v8-profiler.js

var binding = require("./build/Release/profiler"),
    extend = require('util')._extend;

function Snapshot() {}

Snapshot.prototype.getHeader = function() {
  return {
    typeId: this.typeId,
    uid: this.uid,
    title: this.title
  }
}

Snapshot.prototype.compare = function (other) {
  var my_objects = this.nodeCounts(),
      their_objects = other.nodeCounts(),
      diff = {}, i, k, my_val, their_val;
      all_keys = Object.keys(my_objects).concat(Object.keys(their_objects)); //has dupes, oh well
  for (i = 0; i < all_keys.length; i++) {
    k = all_keys[i];
    my_val = my_objects[k] || 0;
    their_val = their_objects[k] || 0;
    diff[k] = their_val - my_val;
  }
  return diff;
};

Snapshot.prototype.allNodes = function() {
  var n = this.nodesCount, i, nodes = [];
  for (i = 0; i < n; i++) {
    nodes[i] = this.getNode(i);
  }
  return nodes;
};

Snapshot.prototype.nodeCounts = function() {
  var objects = {};
  this.allNodes().forEach(function(n){
    if(n.type === "Object") {
      if (objects[n.name]) {
        objects[n.name] += 1;
      }
      else {
        objects[n.name] = 1;
      }
    }
    else {
      if (objects[n.type]) {
        objects[n.type] += 1;
      }
      else {
        objects[n.type] = 1;
      }
    }
  });
  return objects;
};

function CpuProfile() {}

CpuProfile.prototype.getHeader = function() {
  return {
    typeId: this.typeId,
    uid: this.uid,
    title: this.title
  }
}

var starTime, endTime;

var profiler = {
  /*HEAP PROFILER API*/

  get snapshots() { return binding.heap.snapshots; },
  
  takeSnapshot: function(name, control) {
    var snapshot = binding.heap.takeSnapshot.apply(null, arguments);
    snapshot.__proto__ = Snapshot.prototype;
    return snapshot;
  },
  
  getSnapshot: function(index) {
    var snapshot = binding.heap.snapshots[index];
    if (!snapshot) return;
    snapshot.__proto__ = Snapshot.prototype;
    return snapshot;
  },
  
  findSnapshot: function(uid) {
    var snapshot = binding.heap.snapshots.filter(function(snapshot) {
      return snapshot.uid == uid;
    })[0];
    if (!snapshot) return;
    snapshot.__proto__ = Snapshot.prototype;
    return snapshot;
  },
  
  deleteAllSnapshots: function () {
    binding.heap.snapshots.forEach(function(snapshot) {
      snapshot.delete();
    });
  },
  
  startTrackingHeapObjects: binding.heap.startTrackingHeapObjects,
  
  stopTrackingHeapObjects: binding.heap.stopTrackingHeapObjects,
  
  getHeapStats: binding.heap.getHeapStats,
  
  getObjectByHeapObjectId: binding.heap.getObjectByHeapObjectId,
  
  /*CPU PROFILER API*/
  
  get profiles() { return binding.cpu.profiles; },
  
  startProfiling: function(name, recsamples) {
    startTime = Date.now();
    binding.cpu.startProfiling(name, recsamples);
  },
  
  stopProfiling: function(name) {
    var profile = binding.cpu.stopProfiling(name);
    endTime = Date.now();
    profile.__proto__ = CpuProfile.prototype;
    if (!profile.startTime) profile.startTime = startTime;
    if (!profile.endTime) profile.endTime = endTime;
    return profile;
  },
  
  getProfile: function(index) {
    return binding.cpu.profiles[index];
  },
  
  findProfile: function(uid) {
    var profile = binding.cpu.profiles.filter(function(profile) {
      return profile.uid == uid;
    })[0];
    return profile;
  },
  
  deleteAllProfiles: function() {
    binding.cpu.profiles.forEach(function(profile) {
      profile.delete();
    });
  }
};

module.exports = profiler;
process.profiler = profiler;