module: print amount of load time of a module

Author: H4ad

lib/internal/modules/cjs/loader.js

@@ -106,6 +106,7 @@ const {
 const assert = require('internal/assert');
 const fs = require('fs');
 const path = require('path');
+const { performance } = require('perf_hooks');
 const { internalModuleStat } = internalBinding('fs');
 const { safeGetenv } = internalBinding('credentials');
 const {
@@ -966,10 +967,12 @@ function getExportsForCircularRequire(module) {
  * 3. Otherwise, create a new module for the file and save it to the cache.
  * Then have it load the file contents before returning its exports object.
  * @param {string} request Specifier of module to load via `require`
- * @param {string} parent Absolute path of the module importing the child
+ * @param {Module} parent Absolute path of the module importing the child
  * @param {boolean} isMain Whether the module is the main entry point
  */
 Module._load = function(request, parent, isMain) {
+ const start = performance.now();
+
  let relResolveCacheIdentifier;
  if (parent) {
  debug('Module._load REQUEST %s parent: %s', request, parent.id);
@@ -984,8 +987,14 @@ Module._load = function(request, parent, isMain) {
  if (cachedModule !== undefined) {
  updateChildren(parent, cachedModule, true);
  if (!cachedModule.loaded) {
- return getExportsForCircularRequire(cachedModule);
+ const result = getExportsForCircularRequire(cachedModule);
+
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
+
+ return result;
  }
+
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
  return cachedModule.exports;
  }
  delete relativeResolveCache[relResolveCacheIdentifier];
@@ -1001,6 +1010,8 @@ Module._load = function(request, parent, isMain) {
  }
 
  const module = loadBuiltinModule(id, request);
+
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
  return module.exports;
  }
 
@@ -1011,16 +1022,24 @@ Module._load = function(request, parent, isMain) {
  if (!cachedModule.loaded) {
  const parseCachedModule = cjsSourceCache.get(cachedModule);
  if (!parseCachedModule || parseCachedModule.loaded) {
- return getExportsForCircularRequire(cachedModule);
+ const result = getExportsForCircularRequire(cachedModule);
+
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
+
+ return result;
  }
  parseCachedModule.loaded = true;
  } else {
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
  return cachedModule.exports;
  }
  }
 
  if (BuiltinModule.canBeRequiredWithoutScheme(filename)) {
  const mod = loadBuiltinModule(filename, request);
+
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
+
  return mod.exports;
  }
 
@@ -1068,6 +1087,8 @@ Module._load = function(request, parent, isMain) {
  }
  }
 
+ debug('TIMING [%s] [%s]: %d ms', parent?.id || '', request, performance.now() - start);
+
  return module.exports;
 };