Pass cacheStores

Reviewed By: davidaurelio

Differential Revision: D7023425

fbshipit-source-id: 84d0d6585af4075bd7ac11ac3c97520caeae7b01

packages/metro-cache/src/Cache.js

@@ -12,14 +12,14 @@
 
 import type {CacheStore} from 'metro-cache';
 
-class Cache {
-  _stores: $ReadOnlyArray<CacheStore>;
+class Cache<T> {
+  _stores: $ReadOnlyArray<CacheStore<T>>;
 
-  constructor(stores: $ReadOnlyArray<CacheStore>) {
+  constructor(stores: $ReadOnlyArray<CacheStore<T>>) {
     this._stores = stores;
   }
 
-  async get(key: Buffer): Promise<mixed> {
+  async get(key: Buffer): Promise<?T> {
     const stores = this._stores;
     const length = stores.length;
 
@@ -38,7 +38,7 @@ class Cache {
     return null;
   }
 
-  set(key: Buffer, value: mixed): void {
+  set(key: Buffer, value: T): void {
     Promise.all(this._stores.map(store => store.set(key, value))).catch(err => {
       process.nextTick(() => {
         throw err;

packages/metro-cache/src/__tests__/Cache.test.js

@@ -52,6 +52,8 @@ describe('Cache', () => {
   });
 
   it('awaits for promises on stores, even if they return undefined', async () => {
+    jest.useFakeTimers();
+
     let resolve;
 
     const store1 = createStore();
@@ -67,7 +69,9 @@ describe('Cache', () => {
     expect(store2.get).not.toHaveBeenCalled();
 
     resolve(undefined);
+
     await promise;
+    jest.runAllTimers();
 
     expect(store1.get).toHaveBeenCalledTimes(1);
     expect(store2.get).toHaveBeenCalledTimes(1);

packages/metro-cache/src/index.js

@@ -12,6 +12,9 @@
 
 const Cache = require('./Cache');
 
+const stableHash = require('./stableHash');
+
 export type {CacheStore} from './types.flow';
 
 module.exports.Cache = Cache;
+module.exports.stableHash = stableHash;

packages/metro-cache/src/types.flow.js

@@ -10,7 +10,7 @@
 
 'use strict';
 
-export type CacheStore = {
-  get(key: Buffer): ?mixed | Promise<?mixed>,
-  set(key: Buffer, value: mixed): void | Promise<void>,
+export type CacheStore<T> = {
+  get(key: Buffer): ?T | Promise<?T>,
+  set(key: Buffer, value: T): void | Promise<void>,
 };

packages/metro/src/Bundler/__tests__/Bundler-test.js

@@ -34,6 +34,7 @@ var commonOptions = {
   allowBundleUpdates: false,
   assetExts: defaults.assetExts,
   assetRegistryPath: '/AssetRegistry.js',
+  cacheStores: [],
   cacheVersion: 'smth',
   enableBabelRCLookup: true,
   extraNodeModules: {},

packages/metro/src/Bundler/index.js

@@ -18,6 +18,7 @@ const defaults = require('../defaults');
 const fs = require('fs');
 const getTransformCacheKeyFn = require('../lib/getTransformCacheKeyFn');
 
+const {Cache, stableHash} = require('metro-cache');
 const {
   toSegmentTuple,
   fromRawMappings,
@@ -25,12 +26,16 @@ const {
 } = require('metro-source-map');
 
 import type {PostProcessModules} from '../DeltaBundler';
-import type {Options as JSTransformerOptions} from '../JSTransformer/worker';
+import type {
+  Options as JSTransformerOptions,
+  TransformedCode,
+} from '../JSTransformer/worker';
 import type {DynamicRequiresBehavior} from '../ModuleGraph/worker/collectDependencies';
 import type {GlobalTransformCache} from '../lib/GlobalTransformCache';
 import type {TransformCache} from '../lib/TransformCaching';
 import type {Reporter} from '../lib/reporting';
 import type {BabelSourceMap} from '@babel/core';
+import type {CacheStore} from 'metro-cache';
 import type {
   MetroSourceMapSegmentTuple,
   MetroSourceMap,
@@ -80,6 +85,7 @@ export type Options = {|
   +assetRegistryPath: string,
   +asyncRequireModulePath: string,
   +blacklistRE?: RegExp,
+  +cacheStores: $ReadOnlyArray<CacheStore<TransformedCode>>,
   +cacheVersion: string,
   +dynamicDepsInPackages: DynamicRequiresBehavior,
   +enableBabelRCLookup: boolean,
@@ -108,16 +114,18 @@ export type Options = {|
 
 class Bundler {
   _opts: Options;
+  _cache: ?Cache<TransformedCode>;
   _transformer: Transformer;
   _depGraphPromise: Promise<DependencyGraph>;
   _projectRoots: $ReadOnlyArray<string>;
   _getTransformOptions: void | GetTransformOptions;
 
   constructor(opts: Options) {
-    this._opts = opts;
-
     opts.projectRoots.forEach(verifyRootExists);
 
+    this._opts = opts;
+    this._cache = opts.cacheStores.length ? new Cache(opts.cacheStores) : null;
+
     this._transformer = new Transformer({
       asyncRequireModulePath: opts.asyncRequireModulePath,
       maxWorkers: opts.maxWorkers,
@@ -157,16 +165,7 @@ class Bundler {
       reporter: opts.reporter,
       resetCache: opts.resetCache,
       sourceExts: opts.sourceExts,
-      transformCode: (module, code, transformCodeOptions) =>
-        this._transformer.transform(
-          module.path,
-          module.localPath,
-          code,
-          module.isPolyfill(),
-          transformCodeOptions,
-          this._opts.assetExts,
-          this._opts.assetRegistryPath,
-        ),
+      transformCode: this._cachedTransformCode.bind(this),
       transformCache: opts.transformCache,
       watch: opts.watch,
     });
@@ -276,6 +275,50 @@ class Bundler {
       map: result.map ? toBabelSegments(result.map).map(toSegmentTuple) : [],
     };
   }
+
+  async _cachedTransformCode(
+    module,
+    code,
+    transformCodeOptions,
+  ): Promise<TransformedCode> {
+    const cache = this._cache;
+    let result;
+    let key;
+
+    // First, try getting the result from the cache if enabled.
+    if (cache) {
+      key = stableHash([
+        module.localPath,
+        code,
+        transformCodeOptions,
+        this._opts.assetExts,
+        this._opts.assetRegistryPath,
+        this._opts.cacheVersion,
+      ]);
+
+      result = await cache.get(key);
+    }
+
+    // Second, if there was no result, compute it ourselves.
+    if (!result) {
+      result = await this._transformer.transform(
+        module.path,
+        module.localPath,
+        code,
+        module.isPolyfill(),
+        transformCodeOptions,
+        this._opts.assetExts,
+        this._opts.assetRegistryPath,
+      );
+    }
+
+    // Third, propagate the result to all cache layers.
+    if (key && cache) {
+      cache.set(key, result);
+    }
+
+    return result;
+  }
 }
 
 function verifyRootExists(root) {

packages/metro/src/Config.js

@@ -20,6 +20,7 @@ import type {
   PostProcessBundleSourcemap,
 } from './Bundler';
 import type {PostProcessModules} from './DeltaBundler';
+import type {TransformedCode} from './JSTransformer/worker';
 import type {DynamicRequiresBehavior} from './ModuleGraph/worker/collectDependencies';
 import type {IncomingMessage, ServerResponse} from 'http';
 import type {CacheStore} from 'metro-cache';
@@ -35,7 +36,7 @@ export type ConfigT = {
   /**
    * List of all store caches.
    */
-  cacheStores: Array<CacheStore>,
+  cacheStores: Array<CacheStore<TransformedCode>>,
 
   /**
    * Can be used to generate a key that will invalidate the whole metro cache

packages/metro/src/DeltaBundler/__tests__/DeltaTransformer-test.js

@@ -30,6 +30,7 @@ const defaults = require('../../defaults');
 const bundlerOptions = {
   allowBundleUpdates: false,
   assetExts: defaults.assetExts,
+  cacheStores: [],
   cacheVersion: 'smth',
   enableBabelRCLookup: true,
   extraNodeModules: {},

packages/metro/src/Server/index.js

@@ -40,12 +40,14 @@ import type {
   PostMinifyProcess,
   PostProcessBundleSourcemap,
 } from '../Bundler';
+import type {CacheStore} from 'metro-cache';
 import type {MetroSourceMap} from 'metro-source-map';
 import type {TransformCache} from '../lib/TransformCaching';
 import type {Symbolicate} from './symbolicate';
 import type {AssetData} from '../Assets';
 import type {RamBundleInfo} from '../DeltaBundler/Serializers';
 import type {PostProcessModules} from '../DeltaBundler';
+import type {TransformedCode} from '../JSTransformer/worker';
 const {
   Logger: {createActionStartEntry, createActionEndEntry, log},
 } = require('metro-core');
@@ -66,6 +68,7 @@ class Server {
   _opts: {
     assetExts: Array<string>,
     blacklistRE: void | RegExp,
+    cacheStores: $ReadOnlyArray<CacheStore<TransformedCode>>,
     cacheVersion: string,
     createModuleIdFactory?: () => (path: string) => number,
     enableBabelRCLookup: boolean,
@@ -117,6 +120,7 @@ class Server {
       assetExts: options.assetTransforms ? [] : assetExts,
       assetRegistryPath: options.assetRegistryPath,
       blacklistRE: options.blacklistRE,
+      cacheStores: options.cacheStores || [],
       cacheVersion: options.cacheVersion,
       dynamicDepsInPackages: options.dynamicDepsInPackages || 'throwAtRuntime',
       createModuleIdFactory: options.createModuleIdFactory,