react-native/packager/src/ModuleGraph/node-haste/ModuleCache.js

A framework for building native apps using React

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @flow
 */

'use strict';

const Module = require('./Module');
const Package = require('./Package');

import type {PackageData, TransformedFile} from '../types.flow';

type GetFn<T> = (path: string) => Promise<T>;
type GetClosestPackageFn = (filePath: string) => ?string;

module.exports = class ModuleCache {
  _getClosestPackage: GetClosestPackageFn;
  getPackageData: GetFn<PackageData>;
  getTransformedFile: GetFn<TransformedFile>;
  modules: Map<string, Module>;
  packages: Map<string, Package>;

  constructor(getClosestPackage: GetClosestPackageFn, getTransformedFile: GetFn<TransformedFile>) {
    this._getClosestPackage = getClosestPackage;
    this.getTransformedFile = getTransformedFile;
    this.getPackageData = path => getTransformedFile(path).then(
      f => f.package || Promise.reject(new Error(`"${path}" does not exist`))
    );
    this.modules = new Map();
    this.packages = new Map();
  }

  getAssetModule(path: string) {
    return this.getModule(path);
  }

  getModule(path: string) {
    let m = this.modules.get(path);
    if (!m) {
      m = new Module(path, this, this.getTransformedFile(path));
      this.modules.set(path, m);
    }
    return m;
  }

  getPackage(path: string) {
    let p = this.packages.get(path);
    if (!p) {
      p = new Package(path, this.getPackageData(path));
      this.packages.set(path, p);
    }
    return p;
  }

  getPackageOf(filePath: string) {
    const candidate = this._getClosestPackage(filePath);
    return candidate != null ? this.getPackage(candidate) : null;
  }
};