cache.js

'use strict';

// This is only exposed for internal build steps and testing purposes.
// We create new copies of the source and the code cache
// so the resources eventually used to compile builtin modules
// cannot be tampered with even with --expose-internals

const {
  NativeModule, internalBinding
} = require('internal/bootstrap/loaders');

function getCodeCache(id) {
  const cached = NativeModule.getCached(id);
  if (cached && (cached.loaded || cached.loading)) {
    return cached.script.createCachedData();
  }

  // The script has not been compiled and run
  NativeModule.require(id);
  return getCodeCache(id);
}

const depsModule = Object.keys(NativeModule._source).filter(
  (key) => NativeModule.isDepsModule(key) || key.startsWith('internal/deps')
);

// Modules with source code compiled in js2c that
// cannot be compiled with the code cache
const cannotUseCache = [
  'config',
  'sys',  // deprecated
  'internal/v8_prof_polyfill',
  'internal/v8_prof_processor',

  'internal/per_context',

  'internal/test/binding',
  // TODO(joyeecheung): update the C++ side so that
  // the code cache is also used when compiling these
  // two files.
  'internal/bootstrap/loaders',
  'internal/bootstrap/node'
].concat(depsModule);

module.exports = {
  cachableBuiltins: Object.keys(NativeModule._source).filter(
    (key) => !cannotUseCache.includes(key)
  ),
  builtinSource: Object.assign({}, NativeModule._source),
  getCodeCache,
  codeCache: internalBinding('code_cache'),
  compiledWithoutCache: NativeModule.compiledWithoutCache,
  compiledWithCache: NativeModule.compiledWithCache,
  nativeModuleWrap(script) {
    return NativeModule.wrap(script);
  },
  cannotUseCache
};