os: improve networkInterfaces() performance

benchmark/os/networkInterfaces.js

@@ -0,0 +1,15 @@
+'use strict';
+
+const common = require('../common.js');
+const networkInterfaces = require('os').networkInterfaces;
+
+const bench = common.createBenchmark(main, {
+ n: [1e4]
+});
+
+function main({ n }) {
+ bench.start();
+ for (var i = 0; i < n; ++i)
+ networkInterfaces();
+ bench.end(n);
+}

lib/os.js

@@ -143,18 +143,13 @@ endianness[Symbol.toPrimitive] = () => kEndianness;
 // Returns the number of ones in the binary representation of the decimal
 // number.
 function countBinaryOnes(n) {
- let count = 0;
- // Remove one "1" bit from n until n is the power of 2. This iterates k times
- // while k is the number of "1" in the binary representation.
- // For more check https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators
- while (n !== 0) {
- n = n & (n - 1);
- count++;
- }
- return count;
+ // Count the number of bits set in parallel, which is faster than looping
+ n = n - ((n >>> 1) & 0x55555555);
+ n = (n & 0x33333333) + ((n >>> 2) & 0x33333333);
+ return ((n + (n >>> 4) & 0xF0F0F0F) * 0x1010101) >>> 24;
 }
 
-function getCIDR({ address, netmask, family }) {
+function getCIDR(address, netmask, family) {
  let ones = 0;
  let split = '.';
  let range = 10;
@@ -190,17 +185,33 @@ function getCIDR({ address, netmask, family }) {
 }
 
 function networkInterfaces() {
- const interfaceAddresses = getInterfaceAddresses();
+ const data = getInterfaceAddresses();
+ const result = {};
 
- const keys = Object.keys(interfaceAddresses);
- for (var i = 0; i < keys.length; i++) {
- const arr = interfaceAddresses[keys[i]];
- for (var j = 0; j < arr.length; j++) {
- arr[j].cidr = getCIDR(arr[j]);
- }
+ if (data === undefined)
+ return result;
+ for (var i = 0; i < data.length; i += 7) {
+ const name = data[i];
+ const entry = {
+ address: data[i + 1],
+ netmask: data[i + 2],
+ family: data[i + 3],
+ mac: data[i + 4],
+ internal: data[i + 5],
+ cidr: getCIDR(data[i + 1], data[i + 2], data[i + 3])
+ };
+ const scopeid = data[i + 6];
+ if (scopeid !== -1)
+ entry.scopeid = scopeid;
+
+ const existing = result[name];
+ if (existing !== undefined)
+ existing.push(entry);
+ else
+ result[name] = [entry];
  }
 
- return interfaceAddresses;
+ return result;
 }
 
 function setPriority(pid, priority) {

src/node_os.cc

@@ -213,28 +213,28 @@ static void GetLoadAvg(const FunctionCallbackInfo<Value>& args) {
 
 static void GetInterfaceAddresses(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);
+ Isolate* isolate = env->isolate();
  uv_interface_address_t* interfaces;
  int count, i;
  char ip[INET6_ADDRSTRLEN];
  char netmask[INET6_ADDRSTRLEN];
  std::array<char, 18> mac;
- Local<Object> ret, o;
  Local<String> name, family;
- Local<Array> ifarr;
 
  int err = uv_interface_addresses(&interfaces, &count);
 
- ret = Object::New(env->isolate());
+ if (err == UV_ENOSYS)
+ return args.GetReturnValue().SetUndefined();
 
- if (err == UV_ENOSYS) {
- return args.GetReturnValue().Set(ret);
- } else if (err) {
+ if (err) {
  CHECK_GE(args.Length(), 1);
  env->CollectUVExceptionInfo(args[args.Length() - 1], errno,
  "uv_interface_addresses");
  return args.GetReturnValue().SetUndefined();
  }
 
+ Local<Value> no_scope_id = Integer::New(isolate, -1);
+ std::vector<Local<Value>> result(count * 7);
  for (i = 0; i < count; i++) {
  const char* const raw_name = interfaces[i].name;
 
@@ -243,17 +243,9 @@ static void GetInterfaceAddresses(const FunctionCallbackInfo<Value>& args) {
  // to assume UTF8 as the default as well. It’s what people will expect if
  // they name the interface from any input that uses UTF-8, which should be
  // the most frequent case by far these days.)
- name = String::NewFromUtf8(env->isolate(), raw_name,
+ name = String::NewFromUtf8(isolate, raw_name,
  v8::NewStringType::kNormal).ToLocalChecked();
 
- if (ret->Has(env->context(), name).FromJust()) {
- ifarr = Local<Array>::Cast(ret->Get(env->context(),
- name).ToLocalChecked());
- } else {
- ifarr = Array::New(env->isolate());
- ret->Set(env->context(), name, ifarr).FromJust();
- }
-
  snprintf(mac.data(),
  mac.size(),
  "%02x:%02x:%02x:%02x:%02x:%02x",
@@ -277,34 +269,23 @@ static void GetInterfaceAddresses(const FunctionCallbackInfo<Value>& args) {
  family = env->unknown_string();
  }
 
- o = Object::New(env->isolate());
- o->Set(env->context(),
- env->address_string(),
- OneByteString(env->isolate(), ip)).FromJust();
- o->Set(env->context(),
- env->netmask_string(),
- OneByteString(env->isolate(), netmask)).FromJust();
- o->Set(env->context(),
- env->family_string(), family).FromJust();
- o->Set(env->context(),
- env->mac_string(),
- FIXED_ONE_BYTE_STRING(env->isolate(), mac)).FromJust();
-
+ result[i * 7] = name;
+ result[i * 7 + 1] = OneByteString(isolate, ip);
+ result[i * 7 + 2] = OneByteString(isolate, netmask);
+ result[i * 7 + 3] = family;
+ result[i * 7 + 4] = FIXED_ONE_BYTE_STRING(isolate, mac);
+ result[i * 7 + 5] =
+ interfaces[i].is_internal ? True(isolate) : False(isolate);
  if (interfaces[i].address.address4.sin_family == AF_INET6) {
  uint32_t scopeid = interfaces[i].address.address6.sin6_scope_id;
- o->Set(env->context(), env->scopeid_string(),
- Integer::NewFromUnsigned(env->isolate(), scopeid)).FromJust();
+ result[i * 7 + 6] = Integer::NewFromUnsigned(isolate, scopeid);
+ } else {
+ result[i * 7 + 6] = no_scope_id;
  }
-
- const bool internal = interfaces[i].is_internal;
- o->Set(env->context(), env->internal_string(),
- internal ? True(env->isolate()) : False(env->isolate())).FromJust();
-
- ifarr->Set(env->context(), ifarr->Length(), o).FromJust();
  }
 
  uv_free_interface_addresses(interfaces, count);
- args.GetReturnValue().Set(ret);
+ args.GetReturnValue().Set(Array::New(isolate, result.data(), result.size()));
 }