parse_heap.js

var fs = require("fs"), obj, con_nodes = {}, con_counts = {};

obj = JSON.parse(fs.readFileSync("heap.json"));

Object.keys(obj.children).forEach(function (key1) {
	var l1 = obj.children[key1];
	Object.keys(l1).forEach(function (key2) {
		var l2 = l1[key2], cn = l2.constructorName;

		if (typeof l2.constructorName === "string") {
		    if (con_nodes[cn] === undefined) {
			con_nodes[cn] = 0;
			con_counts[cn] = 0;
		    }
		    con_nodes[cn]++;
		    if (typeof l2.count === "number") {
			con_counts[cn] += l2.count;
		    }
		} else {
		    console.log("No constructor name: ", l2);
		}
	    });
    });

console.log("total nodes:\n" + Object.keys(con_nodes).sort(function (a, b) {
            return con_nodes[a] > con_nodes[b];
        }).slice(-10).map(function (val) {
                return val + ": " + con_nodes[val] + "\n";
            }).join(""));

console.log("sum of counts:\n" + Object.keys(con_counts).sort(function (a, b) {
            return con_counts[a] > con_counts[b];
        }).slice(-10).map(function (val) {
                return val + ": " + con_counts[val] + "\n";
            }).join(""));

snap1.txt

total nodes:
(context): 9
number: 21
system / Map: 66
system / JSGlobalPropertyCell: 114
prod-nr146.voxer.com: 129
: 302
Object: 396
Connection: 870
TCP: 3308
HTTPParser: 10443

sum of counts:
indexOf: 51370
(object elements): 87378
Timer: 89834
SlowBuffer: 108144
number: 244481
: 2707876
Object: 3235524
Connection: 7671436
TCP: 27211696
HTTPParser: 89591724

snap2.txt

total nodes:
Array: 5
system / FunctionTemplateInfo: 16
number: 21
system / Map: 66
prod-nr146.voxer.com: 100
system / JSGlobalPropertyCell: 114
: 302
Object: 949
TCP: 3526
HTTPParser: 14787

sum of counts:
Pipe: 88433
lastIndexOf: 65845
indexOf: 66178
(object elements): 112058
Timer: 143768
prod-nr146.voxer.com: 977070
: 3467650
Connection: 9098179
TCP: 33525412
HTTPParser: 166933009