  62731                      json1:json1 json: {"foo":42,"bar":"forty-two"} 
  0  62731                      json1:json1 int: 42 string: forty-two

json.d

nodeapp$target:::json1 {
  this->j = copyinstr(arg0);
  printf("json: %s ", this->j);
}
nodeapp$target:::json1 {
  this->j = copyinstr(arg0);
  printf("int: %d ", strtoll(json(this->j, "foo")));
  printf("string: %s", json(this->j, "bar"));
}

jsonargs.js

var d = require('../dtrace-provider');
var provider = d.createDTraceProvider("nodeapp");
var probe = provider.addProbe("json1", "json");
provider.enable();

var obj = new Object;
obj.foo = 42;
obj.bar = 'forty-two';

probe.fire(function(p) {
    return [obj];
});